Subwoofers that go below 30 hz for music

[rattlesnake]

I've never had a subwoofer that doesn't roll off steeply below 30 hz, and I understand that very little music content is below 30 hz. I've read in a few places that when a music recording does have content below 30 hz, it's usually filtered out during mastering in order to make it play better on most listeners' systems. However, I know that there is music with synths, pipe organs, and even some pianos (the lowest notes on acoustic pianos) that has sound components below 30 hz. I just turned 60 and I'm thinking maybe it's time I spring for a sub that goes really low just to hear what I am missing.

Has anyone had a sub that sounds good below 30 hz and have you ever listened to music (not talking about movies) where it makes a difference?

 

[levimax]

I just finished building one of these monsters because I was frustrated with my modern "too small enclosure" subs https://shop.gsgad.com/collections/...ies/products/roundover-full-marty-single-unit . Compared to my 2 SVS SB-3000 this one sub puts out more SPL with about 30dB less distortion and about 80 ms less group delay at 20 Hz and plays flat and clean to about 15 Hz. These giant subs don't just play low, if you put a "pro" driver in them they will play clean to over 500 Hz with huge SPL. Between 40 Hz and 120 Hz is where "slam" lives and neither the small subs nor smaller mains speakers do as good a job as you would think with this range at high SPL. All in all for low volume listening it doesn't make much difference (see fletcher munson curve) but if you listen loud, high SPL clean bass with extension is a real treat and I am starting to think that the "modern" approach of small enclosures with big drivers and lots of x-max may not be the way to go.

My advice is don't just look at SPL at 20 Hz. Some modern subs have over 100 ms group delay at 20 Hz which does not sound good but more importantly it makes integration really hard. Same with distortion, the common wisdom is we are less sensitive to distortion at low frequencies which is true but a lot of subs have distortion over 30% and some approaching 100% and less sensitive does not mean distortion doesn't matter. Finally be aware that again because of the"fletcher munson curve" LF, even at 90 dB, does not sound "loud". So while it seems crazy to want over 100 dB at 20 Hz it really isn't that loud even though it is hard to achieve. Have fun.

 

[Chrispy]

There are subs that go lower, but somewhat a commitment to cost and size and perhaps multiple subs depending on your use/room. What particular musical content below 30 hz are you not finding accurately, or relatively accurately, represented? My subs sound great at lower frequencies and don't discriminate between "music" and other audio content particularly....

 

[Waxx]

I had a diy one that was tuned to 25Hz F3 but i did not like it, i rebuild the sub in a different design tuned to 32Hz F3 which was a lot better id for music. Even the lowsest bass notes are played (altough softer) due to the slow rolloff it has, but that is actually good in my opinion. 32Hz is the double of the lowest key on an organ (16Hz) and the overtones and psychoacoustics make up for the softer root tone of that 16Hz that you don't hear but more feel. For me (and for many) a sub tuned to +/- 30hz is good enough, even for HT, when the sub has a slow rolloff down (like with sealed or aperiodic ported). There are subs that go to 16Hz also, but they are experimental and not plug and play for sale.

And build more than one sub, that is a lot better dealing with room modes than one, also when using room correction (what can help a lot for good subbass)

On ready made subs i can't help, i'm a diy'er. I know SVS subs are highly rated (and i did like them also the few times i heared them). I don't like Rel or the small B&W subs at all. But most subs that i know are diy build by me or others because the market does not give what bassheads like me want. That's how i got into diy hifi speaker building 25 years ago...

 

[rattlesnake]

Thank you to you for the replies! As for musical content I’m not finding below 30hz, I don’t know what I’m missing because I’ve never heard a system that doesn’t roll off steeply below 30 hz. However, what I am hoping for is low frequencies that might not be easy to hear but that I can feel. For instance on Wagner’s “Zarathustra” (used in 2001 A Space Odyssey) there is a pipe organ note that I understand goes to 20 hz, and sometimes I have felt something when I listen at high volume and I wonder what it would feel like with a sub that is closer to flat to 20 hz. I have read in so many places “stereo systems don’t need to reproduce below 30 hz” but maybe that is because companies that sell budget subwoofers want people to think that.

 

[Waxx]

And to have hearable subbass without disturbing neighbours a ripole kind of sub is the best i know, they don't load the walls when put a bit away from walls (at least 1m) but still give you that low sub. It's a very nearfield kind of speaker what is great in appartments.

It's a kind of open baffle but using the narrow slots to load the woofer to go lower. They do need dsp altough and a steep filter to the bass, as they resonate a lot outside their passband. I don't know the science behind it, but it works. I had one on loan from a friend who was travelling (i was guarding his setup) about 5 years ago and will make soon a new one for myself. These kind of subs are mostly made diy also, altough the inventor does sell commercial version of it also.

 

[Waxx]

Thank you to you both! As for musical content I’m not finding below 30hz, I don’t know what I’m missing because I’ve never heard a system that doesn’t roll off steeply below 30 hz. However, what I am hoping for is low frequencies that might not be easy to hear but that I can feel. For instance on Wagner’s “Zarathustra” (used in 2001 A Space Odyssey) there is a pipe organ note that I understand goes to 20 hz, and sometimes I have felt something when I listen at high volume and I wonder what it would feel like with a sub that is closer to flat to 20 hz. I have read in so many places “stereo systems don’t need to reproduce below 30 hz” but maybe that is because companies that sell budget subwoofers want people to think that.

I know that piece, and i think room correction may solve that issue a lot easier than a sub that is tuned very low (if your actual system goes to the low 30's). That made for me the biggest difference in my main setup. Adding subs makes it eaven easier to get a good subbass if you do it the floyd Toole (multisub) way. The best is a combi of room correction and 4 subwoofers spread of the space, but practicallities and cost (each needs their dsp channel) makes that not always possible.

 

[rattlesnake]

I had a diy one that was tuned to 25Hz F3 but i did not like it, i rebuild the sub in a different design tuned to 32Hz F3 which was a lot better id for music. Even the lowsest bass notes are played (altough softer) due to the slow rolloff it has, but that is actually good in my opinion. 32Hz is the double of the lowest key on an organ (16Hz) and the overtones and psychoacoustics make up for the softer root tone of that 16Hz that you don't hear but more feel. For me (and for many) a sub tuned to +/- 30hz is good enough, even for HT, when the sub has a slow rolloff down (like with sealed or aperiodic ported). There are subs that go to 16Hz also, but they are experimental and not plug and play for sale.

And build more than one sub, that is a lot better dealing with room modes than one, also when using room correction (what can help a lot for good subbass)

On ready made subs i can't help, i'm a diy'er. I know SVS subs are highly rated (and i did like them also the few times i heared them). I don't like Rel or the small B&W subs at all. But most subs that i know are diy build by me or others because the market does not give what bassheads like me want. That's how i got into diy hifi speaker building 25 years ago...

So if a sub is tuned to about 30 hz and it rolls off, are you saying that you find makes a contribution to the music if the roll off is soft enough that you can still feel notes down to 20hz or even 16 hz? I have also thought about building a sub, perhaps using a cabinet from a flat pack kit since I don’t have the tools to cut wood accurately enough.

 

[Chrispy]

Thank you to you for the replies! As for musical content I’m not finding below 30hz, I don’t know what I’m missing because I’ve never heard a system that doesn’t roll off steeply below 30 hz. However, what I am hoping for is low frequencies that might not be easy to hear but that I can feel. For instance on Wagner’s “Zarathustra” (used in 2001 A Space Odyssey) there is a pipe organ note that I understand goes to 20 hz, and sometimes I have felt something when I listen at high volume and I wonder what it would feel like with a sub that is closer to flat to 20 hz. I have read in so many places “stereo systems don’t need to reproduce below 30 hz” but maybe that is because companies that sell budget subwoofers want people to think that.

The limitations of your setup doesn't mean content isn't possible....

 

[Hayabusa]

the sealed SVS sub do quite well for this... (SB17)

 

[ZolaIII]

Pipe organs are basically a spaceship and even so C2 will be more seismic than sound. Why is it so? Well because it lags in time progressively and in the way masks it self. You can use space fundamental to compensate for it partly or even completely, no sub's alone won't get you there. When choosing sub's pay attention to overall linearity trough SPL and capability in lower to mid 30's where defining peeks will be and ensuring it does it proper.

 

[Waxx]

So if a sub is tuned to about 30 hz and it rolls off, are you saying that you find makes a contribution to the music if the roll off is soft enough that you can still feel notes down to 20hz or even 16 hz? I have also thought about building a sub, perhaps using a cabinet from a flat pack kit since I don’t have the tools to cut wood accurately enough.

with a slow rolloff (mostly sealed subs) and in a room (where you got room gain), it works very well when tuneed right. The room makes up for the loss, and with dsp you can finetune it even further. But your sub needs a lot of headroom (xmax) and low distortion flat response in the passband, so it will be big, expensive and not so easy to integrate. I use a scanspeak 10" driver for this, but this only works because my room is small (3.5x6x2.5m). For an average living room i would go at least 12" for the driver that can give you a clean bass (don't run out of xmax) to 110dB (even ifn you use only 90dB or lower).

Idem with amps, take an amp that is rated more than the driver to have a clean bass. 1.6 to 2x the rated power is a good guide for this. It's better to have an amp to strong than to weak for the driver, especially for subs and also when playing on low volume.

 

[ahyespinkelephants]

I have two CSS SDX12s with dual passive radiators in their 18.5" cubed enclosures and they measure to 16hz in my room. I cannot recommend them enough. I'm running both off of a single Buckeye NC502mp so around 500w at 4ohm. I really want to get another amp so i can bridge each one and feed them their RMS of 1000w.
I recently found a playlist on Tidal with a ton of Infrasonic tracks. https://tidal.com/browse/playlist/fe561ea9-429d-415d-801c-59a787ccdcfa

 

[levimax]

So if a sub is tuned to about 30 hz and it rolls off, are you saying that you find makes a contribution to the music if the roll off is soft enough that you can still feel notes down to 20hz or even 16 hz? I have also thought about building a sub, perhaps using a cabinet from a flat pack kit since I don’t have the tools to cut wood accurately enough.

Due to psychacoustics our brain can fill in lower notes based on harmonics but it is not the same as actually hearing / feeling the notes.

I have some pipe organ CD's that go down to 17 Hz. Even the heartbeat on Dark Side Of The Moon is high SPL 30 Hz which most systems don't do a good job with. EDM and similar music is loaded with LF content.

The link I posted was to a flat pack, they are CNC machined with internal braces and porting and could never be made with a table saw. They are the way to go.

 

[sigbergaudio]

Most music don't have a lot of content below 30hz. With regards to perceived differences (beyond actually hearing and feeling content below 30hz when present), one of the main things is perhaps a greater sense of spaciousness and a sense of the recording space or venue. So the sound can feel bigger and you get more of a "you are there" feeling on some recordings when the lowest frequencies are present. This can be due to low frequency reverb and background noise that adds to this feeling.

An interesting example:

Here the continuous reverb (or whatever it is), and feeling of being in a large, cold space like a cathedral or stone church is present in the background. I don't know if it is artificially produced somehow or part of the natural recording (it's a recording from a church). This is barely sensed if at all on normal speakers that don't go to low, but is almost unpleasant if play it loud on subwoofers that go down to 20hz or below.

 

[Palmspar]

Use 3 sealed diy subs with 5 Scan Speak Revelator/Discovery 12'' drivers tuned 22hz-6db and 15hz-10db in the Hypex amps, they play 10hz flat inroom.
Sound great with movies and music, the Beolab 90 speaker uses also these drivers.
High vas and low moving mass drivers are the best for music representation, and the Scan Speaks are well designd for that.

 

[Chris A]

Has anyone had a sub that sounds good below 30 hz and have you ever listened to music (not talking about movies) where it makes a difference?

Yes. One behind each front loudspeaker. I've had them since 2008 in the setup. I listen to music that quite often has significant sub-30 Hz content. Most of the music that is easy to hear the difference is multichannel (5.1), where the mastering guys leave that sub-30 Hz stuff alone for the production tracks (where they need something there to justify having a subwoofer channel--I think this is their logic for not touching the infrasonic bass).

Jazz bass (5- and 6-string electric bass), real kick drum fundamental frequencies (unaffected by mastering EQ), and as you mentioned, very deep pipe organ (my mother was a classically educated pipe organist), very deep synthesized music, full orchestras having contra-bass bassoon and clarinet--all make the recordings come to life and viscerally real. It wouldn't be the same experience without the subs.

I cross them at 40 Hz (the front loudspeakers are good to 31 Hz--F3 frequency), so the subs take up a lot of the very deep bass amplitude to limit the modulation distortion of the front loudspeakers (also fully horn loaded). If you want to know about the recordings that have very deep bass (infrasonic) bass, I can provide those titles.

For stereo music where the mastering guys have attenuated the bass at -3 to -6 dB/octave below ~100 Hz (popular music) or -3 dB below 450 Hz (classical music), it's easy to restore the deep bass, the attenuation of which is visible on spectrograms. I use Audacity for that task. This is also found on pipe organ tracks having 16', 32' or 64' stops in the compositions.

The result is so clean of distortion that the location of the subs in-room is not possible using only your ears. (I've found that if you can point at the location of the sub(s) in-room, typically one of two things is occurring, 1) you're crossing the subs too high in frequency, and/or 2) the subs are producing too much harmonic distortion, so locating the subs in-room is easy.)

Note that the horn-loaded subs I use (and the only kind that I'd recommend due to thermal compression problems with direct radiating subs) require about 18.5 milliseconds of channel delay in the higher frequency channels to time align them to the two subwoofer channels. This also must be compensated through the preamp to match video to audio (music concerts, etc.)

Chris

 

[farhagh]

I've never had a subwoofer that doesn't roll off steeply below 30 hz, and I understand that very little music content is below 30 hz. I've read in a few places that when a music recording does have content below 30 hz, it's usually filtered out during mastering in order to make it play better on most listeners' systems. However, I know that there is music with synths, pipe organs, and even some pianos (the lowest notes on acoustic pianos) that has sound components below 30 hz. I just turned 60 and I'm thinking maybe it's time I spring for a sub that goes really low just to hear what I am missing.

Has anyone had a sub that sounds good below 30 hz and have you ever listened to music (not talking about movies) where it makes a difference?

Nothing beats Rythmik for that matter. Unfortunately they have put lots of their models on hold per tarrifs, and also they are not avalable in many markets.

 

[kyuu]

When you're dealing with space, aesthetic, and budget constraints I think that not worrying about the content under 30Hz is the correct compromise to make. Small subs that are DSP'd to hell and back to achieve that last half an octave are making the wrong compromises, IMO. DSP is a great tool, but it's not magic and the result is compromised max SPL, very high group delay (of questionable audibility, granted), and loads of distortion (approaching 100% at the low end). That's why I, personally, went against conventional wisdom and got a Revel B10 (when it was available at a substantial discount). It's a small 10" ported design with loads of amplifier power but no DSP that I'm aware of (asides an included single band PEQ, and probably an LF filter). The F3 is "only" 35Hz, but it gets down to 30Hz in-room (after Dirac) and can do the frequency range it does cover with authority (read: enough SPL headroom for dynamics) and minimal distortion, at least as far as I can discern.

If you have enough budget and no issues with a big sub that can actually cover down to 20Hz without substantial compromises, then by all means. I think for a lot of people who have a limited budget and no desire for a giant box in their living space, the focus on that last half octave is counterproductive, though.

 

[Oddball]

Going down the sub lane is a tricky and expensive endeavour. Plenty of subs that will cater below 30hz, albeit with less SPL response.

But eventually, if you really want great response below 30hz you would need 4 subs in double bass array and placement capabilities to do so.