NCBob

Hey guys. I've conducted an in-depth search and cannot find how to remove the cover for the rear package shelf in either a C300 or a C63.
I just bought a new C63 with the HK system and I am not real enamored with the bass quality. Therefore I want to add an amplified sub.
I plan on tapping into the existing HK rear deck sub, but I need to remove the cover to access the four dual coil wires.
I have the fold-down rear seats, so removing them is not an issue.

Also, if anyone knows what wires correspond to +/- or right and left in the HK sub, that info will also be appreciated.
Thanks in advance.
Bob

Acapulco Bill

The HK bass speaker output from the amp is highly equalized to compensate for the characteristics of the small long-throw speakers. IMO it will prove unsuitable for providing a proper signal for a self-amplified subwoofer, as some frequencies are highly boosted, and others eliminated.

NCBob

Bill,
Appreciate your comment. I just got rid of a GLK350 with the HK. I added a Bazooka amp/sub and it provided an outstanding bass improvement.
Very few songs actually have good bass quality with the HK sub. Hoping for better results. If I have to, I'll bypass the HK sub totally and use just the wiring.

Acapulco Bill

@NCBob: Were you playing just MP3's on the HK before?

05 MB Komp

I tapped the wires for the rear speakers at the amp. The amp is tucked in the left side of the trunk behind the carpet. You do not need to pull the deck, I have two subs and used a signal converter to get my amp working with the HK system.

I do not remember the wires that need to be tapped but it is on the forum somewhere.

Norm01

As said earlier, tap in at the amp in the left rear quarter. Search posts with my user name, wiring is fully documented. Although I usually agree with Bill I must respectfully disagree this time. Due to th surround sound the bass signal will not be present anywhere else or will certainly be cut off at the lower frequencies. I originally tapped into the rear speakers with less than stellar results, I'm tapped into the sub signal with a JL audio mono 500w and a 10W6 Prowedge.

Acapulco Bill

Norm01 is correct that the lowest frequencies of the bass can only be found at the speaker output of the sub amp. As for which is "+ or -" it is relative, although a voltmeter will show you which is closest to the chassis ground, which should be connected to the "-" on the amplified sub's high-level input.

As for phase, there is usually a switch to invert the phase. Just play some music at medium volume while sitting in the drivers seat and have someone else flick the switch back and forth. Whichever one sounds loudest is the "in phase" position.

However I must repeat that the output to the sub speakers out of the sub amp is VERY highly equalized, and some frequencies will be almost entirely absent and others boosted to 12 dB and sometimes to 18 dB. A CD test disk with a signal sweep (or maybe one can be downloaded from the internet, or even an app for a cell phone which can be plugged in) plus a Radio Shack SPL meter, will surprise many to see the boost and cut of the HK sub equalization.

I am unsure if the parametric equalizer can be used to "unequalize" the fixed EQ of the HK system. Many look for sonic truth while others may be satisfied only with boomy, throbbing earache-level bass, which has nothing to do with the music IMO. Best of luck.