I have searched for about an hour and can't find anything specific for my car. I have an 06 C230 Sport Sedan with Harmon Kardon audio system. I'm trying to add an amp to power 2 subs that I want to put into my car. I was told that my head unit uses fiber optics or something and that this would not be possible. Is there anything I can do? Someone said something about a hi-lo integration unit but I have no idea what that is and I can't find it on google.

Thanks for any help.

 

you can use a signal converter and tap into your rear speakers. it converts the signal from the rear speakers to a RCA output. looks like

http://cgi.ebay.com/ws/eBayISAPI.dll...#ht_3629wt_835

it actually is the high to low adapter. lol

 

What he said......and just disconnect the factory bub in the rear deck for your signal.

 

i have a smiliar problem, although with many threads about subwoofers my lack of knowledge of the various 'standard' setups isn't helping, maybe you guys can...

i have an 2007 cdi200,with comand and want to improve the bass response, particularly at the lounder end, so having had a poke around the car, i find out the following (i think!)

1 there are no 'pre-outs'on the comand unit
2 there are no speakers on the rear deck, despite there being speaker grilles
3 there appears to be a structure in place on the rear desk for a sub-woofer (there's a round hole, with supports - about 10" i think)
4 there's also a 'hole' where an amp might go.

i really want to retain the interior look of the car so had planned the following:
1 upgrade front door speakers & tweeters (any suggestions? what size? how do i remove door trim?)
2 plug in a subwoofer. my pref would be to get something sitting on the rear shelf, wither active or a separate amp - any suggestionos? would a blaupunkt thb200a fit? anyone tried it? are they any good? the other option was to put a Fli Trap 10" active enclosure in the boot, but would prefer the unseen option.

finally, finally, finally, does anyone have any comments about using a speaker level output to power an active sub? i've heard they can be inferior and they pick up interference?

any suggestions welcome.

thanks

 

So there is no way to keep the factory sub and just add one additional sub?

 

There is. Just keep it connected. Actually an easier way to connect the high low adapter is in the dash behind the HU. All the wires are right there, then just run the rcas through the car as you normally would.

 

So I got it done. Bass is incredibly loud and totally over powers the mids and highs. I've got to fiddle with the amp to get it to sound right. I guess they somehow linked my sub with the front speakers? So I can get the bass to decrease if I fade the head unit to the back -8 or -9. So I got the Rockford Fosgate Amp Install kit and an adjustable line out adapter both from best buy. They cost a total of $143 but my friend used his employee discount and it cost me $42 (not a typo). I had it installed at OC Harbor Sound for $75. They literally took forever and the owner wasn't very personable at all. He told me 30 minutes for them to get started on it and an hour for the actual install. I was there over 3 1/2 hours and the install guy managed to leave some dark spots on my backseat. The reason I took it there was because the "mercedes guy" had the day off at Fry's electronics and one best buy knew how to do it but was booked for the day and another best buy said it was not possible to do in my car. Pep boys wanted $150 for the install, so yeah I settled for the independent stereo shop.

Heres pics.

 

Yes, they "tapped" a signal from one of your front speakers to give the signal to your subwoofer amp. That was done incorrectly and you should take it back to have them fix it. Make sure they tap it off of your factory subwoofer wire. You will get a better signal and your fader will work correctly. I would also recommend that you disconnect the wire from the factory subwoofer (this will reduce the load on your factory amplifier), as the bass from that speaker is not needed.

Also, when I got my amp installed initially, the shop did not listen to my instructions to tap the signal off of the factory subwoofer. They tapped it off of my rear right speaker, and that speaker was blown within 1 week and had to be replaced. After having them rewire it to the factory subwoofer, the bass is much cleaner. It was the extra load on the rear right speaker from powering the speaker plus feeding a signal to the line output converter is what caused the speaker to blow. When an amplifier is under a high load that it cannot handle, then it will start "clipping", which is when the amp starts sending out dirty output (wattage) to the speakers, which will blow the voice coil. Most people that blow out speakers is caused by trying to push more wattage out of an amp than it is designed to do.

It sounds like you need to adjust the gains on your amplifier if the bass is too loud. Once you get the wiring fixed, the best way to adjust the subwoofer is to turn down the gain on your subwoofer amplifier all the way down, then turn on a song at the loudest volume level you can go without any distortion from your speakers, and then turn the gain up on your subwoofer amp until you reach the desired level of bass. You will find however that at low to medium volume levels, your subwoofers will tend to overpower your stereo. That is a characteristic you will have to live with, as this is normal when you use a line output converter to provide a signal to your amp. If you had a headunit with RCA outputs, then you wouldn't have this problem. What I do is use the fader to adjust the bass level.

 

That looks nice! I just got a pair of Rockford Fosgate P1s. Not horribly powerful speakers, but the box is top notch. A friend competes with this kind of stuff... built the box perfectly!

 

Thanks for the info. I sent the shop an email. Waiting on a response.

 

hello all,

nice install btw. now this might be a bit off topic. I have a 2005 c230 with the H/K system. The system is ok, but the factory woofer vibrates the rear shelf like crazy! even with the bass set at 0, it rattles like crazy. I tried putting some pressure with my hand and i turned the bass up to like 8 and it actually puts out decent bass! i just need to somehow get rid of the vibration. I tried sending to the dealer when i still had warranty, but they were unable to find any problems. Now that I am out of warranty I will take it upon myself to find a way. I need my trunk space so an aftermarket box is out of question sadly. My questions is: is there a how to on taking the rear deck apart? i wanna stuff some dynamat or something in there so i can get rid of that annoying vibration!

 

I have the same rattle, and my solution, which works perfectly, and was the same solution I used in my Jeep... Turn the music up! But seriously, I've tried everything to get rid of the rattle short of taking the whole rear deck apart. The ting I found that worked the best was to use a business car and fold it to make a wedge to put in between the rear deck and the grill. You can pry up the grill just enough to wedge it in there.

On a side note, what I found to work the best for the sub woofer signal with the H/K system is to tap both the sub signal and a rear speaker. I have tried with just the sub, and that left out some higher frequencies. Using just the rear signal left out the lower frequencies. I taped both so that Ch.1 was the sub, and Ch.2 was the rear. I then bridged the two channels (to get the full power of the amp) which mixed the two signals into one. That gave me a spectrum that more than covered the range of the sub. That allowed me to adjust the crossover frequency on the amp to the limit of the sub covering its entire range. I only have one sub, but it could work with two subs. The two subs will need to be two 2 ohm subs wired in series for 4 ohms. It is not recommended to bridge two channels with less than 4 ohms, as that actually brings it to less than 2 ohms per channel, which is the limit on most amps.

 

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wow, that business card trick worked! the vibration is not completely gone, but greatly reduced! im quite impressed, alot of bass comes out of that little woofer! i never turned it up this high before! only thing i gotta figure out now is to find a better solution than business cards, as it looks ghetto-fab right now! Thank!