When playing CD's with a lot of base - for instance music for Braveheart - the right speaker rattles or has a sound like the cone is torn. I removed the screen for it while the music was playing, and physically it looked perfect.

I am aware that the base speakers are uni-directional so that might be throwing me off.

After I'd bought the XF (via phone) in Texas, they were still going over the car and I was told that one of the items was that the right amp was out. Sometimes with even the music playing in the higher range, the sound coming out of the right speaker sounds muddy. Could a bad amp cause this?

I have a NOS Clarion VZ709 I'd like to install. It has 200W (in theory) - 50Wx4. It is set up for both a cell phone as well as XM - the later being the most important of the two.

Should my problem be the right amp (a) are they available (b) would the amp in the head unit act as a pre-amp or vice-versa? Or is it most likely the speaker?

I was given an answer to this but failed to print it out - what types of adapters would be needed for the speaker wires as well as the XF's separate amps?

I did read one thread where a different head unit was installed. The wiring looked a bit daunting but doable.

I'm just throwing this in, but many, many (pre digital) years ago I was reading a British car magazine where a head unit for sale was designed to automatically adjust the volume in accordance to the decibels in the interior. This should be a mandatory provision on all, at least middle to upper priced head units, in my opinion.