I'm considering buying a condo, but have to consider soundproofing as a limiting factor.

What's a good STC rating for a home theatre enthusiast as myself? I have an Axiom Epic 80 (no sub, but soon to be an SVS sub), and I don't want to become my new neighbor's biggest enemy the day I move in.

I will only buy a place with concrete floors, but it is the walls I am concerned about. Many places are advertising STC rating 63, which I hear is half decent. Others are saying they use a "Cali" system (?) to soundproof to 69. Is there THAT much difference between 63 and 69? Is 63 sufficient to watch Underworld at a nice volume with an SVS sub?

thanks for all your help.

I remember reading somewhere that the Average db levels for a room (fans, cars driving by, etc...) is from 20-30 db.

If you get a condo with 69 STC and you add the average room db levels you get a level of 99 db.

99db is the level of loudness that you are able to play your home theatre at. without someone next door noticably hearing what you are playing.

If your home theatre is set to around 75db (like many people here) your peak explosions will be around 100db. Your neighbors should be fine and not even really notice that you are playing a movie at high levels because in their room, they already have 20 - 30 db of backround noise.

Does this make any sense?

If you get a condo with 69 STC, you are going to be able to play your system at normal levels without worrying about sound transfer.

I've never even HEARD of a STC rating, so take this with a grain of salt:

90dB of a 1KHz tone is not going to annoy the neighbors nearly as much as 90dB of a 20Hz tone....

I know that's obvious, but I wonder how likely that STC "spec" takes subsonic frequencies into play?

here is something I found that explains STC ratings:
http://www.cmhc-schl.gc.ca/en/co/reho/reho_003.cfm

It seems to suggest that anything in the mid 60's or higher is quite good, however, I just wanted people's feedback with these ratings and if they feel that they are adequate.

You need to take into consideration though, that the theatre next to the one playing a movie at 100+ db's is also playing a movie at ear bleeding volumes. That makes a big difference. It's not the same as one room playing a loud movie and the other room trying to relax and read a book.

Ravi, welcome back! An extremely quiet room at home would have about a 30dB background noise level, but more typical would be about 40dB. So, STC ratings actually in the 60s should protect the neighbors against everything but audiophiles who like to go above even reference level.

Hiya Ravi! How have the last few years been? Perhaps inviting your new neighbors in to watch the HT might be a wise thing to do.

I have to admit, I am quite surprised that people here actually remember me! It is flattering

I have been keeping busy, not too much in the audio world, though. But now that I might be purchasing a condo, it's time again to brush up on my knowledge, and to hopefully buy a subwoofer as well.

>>and to hopefully buy a subwoofer as well.

Well, with the STC of 69, you midaswell get 2 EP600s