Locating bass <80Hz?

[youngho]

This kind of pushing the envelope with ever more complicated, and costly tech/ is my objection raised above. "We" do not have any relevant recordings yet, that would contain such "signals" for a listener to be enjoyed, nor do "they" have any idea how to realize the (non existing) concept, and not the least, there are no plans to progress at any speed. Except, of course, selling speakers that allegedly would in some future bring the wonder to the table.
As far as I'm concerned, there is no model yet that would relate all the assumptions and anecdotal remarks to physical reality, let alone specific, quantitative explorations in psychoacoustic teritory.

I'm not here to argue, just wanted to provide some actual links/references for the original poster, including input from some experts, rather that just vaguely referring to "the papers I've read" without being specific. The thread linked above and others in ASR (https://www.audiosciencereview.com/...f-speakers-with-major-audio-luminaries.62951/ and maybe https://www.audiosciencereview.com/...music-has-stereo-bass-with-easyeffects.61716/) do indude some currently available relevant recordings.

Not the least, and that's a personal thing, I'm decidedly *not* after "envelopment"--whatever that means, when listening at home alone. Again alone, because from its very basic idea so much can be said: it will be as with stereo, if you can't share the very same seat, you won't share the experience.

I mentioned possible individual sensitivity, but certainly preference is all.

I perfectly understand the urge to make it sound great which is understood as big, think concerthall,, fat romantic "classics". LOL, the classics ... because of its naturalness etc pp, the perfect test for the stereo. And stereo is to be tested.

There are pop recordings with less correlated bass content, as well.

O/k, practically, take two subs, enjoy.

My personal opinion is that one could most likely achieve this without "ever more complicated, and costly tech" simply by listening in a larger room with more effective bass absorption, at relatively closer proximity to transducers, listening position further from boundaries, and with two bass sources positioned closer to 90 degrees azimuth from median plane driven by non-mono signal. For musical content with correlated bass, one should get the benefits of mode cancellation, while musical content with relatively uncorrelated bass might provide possible perceptual benefit.

I'll bow out now.

 

[levimax]

My personal opinion is that one could most likely achieve this without "ever more complicated, and costly tech" simply by listening in a larger room with more effective bass absorption, at relatively closer proximity to transducers, listening position further from boundaries, and with two bass sources positioned closer to 90 degrees azimuth from median plane driven by non-mono signal

Agree but nothing is more costly than a large properly treated room unfortunately.

 

[Oddball]

What I gather from this thread is bunch of people arguing about different rooms and different setups. How much it will take to take out directivity out of your setup does not have a lowest common denominator, or might have by chance as similar setup and room. Or at the end it might be just you dreaming up things ad there is no REW button saying "directivity"?

And as the lowest common denominator, there is no such thing. Higher common denominators point to more subs, so yeah my best guess is that with 8 subs you will be fine. Not sure if anyone with 8 subs is experiencing any issues. I am not complaining with 4 either. Then there is room correction that builds into this whole thing, but not many have mentioned it...

 

[Curvature]

It took a very long time to align astronomical observations to a coherent theory.

The act of controlled observation has its own value.

This is off-topic but I couldn't resist.

If anyone ever cares read the "father of acoustics", Ernst Chladni, his 1802 book is more or less theoryless and restricted to observation. He's the same person that carefully recorded modal patterns on plates, but had no explanation for what he saw.

It was only much later that the mathematical basis for the phenomenon was established.

This is more true for psychoacoustics. A lot is still unknown because the mechanics of hearing are not completely understood.

 

[Torin Krell]

What speakers You have? Are they calibrated by GLM?

I have a pair of Genelec 8341a "The Ones" which are co-axial monitors (nearly triaxial acoustically - so close to a point source). Although I was considering using GLM, I found after meticulous optimization of listening position, monitor / sub placement and acoustical room treatment (in my well proportioned music room) that GLM seems unnecessary - at least for now (although I do have the GLM kit). These optimization efforts, rather than simply using GLM, apparently provide a larger sweet spot, which is especially noticeable in how my system is able to minimize the difference between nearfield and midfield sound balance.

 

[Sokel]

Part of the different views here is probably use cases and bass definition to each of us.
To me bass is snappy and attacks (with extension low though) to someone else may be rubble.

If that rubble overtakes everything and the use case is HT and many seats stereo bass may not be for you.
Same if limitations dictate subs far from mains or one prioritizes the visuals of a straight line at REW.

I also feel that some people want to conform with the "flock", it's nice to belong to a group that seems to have things figured out.
This topic is not for them, it's far too controversial and personal I suspect.

Localizing bass is trivial, all it takes is the right setup and test signals. Some folks above linked some of those, sines won't cut it in this case.
There has been tests at some of the threads linked which ruled out all the usuals suspects as distortion, cues from noises, etc.

Lund says that a safe bet with one sub is x-overed at 40's. Sounds extreme but who am I to disagree? Never tried a single one other than a horrible carpeted (!) one that came as a gift with an SUV I got and it's only use was to see how far from my house (detached) it could be heard while banging loudly.

One must do it's own tests, and if his setup/ears/etc are pleased it's all fine.
If the above are "sensitive" or listens to material with uncorrelated bass like classical it may worth to explore stereo bass too (or just nicely setup some big speakers without subs, it's as simple as that sometimes. ( Lund says that it's their strong point)

So, that's not a collective task to, no box can be ticked and no "flock" comfort can be achieved. And I consider that a good thing.

 

[krabapple]

Not the least, and that's a personal thing, I'm decidedly *not* after "envelopment"--whatever that means, when listening at home alone. Again alone, because from its very basic idea so much can be said: it will be as with stereo, if you can't share the very same seat, you won't share the experience.

Envelopment means the sense that you are in a larger space than your room, due to percepts from the side and rear of your listening seat.

It might do for you to do an ASR search the word 'envelopment' with the user limited to 'Floyd Toole' , he's had a lot to say about the topic.

(And as I understand it, a frontal 'broadening' effect is not envelopment, it's Apparent Source Width (ASW))

 

[Snickers-is]

How do these words apply to bass below 80Hz?

 

[Curvature]

Lund says that a safe bet with one sub is x-overed at 40's. Sounds extreme but who am I to disagree?

https://www.audiosciencereview.com/...iew-studio-monitor.23432/page-57#post-2183534 Yes, 40Hz. I wrote 60 above. This recommendation is about giving auditory envelopment a chance to occur. I would imagine that VLF envelopment at home is not practical in many situations, and even bass should probably take priority for most people.

Lund had posted a listening test at some point. I was able to distinguish his shaped noise samples down to 72Hz in headphones.

How do these words apply to bass below 80Hz?

Localization is not limited to detecting precise direction. This ability is part of a broad group called "spatial hearing", which includes envelopment, the sense of sound being around and outside you. We may not be able to locate VLF in the same way we do higher frequencies, but we can tell if the sound is originating outside of our bodies or inside our heads. Under the right conditions, of course.

 

[Snickers-is]

Localization is not limited to detecting precise direction. This ability is part of a broad group called "spatial hearing", which includes envelopment, the sense of sound being around and outside you. We may not be able to locate VLF in the same way we do higher frequencies, but we can tell if the sound is originating outside of our bodies or inside our heads. Under the right conditions, of course.

Typically, very little sound originates inside my head.

But to me this sounds like a real mix-up of terminology. I explained it a bit more in detail here:

Locating bass <80Hz?

It appears you are arguing that observations can not be taken seriously without a theoretical basis to explain them which seems a little backwards to me. I'm at a loss for words even. How am I supposed to apply (what does that mean!?) my observation from context 'A' to a situation 'B' if...

www.audiosciencereview.com

But to simplify it, there are lots of terms that are no longer valid when we discuss only a small part of the frequency band. The adoption of transient integrity for audio applications is only valid if you include a significant chunk of the audio band. You will need that to even start discussing subjective audio perception.

Once we get some kind of panning or inside/outside head effect, we have to look into room acoustics. Bass only in anechoic conditions just fill the room like air. These ideas are simply not supported by physics, and it is so easy to hear in anechoic conditions.

 

[Curvature]

IID is very reliable at all frequencies, but it is not a very sensitive function of the ear.

Intensity difference between ears Is not reliable below 700-800Hz. Phase difference is what counts.

There are numerous studies that claim that IPD is reliable down to as low as 1 degree. However, the way the studies I have read are set up, they do not fully rule out other factors. The contribution of higher frequency distortion, the start of tones etc all point towards that these results are not as reliable as the claims might suggest. One obvious problem with tests like this is that while we do hear something going on when we change the phase, we do not reliably determine the direction of the angular difference between the two signals, especially for pure sine waves.

1 degree? This is relevant only at high frequencies above 2kHz, and there the main cue is intensity and envelope detection (i.e., the leading edge of the wave) differences. And the 1 degree refers to angular horizontal resolution, not phase difference detection.

You mentioned in various places, tactile sensations. SPL has to be at least 90dB or higher according to threshold studies.

Edit: Typo.

 

[kyuu]

But to simplify it, there are lots of terms that are no longer valid when we discuss only a small part of the frequency band. The adoption of transient integrity for audio applications is only valid if you include a significant chunk of the audio band. You will need that to even start discussing subjective audio perception.

Once we get some kind of panning or inside/outside head effect, we have to look into room acoustics. Bass only in anechoic conditions just fill the room like air. These ideas are simply not supported by physics, and it is so easy to hear in anechoic conditions.

Maybe it's just me but I have no idea how any of this is a response to anything that's being discussed here. What terminology are you even objecting to? No one has said anything about "transient integrity" except for you, as far as I'm aware. Nevermind anything about panning. While I'm personally skeptical about the practicality and applicability of the whole "audio envelopment" thing as professed by Lund in any real domestic space, it has nothing to do with panning or "transient integrity".

 

[Curvature]

Typically, very little sound originates inside my head.

You are mixing physics and psychoacoustics. The question is not where sound physically originates, but the location of the apparent source, the phantom images.

Put on headphones and listen to anything in mono vs. stereo vs. binaural. The difference in sound will be inside the head, vs. between the ears or perhaps slightly outside vs. way outside with competent recordings (although the involved HRTF has to be similar enough to yours).

 

[Heinrich]

Envelopment means the sense that you are in a larger space than your room, due to percepts from the side and rear of your listening seat.

It might do for you to do an ASR search the word 'envelopment' with the user limited to 'Floyd Toole' , he's had a lot to say about the topic.

(And as I understand it, a frontal 'broadening' effect is not envelopment, it's Apparent Source Width (ASW))

Thanks for teaching me my terminology. The author mentioned also says, that the feel of a bigger room is more easy to achieve in a small room than vice versa.
My remark was about my personal preference, if that word can still be used in public, which preference leans towards a direct, dry sound w/o the stereo panorama that many look for. I'm decidedly not after replicating 'classic' orchestral work. My stereo validates its merits when listening to more contemporary stuff not excluding 'serious' music, if you will.

 

[Snickers-is]

Maybe it's just me but I have no idea how any of this is a response to anything that's being discussed here. What terminology are you even objecting to? No one has said anything about "transient integrity" except for you, as far as I'm aware. Nevermind anything about panning. While I'm personally skeptical about the practicality and applicability of the whole "audio envelopment" thing as professed by Lund in any real domestic space, it has nothing to do with panning or "transient integrity".

Maybe I expressed it a bit unclear... Did you read the post I quoted?

Transient integrity refers to how intact a transient is compared to its original version. This is a very important part of spatial cues. It includes phase, frequeny response, distortion, reflections etc. But the crucial point is that you can not say anything meaningful about transient integrity in a subwoofer alone, and you can not say anything meaningful about spatial hearing or envelopment without having reasonable transient integrity. Therefore, those two terms (spatial hearing and envelopment) will not apply to subwoofers.

They could apply to subwoofers when used as a part of an entire system, but then we have this sentence:

We may not be able to locate VLF in the same way we do higher frequencies

If we can not locate the sound source, it will not add to the spatial abilities of the full system.

Lastly we have this:

we can tell if the sound is originating outside of our bodies or inside our heads. Under the right conditions, of course

Sound from a subwoofer obviously originates from the subwoofer, but if it feels like it originates inside the head, then we have a significant phase issue. This issue is not due to the subwoofer itself, but due to modes in the listening room. So even if the subwoofer sounds like it originates from somewhere, it does not mean we can hear where the direct sound comes from.

Did this help?

 

[Curvature]

even if the subwoofer sounds like it originates from somewhere, it does not mean we can hear where the direct sound comes from.

This is exactly the point. Direction may not be detectable, but spatial hearing is still active.

If we can not locate the sound source, it will not add to the spatial abilities of the full system.

Again, there is more to spatial hearing than localization.

This is the text on the matter, and Griesinger cites Blauert often: https://direct.mit.edu/books/oa-monograph/4885/Spatial-HearingThe-Psychophysics-of-Human-Sound

 

[krabapple]

Thanks for teaching me my terminology. The author mentioned also says, that the feel of a bigger room is more easy to achieve in a small room than vice versa.
My remark was about my personal preference, if that word can still be used in public, which preference leans towards a direct, dry sound w/o the stereo panorama that many look for. I'm decidedly not after replicating 'classic' orchestral work. My stereo validates its merits when listening to more contemporary stuff not excluding 'serious' music, if you will.

And again, I can refer you to the summary work of Dr. Toole, where he notes research indicating that there are two basic types of listeners in this regard , ones who enjoy the spacious sound, and those -- typically in music production -- who prefer a dryer, more detailed presentation.

Your sarcasm about 'preference' is quite misfired. No one is discounting its reality.

 

[Curvature]

And again, I can refer you to the summary work of Dr. Toole, who has noted research indicating that there are two basic types of listeners in this regard , ones who enjoy the spacious sound, and those -- typically in music prodution -- who prefer a dryer, more detailed presentation.

Your sarcasm about 'preference' is quite misfired. No one is discounting its reality.

I'd just like to repeat a phrase I've used a few times elsewhere: there is a difference between liking something and expressing a preference under blind circumstances.

 

[Snickers-is]

Intensity difference between ears Is not reliable below 700-800Hz. Phase difference is what counts.

We do have the ability to hear IID at low frequencies easily, but we need the difference to be significant. Headphones can do this. We have the same issue with phase differences. It does not give us any real angular resolution, especially not at low frequencies, but we can also easily determine phase differences with headphones. We can do both in cases where there are significant local nulls and peaks in a room, but it is not the same as directional sound.

1 degree? This is relevant only at high frequencies above 2kHz, and there the main cue is intensity and envelope detection (i.e., the leading edge of the wave) differences. And the 1 degree refers to angular horizontal resolution, not phase difference detection.

I don't think that 1 degree claim is correct in any case. However, since it had no real application for this topic, I did not bother picking it apart. In order to have 1 degree of angular resolution you will need transients. This means ITD comes into play. We do not need anywhere near the full envelope. The initial transient is typically sufficient.

 

[Snickers-is]

This is exactly the point. Direction may not be detectable, but spatial hearing is still active.

Sure, but isn't that the same as mixing instrument overtones with harmonic distortion? It is kind of not the same thing. And if we have some kind of spatial experience from the subwoofer, that means the room acoustics is so bad we will have some serious frequency response and phase distortion going on as well. I would rather prefer if the subwoofer does not have these issues.

Again, there is more to spatial hearing than localization.

Sure, we need phase and reflections too, but this is still a part of the three ways our ears can localize sound. But is it really relevant if we are just dealing with issues that create some kind of spatial addition that was not originally in the recording?