Room modes, calculated versus measured

Posted: Fri Mar 11, 2005 8:21 pm

It's my experience that the axial modes are by far the most important modes (there is also evidence that historically mathematicians have favored the axials). Listen for yourself; see what you hear. Furthermore, axial modes themselves can be demonstrated to be less important than other room conditions, such as the distance of the listener to the speakers and room boundaries.

My humble $.02 worth.

--Wes

Posted: Fri Mar 11, 2005 9:21 pm

Quote:

Sorry, but that's just hearsay and "arguing from authority." I need proof in the form of hard data.

It's one thing to claim something is not true until it has been proven. It's quite another to claim it is not true until it has been proven to me

There are mountains of information out there available to all students of acoustics everywhere if they just take the time to locate it, examine it and evaluate it. Isn't that what science is all about, a common body of knowledge, and theories based on data, that a community of scholars and practitioners are intimately familiar with--especially those claiming expert knowledge?

I admire Z and avare and many others for their intellectual curiosity and openness.

Ethan, let me thank you once again for helping many on this forum, including me. You've been very generous of your time. I hope we can respectfully disagree with one another in our approaches.

The more I learn, the more I am humbled by all I don't know, and the more I am thankful for those who have done the work of gathering and sharing their data and their theories on that data. Iwouldn't want to just blow off these "authorities" simply because I'm ignorant of their contributions and the body of knowledge which forms their context. Maybe they're right, maybe they're wrong, but just because I don't "get it" doesn't automatically make them wrong.

Lee

Posted: Fri Mar 11, 2005 9:39 pm

Ethan Winer wrote:

I just searched the Barnes & Noble site and apparently this book is out of print, and even used copies are not available. So all the more reason to ask you guys to post a relevant page or three.

--Ethan

Amazon has 4 copies

hopefully it he is just coming out with a new edition, but it seems many of his books are going out of print. Last time I checked he was still alive but he is getting up there.

Technical books have a bad habit of going out of print, they are printed in very low numbers and when they run out you have no idea when if ever there will be a reprint. Before you could buy books online I bought every acoustics text I ran across, they were just so hard to find. For many of them it was a good thing i did since they have never been reprinted
dan

Posted: Sat Mar 12, 2005 11:25 am

Ethan Winer wrote:

......

Quote:

In my room, for instance, a room mode calculator (not Ethan's) comes up with 24.5 Hz as my first axial mode, but a measurement with ETF comes up with about 30 Hz.

.....--Ethan

Do you have a link to the thread that came from?

Posted: Sat Mar 12, 2005 2:09 pm

Paul,

> Do you have a link to the thread that came from? <

I'd have to search. As you know I visit a lot of places. But the statement was not taken out of context and it stands on its own, if that's what you're getting at.

--Ethan

Posted: Sun Mar 13, 2005 5:52 am

Ethan,

I second Paul's question.
You know exactly where you discussed the topic.
You even know every sentence I wrote on the net, even in topics you weren't involved.

You refer to a quote.
Common practice and courtesy towards Autor AND readers, is, or SHOULD BE, that you refer/link to the author/source, so that readers can see the context in which this quote is used.

Posted: Sun Mar 13, 2005 9:08 am

Eric,

> so that readers can see the context in which this quote is used. <

The context is unambiguous. Or maybe you're just fishing for links from me so you'll have new places to start trouble? No thanks.

This now accounts for at least three people with modes that measure substantially higher than mode calculators predict. Since you're the guy with 25 years experience measuring rooms, why haven't you posted anything yet?

--Ethan

Posted: Sun Mar 13, 2005 10:29 am

Ethan Winer wrote:

Paul,

> Do you have a link to the thread that came from? <

I'd have to search. As you know I visit a lot of places. But the statement was not taken out of context and it stands on its own, if that's what you're getting at.
--Ethan

Ethan Winer wrote:

This now accounts for at least three people with modes that measure substantially higher than mode calculators predict.

How do you relate both statements? At its Ethan's?

There are others than me to. Since you """ found """ it, just give it to Paul then. He asked before me.
If somebody else asked, which argument should you have used (found) then?

Ever heard about Fair Use of Copyright?
That assumes that you refer to your source. Messages in forums are subject to fair use of copyright too.

I will come back to this thread in due time;
Most answers of me are stated AND substanciated anyhow in the numeous extensive posts you so friendly referred to (more to prove how wrong I am).
I don't feel the need to start every time all over again.
I'm sorry but I can't help it that you can't interpret your own measurement data.

And I still stand by everything I wrote.

Posted: Sun Mar 13, 2005 11:56 am

Never mind,

I found it:
http://www.audiocircle.com/circles/viewtopic.php?p=151777#151777

I made the Wink

"""forgotten""" part bold myself

ctviggen wrote:

And if your room isn't exactly rectangular, you might not get the right results using the room calculator. In my room, for instance, a room mode calculator (not Ethan's) comes up with 24.5 Hz as my first axial mode, but a measurement with ETF comes up with about 30 Hz. Also, the room mode calculator doesn't tell you the magnitude of the peaks. For me, the 30Hz peak is huge relative to other peaks.

Translation Ethan Winer when it suits him:
http://www.recording.org/ftopicp-206928.html#206928

Ethan Winer wrote:

Finally, I'm not the only person to observe calculated modes disagreeing with measured results. This was posted earlier today in another forum I frequent:

Quote:

In my room, for instance, a room mode calculator (not Ethan's) comes up with 24.5 Hz as my first axial mode, but a measurement with ETF comes up with about 30 Hz.

Notice that in this fellow's room the mode as measured is also about 20 percent too high.

Ethan Winer wrote:

I'd have to search. As you know I visit a lot of places. But the statement was not taken out of context and it stands on its own, if that's what you're getting at.

Ethan Winer wrote:

The context is unambiguous. Or maybe you're just fishing for links from me so you'll have new places to start trouble? No thanks.

I don't mind. It's the Ethan I know.
Now you know why Fair Use of Copyright is invented ..... (additional to respect for Author AND readers).

Posted: Sun Mar 13, 2005 12:08 pm

Eric,

> Ever heard about Fair Use of Copyright? <

This from the guy who has taken more than a few items of copyrighted material from my site, without permission and against my wishes.

The hypocrisy is simply amazing. Rolling Eyes

--Ethan

Posted: Sun Mar 13, 2005 1:07 pm

Ethan Winer wrote:

Eric,

....
The hypocrisy is simply amazing. Rolling Eyes

--Ethan

It certainly is.

You make a big point in this thread ( and others ), about the dangers of simply believing what you read in forums...

for example... Quote Ethan: "Sorry, but that's just hearsay and "arguing from authority." I need proof in the form of hard data. "

With the same notions in mind, I just wanted to see where your 'nonsourced' quote came from so I could see some context behind it.

Your quote, by not specifying source could have come from anywhere, and could even be fictional, so I was using your own 'guidelines'.

Which I'm sure you'll find acceptable Smile

Paul

Posted: Sun Mar 13, 2005 6:43 pm

I thought criticism and comment were "fair use".
http://www.law.cornell.edu/uscode/html/uscode17/usc_sec_17_00000107----000-.html
Of course to criticise or comment by definition implies that one attributes the source. It's twice the work to record and post, but I've been convinced that including the source is an honorable habit to get into, for several good reasons.

Posted: Sun Mar 13, 2005 7:53 pm

Hello z,

Let's not turn this thread into a "Fair Use" discussion, that's endless.

Wink

Ethan forgot to notice that the notion "Fair Use" exists of 2 words: Use AND Fair and that they belong together.
Rolling Eyes

That's probably why he mistakenly called me a Hypocrite.................

The Fair-Use Statute
Section 107 of the Copyright Act of 1976. Limitations on exclusive rights: Fair use

I'm automatically AND always VERY conscious in the concept "Fair Use", proper reference to sources and respect for Copyright, authors etc., and I'm a bit familiar with it.
And all of this is covered by the legal concept "Fair Use" of Copyright.
My measurement graphs posted here at RO are "Fair Use" and the wrongful quote above is plain infringement of Copyright (abuse context content + lack of any proper reference to Author/source).
Persistence in telling lies is not covered by "Fair Use", that's just Ethan Winer.

Posted: Mon Mar 14, 2005 8:52 am

Ethan,

If I'm understanding this, you seek proof that non-axials do or do not matter? And you do not wish the proof to come in the form of:

(a) A literal citation?
OR
(b) The word of anyone on this or any other forum?

Well, that certainly poses a challenge.

A suggestion: Why don't you prove that they don't matter? I think it's pretty much a consensus among some (most?) folks participating in this thread that all modes are potentially important - and some (most?) of us have been of that mindset for a long time. We have our books and experience to back that up. None of which is good enough. (Nor should it be, necessarily.) So, perhaps you might think about pursuing this with zeal and reporting back. If you find that, across the board, tangentials are (e.g.) 17.6% less relevant that axials in all rooms, then we would absolutely love to know that. So would, I imagine, anyone who deals with small rooms on a daily basis.

Have fun with your research! I look forward to reading more about it.

Posted: Mon Mar 14, 2005 9:02 am

z,

z60611 wrote:

Jeff

Quote:

I find tangentials (not so much the obliques - they're much higher

I'm not fond of adjectives like 'much higher' because they mean different things to different people at different times in different conversations, so I looked up an example. Smile

In a room 12.46'x11.42'x7.9':
Lowest Axial: 45.3 hz
Lowest Tangential: 67.1 hz
Lowest Oblique: 98.1 hz

Fair enough. I didn't mean to imply that obliques are not important. And they should never be ignored! Wink

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