How do low frequency room modes travel through walls?

Archived from groups: rec.audio.pro (More info?)

Hello everyone,

I live in an apartment complex and I have a small home studio. I have some
usual low frequency room modes at 40/80 Hz, and their energy builds up like
hell when I move away from my standard monitoring position.

When standing in a corner, where I'm close to the floor and two side wall
surfaces, the 40 Hz wave is almost unbearably loud. It almost feels like
there's a real drummer hitting the drumset's kick drum in my room!

So, my question is: do my neighbours hear the 40 Hz tone as loud as I hear
it when I'm standing in a corner, or is the "modally excited" version of the
frequency limited only to my own apartments dimensions?

I mean, even if the wall between me and my neighbour would be as thick as 10
feet, I fear it isn't enough for attenuating the mode...Or is the boosted
frequency just bouncing between my own walls, so I don't have to worry that
much about the leaking sound?

Thank you so much for the help.

Archived from groups: rec.audio.pro (More info?)

"Ethan Winer" <ethanw at ethanwiner dot com> wrote in message
news:eb6dnckqyfFfEHfcRVn-tw@giganews.com...
>> When standing in a corner, where I'm close to the floor and two side wall
> surfaces, the 40 Hz wave is almost unbearably loud.

> Bass traps will help that, but they need to be pretty substantial traps to
> target 40 Hz. But are you sure it's 40 Hz and not 80 Hz?

Hi Ethan,

I checked the resonance and you're correct, it is in fact 80 Hz, not 40.

>> do my neighbours hear the 40 Hz tone as loud as I hear it when I'm
> standing in a corner, or is the "modally excited" version of the frequency
> limited only to my own apartments dimensions?

> There are two different resonances at play here. One is based on the room
> dimensions, and that affects what you hear inside the room. The other is
> the
> natural resonant frequency of the wall itself, and that affects what
> travels
> through to your neighbors. At the wall's resonant frequency transmission
> through the wall is greatest.
>
> I suspect some of the modal build-up inside the room does make it to the
> other side too, if only because it's so much louder inside the room.

Yes, that's what I had in mind. 80 Hz wave is approximately 8 dB's louder in
the corner than it is in the mixing position. I guess there isn't much I can
do about it, except build/buy some kind of a resonator. I just wished that
somehow the 80 Hz mode wouldn't be too loud a problem for my neighbours...