Where to find good reference source material?

Hi,

Know of any websites where one can download some audiophile recordings & sound checks (in CD format)?

I have a site with some Chesky recordings, will post later (they are probably pirates though).

I'd like a recording with bass test notes & sweeps, to help with speaker placement & ports

And of course any good free music that happens to be recorded brilliantly is also welcome!

Regards
Leon