Subwoofers - 1 or 2, That is the question

[monkumonku]

Aug 4, 2017 16:49:31 GMT -5 Boomzilla said:

A lot of how a sub sounds in a room has to do with the room itself. You CAN overload a room with bass and make it into an echo chamber. Even if you have bass traps galore.

One of the features I particularly like about my new PowerSound Audio S3601 is the fact that it has a "room size" dial on the plate amp. As you turn the dial from "large" to "small," not only does the damping change but also the low end of the frequency response is removed to give the bass a "tighter" sound, regardless of the sized room that the sub is plunked down in. For now, I have a 3,500+ cubic-foot room with vented corners, so I'm running the sub at the limit of its "large" range. But should I move to another house with a smaller listening room, I'm hoping that the size adjustment on the sub will allow me to use the same sub in a smaller room.

When I reviewed the BasX surround system, the two S12 Emotiva subs worked amazingly well in my room. But I wouldn't necessarily recommend them for a much smaller room...

There's a lot to be said for "sizing the subwoofer to fit the room." In a smaller room, I'd expect better performance from the Emotiva S8 or S10 than I would from the S12. Sometimes buying the biggest & baddest isn't the best choice...

And I'd still have to append that last sentence by adding "unless the sub has room-size compensation."



Boom

I'm trying to think through this in a logical way and wonder why would a small sub be better in a small room than a large one? A large sub should have better performance characteristics (I'm assuming we are talking about small versus large from the same manufacturer or from quality manufacturers) so why wouldn't it still be better, no matter what the room? I suppose you could say it depends on the interaction with the room but that is more a function of the sub design rather than the size of the driver.

I think that a large sub could be considered overkill for a small room because it is capable of higher SPL's that aren't needed for a small room and maybe some people turn it up too high just because they can, and they equate louder with better. But sound quality wise, at similar volume levels, I would think a large sub is better than a small one.

[Axis]

Aug 4, 2017 16:49:31 GMT -5 Boomzilla said:

A lot of how a sub sounds in a room has to do with the room itself. You CAN overload a room with bass and make it into an echo chamber. Even if you have bass traps galore.

One of the features I particularly like about my new PowerSound Audio S3601 is the fact that it has a "room size" dial on the plate amp. As you turn the dial from "large" to "small," not only does the damping change but also the low end of the frequency response is removed to give the bass a "tighter" sound, regardless of the sized room that the sub is plunked down in. For now, I have a 3,500+ cubic-foot room with vented corners, so I'm running the sub at the limit of its "large" range. But should I move to another house with a smaller listening room, I'm hoping that the size adjustment on the sub will allow me to use the same sub in a smaller room.

When I reviewed the BasX surround system, the two S12 Emotiva subs worked amazingly well in my room. But I wouldn't necessarily recommend them for a much smaller room...

There's a lot to be said for "sizing the subwoofer to fit the room." In a smaller room, I'd expect better performance from the Emotiva S8 or S10 than I would from the S12. Sometimes buying the biggest & baddest isn't the best choice...

And I'd still have to append that last sentence by adding "unless the sub has room-size compensation."



Boom

I love how you are learning Boom. Isn't that what we are doing here Boom ? We are learning about audio. Some of the stuff myself or you would have said years ago here would be criticized. "sizing the subwoofer to fit the room."

You want to build a room for concert level sound, then do it. You want to build a system that works properly in the room you own, then do it for that room.

[geebo]

Aug 4, 2017 16:49:31 GMT -5 Boomzilla said:

A lot of how a sub sounds in a room has to do with the room itself. You CAN overload a room with bass and make it into an echo chamber. Even if you have bass traps galore.

One of the features I particularly like about my new PowerSound Audio S3601 is the fact that it has a "room size" dial on the plate amp. As you turn the dial from "large" to "small," not only does the damping change but also the low end of the frequency response is removed to give the bass a "tighter" sound, regardless of the sized room that the sub is plunked down in. For now, I have a 3,500+ cubic-foot room with vented corners, so I'm running the sub at the limit of its "large" range. But should I move to another house with a smaller listening room, I'm hoping that the size adjustment on the sub will allow me to use the same sub in a smaller room.

When I reviewed the BasX surround system, the two S12 Emotiva subs worked amazingly well in my room. But I wouldn't necessarily recommend them for a much smaller room...

There's a lot to be said for "sizing the subwoofer to fit the room." In a smaller room, I'd expect better performance from the Emotiva S8 or S10 than I would from the S12. Sometimes buying the biggest & baddest isn't the best choice...

And I'd still have to append that last sentence by adding "unless the sub has room-size compensation."



Boom

The room compensation (Q control) is a nice feature but there are trade-offs. Bass will be tighter with lower numbers and roll off sooner and a bit looser and more extended with higher numbers. I keep mine at the lower numbers to favor music.

[vneal]

2

[Boomzilla]

Smaller subs typically don't have as deep a frequency extension as do large ones. That's the root of my "smaller subs for smaller rooms" theory. But there are ALWAYS exceptions...

And box tuning enters into it as well. Some of the cheap HT subs are "one note wonders" that are tuned to give maximum boom for every explosion in the soundtrack, but which homogenize every musical pitch to their single boom frequency.

[DYohn]

Generic statements about subwoofers can always be proven both right and wrong. The truth is no one can give you the proper advice without being able to test your room. So buy a subwoofer. Set it up to the best of your ability. Listen to some music. If you like what you hear then you are done. If not then there are things you can try. But ignore all advice trying to describe subwoofer behavior based on generalities. Just go for it.

[Boomzilla]

Unless you bought a generic subwoofer...

[DYohn]

Aug 5, 2017 14:43:53 GMT -5 Boomzilla said:

Unless you bought a generic subwoofer...

ESPECIALLY if you did!

[creimes]

Owning two 18's my vote is minimum 2 subs, that being said you could do one 12 now and add another later, something many seem to forget is having more and or larger subs lets you run them at lower volumes which in turn gives you cleaner bass and less introduction of distortion, it seems as though too many people tend to somehow think that someone that has two or four or however many large subs that they are bass heads and listening and extreme volumes at all times, saying that yes there are times I like to make my house foundation rattle(which i can with two DIY 18" subs ) but that happens very little, but for the other 95% I have them on the bass is deep and ohhhh soooo good. So yeah just like amplifier headroom is great so is low frequency SPL.

Go with one of their 12's now and add another later, or if you think that is too much since it is your setup after all I say minimum two 10's

Chad

[joswald21]

Looks like all of the camps have checked-in. Thanks A LOT for the guidance.

I can definitely say that I'm not a bass-head and listen to rock music almost exclusively, but it's been a long time since I had new audio toys.

I'm leaning toward two (2) BasX S8s as my 1st choice right now. A single RSL Speedwoofer S10 was the front-runner for a time, but the idea of two-subs-for-nearly-the-same-price (w/Emotiva shipping) is tipping-the-scales.

My second choice is between RSL S10 vs BasX S10 if I say #### ## and go for simplicity for now. I like the Emotiva BasX S10 as a SLIGHTLY lower cost alternative to the RSL 10S. It has the same slotted port design and costs a little less even with Emotiva's shipping charge.

[leonski]

I don't need to 'test' a 13x13 room of UNKNOWN height to know we've got trouble in River City.
Even with a 10' ceiling that is LESS than 1700 cubic feet. A small room.

Here is the Definitive paper on Subs, location and number from the Harman International Group.

www.harman.com/sites/default/files/multsubs_0.pdf

I would not look at specs or whatever. Rather I'd take a look at the controls of the Plate Amp.
Lowest crossover frequency? 0/180 or Continuous Phase? Speaker level In / Out? Single or
duel RCA or even Balanced? Removable Power cord or 'fixed'?

Than go get a HSU Research :: The entry level sub is NO Slouch. And for 370 per, you could get a pair.

www.hsuresearch.com/products/vtf-1mk3.html

[Boomzilla]

I'd disagree with calling Harman.com's paper "the definitive" analysis of subs. The authors themselves admit that their calculated theories have some disconnect from reality. Their assumptions (central seating, rectangular room with a single door, etc.) are also flawed.

And just because YOU, leonski, "would not look at specs or whatever" doesn't mean that others shouldn't.

And finally, because YOU prefer HSU subs is not any indication that their products are the best or to be highly preferred over other brands.

Now that said, I do think that there's SOME value in Harmon's paper - Their math seems to argue pretty persuasively that more than 4 subs in a room yield diminishing returns (until you get up to absurd numbers). And I'm not knocking HSU brand subs in any way - they make good products.

But I also have to question the utility of some of the controls you mention.

Lowest crossover frequency, for example, is academic for most listeners (who use the crossovers in their AVRs or processors instead of the sub's plate amp to manage bass).
0-180 phase switch or continuous phase pot is probably also academic for most listeners - their room correction systems normally adjust phase for them.
Speaker level - in/out is the most useless thing I've ever heard of - NOBODY any more runs their speaker feeds through their sub.
Single/dual RCA inputs or XLR input are similarly academic. Whatever is available works fine.
And why in the world would one care whether the sub's power cord was fixed or IEC-removable?

So what ARE the important sub controls?
Volume, obviously
Phase (switch or pot are fine - but this only matters if you're NOT doing bass management upstream)
Crossover frequency - but again, this only matters if you're NOT doing bass management upstream
and a nice pot that my sub has called "room size" - this matches the damping of the sub to the sized room that it's being used in.

And that's it. So with the exception of the last, EVERY sub on the market has the "necessary controls."

The other thing that you don't mention that I consider of value is an anechoic response curve of the sub's output. Some cheap subs have a very peaked frequency response (often called "one note wonders"). On movies, this maximizes the "boom for the buck" on explosions, but on music, this causes a gross loss of pitch definition. A good music sub is NOT tuned for maximum boom, but rather has a broad and flat frequency response from its minimum to its maximum. Flat frequency response IS worth looking for.

Cordially - Boomzilla (name NOT indicative of listening preferences)

[joswald21]

Aug 8, 2017 6:23:33 GMT -5 Boomzilla said:

I'd disagree with calling Harman.com's paper "the definitive" analysis of subs...Now that said, I do think...Lowest crossover frequency, for example, is academic for most listeners (who use the crossovers in their AVRs or processors instead of the sub's plate amp to manage bass)...0-180 phase switch or continuous phase pot is probably also academic for most listeners - their room correction systems normally adjust phase for them...So what ARE the important sub controls...Volume, obviously...Phase (switch or pot are fine - but this only matters if you're NOT doing bass management upstream)

FWIW...I'm going for a more old-school 2.1/2.2 set-up. I won't have, and don't want, the AVR/DSP features.

System guts will be...
Pre-Amp: Emotiva BasX PT-100
Power Amp: Emotiva BasX A-150 (most likely)

[geebo]

Aug 7, 2017 22:56:14 GMT -5 leonski said:

I don't need to 'test' a 13x13 room of UNKNOWN height to know we've got trouble in River City.
Even with a 10' ceiling that is LESS than 1700 cubic feet. A small room.

Here is the Definitive paper on Subs, location and number from the Harman International Group.

www.harman.com/sites/default/files/multsubs_0.pdf

I would not look at specs or whatever. Rather I'd take a look at the controls of the Plate Amp.
Lowest crossover frequency? 0/180 or Continuous Phase? Speaker level In / Out? Single or
duel RCA or even Balanced? Removable Power cord or 'fixed'?

Than go get a HSU Research :: The entry level sub is NO Slouch. And for 370 per, you could get a pair.

www.hsuresearch.com/products/vtf-1mk3.html

Agreed. Dr Hsu know his stuff. He's been at this a long time and their customer service is simply outstanding before and after the sale.

www.soundandvision.com/content/dr-poh-hsu-founder-hsu-research

[jefft51]

Aug 8, 2017 6:23:33 GMT -5 Boomzilla said:

...

and a nice pot that my sub has called "room size" - this matches the damping of the sub to the sized room that it's being used in.
...
Cordially - Boomzilla (name NOT indicative of listening preferences)

I an not sure what this setting means? Can't you do the same thing by adjusting the volume? Isn't speaker damping mostly a concern with amps (tube amps?) that have a low damping factor? In which case you're probably not using a tube amp with a subwoofer?

I'm not criticizing, just trying to grok how this all fits together.
Jeff

[geebo]

Aug 8, 2017 11:33:08 GMT -5 jefft51 said:

Aug 8, 2017 6:23:33 GMT -5 Boomzilla said:

...

and a nice pot that my sub has called "room size" - this matches the damping of the sub to the sized room that it's being used in.
...
Cordially - Boomzilla (name NOT indicative of listening preferences)

I an not sure what this setting means? Can't you do the same thing by adjusting the volume? Isn't speaker damping mostly a concern with amps (tube amps?) that have a low damping factor? In which case you're probably not using a tube amp with a subwoofer?

I'm not criticizing, just trying to grok how this all fits together.
Jeff

HSU has this same control and call it simply the "Q" control. It goes from low to high (.3 to .7 for the HSU subs) and will change the damping of the woofer. The low end tightens up the response at the expense of extension and as you move it towards .7 it will extend the response at the expense of control. It looks like PSA calls it a room size control.

[leonski]

Aug 8, 2017 6:23:33 GMT -5 Boomzilla said:

I'd disagree with calling Harman.com's paper "the definitive" analysis of subs. The authors themselves admit that their calculated theories have some disconnect from reality. Their assumptions (central seating, rectangular room with a single door, etc.) are also flawed.

And just because YOU, leonski , "would not look at specs or whatever" doesn't mean that others shouldn't.

And finally, because YOU prefer HSU subs is not any indication that their products are the best or to be highly preferred over other brands.

Now that said, I do think that there's SOME value in Harmon's paper - Their math seems to argue pretty persuasively that more than 4 subs in a room yield diminishing returns (until you get up to absurd numbers). And I'm not knocking HSU brand subs in any way - they make good products.

But I also have to question the utility of some of the controls you mention.

Lowest crossover frequency, for example, is academic for most listeners (who use the crossovers in their AVRs or processors instead of the sub's plate amp to manage bass).
0-180 phase switch or continuous phase pot is probably also academic for most listeners - their room correction systems normally adjust phase for them.
Speaker level - in/out is the most useless thing I've ever heard of - NOBODY any more runs their speaker feeds through their sub.
Single/dual RCA inputs or XLR input are similarly academic. Whatever is available works fine.
And why in the world would one care whether the sub's power cord was fixed or IEC-removable?

So what ARE the important sub controls?
Volume, obviously
Phase (switch or pot are fine - but this only matters if you're NOT doing bass management upstream)
Crossover frequency - but again, this only matters if you're NOT doing bass management upstream
and a nice pot that my sub has called "room size" - this matches the damping of the sub to the sized room that it's being used in.

And that's it. So with the exception of the last, EVERY sub on the market has the "necessary controls."

The other thing that you don't mention that I consider of value is an anechoic response curve of the sub's output. Some cheap subs have a very peaked frequency response (often called "one note wonders"). On movies, this maximizes the "boom for the buck" on explosions, but on music, this causes a gross loss of pitch definition. A good music sub is NOT tuned for maximum boom, but rather has a broad and flat frequency response from its minimum to its maximum. Flat frequency response IS worth looking for.

Cordially - Boomzilla (name NOT indicative of listening preferences)

First, HT users do have some controls I don't have access to.    My 2.1 does have very flexible bass management.   For a stereo Preamp.      I also find that the 80hz common to HT gear is WAY too high for my needs.     That being said, I think that a GAP between Low Pass and High Pass frequencies is of value to prevent bass bloom thru the crossover region by giving each driver a chance to roll-off before the OTHER takes up.  In so doing, it sums flat thru the crossover and you have less phase disruption.    

Sure, flat is good, no question.     I recommend using your ears.     And setup is again KEY.    With my sub corner loaded in the LEFT side of the room (facing speakers) listening while seated in my den was like being in a 55 gallon drum.   Bass was bloomy and indistinct.   One Note?   Sure you could call it that!     But when I moved the sub to the OTHER side, behind the RH speaker, everything changed for the Better.    And I didn't change ANY settings.    Just sub location.     Standup Bass 'runs' now have feel and movies will knock you out of your seat.   The room is mid to large at maybe 5000 cubic feet.    It's tough to measure because it not only has a peaked ceiling but 8 (count 'em, 8) asymmetric walls and 3 'ports', one to my den (nice helmholtz), the Kitchen and the Hall.  

I'm a huge fan of Dr Hsu.    A real Sub-Guy.   His dual ported / plug optional designs are killer.   My VTF-2 maybe 5 or 6 years old easily fills the large room it's in.   The odd shape really helps.    He made subs for OUTLAW and probably others.    Maybe?   EMO subs are custom sourced thru HSU?     I doubt any exclusive production line dedicated to what will essentially be a good seller, but certainly NOT a whole factories worth.  

As for electronic room tune aids?    A double edged sword.    For every correction that helps where you sit, it hurts somewhere else.   For a 2 or maybe 3 person room?   You're good, but for a larger theater space?   Ensuring even and good bass thruout is a setup problem.   Engineering exercise and listening experience.       You can learn to hear bass problems.   Corners are usually awful.    Have a couple bulky friends stand hard into corners and you'll HEAR the difference in bass.    

It is possible that if you sit in a place with a large bass 'dip', you wont' have enough amp power without clipping to correct to flat, while at the same time over driving other parts of the room.  

I'm probably guilty of Hyperbole in calling the Harman White Paper 'definitive'.     But man, what a bunch of information to think over when doing a setup.   And the Principles, I think, are 'sound'. (no pun intended)     For detailed speaker setup you might be better off over at the Cardas Site?   

Your 'room size' pot might actually control the 'Q' of the speaker.   Actually Qts, if memory serves.    A dimensionless 'quality' number.    .707 is the 'ideal' theoretical number.   Above
say, 1.2, bass gets flabby while some find the very low values to be very 'lean' and lacking substance.
As for Anachoic response?     For real use?   Not of critical importance.     Room gain, shape and DIMENSIONS trump anachoic any day of the week.   The OP with his 13x13 room has REAL problems, and he never mentions the height which is critical.   We'll agree to differ on the need or importance of such measures.   

One other thing which has been passed by thus far is a room mode calculator.     Even though bass correction is possible, this is still an important FIRST STEP in seeing what is going on and why.    Call me old fashioned, but I'm not sure I fully 'trust' those programs.    Don't forget that Bass is the most difficult to measure correctly.   The huge wavelengths relative to most rooms and the critical microphone placement ALL play havoc with getting it 'right'.

[Boomzilla]

Thanks, leonski - It's scary, but I think we agree 100%

Probably means we're BOTH bound to be wrong...

[Gary Cook]

Having had all sorts of combinations I've arrived at what I like, which is a large 4 ohm 17" driver in a 140 litre dual ported enclosure, located across a corner using a Class AB power amp (an XPA-100) rated at 400 watts. Being a large driver in large ported enclosure corner located means that I don't need kilowatts of amp power to give it plenty of impact, punch, slam etc for HT sound effects. Having run a sub for music for over 30 years the best bit for me is that it's extremely good for music, 2.1 stereo controlled by an XSP-1, which I have found a quality power amplifier contributes a lot to. I've tried all sorts of plate amps and Class D pro amps and the hifi audio quality Class AB amp with a linear power supply (not SMPS) is the one I'd choose for music every time.

I really don't believe that sub selection for HT use is all that critical, especially with quality room corrected, but for stereo 2.1 music a higher level of sophistication is required in all of the elements, the driver, the enclosure, the power amplifier and the location. Auditoning is really the only answer.


Cheers
Gary

[leonski]

Aug 8, 2017 15:01:38 GMT -5 Boomzilla said:

Thanks, leonski - It's scary, but I think we agree 100%

Probably means we're BOTH bound to be wrong...

Ever have that 'Here We Go' feeling?      Like when a Tire blows out when going around a sharp turn?