C300 Speaker Replacement

[Rygar71]

I just replaced my C300 standard speakers with Infinity Kappa 60.7cs in the front, Infinity Reference 6022si (replaced capacitor with a 4.7uF polyproprelene cap to smooth out the highs) in the rear, and SAS bazooka tube in the trunk (reuse from an old car - great space saver). Considering that the speakers were $240, I'd have to say that it was a kick butt upgrade over any HK audio install that MB could have done!

The front component tweeters fit perfectly in the stock tweeter housing. The 6 1/2 inch speakers required no cutting, just a few drilled holes. I tapped the sub into the high level rear speaker inputs where the wire runs under the front seat belt housing. Power the subs came from the 4 guage power cable that MB so graciously ran to the trunck. And the 12V power on detector came from a line in the rear fuse assembly.

It was a weekend job but the results were awesome, considering I kept the standard stereo head unit to maintain the car's integration.

Highs are smooth and clear. Good low end extension but not overwhelming. Great imaging. Couldn't be pleased and it didn't require any exterior visible mods...

So... yes the standard stereo sound sucks but that's the case for just about every car you buy. Upgrade the speakers and keep the head unit and you'll be well rewarded.

- Larry

[Murray Woo]

I was just thinking about replacing the tweeters to get more highs in my new leased C350. How did you know how to take off the tweeter covers? I have experience installing stereos but I always got my stuff from Crutchfield before and their master diagram helped, but they don't have one for C350 yet. Did you have to drill anything to put on the tweeters?

[Rygar71]

The tweeters were able to fit in the the same place as the stock tweeter. In fact, the Infinity Kappa tweeters I used were a perfect fit so pull dimension specs to get the size.

The tweeter cover actually clips onto the plastic schroud that goes around the window. As I recall, there's no physical attachment between the tweeter cover and door cover but it may be a little tricky to remove without pull the plastic shroud away from the door.

Removal of the door panel is pretty straight forward but I'd recommend using platic prying tools so you can focus the force on the retaining clip and not damage the panel.

[Mongkol]

Do you know what the power output provided by the COMAND head unit? What is the connector? Is there any possibility of putting an amplifier? I am also try to change all the speakers and maybe put an amplifier. My car is equipped with the standard speakers without any HK amplifier. I donno if i need to run a new power cable to the amplifier in the rear trunk. I would be really appreciate if you can give any advice.

[Rygar71]

I don't know the power output from the standard head unit. I went with 94/95 Db sensitive speakers and at 2 ohms you don't need a lot of power to drive them loud (Ex. 3 Db's of sensitivity difference results in twice the audio level so an 89 Db speaker will be 1/4 as loud as a 95 Db sensitive speaker). Given this, I have no headroom issues and a friend of mine couldn't believe the quality I got without an amp. Watts are overrated if you're going for quality...

Doing an amp for the main speakers is going to require more work and I don't know if there are any low level lines in the trunk. If you choose inefficient speakers you may want to go with a pro to re-run the speaker lines to and from the mains (it'll work but it'll take some work and money to make it happen).

The standard tweeter has a filter wired and located on the tweeter housing, filtering is not done in the head unit or amp like some BMW audio systems. Installing speakers will require you to cut the speaker lines and replace with a connector fitted for your speakers. You'll need component speakers in the front and I was able to easily locate the speaker filters behind the door panel.

For the sub I tapped off the high level audio line from the left and right speaker. You can splice the sub in at the rear speaker line that runs behind the seat belt housing on either side.

I needed a sub because the Infinitys are a little lacking on the low end. The standard speakers emphasize the low end spectrum (the crappy stuff the avg Joe likes) but lacks detail so you may find less bass if all you do is replace the mains.

If you need more details on how the tear your beautiful car doors apart, drill holes, and cut wires, send me a note and we can discuss off line. The surgery may be too graphic for some...

- Larry