If a baffle is 2 meters wide, what is the frequency where the sound

[454Casull]

fires completely into 2pi space?

[Equilibrium]

divide the speed of sound by 2 meters

340/2=170

170Hz

give or take

depending on air pressure and temperature

more or less

[GM]

Hmm, 'sound is round', so assuming a round baffle to keep it simple and SoS = 344.424m/sec, then as a rough approximation: 344.424/pi/2 = ~54.82Hz/F3, but there's a terminus end correction of radius*0.613 that needs to be accounted for: 344.424/pi/(2+(2/2*0.613) = ~41.96Hz.

If F6 is what you're looking for, then it is 1/2 octave away, or 41.96*0.707 = ~29.66Hz. Or just use Linkwitz's formula for F6: (0.17*344.424)/2 = ~29.28Hz. I assume the inaudible discrepency is due to him rounding the numbers off a bit in his lumped sum value.

GM

[Hybrid fourdoor]

So...so far we got 144Mhz, 170Hz, and 42Hz. Anyone else????




You know how this scientific stuff is

"Industry, science, and technology! Big men putting screwdrivers into things! Turning them! And adjusting them!"

[Hans L]

F3 of 42Hz and fully into 2pi at 170Hz is pretty close. However, this is all theory. With these kinds of frequencies in a room, you will probably get completely different results due to roomgain and standing waves.

[Svante]

Originally posted by Hybrid fourdoor
So...so far we got 144Mhz, 170Hz, and 42Hz. Anyone else????




You know how this scientific stuff is

"Industry, science, and technology! Big men putting screwdrivers into things! Turning them! And adjusting them!"

Depending on how you define "fully" all answers are correct. Unless you really mean fully (ie nothing gets around to the back side), then the answer is "infinite".

[pinkmouse]

rcavictim

Your comments are inappropriate for this forum, and not required here, so I have removed them to Texas. Please behave from now on or further action will be taken.

[rcavictim]

Originally posted by pinkmouse


rcavictim

Your comments are inappropriate for this forum, and not required here, so I have removed them to Texas. Please behave from now on or further action will be taken.

Well 'ya see officer......here I was in the proper lane doing the speed limit when someone says "2 meters". Just so happens that triggers a nerve because I do care and am most concerned with the direction where amateur radio is going. I apologize for posting clearly off topic.

[454Casull]

Originally posted by rcavictim


Well 'ya see officer......here I was in the proper lane doing the speed limit when someone says "2 meters". Just so happens that triggers a nerve because I do care and am most concerned with the direction where amateur radio is going. I apologize for posting clearly off topic.

What does a distance of 2 meters have to do with amateur radio?

[GM]

Depending on how you define "fully" all answers are correct. Unless you really mean fully (ie nothing gets around to the back side), then the answer is "infinite".

Hmm, obviously I was not thinking in terms of F0 WRT 2pi space radiation, but it would be 1/2 octave above F3, or 1.414*~41.96 = ~59.33Hz, so I don't see how ~170Hz or any other frequency 'up' to 'infinite' can be correct, especially since 'infinite' as I understand the term = DC.

GM