Temporarily soundproofing a single, concrete wall

[maverik]

Hi,
I'm shortly moving into student housing at my university. Its appartment style, with 6 units forming a "quad" that shares kitchen, bathroom, etc.

There is good soundproofing in the form of concrete walls between these units. However, there tends to be very poor soundproofing (despite the walls still being concrete) on the wall that you share with the next quad over.

I am looking for some way to reduce the amount of sound passing through this concrete wall. It needs to be fairly temporary (though some damage to existing is ok) and fairly cheap.

One thing I'm particularly interesting in damping is vibrations from a subwoofer. That might be as simple as simply putting a mat under it though.

Thanks in advance for any advice!

 

[jonnyc]

Mass. Build walls on top of your walls and fill it with whatever the best sound deadening material you can afford. I used multiple layers of drywall and insulation but some sound still leaks thru.