I have just splashed out for some 605 CS for my 02 STi type UK, and am a little concerned that I might need to drive them off an amp. However a dumb question or 2....

Do the 605's need to be driven from an amp? I have the Clarion double DIN unit (apparently 45X4 Watts)is this sufficient to power them?

If I do, how does the amp connect to the head unit? my head unit has an ISO connector, and arial out and thats it!

What size are the rear speakers in a STi UK? and any reccomendations?

 

The speakers really should be driven from an amp. Your headunit does not put out anything like 45 watts per channel in reality. You need an amp that can deliver around 100 watts RMS per channel at least. If you are determined to keep the existing headunit you will need to purchase an amp that allows high level inputs to be connected (in other words you connect the speaker wires from the ISO loom straight into the amp.) Don't really know of any modern amps that allow this. This is not ideal and if you can it is much better to purchase a decent headunit that has RCA outputs that can connect straight into the amp.

Hope that all makes sense.

Cheers

Ed