Paul,
Pioneers RCA Outputs are known to cause whinning issues. Try this...Take a strand of electrical wire, tie it around the connection of the Male/Femail RCA cables and GROUND the other end of the wire. This MIGHT cure your problem. I had to do this with my Avic-N2 when I had it.
Chitown,
I am not sure if the 700 and the 90 have different connectors. I would think that they both have Front Rear and Sub RCA outputs...
The version I have is the F90BT which is from Pioneers Premier line.
__________________
http://i46.tinypic.com/2qx0rqs.jpg
2001 Boxster Artic Silver / Black Interior
-GT3 Front Bumper w/ Lip
-Side Skirts
-Gemballa Exhuast and Cats
-O.Z. Racing 18" Wheels
--18X8.5Front 18X10 Rears
-Michilen PS Tires 225/40/18 & 285/30/18
-5mm Rear Spacers
-Porsche Door Sills
-H&R Springs
-Powerflow Intake
-B&M Short Shifter
-Pioneer Avic-F90BT Navigation
-Focal Polyglass 165VR3
-Alpine PDX 5 Amp
-Bose OEM Subwoofer & Midrange
-Audio Controld DQXS (DSP)