mhh

I've just bought a new s65 with the HK system and although the sound is OK, I was expecting better. Would better speakers help?

trumpet1

I would have to believe that replacing any part of these systems is very, very tricky in the way they fit physically into the car as well as the power/voltage specs involved. I too feel the sound is not as good as I would like it but I find it acceptable enough not to go tampering with the car with aftermarket items.
That being said, if you can yourself (or) if you find a very dependable and responsible aftermarket installer, I highly recommend Quart speakers. They IMO are the finest sounding speakers on the planet for automobiles.
One other thing, I only feel the stereo needs more bass and that might not be that complex to add on as the only demand there would be a pre-out signal and a power source and of course a proper location and with all of the extra space taken up with computer boards and panels, good luck finding a place.