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View Full Version : Upgrade to F18, or second LV12R?



kdaq
12-17-2017, 02:41 PM
I have a 20 x 10 x 7.5 (1500 cu ft) room. I (will soon) have Sierra-2 LCR, and HTM-200SE surrounds. This room is for both 5.1 HT and 2.1 music.

Today, I have a single LV12R. I love it, and it adds a lot to both movies and music. I don't have much flexibility in placement, unfortunately. There's room for subs behind my L/R speakers, no bigger than an F18 each.

Factors that matter to me:

1) Capability below 20Hz for ambiance and dynamics in music. (http://www.rythmikaudio.com/faq.html#14hz) The LV12R is good enough to let you "hear the room" with the right recording. But I can't help but wonder if there's more I'm missing.

2) More slam and awe. I want accurate reproduction, but sometimes, who doesn't want to just giggle like a kid?

3) Address room modes. Bass response varies greatly depending on where you sit in the room.

4) Think long-term. I'm prone to upgradeitis. If I get another LV12R I bet I'll love it, and yet still wonder if I shouldn't go bigger.

I'm not sure if any of these are higher priority than others. Talk sense into me! :)

SunByrne
12-17-2017, 08:44 PM
Second LV12R. Getting a bigger and more powerful sub is cool and all, but it won't do anything to address room modes. Given that your room isn't huge, I think two smaller subs will give you much better real results than one bigger one.

kdaq
12-19-2017, 06:54 PM
Thanks SunByrne.

I'm not sure what I prioritize higher. Also, since I'm pretty limited in sub placement, a second LV12R isn't a sure thing for addressing modes. Gotta admit, my heart is with the bigger sub. :) Just can't help but wonder what that beast can do!

kdaq
12-20-2017, 06:30 AM
I pored over some details on Rythmik's site, and now I wonder about a third option.

What about upgrading to dual LVX12s? These are designed to be able to reach lower than the LV12R, which is one of my objectives.

I'm having trouble finding impressions of the LVX12 vs other options in Rythmik's lineup. Anyone have first-hand experience?

Bruce Watson
12-20-2017, 07:08 AM
I'm having trouble finding impressions of the LVX12 vs other options in Rythmik's lineup. Anyone have first-hand experience?

I've got a pair of LVX12s running in a system with Sierra-2s (LCR) and Sierra-1s (surround), with an old Denon AVR-4000. Room in 13.5 x 20 x 8 feet. Probably 80% HT, 20% music.

I went through more or less this same thought process years ago, coming to the conclusion that I wanted a pair of subs to help handle room modes. And I wanted servo subs because of the accuracy and low distortion. When Rythmik finally produced the LVX12s, I bought a very early pair (first two? IDK). With my restrictions the bigger subs would not physically fit, but the LVX12s do (one barely).

I couldn't be happier. These subs really work well. Interestingly, they make the other speakers sound better in the bargain -- off loading the heavy lifting below 80 Hz really makes the Sierra-2s shine.

Here's the thing. What you get from a bigger sub is higher max. levels, and lower min. frequency. Unless you tend to listen to things at very high levels, the higher max levels thing is pretty meaningless to you. And there's some studies that show that people just aren't comfortable listening at reference levels (0 dB master volume) in small rooms. I know I'm not. About the loudest I can stand is -10 dB, most movies I listen at -20 dB. So having the ability to play even louder would be completely wasted on me.

As to playing lower, humans in general have great difficulty hearing down to 20 Hz. Hardly anyone can actually hear tonally down to 16 Hz (the 32 foot pipe in a conventional pipe organ). By that point the fundamental is perceived as vistibular disturbance. That is, it generates in your body that feeling of awe or dread. What most people get from that bottom note of a pipe organ then is the 32 Hz first overtone, plus a feeling of awe. Which is... the point. Yes? That's why they churches have them.

Below 16 Hz, it just gets weirder. Vistibular responses continue, but mostly what you get is shaking of the environment. Lots of guys are really impressed that they can shake the pictures on the walls, dishes in the kitchen, etc. But really, is this important to you? And again, you'll only get this if you're playing really loud.

I'm thinking owning huge subwoofers that require dedicated 20 amp circuits is like owning a muscle car. For the three or four times a year you can actually open it up it's fun (for a few seconds), but for the rest of the year you're stuck in traffic and in stop light hell with everyone else. What's this really worth to ya?

Anyway, I put my money where my mouth is and bought the pair of LVX12s. And I have to say, I was right. For me. That doesn't mean I'll be right for you. Because with subs, it's really clear that YMMV.

kdaq
12-20-2017, 01:51 PM
Really great and thorough response, thanks Bruce!

I like the feeling of awe from sub-audible stuff, such as 16Hz. It sounds like the LVX12 can pull off a little of that though, no? Beyond that point, I have no interest in shaking stuff just for the sake of being able to.

It's easy to get lost in wondering, would a sealed 18" aluminum sub be tighter and more musical in audible frequencies? Or maybe the smaller 12" paper cone, with its lower moving mass would be tighter, despite the ported enclosure. It would be awesome to be able to audition a bunch all at once!

Bruce Watson
12-21-2017, 02:21 PM
I like the feeling of awe from sub-audible stuff, such as 16Hz. It sounds like the LVX12 can pull off a little of that though, no? Beyond that point, I have no interest in shaking stuff just for the sake of being able to.

Yes, they can (I've got a pair). It does a creditable job with a 32' organ pipe. And a noisy movie like Deep Water Horizon, the back half of which is a serious sub workout.

But what they (and by that I mean servo subs in general) seem to do really well are the everyday sounds, like car doors slamming, a book dropped on a counter from a couple of cm up, thunder, etc. The things that make the sound emersive, that help suck you into the narrative on screen, that's what the LVX12s (and all of Rythmik's subs) do really well.

But then, I bought a pair and want to believe I was smart about it, so you know I'm hopelessly biased, right? No way can I be objective, so you've gotta take what I say in that light.


It's easy to get lost in wondering, would a sealed 18" aluminum sub be tighter and more musical in audible frequencies? Or maybe the smaller 12" paper cone, with its lower moving mass would be tighter, despite the ported enclosure. It would be awesome to be able to audition a bunch all at once!

This is the reason to go with servo subs. The answer is substantially no. From what I can tell, the Rythmik line sounds basically the same from the LVX12s up to the LV18s. They all seem to integrate just as easily with existing speakers, etc. What you're buying when you buy the more expensive subs is the ability to dig deeper, and the ability to play louder. If you buy them and don't use those things, they'll still sound just fine. But if you need those things and don't buy them up front, you end up in the upgrade cycle.

Me, I've had mine for a couple of years without any desire to upgrade at all. But clearly, YMMV.

EDIT: That said, if you're only going to listen to music you may want a sealed sub. But a ported servo sub with high damping does a creditable imitation IMHO. But talk to Rythmik's Enrico Castignetti if you want help deciding on a particular model -- he's helped hundreds of Rythmik's customers and has gotten lots of feedback from them too. He knows what he's talking about; there's a lot of confidence in his recommendations.

kdaq
12-21-2017, 06:16 PM
Awesome. Appreciate the help Bruce!

The more I think about it, and considering impressions I've read, I'm feeling pretty confident that dual LVX12s are going to be just the ticket for me. I feel a little silly selling my LV12R to make the small hop up to LVX12, but I think it's worthwhile to make my two subs identical.

That said, it does sound like a good idea to ping Enrico before I do anything.

enricoclaudio
12-22-2017, 07:56 PM
A single F18 has about +5dB more output than a single LV12R. Basically you will need 2 x LV12R to get the same output as one F18. In terms of extension, the LV12R goes down to 18Hz while the F18 down to 12Hz but because your room is 1500 cu ft, you will get a lot of room gain so for sure you will get flat response down to at least 8Hz. I get flat response down to 7Hz with my pair of F12SEs in a 2700 cu ft room. If you have the budget, my vote and recommendation is to move the LV12R to your bedroom and get a F18 or dual F18s. BTW, did I mention that THD% for the F18 is single digits almost on every frequency above 25Hz and less than 20% down to 10Hz?

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

kdaq
12-23-2017, 03:58 PM
Ah, audio. We all want objective criteria to compare on, but it's never straight-forward what that means in the real world, is it? I suppose that's half the fun. :)

I appreciate the response Enrico! But I must admit, I find myself again a bit hesitant about what the right move is. Cost is a factor, but a clearly superior result would be my priority.

What I find really tricky just reading around, is trying to aggregate and weigh different factors into a real-world end result.


Here's a non-exhaustive list of factors I'm thinking about. In particular, with dual 12" paper cone vented LVX12s vs. a single 18" aluminum cone sealed F18.

Distortion. Reading responses like Brian's discussions of THD vs. other sources of distortion here (http://forum.ascendacoustics.com/showthread.php?6071-Differences-between-SVS-and-Rythmik&p=52082#post52082), it seems to me that distortion modeling is difficult to accurately measure, chart, and interpret. Presumably, all Rythmik subs are as well-optimized as they can be, cost-savings factors aside?

Driver size. All else being equal, smaller drivers should be capable of better transient response, no? I've noticed some discussion around the F8 talking about this, with its 8" drivers (http://forum.ascendacoustics.com/showthread.php?5906-Rythmik-F8&p=50569&highlight=#post50569). Is this noticeable between a 12" and an 18" driver when playing music at the same (say, moderate) output level, in the same (say, 16-60 Hz) frequency range?

Driver material. All else being equal, paper drivers have less mass than aluminum, and thus are capable of "slightly better dynamics at low to moderate volume levels (http://www.rythmikaudio.com/selection_guide.html)".

Enclosure type (sealed or vented). On the one hand, "[Rythmik's] recommendation for a subwoofer for music are [their] sealed Direct Servo subwoofers. If your interest is also home theater as well, one or a number of [their] sealed subwoofers will still be an ideal choice. If you are a home theater enthusiast on a modest budget and don’t listen much to music, you might consider one of [their] vented subwoofers. (http://www.rythmikaudio.com/faq.html#musicht)". But on the other hand, "Don't be fooled by typical comments about vented subs lacking accuracy. [Rythmik's vented] subs are tight and musical. (http://www.rythmikaudio.com/index.html)" So there's a difference. But it's not huge?

Frequency response and masking effect. Perhaps the biggest advantage of bigger subs is lower frequency reproduction. But how often does that matter? "Due to the masking effect, deeper bass will often not be noticeable, unless at very high in amplitude as a special effect. Of course, there is music with high amplitude bass that will mask very low bass. (http://www.rythmikaudio.com/faq.html#musicht)" But on the right recording, low response is necessary to capture all ambiance and dynamics (http://www.rythmikaudio.com/faq.html#14hz). Does the F18 accomplish this noticeably better than dual LVX12s?

Amp type and power output. Rythmik offers class A/B, class H, and class D (Hypex) amps. Not much to say here, as the LVX12 and F18 both use Hypex, and are both sized similarly to their driver size (unlike the LV12R, which uses less power for its size to cut back on cost).

Room modes, etc.. There is no end to discussion around how the room itself affects what we hear, and it's plainly very important (here is a short bit from Rythmik about it (http://www.rythmikaudio.com/faq.html#largeroomvented)). One frequent bit of advice I see is that multiple subs, when placed carefully, can help with evening-out frequency response (room modes) at different points in the room. This is of course not the only factor, but it's an important one.

Perception. Brian makes some good points about this (http://forum.ascendacoustics.com/showthread.php?6146-Alternative-to-Ryhmik&p=52722&highlight=#post52722). My experience over the years with trying various headphones and building amp and DAC kits is that I prefer neutral reproduction overall. But do I feel differently about bass reproduction? I want things that may be opposed, like more "slam", but also more room ambiance. One thing I can definitively say is that the LV12R made all other subs I've heard (which includes nice commercial movie theatres, but not much else for home stuff) sound like boomy crap to me, so clearly I value transient response. Maybe I won't know what sub(s) I prefer until I live with them for a bit...

It all comes down to this: Would a single F18 (or eventually duals) really be noticeably superior to two LVX12s for me?

mikesiskav
12-23-2017, 06:19 PM
Just to throw a wrench into things, I saw on AVSforums, both Brian and Enrico mentioned a paper based 18" driver option that they were investigating which would provide 3dB more output in the upper bass (were you get the "slam" effect) than the current model. At this point, I've seen very little info about this product and it may or may not see the light of day.

kdaq
12-23-2017, 08:06 PM
HAH! I was just wondering if such a thing existed. I'd expect that paper isn't typically used on such huge woofers, since it's not stiff enough to hold high SPL in low frequencies. Perhaps they would tune it with a frequency response closer to their smaller subs.

mikesiskav
12-23-2017, 10:01 PM
If the paper woofer managed to provide 3dB higher output in the upper bass without sacrificing any low end output, that would be impressive. That would put it almost on par (output wise) with the more expensive Funk 18.0.

kdaq
12-26-2017, 09:32 AM
Ah, the Funk uses a paper / carbon fibre weave, neat. Guessing if Rythmik used a similarly spiffy driver, it would raise costs. Not to mention if they needed to up the amplification.


I'm pretty intrigued by the F18 as it is today. It's overkill for my room size, which might have a chance of quelling my upgradeitis!

I just hope that it doesn't have noticeable disadvantages to the smaller subs (room modes aside).

curtis
12-26-2017, 10:43 PM
Ah, the Funk uses a paper / carbon fibre weave, neat. Guessing if Rythmik used a similarly spiffy driver, it would raise costs. Not to mention if they needed to up the amplification.

Don't put stock into any one element of subwoofer/speaker design, as performance is a sum of all aspects.

kdaq
12-27-2017, 10:11 AM
Agreed, Curtis. This is a good segue back to my original question!


Ah, audio. We all want objective criteria to compare on, but it's never straight-forward what that means in the real world, is it? I suppose that's half the fun. :)

I appreciate the response Enrico! But I must admit, I find myself again a bit hesitant about what the right move is. Cost is a factor, but a clearly superior result would be my priority.

What I find really tricky just reading around, is trying to aggregate and weigh different factors into a real-world end result.


Here's a non-exhaustive list of factors I'm thinking about. In particular, with dual 12" paper cone vented LVX12s vs. a single 18" aluminum cone sealed F18.

Distortion. Reading responses like Brian's discussions of THD vs. other sources of distortion here (http://forum.ascendacoustics.com/showthread.php?6071-Differences-between-SVS-and-Rythmik&p=52082#post52082), it seems to me that distortion modeling is difficult to accurately measure, chart, and interpret. Presumably, all Rythmik subs are as well-optimized as they can be, cost-savings factors aside?

Driver size. All else being equal, smaller drivers should be capable of better transient response, no? I've noticed some discussion around the F8 talking about this, with its 8" drivers (http://forum.ascendacoustics.com/showthread.php?5906-Rythmik-F8&p=50569&highlight=#post50569). Is this noticeable between a 12" and an 18" driver when playing music at the same (say, moderate) output level, in the same (say, 16-60 Hz) frequency range?

Driver material. All else being equal, paper drivers have less mass than aluminum, and thus are capable of "slightly better dynamics at low to moderate volume levels (http://www.rythmikaudio.com/selection_guide.html)".

Enclosure type (sealed or vented). On the one hand, "[Rythmik's] recommendation for a subwoofer for music are [their] sealed Direct Servo subwoofers. If your interest is also home theater as well, one or a number of [their] sealed subwoofers will still be an ideal choice. If you are a home theater enthusiast on a modest budget and don’t listen much to music, you might consider one of [their] vented subwoofers. (http://www.rythmikaudio.com/faq.html#musicht)". But on the other hand, "Don't be fooled by typical comments about vented subs lacking accuracy. [Rythmik's vented] subs are tight and musical. (http://www.rythmikaudio.com/index.html)" So there's a difference. But it's not huge?

Frequency response and masking effect. Perhaps the biggest advantage of bigger subs is lower frequency reproduction. But how often does that matter? "Due to the masking effect, deeper bass will often not be noticeable, unless at very high in amplitude as a special effect. Of course, there is music with high amplitude bass that will mask very low bass. (http://www.rythmikaudio.com/faq.html#musicht)" But on the right recording, low response is necessary to capture all ambiance and dynamics (http://www.rythmikaudio.com/faq.html#14hz). Does the F18 accomplish this noticeably better than dual LVX12s?

Amp type and power output. Rythmik offers class A/B, class H, and class D (Hypex) amps. Not much to say here, as the LVX12 and F18 both use Hypex, and are both sized similarly to their driver size (unlike the LV12R, which uses less power for its size to cut back on cost).

Room modes, etc.. There is no end to discussion around how the room itself affects what we hear, and it's plainly very important (here is a short bit from Rythmik about it (http://www.rythmikaudio.com/faq.html#largeroomvented)). One frequent bit of advice I see is that multiple subs, when placed carefully, can help with evening-out frequency response (room modes) at different points in the room. This is of course not the only factor, but it's an important one.

Perception. Brian makes some good points about this (http://forum.ascendacoustics.com/showthread.php?6146-Alternative-to-Ryhmik&p=52722&highlight=#post52722). My experience over the years with trying various headphones and building amp and DAC kits is that I prefer neutral reproduction overall. But do I feel differently about bass reproduction? I want things that may be opposed, like more "slam", but also more room ambiance. One thing I can definitively say is that the LV12R made all other subs I've heard (which includes nice commercial movie theatres, but not much else for home stuff) sound like boomy crap to me, so clearly I value transient response. Maybe I won't know what sub(s) I prefer until I live with them for a bit...

It all comes down to this: Would a single F18 (or eventually duals) really be noticeably superior to two LVX12s for me?

PlasmaPZ80U
01-27-2018, 10:38 AM
I have a single LV12R myself. In a 12' by 12' by 8' high sealed room. Mostly HT, but I do listen to some music. I have wondered about the added extension of LVX12 or better yet sealed L12 or L22 with plenty of room gain. Decided I don't need to upgrade since I only have one good spot for sub placement, other spots have much worse response and SQ.

Have you considered dual L22s? They have a tiny footprint, just like L12, but with twice the drivers and power. LV12R is already a tall sub, so L22 should fit in the same spot.

Consider dual:

LVX12s
L22s
E15HPs

kdaq
01-28-2018, 01:37 PM
Good thought. The L22 is a bit tall for the spot I have though, I need to be able to sit on 'em to get behind my adjacent TV and associated rat nest of wires behind it. :)

Still not sure if I should go LVX12 or F18. For now, just saving up and letting it sit in the back of my mind.

Bruce Watson
01-28-2018, 03:09 PM
It all comes down to this: Would a single F18 (or eventually duals) really be noticeably superior to two LVX12s for me?

In a sealed room with dimensions less than about 60' (that is, the wave length of 20 Hz) in any direction, room modes are a problem. Smaller rooms have more of a problem than bigger rooms. Sealed rooms have more of a problem than open plan spaces. Etc. But for any practical room in any practical house, room modes are a real problem.

So, in general (that is, I'm making generalizations here, so this is not absolute), and IMHO, it's better to have a pair of smaller subs than a single bigger sub. I believe it enough that I put my money where my mouth is and bought a pair of smaller subs. And I'll be darned if it doesn't work just like I hoped it would.

What will work for you? You're the only one who can answer that question. And Rythmik (and other sellers) make that sorta-kinda easy to answer. They give 30 day and 45 day trial periods in your room for the cost of shipping back and forth. A small price to pay maybe for the ability to answer your "two smaller subs or one big one" question definitively.

mikesiskav
01-28-2018, 04:56 PM
Disregarding quantity of subs, going to a larger sub is for more output. In the upper bass, the 18 will have quite a bit more output than your 12. Since yours is ported the difference in the low bass will be smaller.

Dual LVX12's are likely to have more output than a single F18 at 20hz. Dual F18 will have more ouput at 20hz and a lot more output at 40hz and above compared to dual LVX12's. Sound quality wise, I'd say there's not much of a difference between the two of them. All the Rythmiks have great sound quality.

So in summary, dual LVX12 will give you more output than what you have now plus smoother frequency response and less bass localization. A single F18 will give you more output, especially in the upper bass than what you have now, but less output at 20hz than dual LVX12 and less smooth response.

kdaq
01-28-2018, 08:35 PM
I get that ported Rythmiks are tight, but can't help but wonder if I'll appreciate the sealed F18.

N Boros
01-29-2018, 12:43 PM
Sound quality wise, I'd say there's not much of a difference between the two of them. All the Rythmiks have great sound quality.


I remember someone within the past two years, that had listened to both ported and sealed models, describing a little more specifically how the ported and sealed subs are similar. I can't remember who though. Anyway, he said that the sealed Rythmik in medium damping is like the ported Rythmik in high damping, the sealed Rythmik in low damping is like the ported Rythmik in medium damping. So the sealed Rythmik has the ability to go into high damping to get a slight bit better transient response, whereas the ported Rythmik has the ability to go into low damping which will give a slightly fuller bass sound that some like.

The nice thing about a small sealed room like yours is that one has lots of options, whatever the end use would lean towards (HT or music). If you want the slightly better transient response, no way of having any vent noise (even when pushed really hard with the limiter on) and don't mind spending the extra money per output that you get, then by all means get a sealed sub. If you want to maximize your output per dollar, even down low in the frequencies, and don't mind the larger box, then get a ported sub sized to fit your room. If any of those things lean you more one way or the other, then make your decision based on that. Even Josh Ricci who heard both the F18 and FV18 said that the two sound very similar, echoing what others have said.

kdaq
01-29-2018, 12:57 PM
Ahh, I see. That makes sense! Appreciate the details N Boros. It really does feel like sealed is more about form-factor than sound quality with Rythmik (perhaps unlike most other non-active-servo options).

It's so easy to get enthused about the biggest and baddest option. I think I'm partially thinking F18 because I'd hate to go dual LVX12 and later find myself wanting to upgrade again. But if I'm honest, I'm lusting after the F18. It perhaps doesn't make as much sense on paper.

This is half the fun I suppose, saving up for a while, reading and obsession, and then seeing where my heart ends up. :)

N Boros
01-29-2018, 02:47 PM
I say all of this having a room size similar to yours, with HT being the priority and yet considering a larger sealed sub like the F18. :) Why? The size of any of the Rythmik subs isn't much of an issue for me because I will be able to tuck one behind an acoustically transparent screen and the other in the back of the room out of the way. So I don't care as much about the smaller size. The reason why I am strongly leaning towards a larger sealed sub is because:

1) I want the absolute best transient response I can get.
2) I want to have flexibility to cross over any speakers that are producing nulls in the main listening position higher than normal (say 100 to 150 Hz) if necessary.
3) I want to get output, up to as loud as I normally listen, well below 20Hz to avoid any additional distortion up more in the audible band if the sub can't reproduce it well. This means that I need the larger driver in the sealed lineup to get the distortion to be reasonably low even down below 20 Hz to avoid this issue. I could just get a lesser expensive sub in the Rythmik lineup and have it roll off below 20Hz, but the purist in me would prefer the signal to be accurately reproduced.

For me these the points are enough to say spend an extra $500 per subwoofer, over a ported model that would probably do wonderfully in the room. But, it doesn't take much of an increase in room size to where it just doesn't even make financial sense for me to consider a sealed sub for HT and I would likely just go with a ported model. Maybe even in blind testing I couldn't tell the difference anyways.

kdaq
01-29-2018, 02:55 PM
I hear you! If nothing else, there's a gut feeling that I'm less likely to have buyer's remorse from an F18 than other options. :)

My kingdom for an in-house double-blind test of every Rythmik sub combo possible. ...without having to move, setup, and ship back everything myself, of course!

N Boros
01-29-2018, 03:15 PM
Nothing illustrates the difference in output per dollar with a sealed and a ported Rythmik subwoofer than looking at the data-bass measurements of the F18 vs the FV18. The FV18 is basically (within about $150) the same price as the F18. You get a massive amount more output from the FV18 below 30 to 40 Hz. What you are giving up though is what I mentioned in points 1 and 2 in the previous post. If I didn’t care about those things, then it would be an easy choice to go with a smaller ported sub (FVX15 would probably be overkill), in my room I wouldn’t need the output of a FV18. And points 1 and 2 are actually probably very tiny and maybe inaudible things.

mikesiskav
01-29-2018, 03:16 PM
Kdaq, it sounds like the F18 is the one for you. Just go for it!

N Boros
01-29-2018, 05:00 PM
It sounds like the F18 is the one for you. Just go for it!

I’m waiting on the G25HP. The output should be pretty similar, but the dual opposed design should reduce any movement the driver might cause on the subwoofer. Who knows if that is even audible though. It should reduce any structural transmission from one room to the next without resorting to grandma pads, sound isolation feet, or anything like that. But if the price is similar, why not go with a theoretically more accurate design.

mikesiskav
01-29-2018, 07:03 PM
I’m waiting on the G25HP. The output should be pretty similar, but the dual opposed design should reduce any movement the driver might cause on the subwoofer. Who knows if that is even audible though. It should reduce any vibrational transmission from one room to the next without resorting to grandma pads, sound isolation feet, or anything like that. But if the price is similar, why not go with a theoretically more accurate design.

I meant that for kdaq, I should have been more clear. Has the price of the G25HP been announced? I'm guessing it will be more expensive than the F18 due to the higher power amp and dual woofers. Also the G25HP should be higher performance than the F18, assuming the G25HP matches the F25.

N Boros
01-30-2018, 05:39 AM
I meant that for kdaq, I should have been more clear. Has the price of the G25HP been announced? I'm guessing it will be more expensive than the F18 due to the higher power amp and dual woofers. Also the G25HP should be higher performance than the F18, assuming the G25HP matches the F25.

No problem. Sorry for the confusion.

No the price hasn’t yet been announced. Over in the AVS thread they have said early spring for a release date. And that Josh Ricci will get one to measure in the middle of the summer. I think that the price will be close to the F25, but maybe slightly more money because of the larger amplifier. Due to the smaller form factor that allows shipping via traditional methods and not freight, the prices might come out really close. I’m just guessing though.

The performance of the F25 is higher, but Rythmik lists it as only a 1.5 dB advantage at 20 Hz. If they remain that close throughout the frequency band, then really they are pretty close. Who knows, maybe the F25 pulls ahead at higher frequencies, where it would be audible.

Bruce Watson
01-30-2018, 08:10 AM
...there's a gut feeling that I'm less likely to have buyer's remorse from an F18 than other options. :)

The only times I've had buyers remorse is when I've spent too much and bought more capability than I actually needed or used. The remorse was that I could have used that money to improve other things.

The problem with the diminishing returns curve is determining where you are on it. If you're on the straight line section, spending the extra money buys you a lot of return. If you're on the shoulder of the curve, spending the extra money buys you very little.

Alternatively, some people get a lot out of having the biggest pickup truck in the neighborhood. Not that they need it. Not that they use it. Just that it's bigger than everyone else's truck. I'm not saying this is bad. I'm just saying you'll benefit in the long run if you can define what you're really after.

N Boros
01-30-2018, 09:19 AM
The problem with the diminishing returns curve is determining where you are on it. If you're on the straight line section, spending the extra money buys you a lot of return. If you're on the shoulder of the curve, spending the extra money buys you very little.



I 100% agree with this. This is quite difficult to determine with most things. But, subwoofers are actually one of the easier things to nail down though, especially if kdaq is considering the F18, which was measured over on data-bass:

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

First, sit down in your primary seat with an action movie and adjust the volume as loud as you would possible go and watch the entire movie. Some people might crank up the volume if they are just watching one fun scene, but they aren't likely to keep it uncomfortably high for an entire movie. If your receiver has Audyssey or some other room eq and has the relative volume displayed for the volume, then you should have a pretty good idea of how loud this is. If you are listening at -15 dB, then this means that on average you are listening at 75 - 15 = 60 dB, with peaks in the channels to be as loud as 60 + 20 = 80 dB and peaks in the LFE (or subwoofer) as much as 90 dB. (This works for most movies as they were mastered for the home at 75 dB average, but some might be 85 dB. Check a few movies just to be sure.) If your receiver doesn't have these features, then pick up an SPL meter and measure when you are watching the movie for a few minutes to get an idea. If you have Audyssey with Dynamic EQ, then it may be boosting the LFE as much as 5 dB. Not with - 15 dB, because I think that 60 dB in the bass is considered audible and it isn't likely to be boosted. If you also boosted the bass after running Audyssey, then also keep in mind what that was. Say that you raised the gain in the subwoofer by 5 dB. This means that you want your subwoofer to be able to play as loud as 90 + 5 + 5 = 100 dB.

Now click on the measurements for the F18 above from data-bass, select the static graphs tab and look for the F18 CEA 2010 in room measurements. You can see that you can easily hit much more than 100 dB, if needed. Many have said that we can't hear as much as 20% THD from 80 Hz and below, so you are likely even okay there. Some argue that they want distortion to be lower than 20%. At 16 Hz you are really close to 20% distortion and the 3rd order harmonic is the big contribution there. This means that if you hit close to 100 to 103 dB at 16 Hz you will get distortion showing up at around 48 Hz, which is audible. Keep in mind that this is only with an instantaneous peak to an explosion or something else really loud for just a split second. Does that bother you? Is that split second of possibly less distortion worth $500 to $800 more for your subwoofer? This is what Bruce was talking about, as far as diminishing returns. Would you be okay just gently rolling off the bass below 20 Hz, with a toggle switch on the Rythmik amplifier, to still get the feeling of 16 Hz but reduce it a slight bit and the distortion that might be accompanying it?

Say that you only would listen at -20 dB at most and you don't boost the LFE channel at all, so really you need 10 dB less that we were even discussing as the maximum, or 90 dB. In this case you can can go over to the Rythmik homepage

http://www.rythmikaudio.com/

and look at the output comparison at 20 Hz. So you could step down 10 dB in output from the F18, then you are in the range of the L12 or F12, with the output probably being just fine. If you want to play things safe maybe you step up 5 dB to the LVX12, or actually getting just the second LVR12 because you will get an extra 3 dB just putting it in the room with your first LVR12 and it is 2.5 dB above the F12, which is around 5 dB.

mikesiskav
01-30-2018, 11:11 AM
No problem. Sorry for the confusion.

No the price hasn’t yet been announced. Over in the AVS thread they have said early spring for a release date. And that Josh Ricci will get one to measure in the middle of the summer. I think that the price will be close to the F25, but maybe slightly more money because of the larger amplifier. Due to the smaller form factor that allows shipping via traditional methods and not freight, the prices might come out really close. I’m just guessing though.

The performance of the F25 is higher, but Rythmik lists it as only a 1.5 dB advantage at 20 Hz. If they remain that close throughout the frequency band, then really they are pretty close. Who knows, maybe the F25 pulls ahead at higher frequencies, where it would be audible.

Ya, I'm just guessing that the G25 will gain a couple more dB in the upper bass. If you compare the FV15 to the FV18, the FV18 has a 3dB lead at 20hz. At 31.5hz, however, the difference is only 1dB, and above 40hz they are basically even. I think perhaps the 15 inch driver has a higher sensitivity which allows it to excel in the upper bass, where subs tend to be more amplifier limited as opposed to excursion limited.

N Boros
01-30-2018, 12:32 PM
Ya, I'm just guessing that the G25 will gain a couple more dB in the upper bass. If you compare the FV15 to the FV18, the FV18 has a 3dB lead at 20hz. At 31.5hz, however, the difference is only 1dB, and above 40hz they are basically even. I think perhaps the 15 inch driver has a higher sensitivity which allows it to excel in the upper bass, where subs tend to be more amplifier limited as opposed to excursion limited.

Good point about the sensitivity of the 15 inch driver. You may be right.

I was shocked when I looked at the difference in output for the FV15HP with one port open vs the FV18 with two ports open. It isn't until you get about 25 Hz and below (looking at the CEA 2010 burst measurements) that the FV18 pulls ahead of the FV15HP, by about 3 dB as you mentioned. But, what is interesting is when you look at the difference in the distortion. Now, if I am reading things correctly, Josh left the limiter off with the FV15HP, but he left it on with the FV18, unfortunately. Because now I wonder how much of this lower distortion can be attributed to the limiter being left on? How much can be attributed to a 15 inch versus an 18 inch driver? How much can be attributed to maybe Brian dialing in the limiter a little bit better than he did before (I'm not saying that he did anything bad before, but it as been a number of years since the FV15HP was released and people improve upon things that they did previously.)

We can remove the variable of the limiter off with the FV15HP and on with the FV18, yet still compare the 15 and 18 inch drivers. Just look at the FV25HP vs the FV18. Notice how again, the FV18 when pushed with these bursts close to its limits, remains more composed in terms of lower THD, whereas the FV25HP is a little less composed. Yes, the FV25HP has quite a bit more output. But, I'm thinking that perhaps the 18 inch driver has something to do with helping it remain more composed. Plus Josh said this about the FV18, when he is commenting on his measurements:

"The maximum output at the bands above 20Hz was limited by the amplifier and limiter. At 20Hz and below the FV18 would produce about 1dB greater output in the 16Hz tuning, but not while passing the distortion and noise thresholds."

So even with the limiter off on the FV18, you don't get much more output, at the expense of much greater THD.

curtis
01-30-2018, 01:02 PM
I just want to say I love my F15HP. :)

mikesiskav
01-31-2018, 01:13 AM
I just want to say I love my F15HP. :)

It's a great sub for sure. Although it's fun to talk about these powerful subs, the reality for me, is that I have more subwoofer than I need right now. And I'm sure my neighbors would agree.

kongar
02-14-2018, 04:43 PM
Little late to the party but two subs are SO much better than a single one.

Joe12pack
02-27-2020, 04:09 PM
Little late to the party but two subs are SO much better than a single one.

I am looking to add a 2nd sub to my single F25 sealed (one box, two 15s). I would like to step up to the F18 (single sealed 18). Is it ok to mix and match subs? Will it give me the same effect that I've been reading about where multiple swarms of subs greatly enhances the experience?

kongar
02-28-2020, 04:52 AM
I feel identical subs are the way to go. Mismatched subs can and probably do work well for many people - but I think you’re adding complexity to the room dynamics in this case.

kdaq
02-28-2020, 06:18 AM
Oh wow, I don't think I ever posted here about what I ended up doing, did I? In November of 2018 I got the F18!

At first I wasn't sure about it. My basement is carpet on concrete, and I put the sub without feet in a corner (I have no flexibility in placement unfortunately). It rattled everything like crazy! Next I put it on its rubber feet, and this seemed to help the rattling. The accuracy was fantastic, but I was missing tactile response. Eventually I tried the sub without feet again, but with one difference: I pointed the driver away from the wall and out into the room. That did the trick! The rattling went away, and the TR improved.

I recently also upgraded my mains from Sierra-2 to Sierra-2EX. These have what I perceive as improved punch or slam (with only a touch of warmth over neutral), and the whole system really sounds phenomenal together.

This setup uses XT32 room correction, but pretty sure I would benefit from a second sub and/or some DSP correction for the sub specifically. It's a bit of work though, and I'm just really enjoying the setup as it is right now. No regrets!

N Boros
02-28-2020, 02:20 PM
Oh wow, I don't think I ever posted here about what I ended up doing, did I? In November of 2018 I got the F18!

At first I wasn't sure about it. My basement is carpet on concrete, and I put the sub without feet in a corner (I have no flexibility in placement unfortunately). It rattled everything like crazy! Next I put it on its rubber feet, and this seemed to help the rattling. The accuracy was fantastic, but I was missing tactile response. Eventually I tried the sub without feet again, but with one difference: I pointed the driver away from the wall and out into the room. That did the trick! The rattling went away, and the TR improved.

I recently also upgraded my mains from Sierra-2 to Sierra-2EX. These have what I perceive as improved punch or slam (with only a touch of warmth over neutral), and the whole system really sounds phenomenal together.

This setup uses XT32 room correction, but pretty sure I would benefit from a second sub and/or some DSP correction for the sub specifically. It's a bit of work though, and I'm just really enjoying the setup as it is right now. No regrets!

How did the tactile response of the F18 compare with what you had on the LV12R? Many over on the Rythmik AVS thread seem to say that one of the benefits of the ported subs is that they can give more tactile response than the sealed subs. Though you have a huge difference in output capabilities going from the LV12R to the F18. The F18 has more output likely at every frequency in comparison.

kdaq
02-29-2020, 06:58 AM
The LV12R had pretty amazing TR (and overall sound quality) for the money. Really a phenomenal value. That said, once I got my positioning right, the sealed F18 clearly wins on both counts. It's not an enormous difference on the TR front, but it made me happy. I do wonder what a FV18 with a paper cone would sound like, but the accuracy of the F18 is pretty stunning.