evilsaint

Pretty sure that the lack of low-freq bass is *because* it is a free-air sub. True, it essentially uses the trunk as an enclosure, but only to a limited degree. I've thought about trying to replace the free-air one and put a smaller one in its place with a real enclosure below it, attached to the underside of the rear deck, but it seems like entirely too much trouble as compared to just replacing the OEM sub with something else.

loudandheard

I really wanted to do some thing like this, but we do not have a large enough rear deck. This was done in an s500 using 3 10" free air subs.

evilsaint

Maybe a single 10"/12" free-air but not a Bose sub, and with some real power?

peak_oil_101

anyone have luck disabling or removing the HK audio system microphone which adjusts the sound based on cabin noise?

MIKESV8

luckily my family owns the largest car stereo shop in nor cal. and i own a c55 so i'm here to help. one of our installers built me a fiberglass enclosure for 1 12" diamond audio hex pro and he removed the factory subwoofer so that it acts as a port for the sound to go to the cabin. pretty much putting any sort of aftermarket subwoofer system in your trunk (it's not like we have a small trunk so space shouldn't be an issue) would make the difference. it's a very large hassle removing the rear deck to take out the factory woofer, but it is worth it. putting any old 4 or 8 ohm subwoofer in replace of the factory one will not work correctly because they're not really free air subwoofers.