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How Much Subwoofer Is Enough?

mj30250

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Recently I felt compelled to upgrade the subwoofers in my main setup (prompted by audible chuffing during loud, heavy sub-bass material), and I ended up ordering a pair of Monolith 15" V2s a couple weeks ago as they were temporarily made available at a very appealing sales price. I was finally able to put them through their paces over a lot of very loud music and movie material earlier today. The "listening area" for these is not large at roughly 2000 cubic ft, but one side of the room opens to a large basement, and the floor is a concrete slab sitting under medium thickness carpet. So while it's not bad, it's not exactly the most friendly subwoofer environment in existence.

Subjectively, these Monoliths sound exceptionally good. I have yet to notice any audible signs of distortion, strain, mechanical noise, or port chuffing under normal use. They present as extremely clean, short of the multitude of creaks, rattles, and buzzes that they bring out of the house at high volumes. Yes, I can drive the ports into noticeable turbulence by running sub-20Hz sinewaves, but in normal music / movie material that contains strong amounts of ULF content, it's essentially (if not completely) inaudible, which is in happy contrast to the 15" subs that they replaced. Below is their summed response after positioning them and running Audyssey XT32 (I've not brought out the MiniDSP yet as I haven't felt the need). As you can see, they are reasonably neutral and flat to nearly 10Hz in-room prior to dialing in any sort of house curve.

Rectangle Font Line Slope Parallel



Output wise, for music specifically, they appear to be far more capable than my needs and preferences require. If anything, it's often helpful to tone them down for music rather than the opposite. They integrate very well with my mains, and issues with the room/house itself not withstanding, I don't think I could be much (if at all) happier with their music performance in this space.

For home theater use, I am similarly thrilled, and again, run them with plenty of headroom in the tank. For reference, each sub is sitting close to +6dB on the gain knob (this is well below max as the Monolith's analog gain is logarithmic and scales up rapidly towards the higher portion of the dial), with trim levels maintained around -9.0dB on the Denon AVR. They are approximately 10-11ft distant from the MLP. Among many other things, I watched some scenes from the Dune 4K Blu-Ray. Spinning up the volume close to reference during some of the heavy bass scenes was ridiculous. The pressure from the sub-bass and punch from the midbass was something else, and I felt quite disoriented when I stood up (in a good way, of course!). For me, as much fun as this was, and even though the subs did not appear to be at all phased by the situation, pushing the volume even further was causing things to get legitimately uncomfortable. The house was making sounds that I had never heard before, and my body hasn't been rattled like that since riding in stupidly loud competition sub cars many years ago. I could never sit down and simply watch a bass-heavy movie at that sort of output level, and I'm someone who is generally happy to watch a full-length film at volumes that could potentially incur an OSHA fine for lack of hearing protection.

So, while it sounds like I am here to simply give the Monolith 15" V2s a positive review (and I enthusiastically do), the primary purpose of this is to ask...given the multitude of bigger/badder subs out there (and the many owners who happily load up their rooms with them), what's left for me to gain in my space? Specifically, the Monolith 16" subs went on sale earlier this month at a crazy low price. I'd have likely jumped on the deal had the 15s not already been enroute and if I had some readily available means to get those 172lb monsters down the steps and into the basement. Something like the PSA TV1813M is also bigger and much more powerful, and while it's costlier, it has the benefit of being about the same weight as the 15" Monoliths, thanks in large part to its MDF (versus HDF) cabinet. But, let's say I magically dropped a pair of 16" Monoliths or those 18" (or even the 21") PSAs into the room. What would I expect to hear/feel? I'm already not pushing the 15s to their limits, the in-room response and tactical feel are satisfactory, and distortion is presumably below audible levels. I'm truly curious. Help put my rampant FOMO to rest (or go ahead and make it much worse!). Thanks.
 

alex-z

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Sounds like that is enough subwoofer for you.

Some people will keeping getting bigger drivers, more inert cabinets, more power, etc. I am sure somewhere there is a guy rocking 115dB at 10Hz and 1% THD, meanwhile car alarms are going off outside.

If you find yourself looking for an upgrade, add bass shakers to your seating instead. Being able to feel infrasonic directly is far more efficient than pressurizing the entire air volume of your room.
 
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mj30250

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Shakers are something I never really gave serious consideration to, but admittedly they're much less expensive than chasing single-digit infrasonics via subs alone.

I guess I don't really feel any sort of great need to upgrade, it's more of a curiosity at this point. I also really like the matte finish of the 16" Monoliths, so that's probably influencing my desire to upgrade yet again to some extent.
 
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mj30250

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Well, curiosity got the better of me and I ordered dual PSA TV2112Ms. Here is where they ended up after positioning and running through Audyssey:

frequency-resp-tv2112ms-png.3602250


Why yes, we now have extension flat to below 9Hz in-room. Yikes!

Unfortunately, I don't have any practical means to switch between the 15" Monoliths and PSAs, so my comparative subjective impressions are going to be marred by the issues of acoustic memory, sighted bias, etc, but I'll give it a shot. Rather surprisingly, I'd say the biggest improvement I am hearing is in music. The Monoliths and the Hsu subs before them integrated very well with my main speakers and were not localizable or overly "boomy". However, the PSAs blend in supremely well, and at a level I've not experienced before. It truly sounds like I'm listening to giant, full-range speakers, and not a separate subwoofer system. To devolve into some standard audiophile silliness, I'd describe them as extremely nuanced, even delicate - which is at odds with the almost brutal visual experience of 21" drivers staring you in the face. They can also snap to life on a dime, and when there is an especially strong bass hit, they will literally vibrate tiny bits of acoustic ceiling tile loose which I've now watched slowly descend to the floor like a miniature snow flurry. In every music track I listened to, the subs give the impression that they're barely working, even at very high volumes. I hesitate to describe a subwoofer as "musical", but this is the best that music has sounded in my home. Take that for whatever it's worth.

HT content was similarly impressive. I attempted to dial in gain so that raw output at a given MV was roughly comparable to where it was with the Monoliths. Still, there was clearly additional punch and room involvement with the PSAs. It's difficult to explain, but everything just seemed to be energized in a different way. The opening cannon battle in the film Master and Commander had incredible punch and power. I've heard this section very loudly dozens and dozens of times as it's one of my go-to test scenes. I've never heard it sound quite like this. During the opening sequence of Blade Runner 2049, the subs' grills were blown clean off. Perhaps some thicker dowels are in order. Anyway, I'm incredibly pleased and this feels very much like an end game subwoofer setup in this room. As noted in the opening post, I was (and remain) very impressed by the Monoliths, particularly at their price point, but the TV2112Ms do offer a different experience.

If forced to sum up my listening impressions, I'd say that, more than any others that I've auditioned, these subs offer a very high dynamic range. They appear to accurately reproduce even the most subtle bass notes with finesse, while maintaining the headroom to effortlessly generate a localized earthquake when called upon.
 
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Ciobi69

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Well, curiosity got the better of me and I ordered dual PSA TV2112Ms. Here is where they ended up after positioning and running through Audyssey:

frequency-resp-tv2112ms-png.3602250


Why yes, we now have extension flat to below 9Hz in-room. Yikes!

Unfortunately, I don't have any practical means to switch between the 15" Monoliths and PSAs, so my comparative subjective impressions are going to be marred by the issues of acoustic memory, sighted bias, etc, but I'll give it a shot. Rather surprisingly, I'd say the biggest improvement I am hearing is in music. The Monoliths and the Hsu subs before them integrated very well with my main speakers and were not localizable or overly "boomy". However, the PSAs blend in supremely well, and at a level I've not experienced before. It truly sounds like I'm listening to giant, full-range speakers, and not a separate subwoofer system. To devolve into some standard audiophile silliness, I'd describe them as extremely nuanced, even delicate - which is at odds with the almost brutal visual experience of 21" drivers staring you in the face. They can also snap to life on a dime, and when there is an especially strong bass hit, they will literally vibrate tiny bits of acoustic ceiling tile loose which I've now watched slowly descend to the floor like a miniature snow flurry. In every music track I listened to, the subs give the impression that they're barely working, even at very high volumes. I hesitate to describe a subwoofer as "musical", but this is the best that music has sounded in my home. Take that for whatever it's worth.

HT content was similarly impressive. I attempted to dial in gain so that raw output at a given MV was roughly comparable to where it was with the Monoliths. Still, there was clearly additional punch and room involvement with the PSAs. It's difficult to explain, but everything just seemed to be energized in a different way. The opening cannon battle in the film Master and Commander had incredible punch and power. I've heard this section very loudly dozens and dozens of times as it's one of my go-to test scenes. I've never heard it sound quite like this. During the opening sequence of Blade Runner 2049, the subs' grills were blown clean off. Perhaps some thicker dowels are in order. Anyway, I'm incredibly pleased and this feels very much like an end game subwoofer setup in this room. As noted in the opening post, I was (and remain) very impressed by the Monoliths, particularly at their price point, but the TV2112Ms do offer a different experience.

If forced to sum up my listening impressions, I'd say that, more than any others that I've auditioned, these subs offer a very high dynamic range. They appear to accurately reproduce even the most subtle bass notes with finesse, while maintaining the headroom to effortlessly generate a localized earthquake when called upon.
I got 2 bms 18n862 and the bass is very dynamic too. Pa drivers are the way to go. Or big Rubber drivers like the stereo integrity. Sunaudio. Or dayton but they are cheaper
 

FrantzM

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Well, curiosity got the better of me and I ordered dual PSA TV2112Ms. Here is where they ended up after positioning and running through Audyssey:

frequency-resp-tv2112ms-png.3602250


Why yes, we now have extension flat to below 9Hz in-room. Yikes!

Unfortunately, I don't have any practical means to switch between the 15" Monoliths and PSAs, so my comparative subjective impressions are going to be marred by the issues of acoustic memory, sighted bias, etc, but I'll give it a shot. Rather surprisingly, I'd say the biggest improvement I am hearing is in music. The Monoliths and the Hsu subs before them integrated very well with my main speakers and were not localizable or overly "boomy". However, the PSAs blend in supremely well, and at a level I've not experienced before. It truly sounds like I'm listening to giant, full-range speakers, and not a separate subwoofer system. To devolve into some standard audiophile silliness, I'd describe them as extremely nuanced, even delicate - which is at odds with the almost brutal visual experience of 21" drivers staring you in the face. They can also snap to life on a dime, and when there is an especially strong bass hit, they will literally vibrate tiny bits of acoustic ceiling tile loose which I've now watched slowly descend to the floor like a miniature snow flurry. In every music track I listened to, the subs give the impression that they're barely working, even at very high volumes. I hesitate to describe a subwoofer as "musical", but this is the best that music has sounded in my home. Take that for whatever it's worth.

HT content was similarly impressive. I attempted to dial in gain so that raw output at a given MV was roughly comparable to where it was with the Monoliths. Still, there was clearly additional punch and room involvement with the PSAs. It's difficult to explain, but everything just seemed to be energized in a different way. The opening cannon battle in the film Master and Commander had incredible punch and power. I've heard this section very loudly dozens and dozens of times as it's one of my go-to test scenes. I've never heard it sound quite like this. During the opening sequence of Blade Runner 2049, the subs' grills were blown clean off. Perhaps some thicker dowels are in order. Anyway, I'm incredibly pleased and this feels very much like an end game subwoofer setup in this room. As noted in the opening post, I was (and remain) very impressed by the Monoliths, particularly at their price point, but the TV2112Ms do offer a different experience.

If forced to sum up my listening impressions, I'd say that, more than any others that I've auditioned, these subs offer a very high dynamic range. They appear to accurately reproduce even the most subtle bass notes with finesse, while maintaining the headroom to effortlessly generate a localized earthquake when called upon.
Just added you to my “ Hate List”

:p

Peace.
 

Chrispy

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Well, curiosity got the better of me and I ordered dual PSA TV2112Ms. Here is where they ended up after positioning and running through Audyssey:

frequency-resp-tv2112ms-png.3602250


Why yes, we now have extension flat to below 9Hz in-room. Yikes!

Unfortunately, I don't have any practical means to switch between the 15" Monoliths and PSAs, so my comparative subjective impressions are going to be marred by the issues of acoustic memory, sighted bias, etc, but I'll give it a shot. Rather surprisingly, I'd say the biggest improvement I am hearing is in music. The Monoliths and the Hsu subs before them integrated very well with my main speakers and were not localizable or overly "boomy". However, the PSAs blend in supremely well, and at a level I've not experienced before. It truly sounds like I'm listening to giant, full-range speakers, and not a separate subwoofer system. To devolve into some standard audiophile silliness, I'd describe them as extremely nuanced, even delicate - which is at odds with the almost brutal visual experience of 21" drivers staring you in the face. They can also snap to life on a dime, and when there is an especially strong bass hit, they will literally vibrate tiny bits of acoustic ceiling tile loose which I've now watched slowly descend to the floor like a miniature snow flurry. In every music track I listened to, the subs give the impression that they're barely working, even at very high volumes. I hesitate to describe a subwoofer as "musical", but this is the best that music has sounded in my home. Take that for whatever it's worth.

HT content was similarly impressive. I attempted to dial in gain so that raw output at a given MV was roughly comparable to where it was with the Monoliths. Still, there was clearly additional punch and room involvement with the PSAs. It's difficult to explain, but everything just seemed to be energized in a different way. The opening cannon battle in the film Master and Commander had incredible punch and power. I've heard this section very loudly dozens and dozens of times as it's one of my go-to test scenes. I've never heard it sound quite like this. During the opening sequence of Blade Runner 2049, the subs' grills were blown clean off. Perhaps some thicker dowels are in order. Anyway, I'm incredibly pleased and this feels very much like an end game subwoofer setup in this room. As noted in the opening post, I was (and remain) very impressed by the Monoliths, particularly at their price point, but the TV2112Ms do offer a different experience.

If forced to sum up my listening impressions, I'd say that, more than any others that I've auditioned, these subs offer a very high dynamic range. They appear to accurately reproduce even the most subtle bass notes with finesse, while maintaining the headroom to effortlessly generate a localized earthquake when called upon.
What flat?
 
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mj30250

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Just added you to my “ Hate List”

:p

Peace.

You and my wife both.

What flat?

If you're referring to the sub-bass rise, that's primarily room gain. I can flatten it easily enough via the "room size" control on the back of the sub, which applies a progressive LF cut to attenuate room gain. I prefer it this way for movies and it doesn't have any real impact on music because there's virtually no music content down there outside of a low C on a giant pipe organ, so I leave it in.
 
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Chrispy

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You and my wife both.



If you're referring to the sub-bass rise, that's primarily room gain. I can flatten it easily enough via the "room size" control on the back of the sub, which applies a progressive LF cut to attenuate room gain. I prefer it this way for movies and it doesn't have any real impact on music because there's virtually no music content down there, so I leave it in.
Was just curious what was flat about it. :) Might be okay for most music, but could perhaps still account for some of your perceptions mentioned?

In any case, you need at least two more subs.
 

DWPress

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I've got a single 18" located near main speakers and 12" SVS in opposite opposing corner of the room. Every room is different as far as modes and gain go but I can't imagine needing more myself. I can't get down to 9Hz but I'm ok with that lol.
 
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mj30250

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Was just curious what was flat about it. :) Might be okay for most music, but could perhaps still account for some of your perceptions mentioned?

Well, it's flat in the audible range. Better? :)

And I did experiment with the room size control set to small, which flattens the LF response. I couldn't tease out any appreciable differences for music.

In any case, you need at least two more subs.

Two more 21" subs for the nearfield? Yes! A bit tricky to sneak into the house, though.
 

Chrispy

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Well, it's flat in the audible range. Better? :)

And I did experiment with the room size control set to small, which flattens the LF response. I couldn't tease out any appreciable differences for music.



Two more 21" subs for the nearfield? Yes! A bit tricky to sneak into the house, though.
Well sometimes perception may be from lower ranges than audible? What is room size control?

I was more kidding about the subs, but just depends on what you really want. I do find room smoothing with four better than two personally....
 
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mj30250

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Well sometimes perception may be from lower ranges than audible? What is room size control?
It's a dial on the plate amp that progressively applies cuts to the low bass to account for different room sizes / boundary gain. Leaving it at large provides the native response of the sub with no attenuation. I believe going all the way to small results in a 12dB cut.

1713229198784.png
 

Fredygump

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Recently I felt compelled to upgrade the subwoofers in my main setup (prompted by audible chuffing during loud, heavy sub-bass material), and I ended up ordering a pair of Monolith 15" V2s a couple weeks ago as they were temporarily made available at a very appealing sales price. I was finally able to put them through their paces over a lot of very loud music and movie material earlier today. The "listening area" for these is not large at roughly 2000 cubic ft, but one side of the room opens to a large basement, and the floor is a concrete slab sitting under medium thickness carpet. So while it's not bad, it's not exactly the most friendly subwoofer environment in existence.

Subjectively, these Monoliths sound exceptionally good. I have yet to notice any audible signs of distortion, strain, mechanical noise, or port chuffing under normal use. They present as extremely clean, short of the multitude of creaks, rattles, and buzzes that they bring out of the house at high volumes. Yes, I can drive the ports into noticeable turbulence by running sub-20Hz sinewaves, but in normal music / movie material that contains strong amounts of ULF content, it's essentially (if not completely) inaudible, which is in happy contrast to the 15" subs that they replaced. Below is their summed response after positioning them and running Audyssey XT32 (I've not brought out the MiniDSP yet as I haven't felt the need). As you can see, they are reasonably neutral and flat to nearly 10Hz in-room prior to dialing in any sort of house curve.

Rectangle Font Line Slope Parallel



Output wise, for music specifically, they appear to be far more capable than my needs and preferences require. If anything, it's often helpful to tone them down for music rather than the opposite. They integrate very well with my mains, and issues with the room/house itself not withstanding, I don't think I could be much (if at all) happier with their music performance in this space.

For home theater use, I am similarly thrilled, and again, run them with plenty of headroom in the tank. For reference, each sub is sitting close to +6dB on the gain knob (this is well below max as the Monolith's analog gain is logarithmic and scales up rapidly towards the higher portion of the dial), with trim levels maintained around -9.0dB on the Denon AVR. They are approximately 10-11ft distant from the MLP. Among many other things, I watched some scenes from the Dune 4K Blu-Ray. Spinning up the volume close to reference during some of the heavy bass scenes was ridiculous. The pressure from the sub-bass and punch from the midbass was something else, and I felt quite disoriented when I stood up (in a good way, of course!). For me, as much fun as this was, and even though the subs did not appear to be at all phased by the situation, pushing the volume even further was causing things to get legitimately uncomfortable. The house was making sounds that I had never heard before, and my body hasn't been rattled like that since riding in stupidly loud competition sub cars many years ago. I could never sit down and simply watch a bass-heavy movie at that sort of output level, and I'm someone who is generally happy to watch a full-length film at volumes that could potentially incur an OSHA fine for lack of hearing protection.

So, while it sounds like I am here to simply give the Monolith 15" V2s a positive review (and I enthusiastically do), the primary purpose of this is to ask...given the multitude of bigger/badder subs out there (and the many owners who happily load up their rooms with them), what's left for me to gain in my space? Specifically, the Monolith 16" subs went on sale earlier this month at a crazy low price. I'd have likely jumped on the deal had the 15s not already been enroute and if I had some readily available means to get those 172lb monsters down the steps and into the basement. Something like the PSA TV1813M is also bigger and much more powerful, and while it's costlier, it has the benefit of being about the same weight as the 15" Monoliths, thanks in large part to its MDF (versus HDF) cabinet. But, let's say I magically dropped a pair of 16" Monoliths or those 18" (or even the 21") PSAs into the room. What would I expect to hear/feel? I'm already not pushing the 15s to their limits, the in-room response and tactical feel are satisfactory, and distortion is presumably below audible levels. I'm truly curious. Help put my rampant FOMO to rest (or go ahead and make it much worse!). Thanks.

You don't gain anything with a bigger sub. Well, you don't gain anything besides bragging rights, atleast not until you exceed the capability of the subs you have.

I assume you can exceed the 95dB level you measured? On my system, I can achieve 110dB @20hz, with two 12" subs (custom design, ported). Two well made 15" subs should move a lot more air than a pair of 12's. So yeah, the subs you have seem to exceed your requirements by a healthy margin.
 

ThatSoundsGood

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Is there really much content below 20Hz? And Below 10Hz????? You have a remarkably flat frequency response in the low end. Instead of more subs, you should probably get some main speakers so you can hear what's happening above 120Hz. It sounds a lot better, especially with dialogue.
 

Fredygump

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Is there really much content below 20Hz? And Below 10Hz????? You have a remarkably flat frequency response in the low end. Instead of more subs, you should probably get some main speakers so you can hear what's happening above 120Hz. It sounds a lot better, especially with dialogue.
Content below 20hz? Not audible content!

A fun test is to play a 20hz tone. If you have distortion, resonances, or port noise, that is all you are going to hear. We can only "sort-of" hear 20hz; it's the limit, so it's marginal if we actually hear it. The best sub I've ever heard was completely inaudible at 20hz, but I could feel my eyes vibrating and see the measurement. Clearly audible low frequencies start around 23-24hz
 

StigErik

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10 Hz with low distortion is definitely not audible, but at enough SPL it can be felt. I have a double bass array that is flat to about 10 Hz. I've played around with different roll-off frequencies, and I do think that flat to 10 Hz sounds slightly more punchy on some music material.

Here's how it measures in the listening position, with my preferred house-curve EQ.
StigErik-DBA-FR.png
 
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mj30250

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I assume you can exceed the 95dB level you measured? On my system, I can achieve 110dB @20hz, with two 12" subs (custom design, ported). Two well made 15" subs should move a lot more air than a pair of 12's. So yeah, the subs you have seem to exceed your requirements by a healthy margin.

Below are compression sweeps that I ran when the Monolith 15s were in use. The mic was positioned at the MLP, which is about 11ft distant from the subs.

compression-png.3600438


This is a nice amount of headroom and perhaps enough for my needs. I still had to satisfy my curiosity, though. With the PSAs, I'm finding more qualitative differences than quantitative ones. What's most telling is that with the Monoliths tuned hot for loud movie watching, I'd often feel it necessary to reduce the sub signal when switching to music, as bass could become intrusive and overpowering. With the PSAs, I haven't felt the need to do that. It's almost like going from good speakers to great ones - great speakers often don't sound very loud even if they're cranking out the same amount of output as lesser speakers that do. As a result, they (and these PSAs) are less fatiguing and more enjoyable to listen to, particularly over long stretches.
 

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Well, seems you have hit your bass Nirvana - which is great. Don't think that you can do much more on that front. While more subs will always tend to add a bit more, you don't really seem to need it either in frequency response or SPL. Decay time is a different matter, but as long as it sounds reasonably tight, would not really bother.

Perhaps time to upgrade the bed channels to full towers and try how that works? Also, did you thing of the upcoming Dirac ART?
 
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