Help with subwoofer decision

[muslhead]

My setup is a 15x20 room where 10x15 is usable. it was originally set up to be music only but have been adding HT (and also multichannel music) capability over the past year. The first thing i did for HT was to buy a Rythmik ported fvx15. i had no intentions at the time to add another. Fast forward, i have seen the error in my ways and now considering the additoin of a second, matching sub. Unfortunately, adding the same sub will make my setup very cramped with little access to my setup.. in addition, it will decrease the WAF factor. While not a dealbreaker, everyone knows "happy wife ... happy life"


I was thinking an alternative would be to sell the single fxv15 and replace with a pair of l22's https://www.rythmikaudio.com/L22.html

This would give me min acceptable space but i give up the low end extension of the 15" (especially if i could find a way to squeeze a pair in).
My front speakers are the salon2 so was pretty happy without sub when setup was only music. But with the addition of dirac and the sub, i do say the music sound has improved.

Now the quesion, is the difference between a pair of 15" portede and a pair of dual 12" sealed significant enough to push the limits of my space and wifes patience?

 

[rynberg]

How many serious listening seats do you have? The point of having multiple subwoofers is smoother response over an area. If all you really care is that the primary listening position is smooth, you don't need more than one subwoofer.

For home theater, I would not trade an FXV15 for two L22s.

Edit: actually, looking at Rythmik's website, two L22s may just match a single FXV15. But that is a lot of money to spend for, at best, a lateral move.

 

[muslhead]

How many serious listening seats do you have? The point of having multiple subwoofers is smoother response over an area. If all you really care is that the primary listening position is smooth, you don't need more than one subwoofer.

For home theater, I would not trade an FXV15 for two L22s.

Edit: actually, looking at Rythmik's website, two L22s may just match a single FXV15. But that is a lot of money to spend for, at best, a lateral move.

just two seats which are about 8 feet away from my fronts and sub
Wasnt sure its a lateral move as the amount of air two l22s will move is greater but they dont dig as deep as the fxv15 which was my concern.

 

[muslhead]

Bump back up looking for more input

 

[preload]

What is the problem you're trying to solve? What's wrong with the FXV15 that you have right now for movies?

 

[muslhead]

No problem. What sticks in my mind is that the majority of those who i respect at this site advocate for the use of two subs. Am rposting hoping those advocates tell me why i need two. I have never had two subs ever, so i have neot had the chance to either hear or measure any advantage
In case it matters, the sub is not just for movies, i have integrated it with the salons when listening to 2-channel music

 

[muslhead]

Also, was wondering from those that have more experience, what differences, if any could i expect going from a single 15" to two dual 12" or two 15"

 

[sweetchaos]

Also, was wondering from those that have more experience, what differences, if any could i expect going from a single 15" to two dual 12" or two 15"

Here's some thoughts from Matthew Poes (Audioholics), source:
1. "The cool thing about bass summation is that it’s frequency dependent. Well really, wavelength dependent. Do what is random phase at 100hz is fully in phase at 20hz. That means that with multiple subs you only get a 3dB increase for each doubling of subwoofers. But you really are getting a 6dB increase below about 30hz."
2. "Further, it was found that this depended on frequency and once you get into bass frequencies the perception of loudness doubling has ranged from just 1dB to 6dB. It seems our perception of loudness increases follows the equal loudness curves which bunch up at low frequencies. That means less and less of an increase is needed to be perceived as twice as loud when we get down into the low stuff."
3. Let's look at dual woofer subs like:
-Monoprice Monolith M-215. Ported Dual 15" is US$2500.
-JTR Captivator 4000ULF. Ported Dual 18" is US$4200.
"JTR 4000ULF has about 6dB more output than the M-215. So twice the output for less than twice the price."

My thoughts:
1. Larger woofer will have less distortion than a smaller woofer
2. I own a single HSU VTF-3 MK5 (single 15" woofer), never had dual subs (well, excluding listening at my friends house, with dual 10" sealed subs), but plan to upgrade to dual subs in the future.
3. Do your research and find all CEA2010 measurements for the subs you want and see how they rank. Then consider the subwoofer sizes, cost, look, etc for your setup.

 

[sweetchaos]

Also, you must have an accepting wife is she'll allow you to have "Two of dual 12"/15"/18" woofer subwoofers".
They are massive...

 

[muslhead]

thanks for your response.
Yah, i am lucky as my wife is way more accepting than my room is

 

[rynberg]

Muslhead, my point was that two L22s will not have more output where you are traditionally limited (20 Hz). They will have more output at 50 Hz, but are you actually limited there? Doubtful.

Multiple subwoofers are needed to produce smoother response across a wider listening area. As I said above, a single listening position can typically be effectively eq'd with only a single sub.

Especially since you are space limited, I would focus on optimizing your single sub rather than spending a lot of money for no real gain.

 

[muslhead]

RYN, thanks
Bottom line, for music, while not a wash, close enough to likely not be noticeable (assuming optimization of existing sub)
For HT, due to its extended low end, a single 15 is the better option.

If i were able to find a smaller footprint sub that i could integrate within space constraints AND it was able to match or get closer to current Rhythmik 15" specs, would that be worthy of considering? Am not sure what problems might be created by mismatching brands and types.
Or is this just a "shut up and enjoy what you have" scenario?

 

[richard12511]

Multiple subwoofers can help smooth out the response, even for a single seat. Unless you get really lucky with the room, you're almost guaranteed to have peaks and dips with just one subwoofer. I definitely advocate getting a second sub.

 

[muslhead]

Multiple subwoofers can help smooth out the response, even for a single seat. Unless you get really lucky with the room, you're almost guaranteed to have peaks and dips with just one subwoofer. I definitely advocate getting a second sub.

This response was exactly what i was expecting when posting. I was sort of shocked when the responders didn't fall in line. Since i dont know first hand and change my opinion based upon what i learn, i am want to hear both sides. I want to make the best decision and that can only be done when both sides of a position have been thoroughly vetted and understood.
Appreciate any and all input

Richard since i have set a bar with the 15" and dont really have the room for another 15", would adding a second sub of smaller size (w/ likely less output and low frequency extension) create more problems than it would fix in your opinion?