[comprev]

Thanks for the links very interesting to read.

I buy loads of DJ music on Bandcamp and "downsample" (I think the term is) to 16bit if they only offer 24bit for smaller size and wider compatability.

[spacechild1]

That's not downsampling, that's reducing the bit depth. The bit depth determines the resolution of a single sample, i.e. the number of possible values it can represent.