PDA

View Full Version : Differences between Rythmik FV15Hp and F25



N Boros
08-08-2014, 01:10 PM
I know that in general the transient response of sealed subs are supposed to be better than that of ported subs and ported subs are supposed to have quite a bit more output at the lower end. But the output seems very similar between the FV15Hp and the F25 and the F25 should have better transient response than the FV15HP. According to the Rythmik website:

"Output comparison

At 20 Hz, our subs vary in their maximum output capability. The output at 20 Hz is shown relative to F12.

F12: 0db (baseline)
F15: +2db D15: +2db
LV12R: +2.5db
E15HP: + 3.5db
F15HP: +4db
FV15: +7db
FV15HP: +9.5db
F25: +8db"

So the FV15HP has a slight advantage of output at 20Hz. However, since the F25 is sealed it should roll off more gradually, so below 20Hz output should be higher on the F25. If the differences in output are only slight, will I hear much of a difference between the two with music? What about with movies? If a sealed sub has the same output capability as a similarly priced ported sub, wouldn't the sealed sub be the better of the two?

I compared my new Sierra 2s with other similarly priced speakers exhibiting flat frequency response on axis as well as quite far off axis. I could immediately hear the difference between the Sierra 2s and the other speakers and I attribute this mostly to the faster transient response of the ribbon tweeter in the Sierra 2s. A better comparison is the folks that have upgraded the Sierra 1 to the Sierra 2 and preferred the difference in sound quality for almost double the price. I wonder if the same will hold true in the below 80 Hz region with subwoofers?

RicardoJoa
08-10-2014, 09:38 AM
With music, i would be more concern with the higher frequencies rather then the lowest, in which based on the discription of the f25, has more power than the FV15.
It will be most likely hard to hear the difference as frequencies below 20hz are rather sensational.

N Boros
08-11-2014, 10:00 AM
With music, i would be more concern with the higher frequencies rather then the lowest, in which based on the discription of the f25, has more power than the FV15.
It will be most likely hard to hear the difference as frequencies below 20hz are rather sensational.

I guess the reason I was bringing up lower frequencies, is that sealed subwoofers will have the most difficult time getting the same output at 20 Hz in comparison to a ported sub in the same price class. So if the F25 and FV15HP have nearly the same output at 20 Hz then we could expect the same to be true up to around 40 or 50 Hz, where the F25 probably has a little bit more output than the FV15HP, as you mention. So the FV15HP has a slight advantage below 40Hz and the F25 has a slight advantage above 40Hz.

My concern is more with respect to home theater, as the F25 would likely have the advantage for music. If the frequency response is quite similar between the two, and I am okay with the size of the F25 and slightly higher price, then which of the two would have the advantage for home theater? Also, will I be able to hear faster transient response of the F25 and is this something more desirable for home theater use? I cannot see why a main speaker with faster transient response wouldn't be more desirable for home theater or music use, but there seems to be some who prefer the sound of ported subs for home theater use.

RicardoJoa
08-11-2014, 09:20 PM
I guess the reason I was bringing up lower frequencies, is that sealed subwoofers will have the most difficult time getting the same output at 20 Hz in comparison to a ported sub in the same price class. So if the F25 and FV15HP have nearly the same output at 20 Hz then we could expect the same to be true up to around 40 or 50 Hz, where the F25 probably has a little bit more output than the FV15HP, as you mention. So the FV15HP has a slight advantage below 40Hz and the F25 has a slight advantage above 40Hz.

My concern is more with respect to home theater, as the F25 would likely have the advantage for music. If the frequency response is quite similar between the two, and I am okay with the size of the F25 and slightly higher price, then which of the two would have the advantage for home theater? Also, will I be able to hear faster transient response of the F25 and is this something more desirable for home theater use? I cannot see why a main speaker with faster transient response wouldn't be more desirable for home theater or music use, but there seems to be some who prefer the sound of ported subs for home theater use.

I cant say which to which as i dont own either ones. I own a F15 and im compleaty happy with it.
But you can take a look at the sealed version FR and i would assume that the F25 would have similar FR.
If you look at the ported version, the FR is faltter.


Shoot Brian your concerns,:)

Audiolover458
10-31-2014, 05:45 PM
I am interested in the same thing. I am surprised though at the lack of interest in this thread :-).
Would love to know the answer and I did email Rythmik today so let us see if they answer. Maybe I can drive to Austin and find out for myself.

Sivar
10-31-2014, 06:40 PM
I haven't heard the F15HP (or almost any subs in this class), but I got the F25 because it is sealed, has only slightly lower output around 20Hz and (I assume since it is sealed) higher output above and below that range, and was only a little more expensive.

I see it as this: If the huge size and slightly higher cost aren't an issue, why not get the sealed model? Other than low output, which isn't much of an issue in this case, I haven't heard any benefit of ported subs but have heard of many benefits of sealed.
As an aside, the F25s are tall enough to use as an end table, though you'll want to protect the finish.

Audiolover458
10-31-2014, 06:50 PM
I haven't heard the F15HP (or almost any subs in this class), but I got the F25 because it is sealed, has only slightly lower output around 20Hz and (I assume since it is sealed) higher output above and below that range, and was only a little more expensive.

I see it as this: If the huge size and slightly higher cost aren't an issue, why not get the sealed model? Other than low output, which isn't much of an issue in this case, I haven't heard any benefit of ported subs but have heard of many benefits of sealed.
As an aside, the F25s are tall enough to use as an end table, though you'll want to protect the finish.

IT would be nice to hear what you thiink of it. Can you please give us the benefit of your experience with this SUB? I think it is a better value than buying that Glossy finish on the FV15 for 1599.

Sivar
10-31-2014, 07:35 PM
I'm not sure what I can say that will be at all useful. I'll note a few general observations.


I like them.
The room they are in is very open so the subwoofers have to pressurize practically the whole house. They will likely sound much, much more powerful in a sealed, small, dedicated home theater room.
I tend to reduce their volume by about 5dB when listening to music because otherwise they are a little overwhelming, but for bass heavy music they are powerful enough to turn up and vibrate just about everything.
I've had to put every decoration in the room on rubber padding to prevent annoying rattling sounds.
They don't seem to really "punch me in the gut" like a good car audio system, but then, I'm not sure what could in the terrible room these things serve. Maybe a pair of Seaton Submersive's, but those cost quite a bit more.

Audiolover458
11-05-2014, 07:41 PM
Thanks, really appreciate the info. did not feel the love from Rythmik and trying to save money for a possible Horizon center so going DIY and saving 1200 on two. Does not look like there are many F25s out there. I am glad you are enjoying yours.

Sivar
11-11-2014, 12:30 PM
I've since demo'd an SVS PB-2000. The PB-2000 is about half the cost of an F25 if you include shipping, is ported rather than sealed, and has a single 12" driver with a large port rather than dual 15" drivers.

Obviously these subs are in a different class so it would be unfair to compare output, but I can kind of compare them based on their sound characteristics at similar volume levels.
Note that the following comparison sucks:


Different rooms (his is larger and closed, mine is smaller but open to the entire house)
They are paired with different main speakers (he has Aperion Audio Verus Grands)
Different pre-amp (UMC-200) and amp for those speakers (XPA-5)


My impressions:


The SVS PB-2000 is an absolutely incredible subwoofer for the cost and driver size.
Playing the same songs sounded quite different -- much more different than I expected.
The SVS was more talkative, e.g. it seemed to rumble more often (at a wider frequency range) than the Rythmik. It seemed busy more often than not, whereas the Rythmik seems more "on and off".
The bass sounded flappier, looser, thumpier, and more intentional. My first two words should not be read with a negative connotation. The SVS did not at all sound obviously worse, just very different. (Note: We both use an 80Hz crossover for everything).
Specifically Timestretch by Bassnectar sounded flabby. I suggested it as a bass test song. On my subs, it physically rumbles the gut when bass is turned up. It isn't meant to be on the Focal audiophile reference CDs, just to test subwoofers in a more musical fashion than with frequency sweeps.
My friend commented, "Where's the bass?" with the intention of lambasting the song, not the sub. This was reasonable because the sub had just been very impressive with most other test tracks, particularly, You are so Fucked by Infected Mushroom. Whatever frequencies were requested by Timestretch did not come across well in the SVS.


While I've researched audio in various ways for ages, I haven't actually auditioned much equipment. Based on research and numerous charts, I expected that quality subs playing the same song (within each subs freq range) would differ almost exclusively in output and in ways that one can compensate for with a simple mixer.

Many songs played on both systems sounded more akin to different remixes. It was a little surreal, especially since so many of my previous audio comparisons involved me being totally unable to tell between what were apparently "obvious" differences.

I would really like to bring an F25 to the other house (as it is a better test environment than my own) to directly compare the subs, but the F25 isn't exactly portable.

N Boros
07-22-2015, 12:00 PM
I would really like to bring an F25 to the other house (as it is a better test environment than my own) to directly compare the subs, but the F25 isn't exactly portable.

I think you are absolutely right. The room and placement of the subwoofer within the room makes a huge difference. The best way to compare them would be to bring one subwoofer to the other person's house and place it exactly in the same position. This takes the room and placement out of the equation.

I agree with you about not wanting to F25 all that far either. I bet the PB2000 is more portable. Maybe you can convince your friend to bring it to your place, to compare the two. :)

Sivar
07-22-2015, 12:42 PM
I've been trying to get him to do that, but I doubt it will happen.
My friend did finally demo my setup at a party.
Keeping in mind the caveats I mentioned in my previous post:

1) After the demo, he said, "Thanks for jump-starting my heart!"
2) One of the first songs he played on his system was from a test disk I made for him: Time Stretch by Bassnectar. He said "where's the bass?" -- a criticism of the song, not his sub (since it was performing pretty well).
That was the song I played at my place which got the response above. I don't think he remembers.
3) When I demod that same song to another friend about 3-4 months ago, a light fixture fell from my ceiling and shattered all over the floor.

The F25 is more than a capable subwoofer, but the SB-2000 is a great subwoofer and should be plenty of power for most home theaters. A single F25 should outperform it in every way except price and space taken. I happened to choose sealed so I needed to be more flexible with both to get good response, but I'd be happy with an SVS, too. I'd also have been happy with a pair of FV15's. Just about anything from Rythmik, SVS, HSU and others should perform very well and be priced very reasonably. I chose Rythmik because my research indicated they were slightly ahead of the competition.

N Boros
07-23-2015, 11:15 AM
Thanks Sivar. Just to be clear, here you write his sub was the SB-2000. In the previous post you said PB-2000. Does he have the small sealed sub, or the bigger ported sub?

I would expect the Rythmik F25 to be superior to the SB-2000 in every way (except of course size and the larger price tag). The PB-2000 would be an interesting comparison, since it might not be too far away from the F25 in terms of output and extension, at least not as far away as the SB-2000 and F25 will be. However, the natural question is how much better is the F25 in terms of sound quality? This is a tough question to answer, because as you say it is not easy moving subs from one house to another to be able to compare these.

But, I completely agree with you, that if we go with Hsu, SVS or Rythmik, especially in the same price class, the differences should likely be pretty small and I don't think that any would be a bad decision. Though, I too lean slightly towards the Rythmik likely being slightly ahead of the other two in terms of price to performance. All of this is probably meaningless, since I have not been able to compare all three in my room, but looking over detailed measurements on data-bass and comparing professional reviews that is the impression I get.

Sivar
07-23-2015, 12:07 PM
My apologies for the confusion. He has the PORTED sub, the PB-2000.

curtis
07-23-2015, 12:24 PM
But, I completely agree with you, that if we go with Hsu, SVS or Rythmik, especially in the same price class, the differences should likely be pretty small and I don't think that any would be a bad decision.
I think it would depend on how discerning your hearing, and how "picky" one is.

I have not compared subs in a while (5-6 years?), but have heard and compared subs from all three mentioned manufacturers in my own room. They are all good, but definitely sound different.

N Boros
07-23-2015, 01:59 PM
I think it would depend on how discerning your hearing, and how "picky" one is.

I have not compared subs in a while (5-6 years?), but have heard and compared subs from all three mentioned manufacturers in my own room. They are all good, but definitely sound different.

I think most of us on forum would likely fall in the "picky" category. Since you have heard all three manufacturers would you share your thoughts, from what you remember? What were some of the strengths and weaknesses of each?

RythmikAudio
07-23-2015, 05:33 PM
Actually Sivar's depiction of the whole thing is very interesting. Here is my take-away: 1) Our sub blends better and it sounds like on and off. When it sounds as off, it is not because it is turn off, or it has less output. Rather it is because it blends so well that it does not draw attention. When it is on, it is because the bass effect is so much so that someone cannot believe the sound is from a pair of 8" woofer front speakers. On the other hand, PB2000 draws attention all the time reminds the listener it is there. The analogy of subwoofer/front speaker integration is like team work. The two blend well together and from outside you cannot see individuals. 2) When we have a better sub with higher resolution, we get more confidence about judging the music we hear. With a lesser sub that does not play well, it is always a question if it is the song, or it is the equipment (not just sub). So why not get the better sub? The difference is not subtle.

For anyone skeptical of the sound quality of our servo subs, I have no problem sending a unit for comparison. I can even pay for shipping. I did it once before for an AVS forum member. He was skeptical. I sent him a unit so he compared it with Ourlaw. He said he cannot tell the difference on music he played. However, in one of the demo tracks used by Danley Sound with a sound recording of a train seemingly with a lot of randomly orchestrated sound from rail, cart moving, metal striking.. etc. Our sub sounded much cleaner and believable than Outlaw. So much as that even his young son agreed. Now why he cannot hear the difference in music has to do with the type of music he likes. But that aside, our subs are not just for music. Customers can hear more believable sound from movies too.

N Boros
07-23-2015, 06:13 PM
I know that in general the transient response of sealed subs are supposed to be better than that of ported subs and ported subs are supposed to have quite a bit more output at the lower end. But the output seems very similar between the FV15Hp and the F25 and the F25 should have better transient response than the FV15HP. According to the Rythmik website:

"Output comparison

At 20 Hz, our subs vary in their maximum output capability. The output at 20 Hz is shown relative to F12.

F12: 0db (baseline)
F15: +2db D15: +2db
LV12R: +2.5db
E15HP: + 3.5db
F15HP: +4db
FV15: +7db
FV15HP: +9.5db
F25: +8db"

So the FV15HP has a slight advantage of output at 20Hz. However, since the F25 is sealed it should roll off more gradually, so below 20Hz output should be higher on the F25. If the differences in output are only slight, will I hear much of a difference between the two with music? What about with movies? If a sealed sub has the same output capability as a similarly priced ported sub, wouldn't the sealed sub be the better of the two?

I compared my new Sierra 2s with other similarly priced speakers exhibiting flat frequency response on axis as well as quite far off axis. I could immediately hear the difference between the Sierra 2s and the other speakers and I attribute this mostly to the faster transient response of the ribbon tweeter in the Sierra 2s. A better comparison is the folks that have upgraded the Sierra 1 to the Sierra 2 and preferred the difference in sound quality for almost double the price. I wonder if the same will hold true in the below 80 Hz region with subwoofers?










With music, i would be more concern with the higher frequencies rather then the lowest, in which based on the discription of the f25, has more power than the FV15.
It will be most likely hard to hear the difference as frequencies below 20hz are rather sensational.




I guess the reason I was bringing up lower frequencies, is that sealed subwoofers will have the most difficult time getting the same output at 20 Hz in comparison to a ported sub in the same price class. So if the F25 and FV15HP have nearly the same output at 20 Hz then we could expect the same to be true up to around 40 or 50 Hz, where the F25 probably has a little bit more output than the FV15HP, as you mention. So the FV15HP has a slight advantage below 40Hz and the F25 has a slight advantage above 40Hz.

My concern is more with respect to home theater, as the F25 would likely have the advantage for music. If the frequency response is quite similar between the two, and I am okay with the size of the F25 and slightly higher price, then which of the two would have the advantage for home theater? Also, will I be able to hear faster transient response of the F25 and is this something more desirable for home theater use? I cannot see why a main speaker with faster transient response wouldn't be more desirable for home theater or music use, but there seems to be some who prefer the sound of ported subs for home theater use.


Brian,

Since you are here would you be able to enlighten us with the differences between the F25 and the FV15hp? Nobody was really able to answer the original thread questions.

RythmikAudio
07-23-2015, 06:41 PM
F25 has absolutely the least amount of phase shift or group delay (even though group delay is meaningful only for low pass filter). But it is large because it is a sealed design.

FV15HP has all the characteristic of ported subs. It is more efficient and hence output more. Normal nonservo ported subs give us this boomy bass sound. Our servo ported subs greatly reduces that signature and gives us a bit of more "fully body" sound. The instructment may sound slight larger compared to the sound from F25. For anyone with HT application, we recommend FV15HP. For anyone with music as a higher priority, F25 is a better candidate. That does not mean F25 will be bad for movies. It is just that it has less coloration associated with other nonservo subs and can really "disappear" a bit better.

Sivar
07-23-2015, 10:13 PM
Rather it is because it blends so well that it does not draw attention. When it is on, it is because the bass effect is so much so that someone cannot believe the sound is from a pair of 8" woofer front speakers. On the other hand, PB2000 draws attention all the time reminds the listener it is there. The analogy of subwoofer/front speaker integration is like team work. The two blend well together and from outside you cannot see individuals.

I think this wording better conveys my experience, especially the "it is because the bass effect is so much so that someone cannot believe the sound is from a pair of 8" woofer front speakers." (although my fronts have dual 5.25", but you get the idea).
It really is difficult to tell that the bass is coming from the subs (or from anywhere in particular) whereas the SVS is like a mean little Tasmanian devil in the corner (which is exactly how some people like it).


For anyone skeptical of the sound quality of our servo subs, I have no problem sending a unit for comparison. I can even pay for shipping.
I'd be happy if you guys would post the F25 specifications on the website. It's been under construction since my first visit months ago. Even though I shouldn't care, I always like to compare numbers. :)

N Boros
07-24-2015, 11:06 AM
F25 has absolutely the least amount of phase shift or group delay (even though group delay is meaningful only for low pass filter). But it is large because it is a sealed design.

FV15HP has all the characteristic of ported subs. It is more efficient and hence output more. Normal nonservo ported subs give us this boomy bass sound. Our servo ported subs greatly reduces that signature and gives us a bit of more "fully body" sound. The instructment may sound slight larger compared to the sound from F25. For anyone with HT application, we recommend FV15HP. For anyone with music as a higher priority, F25 is a better candidate. That does not mean F25 will be bad for movies. It is just that it has less coloration associated with other nonservo subs and can really "disappear" a bit better.

Brian,

I have a couple more questions:

According to your measurements the FV15HP has a 1.5 dB advantage at 20 Hz over the F25, in terms of maximum output. Would you say that this is about the same from 15 Hz to 80 Hz, generally speaking, or does the FV15HP have a larger advantage over other frequency ranges?

We can see the detailed measurements of the FV15HP on data-bass. It appears that the THD stayed well under control (basically under 10% from 30 to 35 Hz and up depending on one port or two port mode), even while it is pushed close to its output limit. We also see that the dominant component of the THD is the second harmonic from 80 Hz until about 28 Hz in both modes. Going lower in frequency, the 3rd order harmonic becomes the dominant component and rises rapidly. This is when the sub is pushed close to its output limits. It seems that this was likely by design, because when we get below 30 Hz we are less hearing the sound and more feeling it and the 3rd order harmonic in that range shouldn't stand out to us like it would at higher frequencies. People find the 2nd order harmonic distortion, less objectionable and some even find it pleasing. Was the F25 designed with a similar approach to the distortion curves, keeping THD under 10% until close to the output limits and the second order distortion being the dominant component from 28 to 30 Hz and up, except distortion being larger than the FV15HP from 40 Hz and below when the F25 is pushed close to its limits (due to the fact that it is a sealed design)?

curtis
07-24-2015, 11:43 AM
According to your measurements the FV15HP has a 1.5 dB advantage at 20 Hz over the F25, in terms of maximum output. Would you say that this is about the same from 15 Hz to 80 Hz, generally speaking, or does the FV15HP have a larger advantage over other frequency ranges?
I'm not Brian, but I can answer at least some of this.

The greatest advantage of the FV15HP is at the tuning of the port. Above that, the advantage diminishes, and the F25 probably has an output advantage at some point.

RythmikAudio
07-27-2015, 10:46 PM
Brian,

I have a couple more questions:

According to your measurements the FV15HP has a 1.5 dB advantage at 20 Hz over the F25, in terms of maximum output. Would you say that this is about the same from 15 Hz to 80 Hz, generally speaking, or does the FV15HP have a larger advantage over other frequency ranges?


F25 actually has slightly more output above 50hz. But as you know the lowest output point of any sub is at the lowest frequency and I really think at subwoofer should at least reach 20hz and that is why we use 20hz as the reference point. Very often you will expect the sealed sub to have output when frequency increase from 20hz to 40hz, more so than a vented counterpart.





We can see the detailed measurements of the FV15HP on data-bass. It appears that the THD stayed well under control (basically under 10% from 30 to 35 Hz and up depending on one port or two port mode), even while it is pushed close to its output limit. We also see that the dominant component of the THD is the second harmonic from 80 Hz until about 28 Hz in both modes. Going lower in frequency, the 3rd order harmonic becomes the dominant component and rises rapidly. This is when the sub is pushed close to its output limits. It seems that this was likely by design, because when we get below 30 Hz we are less hearing the sound and more feeling it and the 3rd order harmonic in that range shouldn't stand out to us like it would at higher frequencies. People find the 2nd order harmonic distortion, less objectionable and some even find it pleasing. Was the F25 designed with a similar approach to the distortion curves, keeping THD under 10% until close to the output limits and the second order distortion being the dominant component from 28 to 30 Hz and up, except distortion being larger than the FV15HP from 40 Hz and below when the F25 is pushed close to its limits (due to the fact that it is a sealed design)?

You have been correctly pointing out the 3rd order harmonic distortion is due to the fact output is approaching its limit. In fact, it can be proven that a symmetric transfer function with F(-x)=-F(x), there is no even order harmonic distortion. So F(-x)=-F(x) meaning they are symmetric around orign point (x=0). It is largely true when the signal is large that when it approach limit, the characteritic is more similar. Among all odd order harmonic distortoin, 3rd order is the lowest one. So ideally we hope all odd order harmonic distortion will be mainly 3rd order. The 5th and above should be kept minimal.

As we talk about odd order harmonics which are caused by symmetric F(x) and F(-x) curve, we can imagine all even order harmonics should be caused by F(-x)!=-F(x). Sometimes you can interpret this as the curve has a bit offset at the origin point. This is almost inevitable, in particular at small signal level of speakers. Again what is important is keep 4th order harmonic distortion and above minimal.

Servo helps to keep higher order harmonic distortion reduced in level and what we should really see is mainly either 2nd order or 3rd order harmonic distortion.

N Boros
07-30-2015, 12:34 PM
F25 has absolutely the least amount of phase shift or group delay (even though group delay is meaningful only for low pass filter). But it is large because it is a sealed design.

FV15HP has all the characteristic of ported subs. It is more efficient and hence output more. Normal nonservo ported subs give us this boomy bass sound. Our servo ported subs greatly reduces that signature and gives us a bit of more "fully body" sound. The instructment may sound slight larger compared to the sound from F25. For anyone with HT application, we recommend FV15HP. For anyone with music as a higher priority, F25 is a better candidate. That does not mean F25 will be bad for movies. It is just that it has less coloration associated with other nonservo subs and can really "disappear" a bit better.


I think this and everything else you mentioned is finally helping me understand why you suggest the FV15HP with HT as the main priority and the F25 with music as the main priority.

I plan to have a pair of subs to help even out the seat to seat variation. So as long as I can integrate them well, either sub should disappear well regardless of if I go with a pair of F25s or a pair of FV15HPs. But, the F25 has the advantage of having faster transient response. This should likely give (as you say) the ability for the sub(s) to disappear more, but also perhaps wring out a slight bit more detail here and there. Both of these characteristics are big priorities for music. One Downside is that the F25 (since it is sealed) will have more distortion, as it is pushed hard below 40 Hz. This isn't important for music applications, since people will rarely listen to music at the same demanding level as for HT. So the F25 won't likely get into the larger distortion with music, as much, if at all. The other slight downsides are the larger size, larger weight and larger price.

The FV15HP has the advantage of having more output from 50 Hz and below, at lower distortion (at same SPL level when the FV15Hp and F25 are pushed harder). Many movies have quite a bit of content below 50 Hz. Many people enjoy the ability for the subwoofer to give a "gut punch", when a large peak at around 40 Hz occurs and the you get the rapid punch from the sub that you can feel in your chest, when the sound in the movie calls for it. Having a sub that can have more clean output is a priority for home theater, when for example, there can be 115 dB peaks in LFE channel, when the volume is set to reference level of 85 dB. While the F25 may have faster transient response, some may actually prefer the "fuller" sound on movie soundtracks. In comparison, the FV15Hp is slightly smaller in size, slightly smaller in weight and slightly cheaper.

I guess, I'm starting to understand that there is not really a better (in terms of accuracy) subwoofer between the two in general, but it really depends on the application. The faster transient response comes with a price, of less output and higher distortion over the lower half of the frequencies (roughly). The only way we could avoid this is if we were able to buy several F25s to ensure that we have clean output levels needed for the application. In this case, if two FV15HPs would give the clean levels of output, it might take 4 F25s to match the output, while keeping the distortion to the same threshold as the FV15HPs below 40 Hz.

bkdc
08-17-2015, 06:20 PM
If I were contemplating that much output, I would much rather pay the extra cash for two F12's or F15's so I can place them in the room appropriately rather than having a solitary high output F25. Placement is key with bass. If you're pairing them with Sierra-2's, I have to assume you're not trying to fill a huge room.

N Boros
08-18-2015, 10:53 AM
If I were contemplating that much output, I would much rather pay the extra cash for two F12's or F15's so I can place them in the room appropriately rather than having a solitary high output F25. Placement is key with bass. If you're pairing them with Sierra-2's, I have to assume you're not trying to fill a huge room.

You have a very good point, but I have a somewhat odd setup. I have a large open finished basement. Part of my basement I am using as my home theater area. Although it is quite a large open space (about 6500 cubic feet), my home theater area is in a corner of that and I have the Sierra 2s and surround speakers pretty close to my couch. I am probably about 8 feet away, roughly from each speaker. So the smaller bookshelf speakers give me more than enough output how I have them setup right now.

However, I currently have an Outlaw LFM1 subwoofer, that I am using, that was originally purchased for a much smaller room at a previous house. It is way too small to pressurize this large of a space. I have it placed quite close to a corner to help a bit with output, but it is still lacking until I can get a couple of serious subs. I was thinking either a pair of FV15HPs or a pair of F25s would be necessary to pressurize, the space. One would probably be fine, but I want to have good bass at more than one seat, so I plan to get a pair to get more uniform seat to seat variation.


By the way, my listening space is actually closer to about 10,000 cubic feet, until I actually put up wall and doorway to make the room a more manageable size (of about 6500 cubic feet). Right now my Outlaw sub is seriously lacking the impact I would like, when one actually pressurizes the room with it.