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post #1 of 23 Old 11-03-2013, 03:35 AM - Thread Starter
 
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Just a question, I understand using EQ for addressing the very deep bass issues (100 Hz and down) can be beneficial. How about above the Schroeder frequency? Can EQ still be beneficial?

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post #2 of 23 Old 11-03-2013, 04:23 AM
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Originally Posted by Shaun B View Post

Just a question, I understand using EQ for addressing the very deep bass issues (100 Hz and down) can be beneficial. How about above the Schroeder frequency? Can EQ still be beneficial?


By EQ, are you referring to the newer auto EQ, PEQ, or?

That question has been discussed before, there are threads on that.....hard for me to search for them on a ipad.
Did you try a search before posting this question?
I believe some AES papers also.

Btw, Fs in a home theatre is 250-300 Hz

Fwiw, I do use EQ in my setup , audyssey XT32, along with speaker location, acoustic treatments.


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post #3 of 23 Old 11-03-2013, 04:50 AM - Thread Starter
 
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By EQ, are you referring to the newer auto EQ, PEQ, or?

Yes, PEQ. I don't know what type of EQ Audyssey uses, if it's PEQ as well. But I have heard great stories of people preferring the sound of Audyssey's correction across the whole range.

 

Especially XT/XT32. Some people have told me that parametric EQ is not effective above the Schroeder frequency. I've never used Audyssey for myself, so I'm only speculating based on what I've read online.

 

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That question has been discussed before, there are threads on that.....hard for me to search for them on a ipad.

Nope, never read any threads on AVS. I recently joined. I just thought I would ask, as I am using PEQ for the bass range in my system, but it's an external unit.

 

I just wanted to know if PEQ can be effective higher up over the bass range.

 

Quote:
Fwiw, I do use EQ in my setup , audyssey XT32, along with speaker location, acoustic treatments.

I don't have much experience with Audyssey, so I don't know what type of EQ it falls under. It's automatic, but is it parametric, or something else?

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post #4 of 23 Old 11-03-2013, 06:03 AM
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Originally Posted by Shaun B View Post

Just a question, I understand using EQ for addressing the very deep bass issues (100 Hz and down) can be beneficial. How about above the Schroeder frequency? Can EQ still be beneficial?

The Schroeder frequency is the frequency where the room's behavior changes from being described by a single or a small number of resonant modes, and above which it is described by a great many resonant modes.

http://www.soundandvision.com/content/schroeder-frequency-show-and-tell-part-1

"You have at least two listening rooms. Even if you live in a studio apartment, you have at least two listening rooms. Well, in a sense. Every listening room is, in essence, two listening rooms when you look at it from the perspective of sound.

To midrange and treble frequencies, your listening room is like a billiards table. Like billiard balls, mid- and high-frequency sounds tend to bounce all around your room, until they run out of energy. Because of this frenetic reflection, midrange and treble frequencies spread pretty evenly — or diffuse — throughout a room.

To bass frequencies, your listening room is like a beer bottle when you blow across its top. In other words, it’s a resonator. Sounds whose wavelengths match the dimensions of the room will resonate — in other words, they’ll be amplified. Sounds whose wavelengths don’t match the dimensions aren’t amplified. Depending on where your speaker is placed in the room, and where you are placed in the room, some of the bass sound waves will reinforce each other, while others cancel each other out. Move to a different spot in the room and different frequencies may be reinforced or canceled.

Schroeder’s sound science

The scientist who first noted a room’s split acoustical personality (if you will) was a German physicist named Dr. Manfred Schroeder. (Not to be confused with Schrödinger, the dude who discovered that a cat explodes if you put it in the microwave.) Back in 1954, Schroeder referred to the frequency at which rooms go from being resonators to being reflectors/diffusors as the “crossover frequency.” We now call it the Schroeder frequency.

It’s easy to confirm Schroeder’s discovery. First play a bass tone through your speaker system. Walk around the room and you’ll hear the level of the tone change radically from place to place. Now play a midrange tone and walk around the room. It might be slightly quieter in some places, slightly louder in others, but you won’t hear a big difference.
"

From the above it seems reasonable to conclude that room equalization is actually more effective above the Schroeder frequency because the room's response above the Schroeder frequency is more consistent at different locations within the room.

http://mehlau.net/audio/multisub_geddes/ (quoting Earl Geddes)

"
At higher frequencies, above the Schröder frequency, modes are not a big problem because there are so many. Two ears and a brain are very good in suppressing modes that otherwise would lead to coloration of sound (see Bilsen). Music has a more transient nature at higher frequencies and other effects play a major role: Soundwaves need time to travel through the room (about 34.4 cm per millisecond). If the difference between the direct sound and reflected sound is bigger than about 1 ms then our brain is capable of separating the two. However, only one sound sensation is perceived (precedence effect). If the difference is smaller than 1 ms then the two (or more) sounds are melted into one (summing localization).

At frequencies below the Schröder frequency, modes become a problem. Our hearing needs a couple of cycles before it can determine a sound's timbre but in acoustically small rooms reflections become part of the sound almost instantly because wavelengths are in the range of the room's dimensions (e.g. 40 Hz = 8.6 m wavelength). So what we hear is dominated by the room and not by the loudspeaker anymore.

At lower frequencies there are fewer modes and they are more spaced relative to each other. This commonly leads to the typical sensation of "booming" or "one-note" bass or even no bass at all at certain frequencies. In those cases the in-room frequency response shows stationary peaks (booming sound) and dips (no sound), an effect boosted by rigid walls. Contrary to common belief, angled walls or irregular floor plans do not reduce modes. They just change the modal distribution pattern within a room.
"

A conclusion that I reach from all of this is that the Schroeder frequency does not separate the frequencies we need to equalize from the ones we don't. The Schroeder frequency does separate the room's performance into two frequency ranges in which we are equalizing problems that have different sources, and for which equalization has different consequences.

Below the Schroeder frequency the room's response varies quite strongly as you move around in the room, and so you can only equalize to optimize the room's response over a region in the room. Above the Schroeder frequency the room's response is more consistent as you move around the room, and your equalization efforts may apply to a larger region in the room if not most or all of the room. That doesn't mean that the room automagically starts having flat and smooth response above the Schroeder frequency, because there are more reasons for non-uniform response than just room resonances.
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post #5 of 23 Old 11-03-2013, 07:12 AM - Thread Starter
 
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Wow, that's a lot of information. Thanks arnyk. So Audyssey is classified as a type of EQ, correct? Have you used Audyssey before? Do you think it is effective above 200-300 Hz?

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post #6 of 23 Old 11-03-2013, 07:26 AM
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Originally Posted by Shaun B View Post

Wow, that's a lot of information. Thanks arnyk.

Happy to be of service. ;-)

In the cosmic scheme of things the two quotes above are a tiny fraction of what can be known. I tried to filter down the tiny fraction of what I know into something that would be helpful in a post replying to a question like this.
Quote:
So Audyssey is classified as a type of EQ, correct?

Yes.
Quote:
Have you used Audyssey before?

Yes. I found it to be very helpful. It is not the only eq I have ever used, but the effort/reward was about the best I've ever seen.
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Do you think it is effective above 200-300 Hz?

Yes.
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post #7 of 23 Old 11-03-2013, 07:34 AM
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It is a complicated situation. Above transition frequency what you hear is a combination of the direct sound of the speaker and what is reflected from the surfaces in the room. Speakers unfortunately tend to have far different frequency response "off-axis" (i.e. angles that hit the other surfaces). What you then hear is a mixture of multiple frequency responses. If you measure this, you will see that your overall frequency response is impacted. But in theory, you can't correct this because any change you make up stream of the speaker, will apply equally to both direct and indirect sounds so no real correction occurs. This is the reason many people don't believe in correction above the transition frequencies.

That said, there are some finer points. There are speakers that have been designed to have similar response to the direct sound. Examples are Harman brands (Revel, etc) and KEF. Others rely on directing the sound so that what hits the wall is minimized.

Making things much more complicates is the fact that at higher frequencies, psychoacoustics plays a strong role. The distance between your two ears becomes significant, causing each one to hear something different. The single microphone measurement is hopelessly inaccurate in presenting what you hear. Folks ignore this and chase such measurements to their peril smile.gif.

So here is the non-theory side. If you have poor response above transition, first tactic is to get a speaker that has good off-axis response. Such a speaker can them be EQed properly. Once there, measure with one mic the frequency response but make sure to set the filtering to 1/3 octave to roughly match how your hearing works at higher frequencies. If you see a broad dip in the mid frequencies, then you have a speaker problem per above. Assuming not, then you can apply filters to try to get a smoother response. You are in good position with the PEQ in that you can test the effect of individual filters. Use broad bandwidth and don't attempt to correct small peaks and valleys. And then listen with fair amount of content to make sure you still prefer it that way.

Note that you do NOT want a flat response. I was careful above to say you need a "smooth" response. A flat response will sound too bright and lacking bass. The target should be a tilting down response that is higher in bass frequencies and keeps sloping down. Again, use your ears to assess this. Don't force yourself to accept flat response as being "right." It is not smile.gif.

Good luck.

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post #8 of 23 Old 11-03-2013, 07:43 AM - Thread Starter
 
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Note that you do NOT want a flat response. I was careful above to say you need a "smooth" response.

I thought flat was desirable if accurate sound was the goal. I thought wrong. Thanks for clarifying.

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post #9 of 23 Old 11-03-2013, 07:58 AM - Thread Starter
 
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Sorry to be a nuisance, but could someone please post measurements using Audyssey XT/XT32 before and after, preferably with acoustic software, so I can see how effective it works above 200-300 Hz? I don't have access to acoustic software. I'm using the SMS-1, but it's currently disconnected and I want to sell it as I don't feel the results are worth my time.

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post #10 of 23 Old 11-03-2013, 08:03 AM - Thread Starter
 
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A flat response will sound too bright and lacking bass.

Wouldn't that depend on the listening material? For example, if material was recorded hot and sounds overbearing with a peaky response, would it be desirable for a more neutral response? If material was recorded in a more neutral condition then I can see where a flat response might sound "thin".

 

The reason I ask is because I used the Velodyne SMS-1 to manually EQ my room. I managed to achieve a flat response and it never sounded too bass light, but that could be because my room wasn't overly peaky to begin with. There were peaks, but it wasn't very bad as my subwoofer was not positioned in a corner, or close to room boundaries.

 

I do hear from some people that "flat" is not desirable. I don't know if that is the general consensus on the matter.

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post #11 of 23 Old 11-03-2013, 08:13 AM
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To some extent yes, it is content dependent. To the extent you want to have a single curve though, research (including double blind tests) show what I said: tilt it down. How much is up to you so there is some freedom there smile.gif.

As to your sub, your observation is not inconsistent with this recommendation. The sub level will determine how much bass you have, not the fact that it was flat. When I talk about tilting down, I am talking from 20 to 20,000 Hz which includes the sub.

This is the target curve for Audyssey by the way:

350x700px-LL-79f17c94_CE1.jpeg

And here are the preference results in double blind tests of auto-eq system. All the ones that outperformed doing nothing, used a tilted down response:

Room%20Correction%20Preferences.png

Again, feel free to experiment. If ultimately flat is right, go with it! Just don't start thinking that must be right even though it doesn't sound right to you.

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post #12 of 23 Old 11-03-2013, 08:15 AM
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Quote:
Originally Posted by Shaun B View Post

Quote:
A flat response will sound too bright and lacking bass.
Wouldn't that depend on the listening material? For example, if material was recorded hot and sounds overbearing with a peaky response, would it be desirable for a more neutral response? If material was recorded in a more neutral condition then I can see where a flat response might sound "thin".

You are right that how the music was recorded is a big part of the equation, but in fact most music is recorded to sound right with speakers whose in-room response has some kind of a downward tilt, it seems.
Quote:
The reason I ask is because I used the Velodyne SMS-1 to manually EQ my room. I managed to achieve a flat response and it never sounded too bass light, but that could be because my room wasn't overly peaky to begin with. There were peaks, but it wasn't very bad as my subwoofer was not positioned in a corner, or close to room boundaries.

Or you may somehow prefer what people in general think is too bright. It happens!

Or your measurement setup may have had the inverse of the the right tilt built in.
Quote:
I do hear from some people that "flat" is not desirable. I don't know if that is the general consensus on the matter.

All generalities are false but this one about a downward FR tilt being preferable is about 99% agreed on. ;-)
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post #13 of 23 Old 11-03-2013, 08:16 AM
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Originally Posted by Shaun B View Post

could someone please post measurements using Audyssey XT/XT32 before and after, preferably with acoustic software, so I can see how effective it works above 200-300 Hz?

Here you go, though the measurements were made using an older version of Audyssey:

Audyssey Report

There you'll read why EQ is not only not effective above the Schroeder frequency, it's not even that useful below Fs in most rooms. To be fair to EQ, it can be useful to reduce the one or two lowest peaks. But I'd never use it above 80 Hz or so. This next article is about something else, but it shows even more clearly how drastically the LF response in a room can change over extremely small distances:

A common-sense explanation of audiophile beliefs

So any improvements made for one location will surely be made worse elsewhere, even a few inches away.

--Ethan

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post #14 of 23 Old 11-03-2013, 09:31 AM
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Quote:
Originally Posted by Shaun B View Post

Sorry to be a nuisance, but could someone please post measurements using Audyssey XT/XT32 before and after, preferably with acoustic software, so I can see how effective it works above 200-300 Hz?

Please check some of the threads with the word "Audyssey" in them.
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post #15 of 23 Old 11-03-2013, 09:31 AM
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Originally Posted by amirm View Post

To some extent yes, it is content dependent. To the extent you want to have a single curve though, research (including double blind tests) show what I said: tilt it down. How much is up to you so there is some freedom there smile.gif.

As to your sub, your observation is not inconsistent with this recommendation. The sub level will determine how much bass you have, not the fact that it was flat. When I talk about tilting down, I am talking from 20 to 20,000 Hz which includes the sub.

This is the target curve for Audyssey by the way:

350x700px-LL-79f17c94_CE1.jpeg

And here are the preference results in double blind tests of auto-eq system. All the ones that outperformed doing nothing, used a tilted down response:

Room%20Correction%20Preferences.png

Again, feel free to experiment. If ultimately flat is right, go with it! Just don't start thinking that must be right even though it doesn't sound right to you.

amirm here only posted half the story. audyssey has 2 response curves. movie and music (sometimes called audyssey flat) audyssey music curve does not have the high freq roll off shown in the audyssey movie graph that was posted.

op, if you have not done so, post your audyssey related questions in the official audyssey threads. you wont get only half the story from the guys there.

official audyssey thread

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post #16 of 23 Old 11-03-2013, 09:50 AM
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Originally Posted by 67jason View Post

amirm here only posted half the story. audyssey has 2 response curves. movie and music (sometimes called audyssey flat) audyssey music curve does not have the high freq roll off shown in the audyssey movie graph that was posted.
I posted the most common implementation which is no choice in target curve. To the extent you are implying that it always has 2 response curves, seems like you are also providing half the story smile.gif.

BTW, I did not post that graph to show that audyssey curve follows the preferred tilt. It does not, the high frequency roll off notwithstanding. And the flat/music is even worse in that regard. THe right response tilts from bass all the way down to highs and most definitely doesn't have the ill-conceived mid-frequency dip.
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op, if you have not done so, post your audyssey related questions in the official audyssey threads. you wont get only half the story from the guys there.

official audyssey thread
That's an excellent thread if you like to learn the mechanics of audyssey. If you want to know the science of these systems, including that of audyssey, *this* is the correct forum. You have access to much broader knowledge here than the people in love with audyssey. smile.gif

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post #17 of 23 Old 11-03-2013, 10:28 AM - Thread Starter
 
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Originally Posted by Ethan Winer View Post


Here you go, though the measurements were made using an older version of Audyssey:

Audyssey Report

There you'll read why EQ is not only not effective above the Schroeder frequency, it's not even that useful below Fs in most rooms. To be fair to EQ, it can be useful to reduce the one or two lowest peaks. But I'd never use it above 80 Hz or so. This next article is about something else, but it shows even more clearly how drastically the LF response in a room can change over extremely small distances:

A common-sense explanation of audiophile beliefs

So any improvements made for one location will surely be made worse elsewhere, even a few inches away.

--Ethan

 

Thanks for the reply Ethan. Would your view on this change if you only had one seated location? I live alone, so I only have one seat really that matters. I don't need a consistently good response over a wide listening area, at least in my space.

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post #18 of 23 Old 11-03-2013, 10:46 AM
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Quote:
Originally Posted by amirm View Post

Quote:
Originally Posted by 67jason View Post

amirm here only posted half the story. audyssey has 2 response curves. movie and music (sometimes called audyssey flat) audyssey music curve does not have the high freq roll off shown in the audyssey movie graph that was posted.
I posted the most common implementation which is no choice in target curve. To the extent you are implying that it always has 2 response curves, seems like you are also providing half the story smile.gif.

BTW, I did not post that graph to show that audyssey curve follows the preferred tilt. It does not, the high frequency roll off notwithstanding. And the flat/music is even worse in that regard. THe right response tilts from bass all the way down to highs and most definitely doesn't have the ill-conceived mid-frequency dip.
Quote:
op, if you have not done so, post your audyssey related questions in the official audyssey threads. you wont get only half the story from the guys there.

official audyssey thread
That's an excellent thread if you like to learn the mechanics of audyssey. If you want to know the science of these systems, including that of audyssey, *this* is the correct forum. You have access to much broader knowledge here than the people in love with audyssey. smile.gif

every mainstream avr with audyssey made in the last several years have both audyssey music and movie curves available to the user. some low end onkyos very early on only had the music curve available while in thx mode. nad and cambridge audio may implement audyssey differently then the main stream avrs (denon, marantz and onkyo), and may not include both curves, i dont know and i dont care, as those two are far from being main stream. . so stating one curve is more common today is incorrect as both curves are equally common in commonly used and readily available equipment today.


to your second paragraph, you are sorely misguided if you think there is no science involved in the official aydyssey thread. there are guys in that thread who have taken the time to understand all the ins and outs of audessey and have no problem with explaining it scientifically, both the good and bad stuff. there is much effort to not provide only half the story regarding audyssey in that thread. you should read up on it and learn somethings before being quick to dismiss them.

i know you like to argue and you dont react well when your wrong, but your assumptions in your above posts are wrong....but dont worry i wont argue with you any further about them. i just wanted to ensure the OP and any others who may come along had access to the complete strory regarding audyssey curves.

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post #19 of 23 Old 11-03-2013, 12:39 PM - Thread Starter
 
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Thanks Jason67 for the advice! I've just posted in the Audyssey thread. I believe the designer of Audyssey is also there, Chris I believe. Unfortunately I can't read through 1800+ pages, but I did ask my questions there.

 

Thanks again guys.

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post #20 of 23 Old 11-03-2013, 04:40 PM
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Chris K no longer visits AVS, it's been a few years.
Post Q;s to him here https://www.facebook.com/groups/audysseytechtalk/

OP - since you have "just" 1 MLP, your situation is much simplified!
Post a picture/layout of your acoustic listening space, your speaker type & location, if you use a subwoofer & location, etc.
Not clear your real issue....

You can easily use PEQ for your single MLP to "tame" peaks of bass, and then proper location of speakers relative to your MLP, with appropriate acoustic treatments will enhance your experience.
You own your hardware already, so goal I believe is to maximize that, correct?

Or, please state clearly your real goal.

Just learning about EQ?
Cool.

Or applying EQ to your specific situation.

More info below.
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Originally Posted by mtbdudex View Post

Side note:
I have this general suggestion for those wanting to learn about acoustics:

A) read this Acoustics/Treatment Reference Guide , via gearslutz, its a easy read in layman terms, starts you off with basics and good foundation with practical discussion. Studio acoustics and Home Theater acoustics.

From that, simple/straight forward advice via Jens Eklund:
Quote:
1. Learn how to make measurements: REW - Room EQ Wizard Home Page

Don’t do anything without measurements.


2. Define your MLP (Master listening position). Confirm with measurements.

(Mike R modified for HT viewpoint)


3. Identify and treat your modal and SBIR - Speaker Boundary Interference Response related issues and educate yourself about different bass-absorbing techniques.

Other info: SBIR by Bryan Pape


4. Treat areas that otherwise creates early reflections.


5. If the room is big enough, add diffusers (but read up on how to use diffusers before going nuts).


Always base your decisions regarding different treatment, on measurements. Avoid thin porous only absorbers (including wall to wall –carpet, drapes etc.) unless a measurement indicates the need for it.

B) Knowing that for “best” audio/sound in a listening room, these parameters are tackled in prioritized order:

1. Speaker location, 2. Listener position, 3. Acoustic treatments, 4. Electronic correction.

Understand the small room acoustic model you will follow.

Looking at this link, everyone can see visually the various small room models, it's 7 pages from the book "Acoustics and Psychoacoustics Applied"
http://eetimes.com/design/audio-desi...n?pageNumber=0


E) If you have desire for more knowledge:

-read one of many books out there, a great 1st book is "Master Handbook of Acoustics" by F. Alton Everest, a perfect follow-up book is "Sound Reproduction: The Acoustics and Psychoacoustics of Loudspeakers and Rooms" by Floyd Toole.

-study Ethan Winers site, http://www.ethanwiner.com/acoustics.html

-Become familiar with the different small room acoustic models for home listening spaces

-This is also a 101 read on Room Acoustics, http://www.crutchfield.com/learn/learningcenter/home/speakers_roomacoustics.html

-SAE Home Acoustics info site has many definitions and explanations http://www.sae.edu/reference_material/audio/pages/fullindex.htm

-There are many other sites on the web, like

........One of the first ones, StudioTips small room acoustics forum http://forum.studiotips.com/index.php,

........Acoustical measurements defined Rives audio http://www.positive-feedback.com/Issue12/rives2.htm,

........RPG Acoustics Library papers http://www.rpginc.com/news/library.htm, etc.

-Be careful of info overload all at once


F) Measurement info/threads:

-online downloadable file with the Sound System Engineering chapter 6 on measurements http://www.focalpress.com/uploadedFiles/Books/Book_Media/Audio/9780240808307.pdf
-Get the hardware side of REW down quickly, this thread by member omegaslast dummy's guide on setting up REW and his blog http://polaraudio.blogspot.com/2012/01/calibration.html easy 101 read with pictures to walk you thru the mechanical of set-up and taking measurements
-Highly recommend Nyal Mellor's site, http://www.acousticfrontiers.com/Aco...surements.html , and a very detailed/helpful white paper http://blog.acousticfrontiers.com/st...ist.%20Rms.pdf

-Room Measurement & Treatment by "fotto" (Floyd)

- Envelope Time Curve - ETC - Impulse gearslutz thread

-Using energy time curve for acoustic analysis: by "mtbdudex" (Mike R)
-http://www.avsforum.com/t/1421599/etc-isd-gap-question ETC - ISD gap by

-Basic acoustic measurement primer v2.1 (via gearslutz "DanDan")

-http://www.realtraps.com/art_measuring.htm
-http://www.avsforum.com/t/1316623/diy-custom-printed-movie-poster-acoustic-panels-cheap/60#post_20147783 DIY Custom-Printed Movie Poster Acoustic Panels
-first reflection software: http://www.avsforum.com/t/822273/free-software-to-help-determine-your-first-reflection-points/240#post_22619555
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post #21 of 23 Old 11-03-2013, 04:59 PM
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Quote:
Originally Posted by Ethan Winer View Post

Quote:
Originally Posted by Shaun B View Post

could someone please post measurements using Audyssey XT/XT32 before and after, preferably with acoustic software, so I can see how effective it works above 200-300 Hz?

Here you go, though the measurements were made using an older version of Audyssey:

Audyssey Report

There you'll read why EQ is not only not effective above the Schroeder frequency, it's not even that useful below Fs in most rooms. To be fair to EQ, it can be useful to reduce the one or two lowest peaks. But I'd never use it above 80 Hz or so. This next article is about something else, but it shows even more clearly how drastically the LF response in a room can change over extremely small distances:

A common-sense explanation of audiophile beliefs

So any improvements made for one location will surely be made worse elsewhere, even a few inches away.

--Ethan

Ethan - any plan to update your review via using MultEQ XT32?
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post #22 of 23 Old 11-04-2013, 02:05 AM
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Quote:
Originally Posted by amirm View Post

It is a complicated situation. Above transition frequency what you hear is a combination of the direct sound of the speaker and what is reflected from the surfaces in the room. Speakers unfortunately tend to have far different frequency response "off-axis" (i.e. angles that hit the other surfaces). What you then hear is a mixture of multiple frequency responses. If you measure this, you will see that your overall frequency response is impacted. But in theory, you can't correct this because any change you make up stream of the speaker, will apply equally to both direct and indirect sounds so no real correction occurs. This is the reason many people don't believe in correction above the transition frequencies.

That said, there are some finer points. There are speakers that have been designed to have similar response to the direct sound. Examples are Harman brands (Revel, etc) and KEF. Others rely on directing the sound so that what hits the wall is minimized.

Making things much more complicates is the fact that at higher frequencies, psychoacoustics plays a strong role. The distance between your two ears becomes significant, causing each one to hear something different. The single microphone measurement is hopelessly inaccurate in presenting what you hear. Folks ignore this and chase such measurements to their peril smile.gif.

So here is the non-theory side. If you have poor response above transition, first tactic is to get a speaker that has good off-axis response. Such a speaker can them be EQed properly. Once there, measure with one mic the frequency response but make sure to set the filtering to 1/3 octave to roughly match how your hearing works at higher frequencies. If you see a broad dip in the mid frequencies, then you have a speaker problem per above. Assuming not, then you can apply filters to try to get a smoother response. You are in good position with the PEQ in that you can test the effect of individual filters. Use broad bandwidth and don't attempt to correct small peaks and valleys. And then listen with fair amount of content to make sure you still prefer it that way.

Note that you do NOT want a flat response. I was careful above to say you need a "smooth" response. A flat response will sound too bright and lacking bass. The target should be a tilting down response that is higher in bass frequencies and keeps sloping down. Again, use your ears to assess this. Don't force yourself to accept flat response as being "right." It is not smile.gif.

Good luck.

amirm brings diverse viewpoints here @ AVS, so much that a while back (4/26/12) a specific thread was created to not take off topic other peoples posts, as was happening too often.
Unfortunately that thread did not resolve the different viewpoints, guess that's the way the "acoustic particle bounces" rolleyes.gif
http://www.avsforum.com/t/1407637/the-room-acoustics-master-disagreement-thread
Quote:
Originally Posted by amirm View Post

It seems that there is not consensus on how one approaches the topic of room acoustics. As such, threads asking for advice seem to immediately generate deep discussions, full of jargon, that do not appear to converge. This may lead to frustration by the person asking the original question, having had hopes of simple answers.


So I thought it might be useful to have a general thread where these deeper discussions can be redirected to and as such, can be the full archive of the positions taken as opposed to being spread and repeated across many discussion threads.


This has been requested by a number of people so if the thread doesn't get traction, then we know the will of the community is to have them occur as they do now
. So vote with your keyboard if you like this central place to hash out the major disagreements in this area.


For this thread to have long term value, it needs to remain open. As such professional conduct is requested. The topics are near and dear to many's heart to be sure. But there is no reason why we can't stay focused on the topic as opposed to the person. The vocal members among us put a ton of work in these posts. Let's not have them go to waste by having the thread locked.
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post #23 of 23 Old 11-04-2013, 12:26 PM
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Reading the posts, it's quite funny how people put so much effort into listening as much if not more to recording! It's nice to be in the other end of the signal for a change smile.gif
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