Understanding Early Reflected Sound - Article from Nyal @ Acoustic Frontiers - AVS Forum | Home Theater Discussions And Reviews
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post #1 of 180 Old 09-07-2015, 04:51 PM - Thread Starter
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Understanding Early Reflected Sound - Article from Nyal @ Acoustic Frontiers

"One of the most common “generic” acoustic treatment recommendations is to treat the reflection points. Unfortunately properly managing early reflected sounds is actually very complex psychoacoustically. Blindly treating reflection points with the wrong kind of products can make your sound worse. For a high performance high-end audio listening room, home recording studio or home theater there are many factors that need to be considered. These include the level, delay, spectral content and direction of reflections. Only then can a truly high performance acoustic treatment plan be designed and implemented."

http://www.acousticfrontiers.com/early-reflections-101/


Thought this might be of interest to the "more hardcore" enthusiasts, it's probably a bit full on for the "noobs". It is the first time I have managed to write down my thoughts on dealing with early reflections, and as you can tell is strongly influenced by the work of Floyd Toole. Hope it improves people's understanding of this topic, which is probably the most challenging in terms of working out how to properly acoustically treat your room.

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post #2 of 180 Old 09-07-2015, 10:02 PM
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thanks for posting.

i have a question on this. you mentioned that the early reflections are at a lower level than the source. this is common sense to me. but i read somewhere that when two sources create a sound, and one is delayed relative to the other(between 5 and 25 ms iirc) the farther sound becomes quieter and has to be raised about 10dbs for both sources to come back into equilibrium.

have you done testing on this? this was done with stereo speakers but im thinking it could also apply to early reflections?
my thinking is if early reflections are already quieter, and then lose another 10 dbs due to how our brains percieve delayed sound, do we really need to worry about the early reflections? or are they too quiet to really make a difference?
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post #3 of 180 Old 09-08-2015, 09:46 AM - Thread Starter
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Originally Posted by 1201 View Post
thanks for posting.

i have a question on this. you mentioned that the early reflections are at a lower level than the source. this is common sense to me. but i read somewhere that when two sources create a sound, and one is delayed relative to the other(between 5 and 25 ms iirc) the farther sound becomes quieter and has to be raised about 10dbs for both sources to come back into equilibrium.

have you done testing on this? this was done with stereo speakers but im thinking it could also apply to early reflections?
my thinking is if early reflections are already quieter, and then lose another 10 dbs due to how our brains percieve delayed sound, do we really need to worry about the early reflections? or are they too quiet to really make a difference?
You would have to forward the study for me to review, I can't say that it is something I have come across.

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post #4 of 180 Old 09-08-2015, 11:23 AM
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Thanks for the heads up Nyal, certainly a nicely executed grouping of information on a topic that seems to be of interest to so many.

Similarly, this is of particular interest to me. Off and on for the last few years, I've been performing experiments of subjective impressions covering various early reflection treatment approaches. I utilized measurements, but my interest focused primarily upon subjective impressions with my system/my room.

Discussions via both PM and here at AVS, between myself, Ethan, Dennis and others, launched me down a path of experimentation. This is a journey that I'm still on today, so I appreciate the heads up about your article in hopes it will help all that are interested.


I've since experienced so much that my opinions have evolved, however here is the discussion that was a catalyst for my experimentation, you may find it interesting;

https://www.avsforum.com/forum/19-dedicated-theater-design-construction/1318696-why-treat-first-reflection-point-i-m-confused.html


As always Nyal, your contributions here are a pleasure to read and much appreciated. The Acoustic Frontiers website has grown nicely over time into a solid resource. I've sent a multitude of enthusiasts your way.


Thanks
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post #5 of 180 Old 09-08-2015, 01:02 PM
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Thanks for posting, Nyal, hope all is going well for you!

As the question about early reflections, IME they are something needing to be dealt with in the real world.

YMMV - Don

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post #6 of 180 Old 09-08-2015, 05:17 PM
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Originally Posted by FOH View Post

Discussions via both PM and here at AVS, between myself, Ethan, Dennis and others, launched me down a path of experimentation. This is a journey that I'm still on today, so I appreciate the heads up about your article in hopes it will help all that are interested.


I've since experienced so much that my opinions have evolved, however here is the discussion that was a catalyst for my experimentation, you may find it interesting;

https://www.avsforum.com/forum/19-ded...-confused.html
Enjoyed reading that thread. I've been struggling to get my mind around the expert disagreement on first reflection points, I've wondered specifically about disagreements between Toole and Winer.... At this point I find Ethan Winer's points pretty convincing. It just makes sense to me that the main goal of a listening room is to recreate the environment music is mixed in as much as possible and that the reverberations should come mostly from the recording. Of course I understand that music is mixed in many different environments, but I think it's possible to make generalizations about these spaces.... All I really know is that in my own space ceiling clouds made a hugely positive difference. The other treatments I've put up have been more subtle sound quality changes.
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post #7 of 180 Old 09-08-2015, 05:40 PM
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Always a pleasure to see this subject broached once again. Thx Nyal.

I too have been on my own experimental path for a few years now. While I have noticed much disagreement and misunderstanding regarding what reflection levels should be in a listening room, most seem to agree that what ever level they are, they should be spectrally balanced. That is to say, even novices to the subject are aware that the frequency response (direct sound) should be as smooth as possible, so should the magnitude of the radiated reflected energy as it is heard at the listening position.

Unfortunately, many look at a full range ETC and assume that it represents all the reflected energy equally as it pertains to the spectra. It doesnt. And I am happy any time it is pointed out.

One thing that even band limited ETC's, spectrograms, and decay graphs lack is the ability to tell you the directionality of said reflection(s). I'd like to see even more research given to this.

Nyal, your paper touches on these things. Hope it spawns some informative feedback and discussion.

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post #8 of 180 Old 09-09-2015, 09:52 AM - Thread Starter
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Thanks for the positive feedback. Maybe someone else can take what I have tried to say and condense it down even further for people just starting on the acoustic treatment road. It's a complex area both in terms of physics / acoustics and perception / psychoacoustics.


The thought experiment around speaker toe in might also be interesting: http://www.acousticfrontiers.com/spe...peaker-toe-in/


As will be all the articles I wrote about speaker directivity: http://www.acousticfrontiers.com/cat...r-directivity/


Basically, treatment above the transition frequency (room mode dominated region) depends primarily on your speakers (spectral energy of reflections). Your room mainly influences it in terms of how room size changes the relationship between the direct and reflected sounds (level, time delay).

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post #9 of 180 Old 09-09-2015, 10:39 AM
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Quote:
Originally Posted by Nyal Mellor View Post
Thanks for the positive feedback. Maybe someone else can take what I have tried to say and condense it down even further for people just starting on the acoustic treatment road. It's a complex area both in terms of physics / acoustics and perception / psychoacoustics.


The thought experiment around speaker toe in might also be interesting: http://www.acousticfrontiers.com/spe...peaker-toe-in/


As will be all the articles I wrote about speaker directivity: http://www.acousticfrontiers.com/cat...r-directivity/


Basically, treatment above the transition frequency (room mode dominated region) depends primarily on your speakers (spectral energy of reflections). Your room mainly influences it in terms of how room size changes the relationship between the direct and reflected sounds (level, time delay).
How do you feel about reflection treatment with planar/ESLs that to my knowledge have much less activity going on in the off-axis regions?
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post #10 of 180 Old 09-09-2015, 11:49 AM
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I've been struggling to get my mind around the expert disagreement on first reflection points, I've wondered specifically about disagreements between Toole and Winer.... At this point I find Ethan Winer's points pretty convincing. It just makes sense to me that the main goal of a listening room is to recreate the environment music is mixed in as much as possible and that the reverberations should come mostly from the recording.
As it happens, I recently had an email exchange with Gene DellaSala at Audioholics about this. Gene is also a devotee of Floyd Toole, though I don't disagree with most of what Floyd believes! In any case, here's part of what I wrote to Gene, which expands my thoughts further:

Quote:
Originally Posted by Ethan Winer
As for the "value" of early reflections, that flies in the face of accepted practice by every single professional listener I know of. If Floyd Toole's research was testing a bunch of "civilians" who don't listen for a living, I put no stock in his results. Comb filtering from early reflections can seem to improve clarity to an inexperienced listener when the muddy part of the low-midrange gets canceled, as is common. Also, clarity in music is not the same as clarity of communications in a cockpit - boosting 3 KHz by 10 dB or even adding brittle distortion increases clarity too!

The value of absorbers at reflection points is a de facto standard among professional listeners. That should likewise be the goal for audiophiles and HT enthusiasts who would like a listening environment as excellent as a million dollar professional control room. Anything less and they will not experience the same clarity and quality as the mix engineers heard when creating the music. Many of my friends are professional musicians, recording engineers, and composers. They all appreciate the quality of my two audio systems, and several of them bring their mixes here for a final reality check.

Another reason to avoid early reflections is to increase the apparent width of the music. Many audiophiles believe that reflections in a listening room contribute to spaciousness. On the surface this makes sense, though in truth allowing early reflections makes music sound smaller, not larger. Ambience and reverb already present in many recordings is often of a large space - a concert hall, a movie scoring sound stage, or created with artificial reverb. But when played back in a small untreated room, the strong small-room reflections drown out the larger sounding reverb in the recording. This makes the music sound smaller and narrower, not larger and wider.

Correct me if I'm wrong, but I assume you haven't recorded and mixed music, or had to make mixing decisions that rely on hearing music as clearly and accurately as possible. I suspect the same goes for Floyd Toole. But professional listeners know that when a room adds any coloration, including from early reflections, mixes won't translate well to other rooms, and they'll likely contain too much or too little artificial reverb. That's because what's heard does not accurately "reflect" (sorry) what the music really sounds like.
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post #11 of 180 Old 09-09-2015, 06:16 PM - Thread Starter
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Come on Ethan.


Many of those tests Floyd did were done with trained listeners, not "a bunch of civilians".


And you also wrongly indicate that professional control rooms are all designed the same. The approach to control room design is all over the place with respect to management of reflections. All the designers pretty much agree they should be controlled, but the how differs massively. It does not just seem to be a simple case of placing absorbers at all reflection points.


IMO your ability to discern the "ambience" of the recording environment is mostly to do with your noise floor and reverberation time. If you have a low noise floor and low(ish) decay time then you can hear those things. You can have a room that is quite reflective to all early reflections and yet still has a low decay time.


Finally, your comment about early reflections decreasing stage width is exactly the opposite of the conclusions reached by the many studies that have been published in peer reviewed scientific journals.
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post #12 of 180 Old 09-09-2015, 06:19 PM - Thread Starter
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Originally Posted by BB1111 View Post
How do you feel about reflection treatment with planar/ESLs that to my knowledge have much less activity going on in the off-axis regions?
I'd direct you to the Linkwitz website for a discussion of the directivity characteristics of dipoles.


The two differences with tall panel type speakers are the ceiling reflection, which has less mid and high frequency content than for a cone/dome speaker and the reflection of the wall behind the speaker, which is high in amplitude and has more mid and high frequency content than a cone/dome speaker.

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post #13 of 180 Old 09-10-2015, 05:42 AM
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Originally Posted by Nyal Mellor View Post
You would have to forward the study for me to review, I can't say that it is something I have come across.
its the haas effect aka the precedence effect.
I spent some time playing with it last night to see how it works.

I looked at one of my impulse responses in rew room eq wizard and it showed a second impulse 1ms later than the original and only 0.8 db quieter, so i pulled a file into audacity and shifted one channel 1ms and reduced the volume 0.8 db

not very scientific but here is what it sounds like, with the original also attached for comparison

to my ears, the delayed sound totally disappears and i can only hear the first sound. it also seems like i can hear all the original ambience / reverb in the recording.

let me know your thoughts
Attached Files
File Type: zip BMTL ORIGINAL.zip (667.9 KB, 17 views)
File Type: zip BMTL time shift 1ms -0.8db.wma.zip (826.2 KB, 15 views)
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post #14 of 180 Old 09-10-2015, 05:58 AM
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Quote:
Originally Posted by 1201 View Post
thanks for posting.

i have a question on this. you mentioned that the early reflections are at a lower level than the source. this is common sense to me. but i read somewhere that when two sources create a sound, and one is delayed relative to the other(between 5 and 25 ms iirc) the farther sound becomes quieter and has to be raised about 10dbs for both sources to come back into equilibrium.

have you done testing on this? this was done with stereo speakers but im thinking it could also apply to early reflections?
my thinking is if early reflections are already quieter, and then lose another 10 dbs due to how our brains percieve delayed sound, do we really need to worry about the early reflections? or are they too quiet to really make a difference?
There's a phenomenon called the Haas Effect, which says that the sound "location" is dictated by the sound that arrives first, even if another strong reflection from a different location exists. The level of compensation depends on the amount of reflection/diffusion/absorption. Yes, we need to worry about reflections because speech becomes unintelligible when the delays are excessive and when the path length is different for two sources of the same signal, comb filtering occurs and that causes harshness in the midrange and treble (smaller differences) or holes in the bass (larger differences). The reflections from a hard, flat surface are almost as loud as the direct source.
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post #15 of 180 Old 09-10-2015, 06:17 AM
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Originally Posted by highfigh View Post
There's a phenomenon called the Haas Effect, which says that the sound "location" is dictated by the sound that arrives first, even if another strong reflection from a different location exists. The level of compensation depends on the amount of reflection/diffusion/absorption. Yes, we need to worry about reflections because speech becomes unintelligible when the delays are excessive and when the path length is different for two sources of the same signal, comb filtering occurs and that causes harshness in the midrange and treble (smaller differences) or holes in the bass (larger differences). The reflections from a hard, flat surface are almost as loud as the direct source.
Hehe. See my reply just above yours
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post #16 of 180 Old 09-10-2015, 06:26 AM
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Hehe. See my reply just above yours
I think I was still writing that when you posted. Well, writing a bit, make my coffee & breakfast, write a bit more.....

Great mimes think alike, eh?
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post #17 of 180 Old 09-10-2015, 07:49 AM
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Quote:
Originally Posted by 1201 View Post
i read somewhere that when two sources create a sound, and one is delayed relative to the other(between 5 and 25 ms iirc) the farther sound becomes quieter and has to be raised about 10dbs for both sources to come back into equilibrium.

this was done with stereo speakers but im thinking it could also apply to early reflections?
Haven't heard it described as "equilibrium" but, during the time frame you mentioned, the delayed sound would have to be raised almost 10dB to be heard as a separate sound (rather than blending into the earlier sound). Compare the blue line below to the red line to see how much you would have to raise the level of the delayed sound to hear it as a separate source.


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post #18 of 180 Old 09-10-2015, 08:04 AM - Thread Starter
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Ah, now I understand what 1201 was referring to. Thanks Sanjay
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post #19 of 180 Old 09-10-2015, 08:24 AM
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Lets separate some issues here.

1) Control/Mix/Mastering room vs Listening Room.
My experience is with the later (listening room), and not the former(s), so my comments are directed there.

2) Preservation vs Effect
What I mean here is based on what one wants the room to do. Preserve as closely the original recording or intentionally tune the room to augment (color?) the sound in some fashion. Preservation is my main focus.

3) Listening Mode vs Talking Mode
Its one thing to talk about what sounds best when the music is playing. Its another to describe the room when the music is not. The two scenarios are often cross applied in discussion without a distinction being made which one is being described. Especially in listening rooms where the room also serves as ones living room. For my comments, I am interested in the former (music playing).

With the above caveats, I have the following thoughts.

It seems to me strong reflections change the content. This, to me, is obvious given the ambient value intended is already present in the recording. This, taken alone might lead one to believe that I am advocating a anechoic or "dead" listening environment as the one that preserves the original intent best. Yes and no. Let me explain.

For the most part, we listen to music in rooms. Whether that be our home stereo or live music. We are therefore accustomed to this environment when listening. While ones living room and Carnegie Hall are very different room environments, they do share one thing, room cues. We are used to having them, however different they may be which is why many/most do not prefer a anechoic listening environment for in that case, they are removed. Simply said, we prefer a sense of space around us when listening which is what room cues provide.

In relation to the above, we have choices. Room cues can be early (<15ms) or late (>30ms), or somewhere in between. We know strong early reflections cause FR aberrations and comb filtering and strong late reflections result in echo. So in my way of thinking, it is the in between (15-30ms) that gives us the best compromise in terms of time to allow room cues to be present.

To this end, RFZ/LEDE models seem to address this thinking. While I am not saying this design criteria is the only one that can sound good, or that it addresses everyones subjective preference, it does provide an example of a room design/concept that describes and allows for room cues while avoiding the detriments of early and late reflections.

I think ill stop here because I dont want to turn things into a discussion of the merits of a particular room model, or argue the value or detriment of terminators. But I do think much confusion is caused by not being clear about what we are talking about as I outlined in my three caveats. And what may be true or best may vary considerably depending on what those caveats are.
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post #20 of 180 Old 09-10-2015, 10:29 AM
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Originally Posted by Nyal Mellor View Post
Many of those tests Floyd did were done with trained listeners, not "a bunch of civilians".
I'm familiar with much of Floyd's writings, including his recent book, and I don't recall him listing details of who was tested. If you have some references that clarify this, please post them. I'd also like to know what "trained" means in this context.

Quote:
The approach to control room design is all over the place with respect to management of reflections. All the designers pretty much agree they should be controlled, but the how differs massively. It does not just seem to be a simple case of placing absorbers at all reflection points.
Sure, but the common theme is that first / early reflections must be eliminated or at least reduced to 15 dB or more below the direct sound. If not reduced with absorption, then by angling the walls.

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Finally, your comment about early reflections decreasing stage width is exactly the opposite of the conclusions reached by the many studies that have been published in peer reviewed scientific journals.
I know dozens of recording engineers, and the only one I can think of who believes that early reflections are useful is Dave Moulton. To my ears, and the ears of all my professional musician / composer / recording friends, early reflections make music sound worse. This is so obvious to so many people, I'm frankly astonished that there's a "movement" to justify leaving reflections untreated. The only exception I'll acknowledge is for large rooms where the side walls are far away making the reflections softer and later than in a typical living room that's, say, 12 to 18 feet wide.

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post #21 of 180 Old 09-10-2015, 10:35 AM
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Jim,

When it comes to preservation or accuracy, how do you know what you're preserving or being accurate to? For example: mix decisions weren't made in a vacuum, so choices like soundstage width and instrument placement were informed by how they appeared in the mixer's particular room. Without knowing how those things were originally perceived for a particular recording, how can you preserve those aspects for that recording (let alone for all the music recordings in your collection)?

As for strong early reflections colouring the sound, that depends on direction. Good explanation in the Dirac white paper:
Quote:
An interesting aspect of the precedence effect is that the perception depends not just on the delay but also on the spatial separation between the two sources. For instance, if the two sources are located on a straight line extending from the listener so that the listening angle is the same to both sources, the sound will be perceived as colored. If the same delay settings are used but the speakers are separated horizontally, there is no perception of coloration. We simply hear the first source.

If we put an omni-directional microphone in the place of the listener, the two experimental set-ups however yield two identical recordings (assuming the room is well-damped). Both sound awful. The second source interferes with the first one. Taking the magnitude of the Fourier transform of both recordings reveals that they are identical and have the shape of a comb; deep notches permeate the spectrum. Again, we find that the Fourier transform is a poor representation of our hearing sensation. This time the main reason is that a basic Fourier transform does not distinguish between different angles of incidence.
The above also hints that we often don't hear the comb filtering we see in our measurements. If combing was as audible as measurements make it out to be, 2-speaker stereo wouldn't have worked for the last half century, considering how much content is shared between the two channels and played back as dual-mono. As Toole again pointed out in his recent paper: "Two ears and a brain are massively more analytical and adaptable than an omnidirectional microphone and an analyzer."
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post #22 of 180 Old 09-10-2015, 11:15 AM
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I looked at one of my impulse responses in rew room eq wizard and it showed a second impulse 1ms later than the original and only 0.8 db quieter, so i pulled a file into audacity and shifted one channel 1ms and reduced the volume 0.8 db

let me know your thoughts

I've had double-headed Impulse Response, but:

I was measuring with both speakers (2 channel) at the listening position, and the measurement microphone was not measurably centered/equidistant relative to the speakers.

Moving the mic to where it should have been fixed that.

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post #23 of 180 Old 09-10-2015, 12:20 PM
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Jim,

When it comes to preservation or accuracy, how do you know what you're preserving or being accurate to?
The direct response. If said reflection(s) cause the FR to comb, when we know this deviates from a smooth FR which every recording strives for, then preservation in this context means retaining a smooth FR.

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As for strong early reflections colouring the sound, that depends on direction.
Coloration can also be described tonally. Ive seen countless examples where two or more whole octaves are raised or lowered in contrast to the rest as a direct result of uneven (spectral) early specular energy.

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post #24 of 180 Old 09-10-2015, 12:46 PM - Thread Starter
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I'm familiar with much of Floyd's writings, including his recent book, and I don't recall him listing details of who was tested. If you have some references that clarify this, please post them. I'd also like to know what "trained" means in this context.

Sure, but the common theme is that first / early reflections must be eliminated or at least reduced to 15 dB or more below the direct sound. If not reduced with absorption, then by angling the walls.

--Ethan

There is some discussion of the typical population of a participants in tests on pg.350-351 of his book.


Whilst I understand the targets that people have set for early reflections my opinion is that these targets are random lines drawn in the sand with little psychoacoustic research to back them up.
1) as Toole's summary of research in his book shows, the psychoacoustic effect of reflections depends on much more than simply amplitude. Delay and direction are critical factors. We are not just suggesting to leave all reflections untreated as people on "the other side" might think. More we are suggesting that the historical "absorb all reflections" approach is flawed and does not have a link to the actual psychoacoustics of the situation.
2) the measurement that people are using (ETC) to judge when a reflection has been sufficiently "reduced" is pretty useless for the task of understanding the psychoacoustic effect of reflections. The level of the spike you see is dominated by the highest frequencies, yet we know that the response at the listening position is dominated by the energy from the early reflections only up to a certain frequency. As we approach the frequencies above say 5kHz it is dominated by the direct sound. The shape and level of spikes on the ETC changes massively depending on the top frequency of your sweep. The ETC contains no insight into the spectral content of the reflection. And it contains no insight as to the direction of the reflection. So actually it is pretty useless as a reflection measurement. As I alluded to in my article: http://www.hifizine.com/2011/12/list...gy-time-curve/ we may need some new types of ways of presenting reflection information from measurements.


Recommendations like "fully absorbing all reflections" and "limiting reflections to -15dB using an ETC" are basically ignoring the last 20 years of psychoacoustic research. Why would we ignore all this research and continue to stick to the "old ways". If you can provide peer reviewed psychoacoustic studies that back up the "old school" approach then please do.


What Kuhn wrote in 1962 is fully in effect here: https://en.wikipedia.org/wiki/The_St...ic_Revolutions
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post #25 of 180 Old 09-10-2015, 12:46 PM
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Originally Posted by RayDunzl View Post
I've had double-headed Impulse Response, but:

I was measuring with both speakers (2 channel) at the listening position, and the measurement microphone was not measurably centered/equidistant relative to the speakers.

Moving the mic to where it should have been fixed that.

This is not the case in my situation. I was measuring the center channel speaker. the mic is about a foot from the back wall ,which is the mlp
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post #26 of 180 Old 09-10-2015, 03:58 PM
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...though I don't disagree with most of what Floyd believes!...
I don't have a dog in this thread nor any standing in audio but I think and believe that Floyd has come to conclusions based on scientific research over his lifetime. So, I would think it is more than just a belief, no?
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post #27 of 180 Old 09-10-2015, 04:08 PM
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Whilst I understand the targets that people have set for early reflections my opinion is that these targets are random lines drawn in the sand with little psychoacoustic research to back them up.
Thank you for putting into words, what I have tried to formulate in words for years. At some level it seems a perfectly logical conclusion that early reflections are always detrimental. If, however you factor in that it is not a measurement microphone, but a person with two ears and a brain that analyses the sound and transforms a sound event into an auditory event (as defined in Spatial Hearing by Jens Blauert), it gets much more complicated what matters and what dosn't matter for creating an stereophonic illusion (because that's what it is, an illusion, mind trickery). It is two physical sound sources building a continuous sound stage.

Heck, the whole concept of phantom imaging and creating a virtual soundstage is nothing but a massive exploit of the pretty substantial inefficiencies of the human hearing! The signal (spectrally and temporally) that actually reaches the ears are not even close to resembling the original sound event but if we know how to exploit the inefficiencies of the mind the auditory event that is created can actually be a fairly convincing illusion.

Iv'e went down the "absorb every early reflections route because it measures much prettier" rout in the early days and I came to the empiric conclusion it was a dead end long before I started to read up on the subject of psychoacoustics.

A few years back I proposed (or rather resurrected) a fairly simple demo that pretty much anyone can do that show that stereo reproduction in an environment with few early reflections alter the percieved timbre of the phantom projection significantly compared to the real source just to challenge the belief that a dead flat frequency response from each speaker gives the "most accurate" timbre...

Thing is if you add some early reflections to the mix, the timbre shift in the phantom projected auditory event will be much less pronounced...
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post #28 of 180 Old 09-10-2015, 04:17 PM
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The direct response.
But that was my question: how would anyone know that the mixer was hearing only the direct response of his studio monitors? Without knowing that, how do you preserve it?

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post #29 of 180 Old 09-10-2015, 07:01 PM
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But that was my question: how would anyone know that the mixer was hearing only the direct response of his studio monitors? Without knowing that, how do you preserve it?
And, I would think, how good or bad is his hearing?
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post #30 of 180 Old 09-10-2015, 11:20 PM
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Iv'e went down the "absorb every early reflections route because it measures much prettier" rout in the early days and I came to the empiric conclusion it was a dead end long before I started to read up on the subject of psychoacoustics.

A few years back I proposed (or rather resurrected) a fairly simple demo that pretty much anyone can do that show that stereo reproduction in an environment with few early reflections alter the percieved timbre of the phantom projection significantly compared to the real source just to challenge the belief that a dead flat frequency response from each speaker gives the "most accurate" timbre...

Thing is if you add some early reflections to the mix, the timbre shift in the phantom projected auditory event will be much less pronounced...
do you mind sharing what this demo/test is?

ive always wondered- since headhones dont have early reflections ,or room interaction-would that be a fair simulation of what a dead room, with none of that "comb filtering" would sound like?

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