Noise on new install

Hi all, I just had my Scion xB upgraded today at Circuit City with a Pioneer AVIC-D1, 4 Infinity REF component speakers, a 4-channel Infinity Amp, and an Infinity BassLink module. I am hearing a rather loud hissing sound, that doesn't change with the volume. Maybe the amp is bad? Noisy? Any advice on how to debug it would be appreciated. Thanks..

Take it back to the shop that installed it; demostrate the noise to them and let them do the troubleshooting; it's what you paid for.  I work for circuit city and, although we all hate seeing cars come back for issues such as these, I can't believe they'd let the car go and consider the job done if the noise is loud enough to be noticable and even slightly annoying.  Especially if you dropped enough $$ with them for a D1, and a full complimentary system.Life moves pretty fast; if you don't stop and look around once in a while; you could miss it.

oh and hopefully they didn't sell you the D1 with the assumption that it plays DVD's.  We had one sales guy do that; that was a fun return to take  Life moves pretty fast; if you don't stop and look around once in a while; you could miss it.