My receiver does not go to +50. \:\) Luc, all receivers are different, so your -15dB could be -20dB on mine. You have to get an SPL meter to see what SPL your at for a given volume. With that said, it varies for me from -25 to -15dB's

M80s VP180 4xM22ow 4xM3ic EP600 2xEP350
AnthemAVM60 Outlaw7700 EmoA500 Epson5040UB FluanceRT85