John Sayers' Recording Studio Design Forum Archive

Ethan Winer wrote:> So says Newell <

Not so - see my Mon Mar 07, 2005 1:51 pm post above.

The post to which you are referring contains the following:

Philip Newell wrote:It should be stressed that standing waves always exist when like waves interfere, whether a resonance situation exists or not, and that the common usage of the term 'standing wave' to describe only resonant conditions is both erroneous and misleading.

It was my understanding that your argument was (is?) that modes are not standing waves. Which the above Newell quote very obviously contradicts. No one's ever argued that all standing waves are modes in the context of room acoustics. That's basic acoustics theory. But the opposite is absolutely the case - all modes are standing waves. As I've mentioned to you privately, if you feel a need to qualify "standing waves" with "resonant" in the context of "modes," then there is no argument.

Summary: Modes are standing waves and your quote backs that up. Glad I could help clear this up!

Jeff,

> Glad I could help clear this up! <

Nice try!

Seriously, I suppose you're likening this to the logic example:

All cats are animals, and all dogs are animals, but not all animals are cats or dogs. Okay, fine.

Not that long ago I recall reading, here and elsewhere, the argument that standing waves exist only at modal frequencies. That was what I objected to most strongly, because it's clear to me that a wave can stand still at non-modal frequencies, and also outdoors near a rigid boundary. This is why I quoted Newell, because he agrees with me that "resonant" standing waves are a subset of standing waves.

So now I'm the one who's glad to clear that up!

--Ethan

Guess we should be careful how we're saying things, hmm?

Jeff,

> And I recall reading in one of these forums not too too long ago that the sound of a cymbal is not composed of sine waves... <

Yeah, but it certainly wasn't me who said that!

--Ethan