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ematthews
01-04-2016, 12:14 PM
I am here to ask what would be a great alternative to Rythmik? I owned the F12 with my Sierra 2 and I am looking for something different. I have nothing negative to say about the Rythmik. I just prefer a little more boom sound. I know it's not right to have it but I like the bloom/boom. This is for a 2.1 audio only system in a small 11-15 room.
Speakers are RAAL towers.

curtis
01-04-2016, 01:22 PM
Have you adjusted the Rythmik...you can adjust the damping to give you more bloom/boom. Play with the extension/damping switches to see if that will give you what you want.

Also use the PEQ to give you a boost in the 60-100hz range.

ematthews
01-04-2016, 02:02 PM
Have you adjusted the Rythmik...you can adjust the damping to give you more bloom/boom. Play with the extension/damping switches to see if that will give you what you want.

Also use the PEQ to give you a boost in the 60-100hz range.

I don't have the Rythmik anymore, as I sold it off a while ago. I have been using my Martin Logan Grotto. I wouldn't mind getting a sub that I can use either ported or closed. Maybe SVS etc..

curtis
01-04-2016, 03:11 PM
I don't have the Rythmik anymore, as I sold it off a while ago. I have been using my Martin Logan Grotto. I wouldn't mind getting a sub that I can use either ported or closed. Maybe SVS etc..
Ahh...got it.

It will be interesting to see what you find to your liking because sub companies are mostly aiming for clean and accurate vs bloom/boom.

Blutarsky
01-04-2016, 08:44 PM
What about the ported Rythmiks? I don't know if they are boomy but they might be better for stupendous theater effects.

davef
01-05-2016, 12:57 AM
I would recommend giving the Rythmik LV12R a try...

dtsequoia
01-05-2016, 06:34 AM
Hey ematthews,

I currently have the Aperion Bravus IID 10". I think it may have what you are looking for.

Here is a link from Audioholics and their review:
http://www.audioholics.com/subwoofer-reviews/bravus-10d

On the last page for measurements, you can see the bloom you're looking for.

ematthews
01-05-2016, 01:17 PM
I would recommend giving the Rythmik LV12R a try...
Thanks Dave. I know I spoke with you many times when I owned my last Rythmik. Maybe I just like a non accurate sub.;)

ematthews
01-05-2016, 01:18 PM
Hey ematthews,

I currently have the Aperion Bravus IID 10". I think it may have what you are looking for.

Here is a link from Audioholics and their review:
http://www.audioholics.com/subwoofer-reviews/bravus-10d

On the last page for measurements, you can see the bloom you're looking for.

Thanks. I will take a look.

N Boros
01-05-2016, 01:29 PM
I am here to ask what would be a great alternative to Rythmik? I owned the F12 with my Sierra 2 and I am looking for something different. I have nothing negative to say about the Rythmik. I just prefer a little more boom sound. I know it's not right to have it but I like the bloom/boom. This is for a 2.1 audio only system in a small 11-15 room.
Speakers are RAAL towers.


I suggest reading the recent article over at Audioholics. It might help you articulate, for yourself and others, what you are really looking for.

http://www.audioholics.com/room-acoustics/bass-the-physical-sensation-of-sound

Just don't start reading the forum posts that follow, as there are people that get into nonsense about bragging about hitting 120 dB + in their room, etc.

I am guessing that you might want more impact that you feel in some way that is described in the article. If that is the case then get a capable sub in your room and you can boost certain regions to give you the tactile sensation you are looking for, while still having an accurate sub with good transient response and low distortion, etc.

Is your room 11 by 15 sealed, or open to the whole house? Many newer homes have an open concept layout. For the room to be pressurized you need to take the entire space that the listening area is opened to. It could be your sub was way too small for the space.

RythmikAudio
01-05-2016, 06:29 PM
Thanks Dave. I know I spoke with you many times when I owned my last Rythmik. Maybe I just like a non accurate sub.;)

That is a big maybe. Maybe it is the setup. What type of music do you listen to? Since it is a 2.1 system, how do you do bass management? Phase and crossover adjustment is important. In particular phase can cause energy cancellation between front speakers and subwoofer. If you are looking for the kick drum bass impact, that is in the midbass frequency band (60hz to 150hz). That is different from "boomy" though. Boomy also means slow. So the key question how to you think the sound can be improved and we can help better based on that information.

davef
01-07-2016, 12:50 AM
Hey ematthews,

I currently have the Aperion Bravus IID 10". I think it may have what you are looking for.

Here is a link from Audioholics and their review:
http://www.audioholics.com/subwoofer-reviews/bravus-10d

On the last page for measurements, you can see the bloom you're looking for.

Based on the measurements for this sub, I would not recommend it. It would be a significant downgrade from the F12.

dtsequoia
01-08-2016, 06:35 AM
Based on the measurements for this sub, I would not recommend it. It would be a significant downgrade from the F12.

Haha, Dave you are totally right. I just threw it out there. After hearing my father-in-laws LV12R...I have been dying to upgrade. I have the worst buyers remorse buying that Aperion. It was literally the day after the return period that I found out about you guys and Rhythmic...:(.

ematthews
01-08-2016, 08:24 AM
That is a big maybe. Maybe it is the setup. What type of music do you listen to? Since it is a 2.1 system, how do you do bass management? Phase and crossover adjustment is important. In particular phase can cause energy cancellation between front speakers and subwoofer. If you are looking for the kick drum bass impact, that is in the midbass frequency band (60hz to 150hz). That is different from "boomy" though. Boomy also means slow. So the key question how to you think the sound can be improved and we can help better based on that information.

I listen to Prog Rock like Porcupine Tree. Devin Townsend Project, Riverside, Rush. I am using a Preamp from Parasound.. The P5 which has bass management. I am looking for kick drum but also the impact of the bass guitar on low notes. A lot of my music is more bass guitar driven than Elec guitar. My last Rythmik was good, it just didn't seem to get loud enough. I am open to trying another one and get it right here from Dave. Any suggestions? I am running them with RAAL Towers.

davef
01-08-2016, 02:20 PM
I listen to Prog Rock like Porcupine Tree. Devin Townsend Project, Riverside, Rush. I am using a Preamp from Parasound.. The P5 which has bass management. I am looking for kick drum but also the impact of the bass guitar on low notes. A lot of my music is more bass guitar driven than Elec guitar. My last Rythmik was good, it just didn't seem to get loud enough. I am open to trying another one and get it right here from Dave. Any suggestions? I am running them with RAAL Towers.

Go with the best, the FV15HP :)

What are your room dimension?

ematthews
01-09-2016, 07:05 AM
Go with the best, the FV15HP :)

What are your room dimension?

Really??? Ported? Is it wise to do this with an audio only system? Can this sub run with the ports filled and make it non ported/sealed?

RythmikAudio
01-09-2016, 11:42 AM
I listen to Prog Rock like Porcupine Tree. Devin Townsend Project, Riverside, Rush. I am using a Preamp from Parasound.. The P5 which has bass management. I am looking for kick drum but also the impact of the bass guitar on low notes. A lot of my music is more bass guitar driven than Elec guitar. My last Rythmik was good, it just didn't seem to get loud enough. I am open to trying another one and get it right here from Dave. Any suggestions? I am running them with RAAL Towers.


Really??? Ported? Is it wise to do this with an audio only system? Can this sub run with the ports filled and make it non ported/sealed?

Ported vs sealed is just a general guideline. It does not mean sealed subs always sound tighter than ported subs. Some sealed subs are just downright boomy. Your Sierra-2 is also ported. Does that make it less good than a selaed version? Do we suggest customers to plug the port to make it sealed? No. Dave had spend a lot of time to get the frequency response to the damping setting that he think is neutral. The decision of ported vs sealed also affects efficiency. In short, the debate btw sealed and ported goes beyond just labelling. What we need is find out what you really like.

Dave suggest FV15 becasue you mention the output is not enough. So we assume you just need more output and assume you play pretty loud. If you don't play loud, you can just boost the sub volume and that should give you the output. Another question is when you had F12, had you experimented with different damping setting and found what you liked? High damping sound of FV15HP is similar to the mid damping of our F15HP/F12. If you like the "full body" bass of F12 in mid damping or even low damping, then FV15HP or ported subs can actually give you that and at the same time plays 9db louder. It has this flexible damping control. You can create the type of bass sound you'd like.

Lastly, the midbass kick. I know you have said that is not what you are really after. But I think it may be and you just didn't realize. I once went to a demo of PA subwoofer and found that kick drum bass were much stronger and impressive. But as I listened more, I can tell the sound does not have the detail that we normally hear get from a home system. In addition, the midbass is so strong that it has become one-note and lack of texture detail. It is a euphonic form of one-note bass. The way to create that type of sound is 1) cut out low bass becasue low bass not only takes power and less audible, it distracts your brain as unnecessary nuances/background noise that you don't really care, and 2) boost midbass. Midbass is far more audible than low bass. Strong midbass fools a lot of listeners into thinking they hear more bass. To take advantage of that fact, there is a patent from SRS on how to make small subwoofers sound big bass. The trick is to intentionally create a lot of harmonic distortions in the midbass frequency range. The second trick speaker designers use when the bass is limited is to make the roll-off contour low damping. Low damping has a hump in FR before it starts to roll off. So on our F12, if you pick 28hz, then you almost want to use low damping. Again that is a trick to give you one note bass because low damping has more ringing.

fxe02
01-18-2016, 09:01 AM
i was a hsu sub fan , and with my new house, it wouldn't pressurize the room.I tried a Mark Seaton sub, and have never regretted it.He has a upgradable path to add a second if you need it.The 2 -15" sealed enclosure ,will bring a smile.ht is fabulous !

I would like to hear the rhymik .i am doing a second room and the price of one is very attractive !

ematthews
01-18-2016, 10:25 AM
I am just going to buy another Rythmik from Ascend. This time a 15. Thanks everyone.

ematthews
01-18-2016, 10:27 AM
Ported vs sealed is just a general guideline. It does not mean sealed subs always sound tighter than ported subs. Some sealed subs are just downright boomy. Your Sierra-2 is also ported. Does that make it less good than a selaed version? Do we suggest customers to plug the port to make it sealed? No. Dave had spend a lot of time to get the frequency response to the damping setting that he think is neutral. The decision of ported vs sealed also affects efficiency. In short, the debate btw sealed and ported goes beyond just labelling. What we need is find out what you really like.

Dave suggest FV15 becasue you mention the output is not enough. So we assume you just need more output and assume you play pretty loud. If you don't play loud, you can just boost the sub volume and that should give you the output. Another question is when you had F12, had you experimented with different damping setting and found what you liked? High damping sound of FV15HP is similar to the mid damping of our F15HP/F12. If you like the "full body" bass of F12 in mid damping or even low damping, then FV15HP or ported subs can actually give you that and at the same time plays 9db louder. It has this flexible damping control. You can create the type of bass sound you'd like.

Lastly, the midbass kick. I know you have said that is not what you are really after. But I think it may be and you just didn't realize. I once went to a demo of PA subwoofer and found that kick drum bass were much stronger and impressive. But as I listened more, I can tell the sound does not have the detail that we normally hear get from a home system. In addition, the midbass is so strong that it has become one-note and lack of texture detail. It is a euphonic form of one-note bass. The way to create that type of sound is 1) cut out low bass becasue low bass not only takes power and less audible, it distracts your brain as unnecessary nuances/background noise that you don't really care, and 2) boost midbass. Midbass is far more audible than low bass. Strong midbass fools a lot of listeners into thinking they hear more bass. To take advantage of that fact, there is a patent from SRS on how to make small subwoofers sound big bass. The trick is to intentionally create a lot of harmonic distortions in the midbass frequency range. The second trick speaker designers use when the bass is limited is to make the roll-off contour low damping. Low damping has a hump in FR before it starts to roll off. So on our F12, if you pick 28hz, then you almost want to use low damping. Again that is a trick to give you one note bass because low damping has more ringing.

Great info. Thanks a bunch. I am going to order another Rythmik.

MusicHead
01-19-2016, 10:30 PM
Dave suggest FV15 becasue you mention the output is not enough. So we assume you just need more output and assume you play pretty loud. If you don't play loud, you can just boost the sub volume and that should give you the output. Another question is when you had F12, had you experimented with different damping setting and found what you liked? High damping sound of FV15HP is similar to the mid damping of our F15HP/F12. If you like the "full body" bass of F12 in mid damping or even low damping, then FV15HP or ported subs can actually give you that and at the same time plays 9db louder. It has this flexible damping control. You can create the type of bass sound you'd like.

I use my L12 in a similar way. I keep it in "Low Music" for 2-ch listening because that is what sounds best to me in my room and then boost +3dB for multichannel HT via sub trim control in my AVR. It works well for both 2-ch music and movies in my 13x17x8 room.

Wanger 714
01-25-2016, 05:25 PM
Ported vs sealed is just a general guideline. It does not mean sealed subs always sound tighter than ported subs. Some sealed subs are just downright boomy. Your Sierra-2 is also ported. Does that make it less good than a selaed version? Do we suggest customers to plug the port to make it sealed? No. Dave had spend a lot of time to get the frequency response to the damping setting that he think is neutral. The decision of ported vs sealed also affects efficiency. In short, the debate btw sealed and ported goes beyond just labelling. What we need is find out what you really like.

Dave suggest FV15 becasue you mention the output is not enough. So we assume you just need more output and assume you play pretty loud. If you don't play loud, you can just boost the sub volume and that should give you the output. Another question is when you had F12, had you experimented with different damping setting and found what you liked? High damping sound of FV15HP is similar to the mid damping of our F15HP/F12. If you like the "full body" bass of F12 in mid damping or even low damping, then FV15HP or ported subs can actually give you that and at the same time plays 9db louder. It has this flexible damping control. You can create the type of bass sound you'd like.

Lastly, the midbass kick. I know you have said that is not what you are really after. But I think it may be and you just didn't realize. I once went to a demo of PA subwoofer and found that kick drum bass were much stronger and impressive. But as I listened more, I can tell the sound does not have the detail that we normally hear get from a home system. In addition, the midbass is so strong that it has become one-note and lack of texture detail. It is a euphonic form of one-note bass. The way to create that type of sound is 1) cut out low bass becasue low bass not only takes power and less audible, it distracts your brain as unnecessary nuances/background noise that you don't really care, and 2) boost midbass. Midbass is far more audible than low bass. Strong midbass fools a lot of listeners into thinking they hear more bass. To take advantage of that fact, there is a patent from SRS on how to make small subwoofers sound big bass. The trick is to intentionally create a lot of harmonic distortions in the midbass frequency range. The second trick speaker designers use when the bass is limited is to make the roll-off contour low damping. Low damping has a hump in FR before it starts to roll off. So on our F12, if you pick 28hz, then you almost want to use low damping. Again that is a trick to give you one note bass because low damping has more ringing.

Can you tell us a little more about your mid bass drivers ( FM-8) I have a pair of Raal Towers and (2) F12's and I would like to put a pair of FM8's in the room with them.. (12x 16 room) .. One on each side of the couch or maybe right behind it ... I listen to alot of Live concerts loud.. Though it might really add the impact I'm looking for ..Good idea...?

RythmikAudio
01-26-2016, 08:25 AM
Can you tell us a little more about your mid bass drivers ( FM-8) I have a pair of Raal Towers and (2) F12's and I would like to put a pair of FM8's in the room with them.. (12x 16 room) .. One on each side of the couch or maybe right behind it ... I listen to alot of Live concerts loud.. Though it might really add the impact I'm looking for ..Good idea...?

How do you plan to do the bass management? The key is to be able to move the signals between 50hz to 150hz from front speakers to MB modules. So it does take a bit of planning.

Wanger 714
01-26-2016, 01:21 PM
How is the right way to do it? I have a Marantz 8801 as a pre ... Do I just run speaker wire from the subs somehow to the FM-8's ? .... What do I need to make it operational ..
.( My amp is Outlaw 7500) ...

RicardoJoa
02-01-2016, 02:19 PM
How is the right way to do it? I have a Marantz 8801 as a pre ... Do I just run speaker wire from the subs somehow to the FM-8's ? .... What do I need to make it operational ..
.( My amp is Outlaw 7500) ...

You will need at least two set of pre outs, one full range and one low pass and high filter for the front speakers.
I doubt you can do it on the 8801. But you can use the front preout for the FM module (Full range)and sub out for the F12. For speakers, i believe there are some high pass filter that you put in line with the wires.

RicardoJoa
02-01-2016, 03:00 PM
Now that i think about it, you might actually be able to use just the bass management on the 8801.
Not sure if is a good idea to split your sub out to 3 though. You will need to use the adjustment on the sub woofer settings.

Wanger 714
02-01-2016, 03:08 PM
Thanks , I think I should give Dave and Dina a call .. I have 2 F12s and was going (possibly) with 2 Mid Bass Modules .. One on each side of couch .. What did you mean by "3".. Was you thinking I only had one sub?.. I would actually be splitting them out to 4 right? .
If its going to be a unwise move ,I am considering using 2 340s in the surround spots and taking my smaller satellites down .. I'm sure it seams like overkill, but video concerts (I think) would be killer ..If I go this route, I'm going with 4 subs...Well actually, I'm going with a couple more subs whichever way I choose to go .. I will pick up a couple F15HPs for the back of the room and then decide whether the mid bass'es are a good route or not .. This is probably the best way to put headphones in my living room ( LOL) for theses video concerts ..I already was talking to Rob... AKA FirstReflect, about setting up the 4 subs,,, but the 340s are something new I'm considering ..

RicardoJoa
02-01-2016, 03:22 PM
Yes i thought it would be three subs, in your case 4.

loopy
02-03-2016, 09:04 PM
Would 2 LV12 work good with 340's lined up in front L,F,C in a 20x25 room or will I need 15 inch subs do the size of the room.
I don't want base that shakes the walls just want it to sound deep not punchy when it calls for it like in Day of Thunder, when the dragon talks in the Hobbit or the jets in Top Gun.
I was thinking of getting SIERRA-2s across the front but think I would need the Sierra Towers instead so I probably can't come up with the cash for the towers with the subs but the 340's make it more adorable.

davef
02-11-2016, 04:01 PM
Would 2 LV12 work good with 340's lined up in front L,F,C in a 20x25 room or will I need 15 inch subs do the size of the room.
I don't want base that shakes the walls just want it to sound deep not punchy when it calls for it like in Day of Thunder, when the dragon talks in the Hobbit or the jets in Top Gun.
I was thinking of getting SIERRA-2s across the front but think I would need the Sierra Towers instead so I probably can't come up with the cash for the towers with the subs but the 340's make it more adorable.

I would actually recommend going with (2) LV12R over a single 15. Send me an email or PM and we can discuss in more detail regarding your room and Sierra-2 or CMT-340.

Thanks!

rsmt2000
03-14-2016, 03:50 PM
Any one tried a sealed power sound audio sub with ascend speakers?

Octave
11-27-2016, 06:08 PM
Has anyone used both the SVS SB12-NSD and the Rythmik L12 with Sierra-2's, preferably in the same space and with the same gear? (Not at once.) I have read lots of glowing accounts of both subs, but for the moment I haven't read any relatively controlled impressions between the two. The SB12's have been on Black Friday sale ($400), so since that might evaporate at any time, that would be a factor that I should probably rule out. Not gonna rush a sub purchase!

This seemed like a good thread to ask and see if anyone with experience could weigh the strengths and weaknesses of the two speakers, specifically with the Sierra-2.

I would almost certainly not buy two subs up-front. This is my first rodeo and I am not gonna go big.

Please feel free to direct me to extant threads chez RTFM.

N Boros
11-28-2016, 07:51 AM
Has anyone used both the SVS SB12-NSD and the Rythmik L12 with Sierra-2's, preferably in the same space and with the same gear? (Not at once.) I have read lots of glowing accounts of both subs, but for the moment I haven't read any relatively controlled impressions between the two. The SB12's have been on Black Friday sale ($400), so since that might evaporate at any time, that would be a factor that I should probably rule out. Not gonna rush a sub purchase!

This seemed like a good thread to ask and see if anyone with experience could weigh the strengths and weaknesses of the two speakers, specifically with the Sierra-2.

I would almost certainly not buy two subs up-front. This is my first rodeo and I am not gonna go big.

Please feel free to direct me to extant threads chez RTFM.

Hi Octave,

I haven't heard both subwoofers. However, I too have had SVS and Rythmik towards the top of my list for subwoofers I am considering in my dedicated theater room. I had gone back and forth between the two over the past couple of years, but some of the recent posts by Dave and Brian have pushed me over into the Rythmik camp. Typically if you compare some of the Rythmik models to other competing brands, you get about as much output for those other comparable subwoofers. What makes Rythmik an especially good value, in my opinion, is that they are also servo subs at almost the same price. Here is a post from Dave that nicely sums up the difference between Rythmik's approach and most others that simply use DSP to shape the frequency response and others that also add limiters to make sure that it is not over-driven.


DSP is not comparable to servo. DSP is one method (actually, a lesser expensive method these days) for equalizing / contouring the subwoofer's response as opposed to equalizing by analog means. It means the LFE signal that is being sent to the sub is once again converted to digital - then various filters are applied to the digital signal, and then it is once again converted to analog so it can be amplified and then sent to the woofer.

Regardless of how good the DAC's are - each time an analog signal is converted to digital and then back again, information is lost.

Servo is a real time solution whereby the woofer sends a continuous signal back to the amplifier, so that the amplifier makes sure the woofer is properly tracking the signal being sent to it.

DSP does not have any effect on overall sound quality other than adding additional features and a simpler way of implementing eq. In fact, because of the additional A/D D/A conversions, it has a negative effect on the purity of the original signal being sent. These days, there are way to many A/D D/A conversions taking place in the audio chain. DSP in a sub would be more beneficial if the LFE output itself were digital.

I'll take servo any day of the week when it comes to sound quality in a subwoofer.

This was taken from the following thread: http://forum.ascendacoustics.com/showthread.php?6208-Rythmik-Audio-18s/page2. I suggest you look closely at the posts from posts 19 to 35 where Dave and Brian and discussing Rythmik's approach vs. others.

Here is another thread where Brian goes into more technical detail about some of the differences between SVS and Rythmik. http://forum.ascendacoustics.com/showthread.php?6071-Differences-between-SVS-and-Rythmik. I must admit that some of it is still a bit over my head towards the end, but I have a rough idea of what he is saying. My takeaway was that there are multiple kinds of distortion that are more significant than THD. SVS does an exceptional job at getting THD very low, even when the subwoofer is close to its output limits. But, it does this at the expense of other distortions that are a bigger problems when the sub is close to its output limits. Most other subwoofers don't even address these distortions at all.

sludgeogre
11-28-2016, 10:12 AM
My takeaway was that there are multiple kinds of distortion that are more significant than THD. SVS does an exceptional job at getting THD very low, even when the subwoofer is close to its output limits. But, it does this at the expense of other distortions that are a bigger problems when the sub is close to its output limits. Most other subwoofers don't even address these distortions at all.

I think this is a pretty good summation of that thread and of what SVS and other companies are currently doing. Rythmik really stands out in comparison to them because of all of the distortions they are addressing.

From what I see through reviews and other forums is that some people prefer the added distortion of the many subwoofers out there, since so many people like bloated, overly warm, overly-long decay bass. I have met far too many people, especially those in car audio, that don't care for accurate reproduction of bass, they just want a lot of it, and they can't tell added distortion from accuracy. I read head-fi quite a bit as well, and the few guys that get into dedicated stereo have a huge problem with most subwoofers, because they're so used to extremely precise bass that high-end heaphone systems provide. It's really hard to get bass as accurate as the LCD-4 and HE-6 and other legendary headphones provide it. To my ears, Rythmik really nails it.

If you want accuracy and tight bass when called for, Rythmik should always be at the top of your list.

N Boros
11-28-2016, 01:33 PM
From what I see through reviews and other forums is that some people prefer the added distortion of the many subwoofers out there, since so many people like bloated, overly warm, overly-long decay bass. I have met far too many people, especially those in car audio, that don't care for accurate reproduction of bass, they just want a lot of it, and they can't tell added distortion from accuracy.

I think that you are right. I have heard this same criticism from some people about Ascend speakers as well. Some have described them as "dry", where you don't get as much sound as you did before on other speakers. But, if Ascend and Rythmik are giving you more accuracy, less distortion and less overhang because the drivers can start and stop more quickly, which allows you to hear more detail in the soundtrack, then that is generally something I would prefer. So in fact, the criticism of them sounding "dry" is not quite true. Often you end up hearing more than you did before.

I was happy with my Sierra 2s when I first got them and most times they sound fantastic, but there are some instances where I didn't like extra detail I was hearing. For example, on the intro song to the HBO series "Boardwalk Empire" there is a guitar playing. I had listened to this many times on my old Axiom speakers and never before heard the guitar player's fingers dragging and sliding on the strings and he plays. Usually something like this would new and exciting because it is something new that I had never heard before on something I was quite familiar with. However, for whatever reason I found it distracting. That was something that jumped out front and center and I found it kind of irritating. This is the only case I have run into where the extra detail was not welcomed though.

I'm reminded of a couple of reviews that point out these traits of the Rythmik subwoofers ability to be more clean and yet maybe not be as in-your-face exciting as some other subwoofers might be:

http://www.avsforum.com/forum/113-subwoofers-bass-transducers/1471574-rythmik-e15-vs-svs-sb13-ultra-4.html

A little down from the top of that page is a review by Jim Wilson he compares the Rythmik e15hp to the SVS sb13 Ultra. Here are a couple of comments that stood out to me:

Comment when listening to music: "In contrast to the SB13U the E15HP almost seemed weak at times but it was just stealthy, providing a more distinct and clear sound for the most part. I could have "thickened" it up some by choosing the Low tuning configuration, but I chose not to. You could tell a music connoisseur designed this one, because the accuracy and precision were uncanny."

Comment when listening to movie: "The E15HP went about its business in a more low-key manner, but it was no less potent. Deep bass was sneaky; just as you start to think it could use a bit more oomph you realize that the floor is vibrating."

Jim Wilson also reviewed the Rythmik LV12R here:

http://www.hometheatershack.com/forums/speaker-subwoofer-reviews/67309-rythmik-lv12r-subwoofer-review.html

Comment when listening to music: "I have a confession to make; I think music on the LV12R sounds wonderful. Why am I saying it like that? Because I've always believed acoustic suspension designs trump bass reflex when it comes to music (and I still do). Rare is the ported subwoofer which can satisfy my demanding musical requirements, but the LV12R did just that."

Comments when listening to movies: "...the depth and clarity of the blast was spectacular. I both heard and felt a nice deep rumble."

"Whether it was the Balrogs roar, the crumbling staircases or the foreboding rumbles that are the underpinnings of this scene all of it seemed to be in the proper proportions, with excellent definition"



Quite a long time ago Ilkka reviewed a DIY version of the Rythmik 12" sealed subwoofer (http://www.hometheatershack.com/forums/subwoofer-tests-archived/5756-diy-rythmik-audio-direct-servo-12-sealed-56l.html#post48248 ) and said the following:

"I don't want to say a lot of subjective comments about its sound because the listening room and personal preference affect a lot to it. I can say that its sound is slightly drier than what we usually hear with other subwoofers. That might be a good or bad thing, depending what kind of sound one likes."


Since I use my home theater much more for movies than music, I am strongly leaning towards a ported version of the Rythmik. I haven't heard anyone say that they didn't like the sound of the ported Rythmik subs with movies and all have said they even think they are excellent with music. So they are likely more clean sounding than most other subs, not having all of that extra distortion. But, I still want the slightly fuller sound that the ported Rythmik subs with have in comparison to the sealed Rythmiks to give you, even if it is just a smidge less accurate in terms of transient response. The comment from Jim, "The E15HP went about its business in a more low-key manner, but it was no less potent. Deep bass was sneaky; just as you start to think it could use a bit more oomph you realize that the floor is vibrating", was what I am thinking about specifically here. I would prefer to get the slight bit more oomph and have the floor vibrating without losing too much accuracy. I think that the ported Rythmiks or adjusting the bass damping factor on the sealed will likely give you this. The other reason I think I would prefer the ported Rythmik over a sealed Rythmik is that many home theater soundtracks can be quite demanding and it is much more economical to get output from a ported subwoofer (above the port tuning) compared to a sealed design. If my priority was music, I would definitely lean more towards a sealed Rythmik though, just for the extra accuracy and because I wouldn't need the extra output headroom.

sludgeogre
11-28-2016, 03:55 PM
Quite the post N Boros! I agree with you on pretty much everything, as well as the reviewers. It's especially crazy when you think "hey I could use some more output" and then realize your guts are shaking when you turn it up. Getting used to that tactile sound is really interesting. You expect the bloat and warm-ness to be there, so when it isn't, it takes you a minute to realize what just happened.

This reminds me of a post in the AVS forum, in the Ascend Acoustics thread, where a guy was used to his B&W speakers for many years and just couldn't get used to the way the Sierra-2 sounded because he was expecting the "smile shaped" EQ curve that B&W generally adheres to. He just couldn't live without it. The accuracy felt dry to him in the same way you mentioned. I've always been going for increasingly accurate and neutral sound, so that preference just didn't make any sense to me, but hey, to each their own.

I have dual F12's and use them 99% for movies. I went with sealed because it was just always something I've wanted since I've become addicted to musical and movie accuracy. In addition, you actually get more extension with a sealed design. The F12's can get down to subsonic frequencies with the rumble filter off. I'm also moving into a small theater room, so I don't need that much output. Even in the largish-open room that I'm in now, I still run them at half volume and down a few dB in Audyssey. I could see there being a problem if I only used one sub, but with two it's a dream.

billy p
11-29-2016, 04:40 PM
And this is why Jim now owns a JTR S1...just saying boys...:).

curtis
11-29-2016, 06:56 PM
And this is why Jim now owns a JTR S1...just saying boys...:).That JTR seems like a good value.

RythmikAudio
11-29-2016, 11:03 PM
If you ask Jim what he listens to, his reply has always been the unit he currently reviews. So for Jim, the definition of "owning" a sub is different from listening to it every day. My customers often ask me which model do I have in my system. My answer is similar to Jim: the one that I'd like to get long term evaluation of the sound characteristics.

BTW, we do have a plan to introduce F18HP. It is not going to have the same output as S1, but we can offer all 3 different finishes. The price will be $200 more expensive than F15HP. The enclosure will be heavily braced.

Octave
11-29-2016, 11:49 PM
I appreciate the interesting replies, gents.

Sub acquisition is inevitable, though I might be upgrading some of my electronics first. I will be asking some noob questions about that elsewhere here, I'm sure.

rsmt2000
11-30-2016, 04:46 AM
If you ask Jim what he listens to, his reply has always been the unit he currently reviews. So for Jim, the definition of "owning" a sub is different from listening to it every day. My customers often ask me which model do I have in my system. My answer is similar to Jim: the one that I'd like to get long term evaluation of the sound characteristics.

BTW, we do have a plan to introduce F18HP. It is not going to have the same output as S1, but we can offer all 3 different finishes. The price will be $200 more expensive than F15HP. The enclosure will be heavily braced.

Hi Brian

Any chance if we can see Rythmik subs in "standard veneers" other than the current 3 color choices you offer?

Thanks
Ron

RythmikAudio
11-30-2016, 06:51 AM
^^

My experice with veneering options is not good when I tried that. At that time, one local carpenter wanted to get jobs like that. Customers then began to send me his decor or existing speakers and asked me to match. But I ended up nipping the bud. My conclusions are: 1) no matter what I offer, there are still customers not happy with my offering and 2) Companies like SALK can do a much better job becasuse Jim also sells front speakers.

billy p
11-30-2016, 07:27 AM
^^

My experice with veneering options is not good when I tried that. At that time, one local carpenter wanted to get jobs like that. Customers then began to send me his decor or existing speakers and asked me to match. But I ended up nipping the bud. My conclusions are: 1) no matter what I offer, there are still customers not happy with my offering and 2) Companies like SALK can do a much better job becasuse Jim also sells front speakers.


Welcomed news on a potential new f18hp. My understand there were no plans for a sealed 18" until the vented models hit the ground? Another take on offering veneers options...it really only effects(increases) the purchase price and not the resale price...as I found out with my last sub....thou it made it easier to sell....fwiw.

Why do you offer so many different driver configuration + options... would it also not make more business sense to limit the drivers and thus further reducing all these different cabinets and likely operational costs associated with production from your viewpoint?

RythmikAudio
11-30-2016, 09:03 AM
^^^

I have a background in computer industry. I did IC design before. You may wonder why there are so many different options even for the same notebook model, such as the size of RAM, graphic chips, CPU speed, i3 vs i5 vs i7, not to mention how many different series are there. The key is how to make the design modular. In short, that is also how we do it. The trick is we found a way to make it managable. We borrow ideas from other industries.

rsmt2000
11-30-2016, 09:54 AM
^^

My experice with veneering options is not good when I tried that. At that time, one local carpenter wanted to get jobs like that. Customers then began to send me his decor or existing speakers and asked me to match. But I ended up nipping the bud. My conclusions are: 1) no matter what I offer, there are still customers not happy with my offering and 2) Companies like SALK can do a much better job becasuse Jim also sells front speakers.

Thanks Brian. Fair enough. Your subs are so amazing to listen to that this small nitpick is easy to ignore. Besides as Billyp mentions the veneer options won't hold their retail value for the price paid for the veneer.

Is it too early to expect the dimensions for F18HP and any reason why it can't play louder than the competition? How does it compare to F25?

Thanks
Ron

RythmikAudio
11-30-2016, 10:56 AM
Thanks Brian. Fair enough. Your subs are so amazing to listen to that this small nitpick is easy to ignore. Besides as Billyp mentions the veneer options won't hold their retail value for the price paid for the veneer.

Is it too early to expect the dimensions for F18HP and any reason why it can't play louder than the competition? How does it compare to F25?

Thanks
Ron

When I design the drivers, I'd like to use low voice coil inductance. It is to keep the cone inertia low. So in short, there are design considerations. The driver used in JTR is very impressive. But it comes with compromises. To support the longer excursion, the spider needs to be very tight (two spiders maybe) Tighter spider results in more spider memory effect and also makes it stiffer (more power to move the cone). I won't go into other boring details. F18HP will be 20.5" tall and wide and 21" deep. For higher output, F28HP is on the table. Our amp wattage is about 900WRMS. The JTR is 2400WRMS. So single F18HP has about 3db less output than single S1. But single F18HP is less expensive than one S1. We cannot win on all fronts. Otherwise, we all end up with the same sub. Each company has its own selling points. Output wise, F18HP is 1 db to 1.5db less than F25.

N Boros
12-01-2016, 01:51 PM
When I design the drivers, I'd like to use low voice coil inductance. It is to keep the cone inertia low. So in short, there are design considerations. The driver used in JTR is very impressive. But it comes with compromises. To support the longer excursion, the spider needs to be very tight (two spiders maybe) Tighter spider results in more spider memory effect and also makes it stiffer (more power to move the cone). I won't go into other boring details. F18HP will be 20.5" tall and wide and 21" deep. For higher output, F28HP is on the table. Our amp wattage is about 900WRMS. The JTR is 2400WRMS. So single F18HP has about 3db less output than single S1. But single F18HP is less expensive than one S1. We cannot win on all fronts. Otherwise, we all end up with the same sub. Each company has its own selling points. Output wise, F18HP is 1 db to 1.5db less than F25.

I have a question then. This seems like the F18HP would have close to the output of a FVX15 at about 20 Hz, according to the output chart on your webpage. We would expect the advantage of the F18HP to be that it should have a more gradual rolloff below 20 Hz to where maybe there is more output from there and below than on the FVX15. Above 20 Hz the two won't be too far off in output from one another, but the FVX15 is a ported design and since it is above the tuning port it might have a bit of an advantage above 20 Hz. If we are not not pushing either subwoofer close to the output limits, then we can probably have a pretty similar frequency response of one vs. the other.

Here is my question. If you adjust the Q to 1.1 on both subs will there be much of a difference in what you hear? If you adjust them both to 0.5, will you be able to hear a difference between the two? Is it possible to adjust the knobs and dials on the back to where you would not be able to distinguish easily between the two?

eyecatcher
12-01-2016, 08:21 PM
I own an F15HP and some Raal towers and I'm very excited to hear about the F18HP as i've been admiring the engineering on the funk and jtr but they were a little out of my budget and one is gorgeous and the other is less attractive imho. Looking at the databass measurement of the s2, if you knock 6db off for an s1 approximately it is pretty amazing numbers for impulse reponse, decay, and output/distortion. The only other drivers that come close are diy like the tc sounds 18..and of course that rockford fosgate 19 is $tunning.

However, I think the proposed f18hp rythmik size is perfect and the oak is a good compromise in looks and cost. Question on the new design, is it possible to accommodate the freq response on the line in input to extend flat to 120hz and/or allow LFE input phase and crossover adjustment? I never understood the 90hz limit. Nice to have would be 12/24 dB octave low and high pass crossover choice on the variable adj and possibly an additional rumble filter an octave lower than the current like 10 - 14hz. They could be a slight competitive edge in addition to the current servo options that we all love. I'd really be blown out of my seat if i didn't have to get up to adjust everything and it could be done remotely.. but I don't want to get too needy. It sounds like a win already.

RythmikAudio
12-09-2016, 08:12 AM
I have a question then. This seems like the F18HP would have close to the output of a FVX15 at about 20 Hz, according to the output chart on your webpage. We would expect the advantage of the F18HP to be that it should have a more gradual rolloff below 20 Hz to where maybe there is more output from there and below than on the FVX15. Above 20 Hz the two won't be too far off in output from one another, but the FVX15 is a ported design and since it is above the tuning port it might have a bit of an advantage above 20 Hz. If we are not not pushing either subwoofer close to the output limits, then we can probably have a pretty similar frequency response of one vs. the other.

Here is my question. If you adjust the Q to 1.1 on both subs will there be much of a difference in what you hear? If you adjust them both to 0.5, will you be able to hear a difference between the two? Is it possible to adjust the knobs and dials on the back to where you would not be able to distinguish easily between the two?

The Q value of sealed subs and ported subs are different. This is mainly becasue a sealed sub has only 2nd order roll off and a ported sub has a 4th order roll-off. So it can never do an apple to apple comparison. For some customers, the extra ringing from the ported subwoofers are actually better. But we still think our ported subs are better than non-servo ported subs in terms of articulation, contrast, and dynamics.
Here is the frequency response of FV18 at 12hz low damping. We design it so that it has the max flatness at low damping.
1387

The following is the sealed version F18HP and you notice that it is tilted up a bit. That is by design. In sealed subs, we can allow the Q value to be higher while maintaining similar time domain ringing characteristics.

1388

The high damping has smaller phase shift (70 degrees less at 10hz) and a more gradual roll-off.
1389

What is interesting is you can compare that with the F12 response at 14hz high damping that we have on web. In terms of phase shift, it is so amazingly close below 20hz. BTW, there is another trade secret that is not commonly discussed. Microphose also has phase shift which means the actual phase shift from these sealed subs are a bit smaller. On the mic I use, the phase shift is 18 degrees and 45 degrees at 20hz and 10hz, respectively.

The way to read phase response is to follow the blue line. The scale of phase is on the right. The very top is +180 degrees and the very bottom is -180 degrees. Each division is 45 degrees. Phase is like clock, once you go out of the chart, the phase rotates to the other side of the chart.
1390


Back to F18HP sealed sub. Here is the overlay of all 3 damping setting on F18HP. The damping provides the bass contouring in a very subtle way. When the equipment and setup is good, one can hear the difference these damping settings make. If he cannot, don't lose hope. It can be equipement or it can be room related. But hopefully one day in the future he can hear the difference.

1386

N Boros
12-09-2016, 12:45 PM
Back to F18HP sealed sub. Here is the overlay of all 3 damping setting on F18HP. The damping provides the bass contouring in a very subtle way. When the equipment and setup is good, one can hear the difference these damping settings make. If he cannot, don't lose hope. It can be equipement or it can be room related. But hopefully one day in the future he can hear the difference.


Thank you for the detailed explanation. This helps a lot. Okay, so the high damping setting on your subs are going to be the most accurate in terms of phase. The sealed subs can be more accurate than the ported subs in this regard. What does the more accurate phase setting give you in terms of sound quality? Are you able to get more detail out of the same piece of music? Does it allow a more accurate location of where the bass is supposed to be located in the room (I have no idea, I'm just thinking about how phase is important in your main speakers in being able to locate sounds in three dimensional space, sometimes even behind you. But, with a subwoofer the signal is in mono so I don't think that this makes sense)?

mikesiskav
12-10-2016, 01:15 PM
Hi Brian, got any pictures of the F18HP? And how much more output will it have compared to the F15HP?

RythmikAudio
12-12-2016, 10:31 AM
Thank you for the detailed explanation. This helps a lot. Okay, so the high damping setting on your subs are going to be the most accurate in terms of phase. The sealed subs can be more accurate than the ported subs in this regard. What does the more accurate phase setting give you in terms of sound quality? Are you able to get more detail out of the same piece of music? Does it allow a more accurate location of where the bass is supposed to be located in the room (I have no idea, I'm just thinking about how phase is important in your main speakers in being able to locate sounds in three dimensional space, sometimes even behind you. But, with a subwoofer the signal is in mono so I don't think that this makes sense)?

Phase and ring are related. You cannot get a system with high phase shift and yet give you no ringing in time domain. I understand most people treat some of the characteristics as if they have total degree of freedom. For instance, one thing I mentioned about ported sub is it has 4th order roll off. Most will think it is no big deal, I can live with that. But what i have not told you is 4th order has 2 Q values because a 4th order system can be thought of cascade of two 2nd order system with each 2nd order has a corner frequency F and a Q value. In other words, we have F1,F2,Q1,and Q2. Most will think he has complete freedom of picking F1, F2, Q1, and Q2. Unfortunately, it is not the case. So in reality, when some DIY picks a driver A and puts in a ported box B, most often he will get one high Q value and one low Q value. He cannot get low Q values for both both Q1 and Q2. The most commonly Q value combination is something like Q1=1.1 and Q2=0.6, or Q1=1.2 and Q2=0.5. Now you see the trend? If you try to reduce one Q, then the other Q pops up or if you want to make F1=15hz and keep Q1 and Q2 to the values you want, then F2 becomes 25hz. It is a constant game of seesaw.
[EDIT]

Another way to look at this problem is we compare sealed subs with ported subs. What is added to the system when we go from a sealed sub to a ported sub? The only thing we add is the port tuning frequnecy. That is, we add only one extra degree of freedom and yet we have two new variables F2, Q2 introduced in the system. That is why it is so difficult to controll all F1/Q1/F2/Q2 values exactly what we want them.


Now if someone in college say I have access to symbolic math equation solver that I can solve this problem exactly. What he wil find is in order to get both Q values to be at 0.6 or lower, the enclosure may need to be so big or the driver needs to be so compliant that it becomes impractical. When we have one high Q and one low Q in your system, the ringing at the time domain is mainly determined by the high Q characteristics. That is why it is not a fair comparison for sealed and ported subs. Josh and other has tried to EQ a ported sub to a sealed sub in order to do subjective evaluation. Once you understand the big picture, you don't even bother to do that.

goldark
12-13-2016, 05:14 PM
Phase and ring are related. You cannot get a system with high phase shift and yet give you no ringing in time domain. I understand most people treat some of the characteristics as if they have total degree of freedom. For instance, one thing I mentioned about ported sub is it has 4th order roll off. Most will think it is no big deal, I can live with that. But what i have not told you is 4th order has 2 Q values because a 4th order system can be thought of cascade of two 2nd order system with each 2nd order has a corner frequency F and a Q value. In other words, we have F1,F2,Q1,and Q2. Most will think he has complete freedom of picking F1, F2, Q1, and Q2. Unfortunately, it is not the case. So in reality, when some DIY picks a driver A and puts in a ported box B, most often he will get one high Q value and one low Q value. He cannot get low Q values for both both Q1 and Q2. The most commonly Q value combination is something like Q1=1.1 and Q2=0.6, or Q1=1.2 and Q2=0.5. Now you see the trend? If you try to reduce one Q, then the other Q pops up or if you want to make F1=15hz and keep Q1 and Q2 to the values you want, then F2 becomes 25hz. It is a constant game of seesaw.
[EDIT]

Another way to look at this problem is we compare sealed subs with ported subs. What is added to the system when we go from a sealed sub to a ported sub? The only thing we add is the port tuning frequnecy. That is, we add only one extra degree of freedom and yet we have two new variables F2, Q2 introduced in the system. That is why it is so difficult to controll all F1/Q1/F2/Q2 values exactly what we want them.


Now if someone in college say I have access to symbolic math equation solver that I can solve this problem exactly. What he wil find is in order to get both Q values to be at 0.6 or lower, the enclosure may need to be so big or the driver needs to be so compliant that it becomes impractical. When we have one high Q and one low Q in your system, the ringing at the time domain is mainly determined by the high Q characteristics. That is why it is not a fair comparison for sealed and ported subs. Josh and other has tried to EQ a ported sub to a sealed sub in order to do subjective evaluation. Once you understand the big picture, you don't even bother to do that.

I always feel dumber after reading one of Brian's posts, but sure makes me glad I'm a Rythmik owner ;)

N Boros
12-14-2016, 10:38 AM
Phase and ring are related. You cannot get a system with high phase shift and yet give you no ringing in time domain. I understand most people treat some of the characteristics as if they have total degree of freedom. For instance, one thing I mentioned about ported sub is it has 4th order roll off. Most will think it is no big deal, I can live with that. But what i have not told you is 4th order has 2 Q values because a 4th order system can be thought of cascade of two 2nd order system with each 2nd order has a corner frequency F and a Q value. In other words, we have F1,F2,Q1,and Q2. Most will think he has complete freedom of picking F1, F2, Q1, and Q2. Unfortunately, it is not the case. So in reality, when some DIY picks a driver A and puts in a ported box B, most often he will get one high Q value and one low Q value. He cannot get low Q values for both both Q1 and Q2. The most commonly Q value combination is something like Q1=1.1 and Q2=0.6, or Q1=1.2 and Q2=0.5. Now you see the trend? If you try to reduce one Q, then the other Q pops up or if you want to make F1=15hz and keep Q1 and Q2 to the values you want, then F2 becomes 25hz. It is a constant game of seesaw.
[EDIT]

Another way to look at this problem is we compare sealed subs with ported subs. What is added to the system when we go from a sealed sub to a ported sub? The only thing we add is the port tuning frequnecy. That is, we add only one extra degree of freedom and yet we have two new variables F2, Q2 introduced in the system. That is why it is so difficult to controll all F1/Q1/F2/Q2 values exactly what we want them.


Now if someone in college say I have access to symbolic math equation solver that I can solve this problem exactly. What he wil find is in order to get both Q values to be at 0.6 or lower, the enclosure may need to be so big or the driver needs to be so compliant that it becomes impractical. When we have one high Q and one low Q in your system, the ringing at the time domain is mainly determined by the high Q characteristics. That is why it is not a fair comparison for sealed and ported subs. Josh and other has tried to EQ a ported sub to a sealed sub in order to do subjective evaluation. Once you understand the big picture, you don't even bother to do that.

Thank you for the explanation. I wasn't aware. This helps a lot!

I have one more followup question. All things being equal, the sealed designs will always be more accurate in terms of minimizing ringing. So the sealed subwoofers will best match my Sierra 2 speakers, which have exceptional transient response. I like the accurate sound of those speakers 98% of the time (sometimes that extra detail is too much on certain passages).


1) So if I am after the most accurate in terms of a matching subwoofer to these speaker, is a sealed subwoofer always going to be the best choice in my situation? My primary use is for home theater and I have a dedicated theater room that is about 1660 cubic feet and sealed.

2) If so, is it just a matter of choosing the right sized sealed subwoofer that can give me the maximum clean output I would want?

For example, I think the loudest I would ever listen to a movie would be at reference volume, which can demand up to 115 dB peaks in the LFE channel. So the F12 will not be able to cleanly hit those levels, even in this smaller room with 2 or 4 of them. Multiple F15HPs would likely be able to do this though. Now I could go with multiple FVX15s and use them with one port plugged to probably get similar output capabilities and similar transient accuracy, but the F15HPs will technically still have a little better transient response. We already start to see the need for a ported subwoofer. I can get the same output for a bit cheaper, if I am okay with the extra ringing. But, if I had a larger room and still wanted to hit 115 dB peaks, then it gets even more difficult try to stay with a sealed subwoofer in my application. The reason everyone can't choose a sealed sub to give the most accuracy is because some will have larger rooms and may want to listen at reference volume and a sealed subwoofer will just be too big and too expensive to use, when a more efficient ported subwoofer can be made to give the output needed, with the tradeoff of not quite as accurate transient response.

3) Is this a reasonable way to decide when to go with ported over sealed, if you want to maintain the most accurate transient response?

ggarner149
02-15-2018, 05:56 PM
I was reading through this thread today; too bad it didn't keep going to provide the answers to the above post.

Greg

N Boros
02-17-2018, 03:21 PM
I was reading through this thread today; too bad it didn't keep going to provide the answers to the above post.

Greg

Since making the last post a little over a year ago now, I have learned quite a bit more about subwoofers and choosing the appropriate size for a room. Here are a collection of those thoughts, in case nobody else comes to add to the conversation.

First of all, in a small room (any room that any of us have at home) full reference volume of 85 dB on average and 115 dB peaks in the LFE is not something that I or most any people want to listen at. Over at AVS forum there are a small group of people that talk about regularly listening to movie soundtracks at this level, or even above that level. (Consistently listening above this level regularly will cause permanent hearing damage slowly over time). But, really if you get an action Blu-Ray movie with an over the top soundtrack and adjust the volume dial, where is it usually set, where will you find it comfortable for the entire movie? If your receiver came with room EQ like Audyssey, then it will tell you where the volume is at with respect to reference volume, where it was mastered. If you don't have a relative volume setting on your receiver that was EQed in this way, you can just use a SPL meter to get a rough idea of how loud you like to listen. Most Blu-Rays for the home are mixed at 75 dB on average with as much as 105 dB peaks in the LFE. Typically I will listen somewhere between -20 dB and -15 dB, for such movies. I did nudge my subwoofer trim level up a bit after I ran Audyssey, maybe by 5 dB. The room EQ could be boosting things, maybe as much as say 5 dB. Let's say that if I really get crazy and crank things up when I have guests, then maybe I nudge things up by another 5 dB. So the absolute loudest that the LFE would need to be in my room would be about 75 dB - 15 dB + 5 dB + 5 dB + 5 dB = 75 dB on average with 105 dB peaks. This is a very safe estimate.

Before when I was thinking that I want subwoofers to be capable of safely playing at full reference volume and as much as 115 dB peaks, this was simply because when I go to a movie theater to watch a movie, that is the level that most movies play at, or maybe slightly louder as many are mixed hot and I sit 1/3 of the way into the room from the screen for a more immersive viewing experience. At home this is uncomfortably loud. So how much subwoofer do I need? Well I can go over to data-bass.com, where Josh Ricci measured the new Rythmik subwoofers and pick out the one that will give me clean 105 dB peaks.

http://data-bass.com/data?page=system&id=145&mset=171

Just look under the "Static Graphs" tabs of the measurements and find the "In Room" CEA 2010 bursts. I find that for the F18 the subwoofer struggles most at 16 Hz with 103 dB output levels. For all other frequencies in the table, the subwoofer can put out either a little bit more, or a massive amount more. I want to make sure that I can hit 105 dB peaks and that it is clean (quite a bit less than 20% THD). Well I plan to get two subwoofers, so I can get about another 3 dB from the second F18. This gives me the 105 dB peaks. The distortion is a little higher at 16 Hz than I would like with 3rd order distortion being the main contributor. This would show up as around 48 Hz, which we can hear. However, Josh's room is a 3500 cubic foot room, with at least one hallway open to other parts of the house. So, I would probably get a little bit of room gain down low to where the distortion at 16 Hz, wouldn't be quite that high at 16 Hz and like I already mentioned I would rarely listen where peaks would be that loud. I would typically listen at least 5 dB less. So in my case, a pair of F18's can play anything that I can throw at it, within the levels that I would normally listen, with very low distortion.

If I wanted to save some money, I could just shoot for getting two sealed Rythmiks that can hit 105 dB peaks cleanly at 20 Hz and then have the sub roll off below 20 Hz. Looking at Rythmik's chart ( http://www.rythmikaudio.com/ ) I could probably step all the way down to an F12, since a pair of F18s could put out about 111 dB at 20 Hz, cleanly. When we step down in driver size, the distortion will likely rise. So maybe I could step down to a pair of L22s or F15HPs would probably be safe, or even down to an F12 is probably even okay, but it might have high distortion at 20 Hz with a 105 dB peak. I guess I am a little picky though. I would prefer that the speakers and subwoofer are just reproducing the signal as faithfully as possible. So if there are some rare sounds below 20 Hz, which I know that we can't hear, only feel, I would like the subwoofer to reproduce it without adding distortion up in the audible band with 3rd or 4th order harmonics.

Since I have a room smaller than Josh's room and I don't listen to movie soundtracks at really high levels, I have the flexibility of going with a sealed subwoofer. If my room were larger, or I listened at louder playback levels, or I just wanted to be the same output (at most frequencies) for less money, then I could just get ported Rythmik with a smaller driver. There are downsides here going with a ported model, in terms of having a larger subwoofer cabinet and transient response that isn't quite as good as a sealed Rythmik. But, since I have a smaller room and don't listen too loud, I am planning to go for a sealed Rythmik because I don't mind spending a little extra money to get a little bit better transient response. I remember one forum member within the past year describing the difference between the ported and sealed Rythmiks like this: high damping on the ported model is like mid damping on the sealed model, mid damping on the ported model is like low damping on the sealed model. So how are the ported and sealed Rythmik's different with respect to transient response? The sealed model has one more notch to go for faster transient response and the ported model has one more notch to for a more fuller sound. I am seeking the most accurate, so the sealed on high damping is what I want.

I have Sierra 2s for my front speakers. So wouldn't a pair of F18's be ridiculous because of the mismatch in output levels? Well the F18's can likely cleanly get to 105 dB peaks in my room. The Sierra 2s can play 95 dB sustained in room without showing any compression, as measured by a forum member here:

http://forum.ascendacoustics.com/showthread.php?6546-Sierra-2-output-measurements-in-my-room

I only need them to play 95 dB peaks cleanly. So I think that they do actually match well. And again, the only reason for the F18s over say the F15HPs or L22s would be so that I can play below 20 Hz content that some movies call for.

ggarner149
02-18-2018, 06:31 PM
Hi, Thanks for chiming back in with your experience. Your listening preferences match my own and I like your logic and analysis. My biggest issue is my room size. It is a 3,000 cu ft room but opens to another ~7,000 cu ft. There are some walls in each room, but it still presents a big space for bass. My preference though, like your own, is for sealed subs. I'm even thinking the new E15HP2 (pair, eventually) is an interesting option as it is almost as loud at 20 hz as the F18. But even Rythmik hasn't published it's performance curves yet and I haven't seen anyone comment on them at AVS or here.

For a single-sub placement, is there anything magic about placing it in the front of the room? the FV18 installation guide says one good placement is in between the front speakers. I prefer mine behind me as it is less in the way, but also a few feet closer to my ears.

N Boros
02-21-2018, 12:21 PM
Maybe I should expand a little on my comments and add some context. Currently I have an old Outlaw LFM-1 subwoofer in the corner of a finished basement that is completely open concept. So the total space might be 10,000 to 12,000 cubic feet. My priority is home theater, though I do a slight bit of listening to concert Blu-rays and music. Anyways, if I were to go with a subwoofer in this particular space I would not at all be looking for a sealed subwoofer. The ever so slight improvement to transient response would in no way make up for the fact that I have a huge space and can get output much more economically with a ported subwoofer. Currently I'm not happy with the bass, because there is very little feeling to the bass, even though I hear things mostly fine. I can hear that my Sierra 2s as mains have better transient response than my subwoofer and I have it placed and integrated well.

Because of this I plan to put up a couple of walls to get down to about a sealed, rectangular 2,000 cubic foot room. What is nice here is that as I mentioned above, even a small sealed subwoofer basically gives me all of the output down to 20 Hz that I need and should be pretty much clean even down at 20Hz. However, there are some movie soundtracks that dip below 20Hz, so I want to make sure that the subwoofer can also produce those well and with low distortion, which is why I'm leaning towards the F18s. The sealed rectangular room allows me to know, because of Todd Welti's research at Harman (https://www.harman.com/sites/default/files/multsubs_0.pdf), where the optimal placement of two subs will be to minimize the standing waves (and as a result each seat will sound very similar). The smaller sealed room also makes the use of bookshelf speakers for mains and smaller speakers in other areas also fine. Things are predictable and easier to plan, even into the room treatments to help fix some of the room anomalies. Best of all, the smaller sealed room allows me to pressurize the room with bass. This will give me the bass that I can feel, that is currently lacking. If I want to pressurize a 10,000 to 12,000 cubic foot space, then I need subs with massive output capabilities. A single FV25HP might not be enough. So do I want to spend large sums of money on subwoofers to try to pressurize the whole basement, and have my wife and kids probably upset with me :), or just put up a couple of walls to come at the problem from a different angle?

If my room were much larger than 2000 cubic feet, or I liked to listen a bit louder, then sealed subwoofers would no longer be feasible for me. I would be looking at bigger ported models. If music were a priority and I weren't quite as concerned about the tactile feel of the bass, then maybe smaller sealed subwoofers would be fine for me in a larger space though.

For the placement of a single subwoofer, typically the best thing to do is the "subwoofer crawl". With this technique you put subwoofer in your seat that you will listen at. You can only typically get one good seat for the bass with one subwoofer. To find the best location for the subwoofer you crawl around to the different locations for the subwoofer while listening to sweeps. Make a sweep for about 10 seconds from 100Hz down to 20 Hz here (http://onlinetonegenerator.com/frequency-sweep-generator.html). Unplug or turn off your other speakers. Once you find the location where the sweep sounds either the most even, or there aren't any nulls or dips, then you have found a good location for the subwoofer. Take the subwoofer out of your seat and put it in that spot. The bass that you heard in the location should be very similar to what you have now in your seat. If the bass doesn't have any nulls yet it doesn't sound even, you should be able to run a room EQ like Audyssey, which will be able to bring down any peaks and make the bass even from 20 to 80Hz.