I don't think you can draw too much from the "-32" dB on the display other than a relative figure for comparison purposes.
On some Yamaha receivers where the range ends at "0 dB", Yamaha recommends safe playback up to -15 dB.
Since the RX-V5760 will go to +16.5 dB or something, it may be possible on your receiver to exceed -15 dB. Don't try it on my advice though, I'd consult with Yamaha first.

Here's a link to Yamaha's FAQ's on this subject (which appear slightly outdated since receivers now go above "0dB").
http://www.yamaha.com/yec/customer/f...vers/faq41.htm