MAC4Runner
New member
While hanging out in the scionlife forums yesterday, I learned you can change the ssp settings on the Scion radio, besides the usual neutral, hear, and feel. If you hold the ssp button for approx. 5 seconds the display will indicate the type of Scion, either Xb or Xa. You change the type by using the arrow buttons for volume control. Mine was set to Xb and by chaning it to Xa it greatly increased the high-end of the HU. 
YMMV
In addition, you can purchase the OEM Scion Bazooka Tube Harness, Toytota Part Number: PT520-52040-WH, for approx. $60. This will allow you to hook-up a powered bazooka tube, such as the CS8A, and it will be driven off the stock Scion HU. There are numerous posts in the audio section of scionlife regarding this mod.
Enjoy
YMMVIn addition, you can purchase the OEM Scion Bazooka Tube Harness, Toytota Part Number: PT520-52040-WH, for approx. $60. This will allow you to hook-up a powered bazooka tube, such as the CS8A, and it will be driven off the stock Scion HU. There are numerous posts in the audio section of scionlife regarding this mod.
Enjoy
