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Need Room Treatment Advice. Willing to pay! - Page 2

post #31 of 97
1/14/13 at 6:03pm
Quote:
Originally Posted by fbov View Post

"The result was that early reflections (<50 ms) had the same desirable effect on speech intelligibility as increasing the level of the direct sound. The authors go on to point out that late reflections (including reverberation) are undesirable, but controlling them should not be the first priority,"

don't fall into the same trap that many other people on this forum do regarding speech intelligibility in speech rooms and relevant studies. they are usually related to UNAMPLIFIED sources and SNR issues where-by the additional perceived gain by the "fusing" within the haas interval of the direct and indirect signals yields better intelligibility.

in our amplified home reproduction rooms, direct signal gain is NOT a factor as we have something at our disposal commonly referred to as the volume knob. or, do you by chance live near a train station? if so, focusing on sound isolation will likely be highest priority for a reproduction space with poor SNR.

there is much more to "speech intelligibility" than simply gain. we've been over this in countless threads.

Quote:
Originally Posted by fbov View Post

Thus, the rational for including sidewall reflections is based on multiple studies by a number of investigators in various countries over several decades, or what one might call "scientific consensus."

yet the studio world has disagreed for many decades - as evident by the primary acoustical control room models (including BBC). you know, the people who have to "work" in such rooms.

care to describe the "poor" speech intelligibility in any Non-Environment, FTB, LEDE/RFZ, or Ambechoic control room?
Edited by localhost127 - 1/14/13 at 7:06pm
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post #32 of 97
1/14/13 at 6:26pm
Quote:
Originally Posted by Nyal Mellor View Post

Your ear sums the direct sound and reflections for all reflections arriving before 40ms.

this statement is horrendously vague...
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post #33 of 97
1/15/13 at 9:41am
Quote:
Originally Posted by localhost127 View Post

Quote:
Originally Posted by fbov View Post

So... what do you mean by "better" imaging? What makes it "better?" Please be specific.

HAve fun,
Frank

http://www.audiocheck.net/audiotests_ledr.php

Local - neat test tones, I'll have to try those out in the HT, thx for posting.
Quote:
LEDR™ - Listening Environment Diagnostic Recording TestThe trademarked LEDR test signal is the brainchild of acoustician Doug Jones. We'd like to thank Prof. Jones for granting us the permission to put this test online.Background
LEDR™ stands for Listening Environment Diagnostic Recording, a test to subjectively evaluate the accuracy of stereo image reproduction.
In the eighties, psychoacousticians began researching what are called pinna transforms, the way in which the shape of the outer ear filters the incoming sounds and permits our brain to infer their location. By embedding the filtering characteristics of the pinna into the audio signal, sound can be moved around the listener's head from a single pair of loudspeakers.

The LEDR test generates pinna-filtered audio that will literally float around your speakers, assuming your sound reproduction system is neutral enough to preserve the original signal characteristics.

The test files
You will now be testing your stereo system and room acoustics for correct imaging. If you have any problem reproducing the LEDR test, look for interfering room surfaces in the direction of the distortion.

↓ ↓ ↓ ↓ ↓
UP Left UP Right OVER LATERAL BEHIND
UP paths, Left and Right. The sound should begin at about eye level and then travel as straight as possible up to one or two meters above the loudspeaker. Use the Left and Right paths to check for symmetry. If the sound does not rise up from your loudspeakers, try using high quality headphones instead. If headphones work, your loudspeakers and/or listening environment are at fault. If not, the pinna transform embedded into the test signal is possibly too different from your own pinna transfer function; the LEDR test will then fail in this particular case.
OVER. The sound should begin at one speaker and travel in a smooth arc to the other speaker, from left to right and then return back to the left. The arc should be unbroken, smooth and symmetrical. The top of the rainbow should be as high as the Up signals.

LATERAL. This signal tests for conventional left-to-right stereo imaging. Since a speaker's acoustic center may not be its physical center, you should use the Lateral test to adjust your speakers until the sound traverses a 60 degrees angle from the listener's point of view.

BEHIND. This signal moves from behind the left to behind the right, then back behind the left again.
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post #34 of 97
1/15/13 at 11:25am
Quote:
Originally Posted by localhost127 View Post

yet the studio world has disagreed for many decades - as evident by the primary acoustical control room models (including BBC). you know, the people who have to "work" in such rooms.

Indeed. Further, the argument that absorbing reflections is good for pro engineers who mix audio, but bad for music lovers listening for enjoyment, is silly IMO. A pro wants to hear the music clearly and accurately, without a colored response and vague imaging that changes as you move your head slightly. This should be the goal for audiophiles too. I'll risk angering some people and say that professional mix engineers know better what sounds good than many audiophiles. This is not to discount preference, which trumps everything else. But listening skills can be improved with experience, and tastes can be refined over time.

I also call BS on the notion that speakers with a good off-axis response benefit from bare walls, versus speakers that are colored off-axis. This is backwards. A speaker that is flat off-axis creates the strongest comb filtering over the widest range of frequencies. A speaker that is colored creates less acoustic interference because the peaks and nulls caused by reflections are shallower and extend over a limited range of frequencies.

--Ethan
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post #35 of 97
1/15/13 at 12:01pm
Quote:
Originally Posted by localhost127 View Post

...yet the studio world has disagreed for many decades - as evident by the primary acoustical control room models (including BBC). you know, the people who have to "work" in such rooms....
EXACTLY THE POINT.

Recording studios are workspaces, not entertainment venues. Requirements are different in workspaces than in entertainment venues, and this is no exception. You can build yourself a workspace, but I think it's misleading to suggest to others like the OP that their entertainment spaces should be built like a workspace, when they truly want to be entertained. Note that there's no difference in preference between audio professionals and the public when listening for enjoyment.

Jim, good point about path length difference. My room's big enough, and 10ms is far longer than necessary; IACC's dropped enough to affect preference by 5msec.

Remember the Precedence effect; we don't hear the early reflection as anything more than a modification of the original sound. Granted, the exact nature of that modification changes with delay and intensity, but the first reflection is typically the loudest (if present) so additional reflections (Nyal's "speaker in a room") should have minor effect on your perception. The lab data applies.

And Nyal, part of Toole's "whole point" as you say, is that room treatment must be broadband; it you treat, treat properly. You can't just mount an OC 703 panel at the first reflection point and think you've necessarily done something good. Even 2" panels are 17% effective at 125Hz and 87% at 250Hz, right in the 100-175Hz range that the BBC has found is the most sensitive to timbral defects in male voices (Everest, Fig. 13.9).

Even more telling... look at Toole's room acoustics optimization toward the end of his book - no first reflection treatment is present. There are panels up front on sidewalls, but above tweeter/ear level.

Again, everything has its place...

HAve fun,
Frank

PS +1 on the test tones; need to try them when I get home.
Edited by fbov - 1/15/13 at 12:10pm
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post #36 of 97
1/15/13 at 1:04pm
Quote:
Originally Posted by fbov View Post

EXACTLY THE POINT.

no, the point is YOU do not dictate whether a user has design requirements for a critically accurate reproduction space (re: imaging, localization, intelligibility) or a pleasurable listening space based on their own personal preferences.

toole even states this in his paper regarding the attenuation of sidewall reflections regarding imaging as coming down to "a matter of preference".
Quote:
Originally Posted by fbov View Post

Recording studios are workspaces, not entertainment venues.

oh i wasn't aware they are mutually exclusive. so, one cannot enjoy reproduction in a control room? get real. ask anyone who has worked or interned at blackbird C whether they jumped at the chance to listen to some of their favorite tunes in said space - and whether they would opt for such a "workspace" for their own personal entertainment venue, if given the chance. rolleyes.gif

gee, and why on earth do they put "couches" in those multi-million dollar control rooms. rolleyes.gif

it's really a shame that people attempt to learn what happens in the studio world solely from toole's commentary. totally misguided - why not try going directly to the source.
i even had another user on this forum attempt to tell me what LEDE is by directly quoting toole's statements on the matter - which was completely oblivious to reality!

Quote:
Originally Posted by fbov View Post

Requirements are different in workspaces than in entertainment venues, and this is no exception.

more logic fallacy. you're implying that no one should want to strive for design requirements re: an accurate representation of the direct signal without the small acoustical space masking/skewing localization and imaging in their home "entertainment venue". i guess jim's commentary, personal preferences, and experience detailed by him in his own reproduction space by emulating the LEDE total specular response is just an outlier/hogwash. rolleyes.gif

Quote:
Originally Posted by fbov View Post

You can build yourself a workspace, but I think it's misleading to suggest to others like the OP that their entertainment spaces should be built like a workspace, when they truly want to be entertained. Note that there's no difference in preference between audio professionals and the public when listening for enjoyment.

"that their entertainment spaces should be built like a workspace"? and pray-tell what exactly have i stated that implies such a statement from you. emulating a specular response does not imply the room needs to be built like a workspace. do you use the same logic to the home theater guys who spend tens of thousands of dollars on sound isolation - just like the studio workspaces? rolleyes.gifrolleyes.gif

"no difference in preference", ya? and your sample size is what, exactly - you mean to imply you're taking toole's polls and surveys and attempting to apply globally? just who are these audio professionals? did toole survey all of them? get real.

"no difference", he says - lol.

quite a strange revelation on what is happening in the dedicated home-theater sub-forum here on AVS. maybe we should inform dennis e. that his designs are fundamentally wrong via treating the first-order sidewalls.

Quote:
Originally Posted by fbov View Post

Remember the Precedence effect; we don't hear the early reflection as anything more than a modification of the original sound. Granted, the exact nature of that modification changes with delay and intensity, but the first reflection is typically the loudest (if present) so additional reflections (Nyal's "speaker in a room") should have minor effect on your perception. The lab data applies.

shame you seem to be unfamiliar with what the late/great dick heyser had to say on the subject.

Quote:
Originally Posted by fbov View Post

And Nyal, part of Toole's "whole point" as you say, is that room treatment must be broadband; it you treat, treat properly. You can't just mount an OC 703 panel at the first reflection point and think you've necessarily done something good. Even 2" panels are 17% effective at 125Hz and 87% at 250Hz, right in the 100-175Hz range that the BBC has found is the most sensitive to timbral defects in male voices (Everest, Fig. 13.9).

Toole's "whole point", ya? - sorry, but the understanding of the use of BROADBAND treatments in such an application have been well known, understood, and recommended well before toole's paper. this information is not new and has been recommended on this forum by myself for as long as i've been here - and for decades in the studio world.

we know from Delaney Bazely / Miki models (and subsequent modifications, as they satisfy all of the various mods to it) - that 4" absorber w/ 4" air-gap (of the commonly sourced and often recommended rigid fiberglass 3pcf or 4pcf mineral wool) will be sufficient to fully attenuate a broadband indirect signal to the lower Schroeder cut-off region of which is 250-300hz in typical volume home residential spaces. no one here debates the requirement for BROADBAND treatments. and ideally we can utilize geometry to redirect the indirect specular reflection away from the listening position - which attenuates the signal without removing energy from the room! many ways to skin a cat. and never mind the fact some of us here recommend actual time-domain measurements of the space before blindly placing an absorber - for the sole reason to SURGICALLY limit the amount of broadband absorption within the room only where it is needed to achieve the design requirements.

why aren't the primitive root reflection phase gratings in the harman listening rooms truly broadband? i never understood this. of all of the talk about broadband treatments in toole's paper, the harman listening rooms deploy non-broadband diffusers.


and by the way, your "percentage claims" are ridiculously vague and do not take into account the complex nature of what is happening and the myriad of variables regarding porous absorbers and their effectiveness on attenuation of an indirect specular signal. i would be cautious of making such statements without relevant context.





oh, and im still waiting to hear about the apparent "poor intelligibility" in any properly designed LEDE/RFZ, FTB, NE, or Ambechoic room - as they ALL have attenuated first-order lateral sidewall reflections...

does anyone have any more unamplified speech room's w/ poor SNR case studies to present?
Edited by localhost127 - 1/15/13 at 1:11pm
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post #37 of 97
1/15/13 at 1:43pm
Quote:
Originally Posted by Ethan Winer View Post

Indeed. Further, the argument that absorbing reflections is good for pro engineers who mix audio, but bad for music lovers listening for enjoyment, is silly IMO

i don't disagree that user preferences can be partial to "smearing" with respect to certain types of music - but those that put forth unamplified/poor SNR speech room studies as "proof" that that high-gain, sparse, early arriving, indirect specular reflections are beneficial to intelligibility in our home reproduction spaces where we have direct control over the gain of the direct signal are comical. talk about missing the entire context of the study!
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post #38 of 97
1/15/13 at 2:19pm
Quote:
Originally Posted by localhost127 View Post

this statement is horrendously vague...

I was simplifying for the purposes of the paragraph.
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post #39 of 97
1/15/13 at 2:25pm
Quote:
Originally Posted by localhost127 View Post



we know from Delaney Bazely / Miki models (and subsequent modifications, as they satisfy all of the various mods to it) - that 4" absorber w/ 4" air-gap (of the commonly sourced and often recommended rigid fiberglass 3pcf or 4pcf mineral wool) will be sufficient to fully attenuate a broadband indirect signal to the lower Schroeder cut-off region of which is 250-300hz in typical volume home residential spaces. no one here debates the requirement for BROADBAND treatments. and ideally we can utilize geometry to redirect the indirect specular reflection away from the listening position - which attenuates the signal without removing energy from the room! many ways to skin a cat. and never mind the fact some of us here recommend actual time-domain measurements of the space before blindly placing an absorber - for the sole reason to SURGICALLY limit the amount of broadband absorption within the room only where it is needed to achieve the design requirements.

While 4" OC703 + a 4" gap maybe sufficient, I find for 4" more real estate 12" pink fluffy to work more broadly.


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post #40 of 97
1/15/13 at 2:29pm
Quote:
Originally Posted by Nyal Mellor View Post

I was simplifying for the purposes of the paragraph.

I would like to hear the unsimplified version for the subject of time-merging is interesting to me and I dont know what the facts are.

For instance ive heard everything from 10ms to 50ms as being the threshold for integration. Additionally, ive havent heard a concise description of what elements are being integrated.
A) are we talking about tonal / timbre integration?
B) are we talking about image integration ?
C) are we talking about directional integration?
D) are we talking about the general magnitude of reflections over a time period?
E) and lastly what integration period? Or is it a stepped kind of thing whereby <10ms are treated one way, 10-20ms another, and so on.
Edited by jim19611961 - 1/15/13 at 2:38pm
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post #41 of 97
1/15/13 at 2:40pm
Quote:
Originally Posted by jim19611961 View Post

While 4" OC703 + a 4" gap maybe sufficient, I find for 4" more real estate 12" pink fluffy to work more broadly.



sure, granted that to at the lower frequencies you need to make sure the panel is sufficiently large with respect to wavelength -

what i stated is certainly suitable to the lower schroeder cut-off in typical residential sized rooms.
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post #42 of 97
1/15/13 at 2:46pm
Quote:
Originally Posted by Ethan Winer View Post

I also call BS on the notion that speakers with a good off-axis response benefit from bare walls, versus speakers that are colored off-axis. This is backwards. A speaker that is flat off-axis creates the strongest comb filtering over the widest range of frequencies. A speaker that is colored creates less acoustic interference because the peaks and nulls caused by reflections are shallower and extend over a limited range of frequencies.

--Ethan

I wouldn't use the word "benefit", more that if you have speakers with good off axis then you have a choice in my view about how to treat the sidewalls. Not one that you get with a speaker with poor off axis performance

Also don't confuse good off axis performance with flat off axis performance. Speakers with smoothly increasing directivity without any bumps due to typical poorly matched mid to tweeter interfacing generally fit into the good off axis performance category, as to constant directivity types or those with wide baffles. The best of these can exhibit an off axis response at 60 degrees that is maybe 5dB+ down from the direct sound even at 300Hz and much more above that. Even if you left the side wall untreated for this off axis reflection you would see virtually no comb filtering, due to the a) laws of logarithmic addition and b) fall off of SPL with the reflected sound due to the longer path length.

Whilst I don't disagree that comb filtering is a measurable effect I just don't think it is important perceptually. The frequencies where you begin to see it more strongly end up in the modal region anyway where comb filtering is the least of your worries.
Edited by Nyal Mellor - 1/15/13 at 3:02pm
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post #43 of 97
1/15/13 at 2:50pm
Quote:
Originally Posted by jim19611961 View Post

I would like to hear the unsimplified version for the subject of time-merging is interesting to me and I dont know what the facts are.

For instance ive heard everything from 10ms to 50ms as being the threshold for integration. Additionally, ive havent heard a concise description of what elements are being integrated.
A) are we talking about tonal / timbre integration?
B) are we talking about image integration ?
C) are we talking about directional integration?
D) are we talking about the general magnitude of reflections over a time period?
E) and lastly what integration period? Or is it a stepped kind of thing whereby <10ms are treated one way, 10-20ms another, and so on.

This is as much as I have time for today: http://www.hifizine.com/2011/12/listening-room-reflections-and-the-energy-time-curve/

Other than that please read Toole and Jens Blauert as a start
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post #44 of 97
1/15/13 at 2:59pm
Quote:
Originally Posted by localhost127 View Post

why aren't the primitive root reflection phase gratings in the harman listening rooms truly broadband? i never understood this. of all of the talk about broadband treatments in toole's paper, the harman listening rooms deploy non-broadband diffusers.

Hi Local, I wondered similarly on use of diffusers at reflection points for quite a while until I listened to this podcast http://www.hometheater.com/content/podcast-90-kevin-voecks from Kevin Voecks, the main Revel dude. I couldn't tell you exactly where in the podcast it is but there is an interesting bit where Kevin says something like 'one of the things Toole and I disagree on is what to do with the first reflections' and I think (don't quote me on this, it's been a while since I listened to it) that he personally prefers absorption at first reflection points. Seems there is disagreement in the ranks even at Harman! So I guess someone there prefers diffusers at that point. Not sure why they are not broadband. Room geometry and well shading? Who knows.

BTW, whether or not you think it is important, the Revels typically have good off axis performance, in this example at least until the waveguide used for the tweeter limits dispersion >10k.

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post #45 of 97
1/15/13 at 2:59pm
Quote:
Originally Posted by Nyal Mellor View Post

Whilst I don't disagree that comb filtering is a measurable effect I just don't think it is important perceptually.

The reason comb filtering due to side-wall (and ceiling) reflections is damaging goes behind the skewed frequency response. Another problem is that the skewed response changes constantly as you move your head even a little. And when the response changes with head movement, so does imaging. So instruments panned front and center are not stable, nor are other sounds panned anywhere else.

Again, in the end this is a matter of preference. But I've sold reflection absorbers to many thousands of customers with a full money-back guarantee, and I can count the number of returns due to "I didn't like the change" on one hand. The vast majority of people who try absorption find it a huge improvement and would never go back to bare walls. So the notion that bare walls are better is very much the minority opinion. Just sayin'. biggrin.gif

--Ethan
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post #46 of 97
1/15/13 at 3:12pm
Quote:
Originally Posted by Ethan Winer View Post

Again, in the end this is a matter of preference. But I've sold reflection absorbers to many thousands of customers with a full money-back guarantee, and I can count the number of returns due to "I didn't like the change" on one hand. The vast majority of people who try absorption find it a huge improvement and would never go back to bare walls. So the notion that bare walls are better is very much the minority opinion. Just sayin'. biggrin.gif

--Ethan

Sure, makes sense to me. How I rationalize it though is that most people have speakers with crappy off axis performance or they have a preference for more focused imaging over envelopment.
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post #47 of 97
1/15/13 at 3:24pm
Quote:
Originally Posted by Nyal Mellor View Post

Sure, makes sense to me. How I rationalize it though is that most people have speakers with crappy off axis performance or they have a preference for more focused imaging over envelopment.

Focused imaging and envelopment are not mutually exclusive.
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post #48 of 97
1/15/13 at 3:28pm
Quote:
Originally Posted by jim19611961 View Post

Focused imaging and envelopment are not mutually exclusive.

Agree, never said they were, but you can definitely optimize your setup towards one or the other through speaker placement (width, toe) and lateral reflection point treatment (absorptive, reflective, phase gratings, etc)
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post #49 of 97
1/15/13 at 3:47pm
Quote:
Originally Posted by Nyal Mellor View Post

Agree, never said they were, but you can definitely optimize your setup towards one or the other through speaker placement (width, toe) and lateral reflection point treatment (absorptive, reflective, phase gratings, etc)

In my experience, pinpoint detail in images is rather easy if you simply take care in the basic setup and treat 1st reflection points. Envelopment on the other hand I find very tricky and difficult to accomplish properly in smaller rooms (no piece of cake in larger ones either).
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post #50 of 97
1/15/13 at 3:57pm
Quote:
Originally Posted by Ethan Winer View Post

A speaker that is flat off-axis creates the strongest comb filtering over the widest range of frequencies. A speaker that is colored creates less acoustic interference because the peaks and nulls caused by reflections are shallower and extend over a limited range of frequencies.
So if I have two sources of sound, the more similar they are the worse the comb filtering? If that's an audible problem, how has 2-speaker playback survived all these decades, considering how much content is mixed and heard as dual mono? Why don't listeners complain about severe combing?
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post #51 of 97
1/15/13 at 4:07pm
Great discussion.

Pin-point imaging, strongly immersive envelopment (and all adjectives in-between), yes, not mutually exclusive.

In a system/room executed properly, these metrics are function of the recorded event.



IIRC, I seem to remembr those LEDR tests back in the 80's, maybe on a test disc, Chesky perhaps.
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post #52 of 97
1/15/13 at 5:31pm
Quote:
Originally Posted by FOH View Post

IIRC, I seem to remembr those LEDR tests back in the 80's, maybe on a test disc, Chesky perhaps.

Doug Jones LEDR tape: "quarter-inch, 15-ips open-reel analog or sony beta F1 digital" - tongue.gif

..and used heavily throughout LEDE development and SAC workshops



- 1987
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post #53 of 97
1/15/13 at 6:25pm
Quote:
Originally Posted by Nyal Mellor View Post

http://www.hifizine.com/2011/12/listening-room-reflections-and-the-energy-time-curve/


Quote:
Originally Posted by article 
When we listen to music on our stereo system in rooms that are the size of those found in most typical homes we are more often than not listening at a distance where the sound pressure level of the reflected sounds is greater than that of the direct sound from the loudspeakers.

what residential rooms (small acoustical spaces) are you encountering where "more often than not" the listening position is past the critical-distance (Dc) of which the reverberant sound-field is greater in gain than the direct signal?

i can't even provide an example of one residential room where the listening position is past Dc - unless there is some strange architectural concave monstrosity present...

Quote:
Originally Posted by article 
The body of evidence is sufficient for the perceptual effect to be given a name – it is called the Haas effect, precedence effect or ‘law of the first wavefront’.

i wouldn't consider the haas effect and precedence effect as interchangeable entities representing the same behavior. haas was doing special case-studies of the Henry's precedence effect...

Quote:
Originally Posted by article 
In the absence of properly smoothed waterfall type measurements we must therefore rely upon the flawed ETC as a way of measuring our rooms and determining the changes we should make.

"flawed ETC"? this is utterly laughable and completely disrespectful language. the type of perspective the ETC provides is responsible for the quantum leap in acoustics many decades ago.
surely you will also refer to the frequency response as "flawed", since it does not provide any time-domain perspective? and maybe my laundry machine is flawed because it does not wash the dishes as well. tongue.gif
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post #54 of 97
1/16/13 at 9:15am
Quote:
Originally Posted by localhost127 View Post


what residential rooms (small acoustical spaces) are you encountering where "more often than not" the listening position is past the critical-distance (Dc) of which the reverberant sound-field is greater in gain than the direct signal?

Hi Local,

Kindly note I did not use the words critical distance or reverberant sound field in that sentence. I am fully aware that they are not relevant.

That sentence could probably have been written better, but if you read on to the next sentence you will see the key piece of information: "measurements published by Toole (chapter 18) show that the frequency response measured at the listening position above around 250Hz is dominated by the spectral characteristics of the sound energy returned to the listener from the major reflection points in the room"...my point in the paragraph being from the sound pressure level perspective reflections have a greater contribution than the direct sound. The intent was that I would now have the attention of a lay person reading this article (they are now thinking 'wow, I didn't know reflections were that important!'), and they would want to read further.

I have seen many times that your form of debate and discussion is what I would refer to as non-constructive 'wordsmithing' which generally involves picking holes in individual sentences taken out of context. You are also borderline aggressive in your writing style. Personally I don't find these attributes conducive to constructive progress and learning. Each to their own of course.

Nyal
Edited by Nyal Mellor - 1/16/13 at 9:22am
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post #55 of 97
1/16/13 at 10:04am
Quote:
Originally Posted by sdurani View Post

So if I have two sources of sound, the more similar they are the worse the comb filtering?

Yes, exactly.
Quote:
If that's an audible problem, how has 2-speaker playback survived all these decades, considering how much content is mixed and heard as dual mono? Why don't listeners complain about severe combing?

When you sit centered in front of two speakers, the same (mono) sound arrives at your head at the same time. Comb filtering requires a delay, which is what happens when sound reflects off a side wall and arrives later than the direct sound.

--Ethan
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post #56 of 97
1/16/13 at 10:18am
Quote:
Originally Posted by localhost127 View Post

no, the point is YOU do not dictate whether a user has design requirements for a critically accurate reproduction space (re: imaging, localization, intelligibility) or a pleasurable listening space based on their own personal preferences. ...
You would do well to listen to your own advice...

As long as you presume to tell the user what their personal preference is, rather than allowing them to make the choice, you will find yourself in a lot of arguements... present both sides or you're dictating design requirements.

Go back to my first post, before anyone but Ethan had chimed in, and you'll see assumptions right next to suggestions, with recommendations to read the experts in their own words, and to take Ethan up on his offer of professional services, since that's what serves the OP.

Because ultimately, the only reason to reply is to serve the OP. Remind yourself of that before you post and you'll make a bigger difference.

HAv efun,
Frank
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post #57 of 97
1/16/13 at 10:20am
Quote:
Originally Posted by Nyal Mellor View Post

You are also borderline aggressive in your writing style

Nyal

unfortunately, i cannot control the tone of voice in your head of which you read my text-based commentary. human psychology is a marvelous thing.


you may not have used the words "critical-distance", but your direct quote (no wordsmithing or out of context quotes here!) is essentially the exact definition of being past Dc: "we are more often than not listening at a distance where the sound pressure level of the reflected sounds is greater than that of the direct sound from the loudspeakers."

spin it as you wish - if you're going to link to your company's texts on a public forum, then by all means it is up for scrutiny.
Edited by localhost127 - 1/16/13 at 10:37am
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post #58 of 97
1/16/13 at 10:31am
Quote:
Originally Posted by FOH View Post

Great discussion.

Pin-point imaging, strongly immersive envelopment (and all adjectives in-between), yes, not mutually exclusive.
...
Then I'm curious what you mean by "pinpoint" and "immersive."

The analogous terms used in Harman's perceptual studies (and I assume by other investigators) are "apparent source width" and "envelopment." Perhaps immersive is a level of envelopment?

Apparent source wight (ASW) is the perception of how much of the sound field is occupied by an instrument. High ASW imaging can only be located by waving a hand as the sound springs from an area far larger than you palm at arms length. Low ASW or "pinpoint" imaging is very narrow, as if it fit on the point of a pin. If you mean something else, them "pinpoint" is a poor descriptor.

I find my MTMs have what etymology allows me to call pinpiont imaging; I can always close my eyes and point to the speaker. My Continuum have marvelously large ASW; close my eyes and I have no idea where the speakers are located. Just like the first time I heard them.

Both types yield a sense of envelopment, and I have to do some more listening as I don't recall that facet catching my attention, compared with the huge difference in ASW. Maybe pinpoint and immersive envelopment aren't contradictory after all...

Have fun,
Frnak
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post #59 of 97
1/16/13 at 11:05am
Quote:
Originally Posted by localhost127 View Post



you may not have used the words "critical-distance", but your direct quote (no wordsmithing or out of context quotes here!) is essentially the exact definition of being past Dc: "we are more often than not listening at a distance where the sound pressure level of the reflected sounds is greater than that of the direct sound from the loudspeakers."

.

The bolded area I assume to mean that many a listening room (novice listener) have the seating position too far away from the speakers and too close to the back wall. This would have the effect of boosting the reflections relative to the direct sound. Many also do not adhere to the equilateral triangle in regards to the speaker to speaker to listening position configuration. Rather than a 60-60-60 triangle you have something like a 75-75-30 one.

Perhaps Nyal will qualify what he meant here.
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post #60 of 97
1/16/13 at 11:22am
Quote:
Originally Posted by fbov View Post

Then I'm curious what you mean by "pinpoint" and "immersive."

The analogous terms used in Harman's perceptual studies (and I assume by other investigators) are "apparent source width" and "envelopment." Perhaps immersive is a level of envelopment?

Apparent source wight (ASW) is the perception of how much of the sound field is occupied by an instrument. High ASW imaging can only be located by waving a hand as the sound springs from an area far larger than you palm at arms length. Low ASW or "pinpoint" imaging is very narrow, as if it fit on the point of a pin. If you mean something else, them "pinpoint" is a poor descriptor.

I find my MTMs have what etymology allows me to call pinpiont imaging; I can always close my eyes and point to the speaker. My Continuum have marvelously large ASW; close my eyes and I have no idea where the speakers are located. Just like the first time I heard them.

Both types yield a sense of envelopment, and I have to do some more listening as I don't recall that facet catching my attention, compared with the huge difference in ASW. Maybe pinpoint and immersive envelopment aren't contradictory after all...

Have fun,
Frnak

I wont answer for FOH, but my take is this.

Pinpoint is a relative term to mean exact or well defined. Close your eyes and point to exactly where the sound is coming from as an illustration. The broadness or size of the image to me is a slightly different issue. It can still have a "pinpoint" location, but a wider image can start to become cloudy or thin if it becomes too wide. Whereas a very distinct but narrow image can be "pinpoint" in location, distinct in detail, but lacking a sense of "air" or "bloom" about it making it less desirable. Again, a slightly different subject than that of location or immersion.

Immersion I closely associate with surround. That is, the feeling of being within the sound field but not separated from it where the sound field seems on the other side of the room only. Certainly a Bose 901 can give you immersion, but at the expense of ANY image detail. My path to having both is achieved through the time domain. That is, an ISD gap (> or = 20ms) to allow the direct sound field to establish the imaging properly followed by a delayed (>20ms) room response.
Edited by jim19611961 - 1/16/13 at 11:30am
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