Soundproofing and room correction for apartment?

So I had a small chat with my neighbors yesterday who said they can hear the bass from my stereo. I was listening at not-overly loud levels, although for me that may be louder than for them. I'm clearly going to have to address this. That, or give up listening, which I don't see doing.

I'm looking into having a sheetrock ceiling put up with insulation between the original ceiling and the lowered one. I'll also have acoustic padding put on the floor with wall-to-wall over it. I just simply don't have the extra room (sorry for the pun) to put up additional walls, so I'm really looking for recommendations on what I can do with the walls now to make it better: canvases with acoustic batting in them? Corner mounts? Bass traps? What?

Also, anyone have any experience with putting their speakers on platforms to prevent bass traveling? That seems to be the biggest issue here.

Thanks,

Matt

Brookjoo,

You need to get a book on acoustics and soundproofing. It is pretty hard to isolate bass frequencies.

Most of what you can put on the walls and ceiling will attenuate higher frequencies, but lower frequencies are tough. I don't think bass traps will actually lower the amount of bass transmitted to another apartment appreciably, but, if they, and other acoustic treatment improves the sound, you would tend to want to listen at lower levels than before.

As i mentioned before, the use of another layer of drywall with "green glue" between the layers will provide some bass isolation. This should not take up that much more room (compared to a second wall). There is quite a bit of discussion of green glue if you google the term, such as the following:

http://www.housingzone.com/blog/1290000529/post/1980051998.html

A friend had a professionally designed (Rives) dedicated listening room installed in his home and a lot of that stuff was used in the construction.

I bet that the extrasheet rock on the ceiling (with green glue in between) and a really good pad under a thick carpet will do quite a bit to reduce noise transmission. This would absorb some of the energy and provide extra mass, which also inhibits transmission of sound. Doing the walls too, would help, even if the big problem is with transmission to higher and lower floors rather than next door, because bass energy transmitted into the structure travels everywhere.

An energy absorbing platform under the speaker or speaker stand should provide some isolation from direct transmission of vibration from the speaker itself to the floor. Even if it only provides a little help, it is better than nothing, and besides, it often improves the sound of the system.

One more reference to Green Glue. I recently heard an NPR broadcast about environmental noise. The guest, who recently wrote a book, actually mentioned Green Glue as one of the modern technological marvels that helps in reducing noise. A transcript can be found here:

http://www.npr.org/templates/transcript/transcript.php?storyId=125511963

Thanks so much Larry, really helpful! I'm going to start bit by bit so I can get a sense of how the things I add change things for the better.

First definite changes will be platforms for my speakers, then wall to wall carpet with acoustic padding underneath. Then I'll some bass traps and wall/corner treatments and make sure the door seals well.

My neighbor is fine with me being in their space to see how much sound is transferring, so I can get a sense for how I'm doing with the treatments. Last resort will be dropping the ceiling.

One thing that I am thinking in the back of my head is that I may have too much speaker for the room. I have Devore 9's, and the room is roughly 12 x 12. Should I try the super 8's?

Thanks!

I have heard both DeVore speakers in somewhat small rooms and really like both. I don't think there would be that much difference between the two for your sound transmission problems. The BIG difference would involve the use of a fundamentally different kind of speaker, like the Quad electrostatics or Magnepan speakers (for the dipole cancellation reasons I mentioned before). The current Quads sound pretty good at low volume too, helping your problem even more. But, I can understand your desire to stick with the DeVores; they are really nice sounding speakers.