How do I compress pdfs comprised of images and sound bites without losing quality?

I’m a musician from Cape town South Africa and have to send pictures, information and samples of my work via email to people in my industry in other countries. I need to be able to compress large files (both images and music) without loosing quality. I’ve scoured the net and most advice is to archive (I use Mac) or use preview to compress. however, archiving will only compress by .1 of a meg and preview completely corrodes the quality of the images. The pdf is just over 8 MB so it exceeds the limit on many mail programs the sound samples are in that region too…
Has anyone else had the same problem? if so how did you get around it?