[acoustat6]

Hello Everyone, I was purusing another audiophile site and was reading a thread on acoustics and subwoofers and their interactions, set-up etc.

Someone posted this interesting post below and was wondering, does this sounds true to me? My initial thought was yea that makes sense, then I thought well if it is true, then 10hz to perhaps his stated 45hz would not be a problem in our rooms and would not have peaks/dips till starting at 45hz and up.
Ethan and other knowledgeable acoustics friends could you comment on the statement below.


HE SAID,
"Frequencies below about 45 hz or so pass through typical sheetrock walls and so no cancellation takes place. Therefore speakers more than 6 feet or so from this wall will not be affected by 1/4 wavelength cancellations. If the wall is reinforced then it is still O.K. if the speakers are more than 8 feet or so away as the loss will be attenuated by typical " room gain" below 35 hz or so. If 6 or 8 feet is not practical then try pushing the speakers very close to the rear wall and use thick absorption behind them. ( thick enough to absorb 125 hz) If this is not practical then yes nonalignment is a good idea."

My main concern is the first sentance where he states; ""Frequencies below about 45 hz or so pass through typical sheetrock walls and so no cancellation takes place."
How much truth is there to this?

Of course feel free to comment on the rest of his statement if you feel so inclined.

Any truth to this?

Bob

[Ethan Winer]

As they say, a little bit of knowledge is a dangerous thing.

Very low frequencies do indeed partially go through walls. But it depends on the frequency, and especially the mass of the wall. 45 Hz does not go through standard sheet rock walls 100 percent. If that were true you'd never see peaks and nulls below 45 Hz, which of course is not the case. So in a practical sense those comments are incorrect.

--Ethan

[acoustat6]

Hello Ethan, Thanks for the reply. It is what I thought.

Also I did after posting this  thread "feel badly" using his quote directly as I should have just rephrased it. So if the person who posted this (on the other site) reads this no harm intended. I apoligize in advance. I do know that the internet is "fair game", and I have seen some of my internet postings (words/photos) used elsewhere. I am old SKOOL and it just does not seem right to me at times.

Bob

[Ethan Winer]

LOL, you should see what they do to me!

--Ethan