How to select subwoofers?

[Boomzilla]

Simple enough...

I like having the bottom octave of bass (20 to 40 Hz.). Even when the music at hand doesn't use that octave, the music sounds more "real" because the capability is there.

I also like having the main speakers sound cleaner and more "quick." This ONLY happens when a bass management system is being used that has a good high-pass filter that prevents the main speakers from trying to reproduce that bottom octave. This is not opinion, by the way, but fact. How? When a woofer cone, for example, is trying to reproduce two simultaneous tones, the two tones modulate each other causing peaks and dips in the frequency response. This type of interference is called "intermodulation distortion." It is measurable, and the less excursion that the woofer cone must use to reproduce the lower of the two tones, the lower the IM distortion. This is why horn-loaded speakers (especially in the bass) have such measurably low IM distortion. By using a high-pass filter for the main speaker and a low-pass for the subwoofer, IM distortion is minimized.

Subwoofers can be placed in the room wherever they need to go for the best bass reproduction. When the main speakers are trying to both image well and produce good bass, any position is basically a compromise. So higher ultimate performance (both bass and imaging) is possible with subs.

And that's it. Those three benefits are the only ones that I find for subwoofers. So with at least seven negatives and three positives, subwoofers overall score a solid minus four. YMMV

[daveczski65]

Jul 31, 2020 16:49:34 GMT -5 Boomzilla said:

Rythymik DOES look like a good bet... And yes, I will want two. Emotiva S8 might be a contender, but here's a list I put together:

PSB Alpah S8 $450
Martin Logan Dynamo 400 $450
JL Audio Dominion d108 $800
Dayton Audio Sub-800 $150
Monoprice 8-inch $65
Klipsch C-308ASWI $1,500
Polk PSW-11 $202
Yamaha NS-SW050 $150
Axiom EP-125 $600
KEF C4 $330
BIC Venturi V80 $138
NHT Super 8 $... (Discontinued)
DefTech Supercube 4000 $800
GoldenEar ForceField 3 $550
HSU CCB 8 $370
Paradigm Cinema Sub $350

What about tekton 2 -10 subwoofer..i know above ur price at 600. But u get 2 in one

[Boomzilla]

And we're also reeled, not only reluctantly, but also hook, line, and sinker, back into the MOST critical question concerning subwoofers - the question that should precede every other subwoofer consideration, and the one that is the most difficult to answer (mostly because the manufacturers don't want you to ask the question):

IS IT A HOME THEATER SUBWOOFER OR IS IT A MUSIC SUBWOOFER?

And a world of expense, irritation, and frustration awaits you should you choose the wrong one. So what's the difference?

HOME THEATER SUBWOOFERS:

HT subs are built for maximum output. Their primary purpose is to give voice to the "point-one" track on movies. When the dinosaur stomps, or when the building explodes, the moviemaker and the sub manufacturer want you to give a startled scream and leap from your couch. To do this, the transient must be several times louder than the background dialogue.

Now to achieve such transient output, the sub makers dispense with a lot of other things. If the sub driver rings for awhile after the transient, who cares? Your ears are still ringing from the explosion and you'll never notice. If the sub distorts by 50% or more during the transient, who cares? As long as the driver suspension doesn't damage itself, everything's OK. The sub's frequency response is tailored to provide maximum output at the frequencies most likely to be on the movie soundtrack, and if you look at the frequency response curve of a HT sub, it will usually look like a steep hill, rolling off precipitously above and below its maximum output. Also, by convention, the "point-one" track of movies is typically crossed over to the satellite speakers at 80 Hz. so there's little motivation for the sub makers to extend the sub frequency response much above that.

So lets summarize: Home Theater subwoofers usually (not always, but in 90% of the cases) are high-resonance, high-distortion, high-output, narrow-band, and high-frequency limited. A HT sub can have ALL of these "flaws," and yet still be an excellent HT sub. And although it might suffice for occasional music, that was NOT its primary design intent.

MUSIC SUBWOOFERS:

I'd contend that music subs have a completely different set of design criteria. When the signal stops, the sub needs to stop as well. A slow rise time and extended after-ringing do not sound like music. Sub distortion is also critical. A sub that makes a cello sound like a synthesizer is not compatible with music. Maximum output is generally less important. Unless you're listening to rap, synth, or at party levels, the music sub will rarely be asked to go so loud. A flat frequency response is desirable for music sub. While it's true that you sometimes CAN equalize a HT sub for flatter response, it's also true that you'll increase distortion exponentially by doing so. And finally, it is not unusual for music subs (particularly those used with mini monitors such as the KEF LS50) to be crossed over at 100 Hz. or even 120. Few if any HT subs can reach that high.

So let's summarize: Music subwoofers need to have quick transient response with no after-ringing, low distortion over at least two octaves, a flat frequency response over at least two octaves, and be able to reach 100, 150, or even 200 Hz. with minimum distortion. Music subs can suffice for HT subs, but generally NOT vice versa. So let's get down to it:

HOW CAN YOU TELL IF A SUBWOOFER IS A MUSIC SUB OR A HT SUB?

And the answer, most of the time, is "you can't." Few subwoofer manufacturers provide impulse response plots for their products. Few subwoofer manufacturers provide a distortion curve (and even if they do, it's usually taken at an unrealistically low volume, where the sub produces the lowest distortion). Even if the manufacturer provides a frequency response curve, it isn't reliable because the manufacturers don't tell you how the measurement was made (anechoic? In-room? What size room? Plus-or-minus how many dB?). And it's not unusual for manufacturers to either fudge their published specs or even to outright lie to make their products sell.

So what's a consumer to do? If you're buying for HT use, don't worry, be happy. Just buy a sub in your price range and it should be fine for movies. But if you're buying for music, caveat emptor ("buyer beware!"). Since specifications are often missing and what specs you may get are so unreliable, you'll usually just have to listen. Your own ears are your best instruments in finding a sub that you think sounds good with music. Another latin phrase that applies: "Res Ipsa Loquitur" (the thing speaks for itself). In general, you're more likely to find good music subs in the "less than 15" diameter" choices. You're also more likely to find good music subs with sealed enclosures rather than ported ones (although there are some exceptions). And you're also well advised to ask the manufacturer (NOT the salesman, who will tell you want he thinks you want to hear to make his commission). And the way to phrase your question is not "Is this a good sub for music?" but rather "Of all the subs your company makes, which would you recommend for music - and why?"

And finally, it will be human nature for EVERYONE who has a sub to recommend highly the make and model that they bought. Their advice, although well intentioned, is tempered by the fact that they may not have enough experience with different subs to actually know which makes and models are best for YOUR purposes. In other words, if they use their sub for movies, they'll praise it to the heavens to you even though you may be looking for a sub for music. And that's the problem with endorsements - without knowing the owner's usage of their subwoofer, it may be excellent for them, but not so much for you.

So even more than loudspeakers, subwoofer shopping is fraught with many, many problems. NEVER buy a sub you've not heard, and ideally, only buy with a money-back return period.

Happy Shopping - Boomzilla

[frenchyfranky]

Jul 30, 2020 14:24:40 GMT -5 Boomzilla said:

Rythmik L12 and SVS SB1000 = maybe too large (looking for an 8" or 10" driver), but I'll put them in the hopper anyway on y'all's recommendation. Thanks.

These two have very small footprint particularly the SB-1000 with 13in cubic and if you find a 8 or 10in driver sub with this performance it will probably be in the same footprint size. Last December I help a friend to setup a system with two SB-1000 (with a pair of Airmotiv T1) and they're really small in a room and very astonishing in stereo music listening.

[jackfish]

I thought by now it had been well established that Rythmik servo subwoofers are the best subwoofers under $1000 for music. You can return them if you don’t like them. You are only out return shipping for the privilege of the audition of a Rythmik.

[Boomzilla]

Aug 3, 2020 19:35:50 GMT -5 jackfish said:

I thought by now it had been well established that Rythmik servo subwoofers are the best subwoofers under $1000 for music. You can return them if you don’t like them. You are only out return shipping for the privilege of the audition of a Rythmik.

Who am I to blow against the wind? Once my S15s sell on CraigsList, I'll try Rythmik.

Thanks - Boom