I know it's a process but I'm looking for a little advice. I replaced the Head unit and the installer was able to bypass the HK amp and get sound out of all the speakers but bass and treble adjustments made at the head don't make any audible changes.

If I just buy new speakers am I going to have the same problem? If I buy an amp and use the RCA pre outs can I reuse the existing speaker wires? I'm just trying to understand what level of complication I'm up against.

If I can just replace the speakers I was thinking of the Polk db6501 front and 651 rear. If I have to add an amp I'm curious to know if anyone has been able to find a good 6.5" woofer to get "decent" mid-bass from the factory speaker location in the convertible. Thank you for the help in advance.