I'm not super-knowledgeable in the audio world, but I do love a great sounding system, so hopefully this isn't too dumb of a question. My dealer installed my entire system a couple of years ago, including a WS420, and it has sounded really good, but I have always had the "hiss". After reading through the WS420 tuning instructions on the WS site, they had the gains on my amps way too high, almost maxed out...

Typically, I play my iphone directly through the aux on the EQ, but I want to take advantage of the mute button on my remote, so I bought a bluetooth puck to plug into the aux of my HU. I never listen to CD's anymore, but I tuned today using a CD as the WS420 manual suggests. Doing this worked great, and the gains on my amps are way lower, and no more "hiss", and the sound is fantastic.

However, using the same setting with the bluetooth puck and my iphone, it's not nearly as loud. I can crank the volume all the way, and it's not loud enough. Is this expected just due to the quality of the connection? Or should the volume (not necessarily the quality) be the same as a CD?

Since I never listen to CDs, should I be tuning the gains based on my bluetooth connection, and bypass tuning with a CD?