Bass and subwoofers

[livinon2wheels]

Except that almost all recordings mono the bass, not keeping it "as it was" to start with. Now, some variation in phase at low frequencies might be a good idea, or not, but you DO NOT KNOW if there was any in the original master, because most often it's been removed, and the bass is mono.

There are many issues involved in why this started to happen (LP cutting), continued (woofer excursions, etc), and just lives on. The discussion and various ideas remain, with much unhelpful name calling (don't mean here!) and tossing about of metrics that "do not mean what you think they mean". Yeah, it's a bit frustrating.

I didn't realize that making the bass monaural was the common practice. As I think about orchestral positioning on stage, I seem to remember that kettle drums and Contrabass instruments are in the back and to left of stage center with tubas and such on the right of center. It seems to me as I think about this that its an attempt to spread instruments that play in the lower octaves across the sound field so that the bass energy is relatively evenly distributed but that in no way makes the live performance monaural...I can only wonder why throwing all the low frequency content into one bucket is necessary or useful...is there some technical limitation when pressing LP's that forces this to be done?

 

[anotherhobby]

I didn't realize that making the bass monaural was the common practice.

It's not in Jazz, most electronic genres, or folk/Americana. I don't know what genres it even is common to. I just see people claim it online, meanwhile my visualizer shows the opposite to me all day long. I've asked 3 friends that operate recording studios, and none of them do it and they all looked confused when I asked. I mean, it must be common in some genre since people like to make the claim?

 

[j_j]

It's not in Jazz, most electronic genres, or folk/Americana. I don't know what genres it even is common to. I just see people claim it online, meanwhile my visualizer shows the opposite to me all day long. I've asked 3 friends that operate recording studios, and none of them do it and they all looked confused when I asked.

Ask mastering people.

I have analyzed (and continue to analyze) lots of things. Remember we are only talking in the 20-300 range or so, and unless you filter your L and R signals to include only low frequencies you won't see anything. (Or alternatively if you have a system that shows you band by band, that would show stuff up.)

So, we don't agree.

 

[audiofooled]

While I agree with @j_j that bass is usually mono, there's this track as an example of large toms panned hard to the left:

 

[Sokel]

While I agree with @j_j that bass is usually mono, there's this track as an example of large toms panned hard to the left:

It's WAV analysis shows differences,yes,as the one I posted at the start of this thread:

 

[anotherhobby]

and unless you filter your L and R signals to include only low frequencies you won't see anything

Yes, that's precisely what my display does, which I thought the pic I posted in this thread showed quite clearly, but maybe you didn't look at it or understand what it was showing. It's a split screen with the top half full spectrum and the bottom half 10-80 Hz. I created the display because I was specifically interested in this topic. We clearly have observed different music, and that's fine. I do believe your analysis of whatever music you analyzed and I'm not debating the findings of what you found, I'm simply saying that depending on the genres one listens to (i.e. jazz, electronic, folk/Americana), there may actually be a lot of stereo bass in what they listen to.

 

[Thomas Lund]

We clearly have observed different music, and that's fine. I do believe your analysis of whatever music you analyzed and I'm not debating the findings of what you found, I'm simply saying that depending on the genres one listens to (i.e. jazz, electronic, folk/Americana), there may actually be a lot of stereo bass in what they listen to.

While LPs have restricted L/R difference at low frequency, the pick-up itself actually contributes enjoyable LF difference. Linear digital formats, however, often offer the actual LF fluctuations intended by the artist.

Perceptually, auditory envelopment (AE) may be regarded a messenger of friendly motion, and new 3D formats have the capacity to influence AE more in both directions than stereo. If you haven’t listened to extraordinary recordings by e.g. Morten Lindberg or Kimio Hamasaki on a decent 3D system, you may not know how high the AE bar has recently been raised.

Stereo, however, also offers golden AE examples, though the format depends even more on the listening room. Many Telarc recordings are extraordinary in this respect, for instance Jack Renner's recordings from Walthamstow Assembly Hall outside London, or Bruce Swedien’s Count Basie recordings at Universal Studios in Chicago as early as 1959. Contemporary pop/rock is also ripe with examples of AE contrasts, for instance much of George Massenburg’s work, Yello and Beyoncé; or listen to Billie Eilish’s I Didn’t Change My Number, where, in a bone-dry track, verses have correlated bass, developing into AE explosions in the choruses. Unless listened to in linear audio with neutral LF time-domain (i.e. headphones or a transparent stereo system/room), you may entirely miss such joy.

To know in which tracks/versions one ought to be able to hear this dimension, I prefer my ears and temporal integrity over a meter. Simply listen to the L/R difference and notice if it has VLF or at least LF content; and that the diff is without space monkeys (data reduction artefacts).

 

[j_j]

I have to point out that amplitude (or power) spectra are not the way to resolve stereo effects at any frequency. They are a part, but only a part. Time arrival is a key issue.

 

[Doodski]

@Thomas Lund. Hi Thomas. I have not seen you here before. What company do you hail from?

 

[Sokel]

@Thomas Lund. Hi Thomas. I have not seen you here before. What company do you hail from?

He is around quite a while,Genelec.

 

[Doodski]

He is around quite a while,Genelec.

O' cool... Great having Genelec here.

 

[Steven Holt]

This is a very intelligent discussion, so let me jump in and dumb it down a little. First, name me one integrated amp that has multiple subwoofer inputs. Less than 1500US please. It's simply not practical to have four damn subwoofers for the semi-casual listener. Not gonna happpen. Second, why can't you locate the subwoofer in the middle, between the speakers? Wouldn't this give you a nice LF average as opposed to a summed total? The way I understand it, this should give you a very nice radiant spread throughout the entire room, provided that it's not 'too big'.

 

[sigbergaudio]

This is a very intelligent discussion, so let me jump in and dumb it down a little. First, name me one integrated amp that has multiple subwoofer inputs. Less than 1500US please. It's simply not practical to have four damn subwoofers for the semi-casual listener. Not gonna happpen. Second, why can't you locate the subwoofer in the middle, between the speakers? Wouldn't this give you a nice LF average as opposed to a summed total? The way I understand it, this should give you a very nice radiant spread throughout the entire room, provided that it's not 'too big'.

I don't think anyone is expecting or suggesting that a semi-casual listener with a 1500usd integrated Amp should employ 4 subwoofers?

 

[Chromatischism]

This is a very intelligent discussion, so let me jump in and dumb it down a little. First, name me one integrated amp that has multiple subwoofer inputs. Less than 1500US please. It's simply not practical to have four damn subwoofers for the semi-casual listener. Not gonna happpen. Second, why can't you locate the subwoofer in the middle, between the speakers? Wouldn't this give you a nice LF average as opposed to a summed total? The way I understand it, this should give you a very nice radiant spread throughout the entire room, provided that it's not 'too big'.

If you only have one subwoofer, that is often the best place for it, on average.

 

[Steven Holt]

I don't think anyone is expecting or suggesting that a semi-casual listener with a 1500usd integrated Amp should employ 4 subwoofers?

Point taken; perhaps I was reading into things a bit too much.

 

[Duke]

This is a very intelligent discussion, so let me jump in and dumb it down a little. First, name me one integrated amp that has multiple subwoofer inputs. Less than 1500US please. It's simply not practical to have four damn subwoofers for the semi-casual listener. Not gonna happpen. Second, why can't you locate the subwoofer in the middle, between the speakers? Wouldn't this give you a nice LF average as opposed to a summed total? The way I understand it, this should give you a very nice radiant spread throughout the entire room, provided that it's not 'too big'.

I don't know whether any of my customers would describe themselves as "semi-casual", but the four-sub system I make (the "Swarm") uses a single amplifier to drive the four subs.

Note that a voltage divider network can be used to derive a line-level signal from a speaker-level signal if needed. REL subs have a voltage divider network built into them, as do many plate amps. Suitable voltage divider networks are available online, but by now we've probably exited the "semi-casual listener" category.

 

[Willem]

I have been reading this thread with my limited knowledge of the science behind the acoustics, particularly after my recent comparison of a live afternoon orchestral performance in the wonderful acoustics of the Amsterdam Concertgebouw, and the TV broadcast of the exact same concert the very same evening. The differences were quite substantial. The timbre of the instruments was very accurately reproduced, other than some lack of bass, and dynamics were also reduced, but the TV recording primarily lacked much of the spatial envelopement of the actual live performance. I appreciate that the close miking for TV probably removed most of the spatial cues so that no system could ever hope to reproduce the acoustics of the live event. But it made me think, reading all these posts about the localization information below 80 Hz.
At 70 sqm my listening room is quite large, and the system is not particaulry lacking either (Quad 2805 speakers highpassed at 80 Hz, three small to medium size subwoofers in uncorrelated positions, low passed at 80 Hz and equalized by MSO/miniDSP 2x4HD).
Would it have helped (using a more realistic recording) if I had not high passed the main speakers while still using only mono subs? I know Earl Geddes advocates to use the main speakers full range, and MSO can also equalize the bass of the main speakers used full range. Doing this the stereo information from the main speakers plays a bigger role in the range below 80 Hz. And if one does this, is it better to low pass the subs at a lower frequency (my Quads are flat down to 37 Hz, below which they then drop off rapidly)? I appreciate that without highpassing I would lose the benefit of greater headroom for the main speakers and amplifier.

 

[sigbergaudio]

I have been reading this thread with my limited knowledge of the science behind the acoustics, particularly after my recent comparison of a live afternoon orchestral performance in the wonderful acoustics of the Amsterdam Concertgebouw, and the TV broadcast of the exact same concert the very same evening. The differences were quite substantial. The timbre of the instruments was very accurately reproduced, other than some lack of bass, and dynamics were also reduced, but the TV recording primarily lacked much of the spatial envelopement of the actual live performance. I appreciate that the close miking for TV probably removed most of the spatial cues so that no system could ever hope to reproduce the acoustics of the live event. But it made me think, reading all these posts about the localization information below 80 Hz.
At 70 sqm my listening room is quite large, and the system is not particaulry lacking either (Quad 2805 speakers highpassed at 80 Hz, three small to medium size subwoofers in uncorrelated positions, low passed at 80 Hz and equalized by MSO/miniDSP 2x4HD).
Would it have helped (using a more realistic recording) if I had not high passed the main speakers while still using only mono subs? I know Earl Geddes advocates to use the main speakers full range, and MSO can also equalize the bass of the main speakers used full range. Doing this the stereo information from the main speakers plays a bigger role in the range below 80 Hz. And if one does this, is it better to low pass the subs at a lower frequency (my Quads are flat down to 37 Hz, below which they then drop off rapidly)? I appreciate that without highpassing I would lose the benefit of greater headroom for the main speakers and amplifier.

The main reason for the difference is the fact that the production you listened to through your system is a mix of recordings by microphones located very differently from where you sat during the live event, and also heavily processed after the fact.

 

[NTK]

I have been reading this thread with my limited knowledge of the science behind the acoustics, particularly after my recent comparison of a live afternoon orchestral performance in the wonderful acoustics of the Amsterdam Concertgebouw, and the TV broadcast of the exact same concert the very same evening. The differences were quite substantial. The timbre of the instruments was very accurately reproduced, other than some lack of bass, and dynamics were also reduced, but the TV recording primarily lacked much of the spatial envelopement of the actual live performance. I appreciate that the close miking for TV probably removed most of the spatial cues so that no system could ever hope to reproduce the acoustics of the live event. But it made me think, reading all these posts about the localization information below 80 Hz.
At 70 sqm my listening room is quite large, and the system is not particaulry lacking either (Quad 2805 speakers highpassed at 80 Hz, three small to medium size subwoofers in uncorrelated positions, low passed at 80 Hz and equalized by MSO/miniDSP 2x4HD).
Would it have helped (using a more realistic recording) if I had not high passed the main speakers while still using only mono subs? I know Earl Geddes advocates to use the main speakers full range, and MSO can also equalize the bass of the main speakers used full range. Doing this the stereo information from the main speakers plays a bigger role in the range below 80 Hz. And if one does this, is it better to low pass the subs at a lower frequency (my Quads are flat down to 37 Hz, below which they then drop off rapidly)? I appreciate that without highpassing I would lose the benefit of greater headroom for the main speakers and amplifier.

You really need multi-channel to satisfactorily reproduce the spatial effects of the concert hall. The recordings also need to have the right information.

Also, quoting Thomas Lund of Genelec ...

Genelec 8351B Review (Studio Monitor)

It's not particularly difficult to make them complain without hitting the limiters. Sub heavy content (hip hop, especially) even at reasonable levels will do it. If you need a good example, Hey Now on Kendrick Lamar's new album will do it. That's a speaker killer. Either speakers are faulty or...

www.audiosciencereview.com

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Great questions for a New Year. Floorstanders come with benefits, beyond headroom and low frequency extension. However, the main advantage has been somewhat kept a secret; due to a stubborn and detrimental simplification of reproduced sound in engineering literature: Disregard for inter-aural time domain coherency at low frequency. In case LF inter-aural time and magnitude differences have been recorded across channels, and made it safely through a reproduction chain, it is such a pity to kill Auditory Envelopment (AE) at the last stage, by using mono sub(s) with bookshelf/nearfield monitors. That’s game over before even started.​

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Floorstander-users expect at least some ability of a room and system to convey AE, possibly the most universal and enjoyable dimension the human auditory system is able to declare. The topic has been discussed before on ASR, and we will report from new studies in 2025. To the questions:​

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Genelec 83 series monitors include extensive per channel frequency domain and time domain adjustment capability. The GLM application can be used to adjust those parameters automatically, manually or in a combination of both. You might also make adjustments upstream instead, or partly upstream and partly in the 83s. Anyway, settings may be stored and set in stone per monitor. Settings will stay the same despite power-down; until GLM is connected again and deliberate changes made.​

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Building your own subs, for instance into walls, or buying a different brand, is therefore also fine. Because of AE, I would *always* use at least two sub channels. If later movement of subs will be impossible, consider listening to AE test samples before committing to placement. If two subs are not possible, I would not cross-over higher than 40 Hz.​

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Regarding hearing safety, with an average listening level of 105 dB(A), according to the clinical gold standard, adults should be listening for no more than 2 minutes per day (risk of material hearing loss ~1%). Happy New Year ​

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[Willem]

Multi channel is not really on for me, with two large Quad 2805 electrostats as my main speakers. I would not want to have five (or more) of those, apart from the fact that there are so few multichannel music recordings.