What is the best noise attenuating material?

[kez1]

I have a tenanted flat with neighbour noise problems.
Easiest way to reduce noise travel to and from the flat above is to lower my ceiling and stuff the lowered area with noise attenuating material.

Whats the very best stuff to stuff into the lowered ceiling area to really get the noise moving between the two flats right down?
(both high and low frequencies, particularly music "dush-dush-dush" beat)

What depth of this stuff do I need, ie how much should I bring the roof down by?

 

[IT Minion]

Damping low frequency noise is hard. For that you're pretty much down to adding mass. Concrete should do the job. Or lead.

Get them to put their speakers on stands to mechanically decouple them. Heck, buy them the stands. It'll be the cheapest way to reduce noise and the most effective. It'll also sound better for upstairs.

On a more helpful note, generally thermally insulating material works well as an acoustic insulating material. More advanced and expensive options exist but the price/benefit is incredibly hard to measure /justify.

 

[tony1851]

If you want to do the best job for the ceiling, you are going to loose about 300mm of floor-to-ceiling height as follows;

form a suspended ceiling of 5x2 or 4x2 joists (depending on span)@ 400 centres wall-to-wall; top of joists at least 150mm below the ceiling; joists must not
be supported off the exisring ceiling structure. Above joists drape acoustic quilt (not the lighter fibreglass thermal insulation quilt); to the underside of the joists, fit resilient bars, and to those screw two layers of soundbloc board with stagggered joints (= plasterboard about 15mm thick) and skim.

That is the standard commonly accepted when converting older houses to flats. It will be expensive and whether or not you find it worthwhile is subjective.

Also, be warned that sound will also find its way down through the walls, so overall the attenuation may not be as good as you want or expect.