The (dubious) usefulness of subwoofers - opinions needed

[Beershaun]

At this point I think you should pick a subwoofer to audition in your home and decide for yourself and return it if you don't like it. Many companies have a home audition and free return policy. I think we've given you the answers you were looking for and now it's just seeing if a subwoofer is worth it or not to you in your particular room with your particular speakers.

 

[Aerith Gainsborough]

At your listening levels and given the extension you already have, I think the audible benefits of a subwoofer will be minor.
You may get a smoother bass response if you are able to place it in a better location in the room compared to your mains but I don't think you will get much more clarity etc. 90dB SPL is simply too quiet, most speakers won't struggle at such a volume, even bookshelves don't have audible distortion at that level.

For 30Hz and below to be fun, IMHO you need 100dB+ SPL. You are going more into the tactile sub bass area than the audible one.

If you have the ability to measure and correct responses on the digital side and are able to order a sub for 1-2 weeks to try it out w/o it ending up a major investment, I'd give it a shot. What the heck, worst case: wasted shipping costs but at least you have tangible data whether it makes enough of a difference to be worth it.

 

[Slayer]

This depends on your setup. If you have a sealed sub and sealed speakers you are less likely to have phase issues, and this also depends on crossover slopes, whether you're highpassing mains or not, whether you have room calibration capabilities in amplifier/processor, how your sub is placed in the room, etc etc.

Phase is also frequency dependent, so you won't necessarily get perfect phase even with a phase control.

sigbergaudio, I don't disagree with what you have said, in fact i fully agree with your statement, i don't think anything in my previous post contradicts it either.
Yes my post may be more relevant for ported mains vs sealed. That is because, if i am correct his mains are ported. That is why i stated my post as i did. I did not see the need to bring in the sealed mains comparison. I may have taken for granted the OP had the abilities to highpass his mains seeing how it is so common these days. Of course you may not get perfect phase with having phase control, but you darn sure are going to get closer by not having it. Good thing is, most quality subs these days have some form of dsp and variable phase control built into the sub, would be a shame getting one without it. Either way, i don't think we're in disagreement. Cheers mate


Freddylost, What you should think about is, no matter how capable your mains are, reducing the low end duties of your main speakers, they are bound to sound cleaner, while also reducing the stress on your amplifier amplifying your main speakers. Removing the low-end duties from the mains, now your mains (woofers) are not trying to reproduce the mids and lows simultaneously, which only stands to reason that it will help with the clarity. Even at low volumes you will or should be able to tell the difference.

Have you ever noticed one of the biggest complaints about listening to audio at low levels people feel as if they are missing out on the lows? Having a sub or multiple subs, will eliminate this problem almost entirely. 90% of my listening is down at low volume levels, sometimes even at what some might call whisper levels. Regardless of levels, i never feel as i am missing out on the lows. As someone stated above, get one to audition in your set-up, i think you will be pleasantly surprised. Good luck my, rock-on.

 

[Aerith Gainsborough]

Have you ever noticed one of the biggest complaints about listening to audio at low levels people feel as if they are missing out on the lows? Having a sub or multiple subs, will eliminate this problem almost entirely.

No it won't.

The effect you describe is a result from non linearities of the human sense of hearing.
Yeah sure, if your sub is giving you +10dB of bass, you will be able to counteract that but then your sub is not properly integrated.

Sonically, a properly integrated sub is indistinguishable from the mains. Simple as that. Subs are not there to add bass amplitude. They are used to extend bass. 37Hz is already plenty low for most music, so there isn't much more information to be had by extending further.

As you said: the most interesting effects besides headroom/extension/smoothness are taking strain off the drivers and amps (esp. weak AVRs).

 

[sigbergaudio]

No it won't.

The effect you describe is a result from non linearities of the human sense of hearing.
Yeah sure, if your sub is giving you +10dB of bass, you will be able to counteract that but then your sub is not properly integrated.

Sonically, a properly integrated sub is indistinguishable from the mains. Simple as that. Subs are not there to add bass amplitude. They are used to extend bass. 37Hz is already plenty low for most music, so there isn't much more information to be had by extending further.

As you said: the most interesting effects besides headroom/extension/smoothness are taking strain off the drivers and amps (esp. weak AVRs).

This is only partially true. There's a correlation between bass extension and the subjective performance of a sound system, and a properly integrated system will have elevated low end due to the non linearities of human hearing as you point out. This will help out even more at moderate levels, because at those levels a flat system would leave the low end completely inaudible.

To have even more benefit of this, active / dynamic EQ systems like Audyssey and other room calibration systems would be beneficial (that automatically increases bass at low levels to compensate for non-linear hearing).

 

[Sal1950]

Be happy dont bother .

For shame on you Thomas

 

[Frank Dernie]

I mean, currently I have PSI A-25 mkI with free field F6 of 32 Hz

If you have full range speakers with enough volume capability my advice would be not to bother, unless you prefer dicking about with measurements and test tones to listening to music.
It depends how you want to allocate your use of spare time.
I have a sub and only use it with films, for music my carefully positioned full range speakers have yet to be improved on by a sub.
It seems if I spend most of my free time with microphones and measuring stuff after many hours of effort and a bit of luck it may be a bit better.
It may be worth it for you, it wasn't for me, for music. Edit: my speakers go down to 26Hz though.
If you only had little 2 ways I would be advising you to get a couple of subs and work on it, but with those PSIs I would not bother personally.

 

[Aerith Gainsborough]

This is only partially true. There's a correlation between bass extension and the subjective performance of a sound system, and a properly integrated system will have elevated low end due to the non linearities of human hearing as you point out.

Only if the content actually has relevant information down there, so it comes down to what the user listens to. If your music doesn't contain much data at 30Hz, the extension won't get you anything audible.

Whether or not you have an elevated response down there is dependent on your house curve. I believe Harman suggests a slope to some +6dB @ 20Hz but not every listener subscribes to that.

BTW: dynamic EQ would attenuate the mids relative to the volume used and not amplify the highs/lows. My RME does this.

 

[jhaider]

Hello everyone.

I need to get some opinions from experienced people.
I'm sluggishly think about augmenting my stereo (currently) setup with at least one decent subwoofer. Maybe 2 subs for DBA or 2.2.
My main concern is simple - will it really make enough difference to call this upgrade with all expenses and hassle and calibration work justified?
...

Would like to know opinions about that and real worl experience if someone have such...

IMO the threshold question is, how many seats do you care about? If just one and you’re already satisfied with bass quantity/extension, you can skip the sub and just use EQ. If you care about sound quality over a listening area, multiple subs are IMO required.

 

[dasdoing]

How clean?

(audible) distorsion free

how loud?

linear to about 33Hz I would say

Some bands use cool LF effects, as I've read. Maybe it will add some emotional improvement.

that's the main use-case for below 30Hz content. I call it rumble lol

If I go throug the examples in this thread on my system: https://www.audiosciencereview.com/forum/index.php?threads/bass.18999/

powerfull basslines energy is always in the 40-50Hz range on normal music

that low level <30Hz stuff on most of the examples are mostly far in the background energy-wise or it is "rumble"

when there are "true notes" in that range it is a) a show-off track like in post #20, or they are detached from the bassline cause they are lower in level cause making them stand out would cost a lot of headroom.

I would say that having those frequencies is nice, but the cost-benefit is very low.

personaly the rumble stuff is just getting on my nerves. that might also be because I have a lot of ringing in that range, cause even I have a lot of treatment material, hitting those frequencies with absorbtion is nearly impossible. it would have to be meters thick

 

[sigbergaudio]

One reason for wanting the capability to reproduce pretty low frequency content (20-30hz) is that you want the ability to actually reproduce 40hz cleanly, and ideally louder than the rest of the frequency range (due to our non-linear hearing). That is pretty hard if your speakers have already started to roll off significantly at 40hz.

So the fact that most music doesn't extend lower than 40hz doesn't mean you're necessarily fine with speakers that roll off at 40hz.

 

[Thunder22]

Go for it! Example: ULS-15 MK2 Subwoofer x 2. It's what I did and would not go back.

 

[Aerith Gainsborough]

One reason for wanting the capability to reproduce pretty low frequency content (20-30hz) is that you want the ability to actually reproduce 40hz cleanly, and ideally louder than the rest of the frequency range (due to our non-linear hearing). That is pretty hard if your speakers have already started to roll off significantly at 40hz.

So the fact that most music doesn't extend lower than 40hz doesn't mean you're necessarily fine with speakers that roll off at 40hz.

True.
Unless you are like me and have an assisting room mode at that frequency *chuckles*.
It's a bit on the ringy side but hey, at least I can feel the pressure on my lungs and hear it.

 

[FeddyLost]

unless you prefer dicking about with measurements and test tones to listening to music.

I'm not competent "by ear" at all, so I prefer instrumenary control according to recommendations. It's faster and easier than blind (deaf) trial and error.
If 2x15" subs would cost much less, I'd not weigh pro and contras.

I would say that having those frequencies is nice, but the cost-benefit is very low.
personaly the rumble stuff is just getting on my nerves. that might also be because I have a lot of ringing in that range, cause even I have a lot of treatment material, hitting those frequencies with absorbtion is early impossible

No bass - no problem. Sometimes cutting lows off is a remedy.

Example: ULS-15 MK2 Subwoofer x 2

As I thought. 12" don't have enough headroom, even if it will be never used.

Unless you are like me and have an assisting room mode at that frequency *chuckles*

I'd say that IMO really assisting room mode somehow suitable at ~30 Hz and below, because any "fast" musical instrument not nessessary will really benefit from loooooooong sustain.
Natural disasters in movies have poorer definition anyway, so if it's only movie system, modal assistance might be used higher.

 

[Frank Dernie]

I'm not competent "by ear" at all, so I prefer instrumenary control according to recommendations. It's faster and easier than blind (deaf) trial and error.
If 2x15" subs would cost much less, I'd not weigh pro and contras.

I wouldn't recommend trying to balance subs by ear!
Just I am pretty sure that it is better spending more hours listening to music rather than the same number of hours dicking about with subs when he already has full range speakers (ask me how I know).
For film special effects yes. I have found a sub with full (musical) range mains to be audible.

 

[Aerith Gainsborough]

I'd say that IMO really assisting room mode somehow suitable at ~30 Hz and below, because any "fast" musical instrument not nessessary will really benefit from loooooooong sustain.

Dunno, go give me an example of a fast musical instrument at 37Hz and I take a listen. I have nothing like that in my library, typically tones at that range are mostly sustained anyway, hence the ringy character isn't much of a problem.

 

[FeddyLost]

For film special effects yes. I have found a sub with full (musical) range mains to be audible.

With proper mixdown in stereo?
I think if LFE track is separate, it's better to use sub for it. Even if fronts will manage this.

Dunno, go give me an example of a fast musical instrument at 37Hz and I take a listen.

Check out fast D1 pace on bass guitar.
With ~1000 ms RT high tempo will barely be auditioned properly, like fast pulse. It will just bloaty roar instead.
When I compare bass definition in room and in BA IEMs ... it's very different.
Maybe I'm wrong, but now in my room with current compromised placement elevated bass with long RT have some pumpy character, which is totally OK for consumption, but not tactile and not real enough, I'd say.

 

[Aerith Gainsborough]

Check out fast D1 pace on bass guitar.

You man sth like this?

I don't see any notable activity in the 40Hz band of my RME, let alone 37Hz and below.

If you don't have a sub, you can route the LFE to the mains.
Just be mindful of killer samples like the "Edge of Tomorrow" into 15Hz.

 

[DonH56]

My reasons for subwoofers below (from very old posts; I finally copied to a local text file to keep from typing it all in again).

I use subs, and have for decades, for all the usual reasons:

- Very (perhaps extremely) few "large" speakers actually play well below 40 Hz let alone 20 Hz. They distort heavily when presented with large bass signals (which most are -- see Fletcher-Munson) and driving them down low robs headroom for higher frequencies and causes distortion well above the fundamental signal frequency (harmonic and nasty intermodulation). Subs typically enable the mains to operate with much lower distortion.

- Very rare is the room setup such that the best place for stereo imaging and soundfield is the best place for the subs (or deep bass drivers) to counter room modes and such. Having independent subs provides placement options to smooth the in-room response. It is almost impossible to counter a null without subs (typically must move the MLP or change the room's dimensions though there are purpose-built panels that can also work). This is one of the things that led me to subs despite having quite capable mains.

- Powered subs offload the main amplifiers of the need to provide deep bass energy, providing more headroom and cleaner sound from the amplifiers.

- Music (let alone action movies) often contains deep bass content even if it is not real obvious. Kick drums, tympani, organ, sure, but also piano hammer strikes, plucked strings, beat patterns from instruments playing together, etc. May not really notice when they are there but usually obvious when they are taken away. Having subs fill in the bottom octave or three can make a difference.

- Purpose-built subs can provide high output cleanly at relatively low cost. The amplifiers and drivers need only cover a fairly limited frequency range so have fewer constraints upon them than woofers in a full-range system.

I do prefer main speakers with fairly deep bass and always have. Crossovers are not brick walls so a fair amount of energy still comes from the mains an octave below the crossover frequency. Higher-order crossovers allow you to reduce the overlap, but I still like having the capability. I have never really understood the idea of running "passive" bi-amping as implemented by an AVR (sending full-range signals to multiple channels and letting the speaker's crossovers separate frequency bands -- wastes amplifier headroom and seems to me of little benefit). Nor do I agree with the "plus" setting putting subs and mains in parallel; again, my idea has always been to isolate the two for the reasons above.

My first sub was a DIY design using an Infinity IRS woofer with my own control box to provide the crossover and a servo circuit using the second voice coil of the woofer. I had a Hafler DH-220 around so also incorporated a circuit to bridge it for use as a subwoofer amp. It worked well and the -3 dB point was ~16 Hz. I now run four small (F12) Rythmik subs using a similar (but updated) servo design with my Revel Salon2's and am happy with the result.

Stereo subs:

I have gone back and forth on stereo subs over many years (since ~1979/1980 when I built my first sub) and ultimately decided it is not worth it. It limits placement and correction options, almost no stereo content exits at sub frequencies (remember a wavelength is >11 feet at 100 Hz, >22 feet at 50 Hz, just how much stereo separation can there be in a normal listening situation?), and the end result was always much better when I ran the subs mono and placed them optimally for best in-room bass response. If your crossover is so high and/or filter roll-off so low that your subs intrude into the lower midrange you might appreciate stereo but I have always rolled off well below the point at which I could localize the subs. For years I ran stereo subs but many tests blind and otherwise convinced me stereo subs are just an unnecessary hassle that actually reduced my system's performance and sound.

FWIWFM/IME/IMO/my 0.000001 cent (microcent) - Don

 

[Sal1950]

Just I am pretty sure that it is better spending more hours listening to music rather than the same number of hours dicking about with subs when he already has full range speakers (ask me how I know).

I got to disagree with that conclusion just a bit Frank. Firstly how many hours of setup is he really going to lose from listening in the big picture? Even if you spent 2 or 3 days getting it just right, you have the rest of your life to enjoy the fruits of that labor. A top notch HiFi is just like a race car, you have to spend a lot of time on the little details to come out with a winner.
Also, it's the rare system that won't benefit from the reduction in driver excursion in the deep bass.
If your using any room correction, and your room has bad suckouts in a bass range or two that can't be improved by position or treatment, (many), trying to improve the situation via boosting that range into your current towers alone is unwise if not dangerous to your speakers. A good a subwoofer or two will greatly ease the strain put upon your main L & R's.
Personally I believe it's a rare system that can't benefit from a subwoofer or 2.
JMHO