Mercedes-Benz Forum banner

1 - 10 of 10 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter #1
OK, I know the subject has been 'beaten' to death but I can seem to find the answer that I am looking for. I have a '99 c280 with a Audio 30 with the Bose system. I want to put an aftermarket HU and integrate it with the Bose system. It seems like pre-99 model, the consensus is that you need a line converter between the aftermarket HU and the Bose system. For 99 and later model, it seems like I don't need a line converter. I talked to a Becker tech over the phone but he didn't know what type of signal coming out of the Becker HU going to the Bose. Anybody knows for sure which way shoudl I hook up the aftermarket HU, line converter or not. Remember this is on a 99 C280. Thanks a lot.
 

·
Registered
Joined
·
3 Posts
This is how I did my 99 E320... The aftermarket HU had a built in 4x50 watt amp which I used to power the speakers of the car. Then proceeded to locate the bose amp and jump the wires across the wiring harness... (plug input into output)... and finally picked up a subwoofer amp and am currently power the factory subs which I am replacing in the next month
Hope this helps
 

·
Registered
Joined
·
4 Posts
Discussion Starter #3
320wagon,

If you have a Bose amp, which sounds like you have, bypassing the amp and go straight to the speakers may not be a good idea. From what I know, the OEM speakers are 2 ohms and the output from any aftermarket HU are 4 ohms. It may damage your internal amp on your HU in the long run. Just my $0.02.
 

·
Registered
Joined
·
152 Posts
The low 2 ohm resistance might not initailly damage the head unit amp, but it will make it run a bit hot which ultimately may damage its amp. Two ohms is a very low load for an amp, and Bose does this to make their cheesy 40 watt amps sound better.

Also, Bose electrically compensates in amp for the inadequacies of the toilet paper drivers they sell.

So, the system might not sound so great overall.

Look up better quality after market drivers such as www.morelusa.com. They are a bit pricey but are exceptional.
 

·
Registered
S420
Joined
·
49 Posts
http://I talked to a Becker tech over the phone but he didn't know what type of signal coming out of the Becker HU going to the Bose.
Wow!

The radio in your car has an internal amp rated at about 20 watts x 4. It feeds the Bose amp. (Yep, the Bose amp takes a high-level input.) Also, the systems used in '98-'99, are basically the same. Different HU maybe, but work the same (apart from fiber optics which wasn't part of the question).

So if you're changing to a similar head unit, no problem. If you're changing to something with lots of power, you'd probably better bypass the amp. If its something with low-level pre-amp outputs, it probably won't work.

What is a line converter, anyway? Something that changes high-level to low?
 

·
Registered
98 SL500 SPORT SLVR
Joined
·
280 Posts
Screw the factory amp!! If it hasnt failed yet it will! Just get a good 5 channel amp to run everything and be done with it!
 

·
Registered
2004.5 C230 SS (M-F) / 2003 SL500 (Sat/Sun)
Joined
·
14 Posts
I may be a newbie on this site but I have worked in the install dept at circuit city for almost three years now.
From my experience, yes, bose amps have so many problems, it good to get an aftermarket amp and bypass the whole thing. Soon they do fail, its quite common.
All of the bose systems we have worked on require bypassing the factory amps...in which there should be 5 of them. 4 for front and rear (L/R) and one for the sub if you have one. You would need to run speaker wires from the speakers in your doors to the aftermarket amp and use RCA's to feed the preamp line from your head unit to your amp. Cut and cap any wires presently connecting the speakers. BOSE amps usually are attached closely to the speakers. BAsically get rid of all bose stuff except the speakers. Be careful in taking the doors apart if you have airbags, diconnect the battery first.
I'm not sure if bose speakers are two ohms but I doubt it since 2ohm speakers present larger loads to the amp and lower sound qaulity, not what bose is going for. Either way, a preamp signal will not even drive 4 ohms if there is no amplification. A bose head unit by itself will not power the speakers. As far as i know, All of the bose headunits by themselves send a preamp singnal to the amps. Normal head units have line level signals. Truthfully, I love the sound coming from my bose system so I just tapped the sublines with a high to low converter and added just a sub and kept the stock radio and highs. Its sounds FANTASTIC! Skip the converter...use your new headunit to send signal signal the aftermarket amps..run stock speakers if you wish..be carefull though. Distortion blows speakers before high power does! PS, no offense but becker is probably the worst brand of stereo I know of (quality features etc..), why do you want to install that? Anyway good luck
[;)]
 

·
Registered
98 SL500 SPORT SLVR
Joined
·
280 Posts
HEY,
MY SHOP TOLD ME I DONT HAVE AMPS ON MY SPEAKERS OTHER THAN THE SUB.
IS THIS TRU FOR 98 SL500 SPORT?
 

·
Registered
2004.5 C230 SS (M-F) / 2003 SL500 (Sat/Sun)
Joined
·
14 Posts
I have yet to work on that specific car but I doubt you have only an amp for the sub. that would mean your radio was sending high and low level signal at the same time; one for the sub and one high level for the highs. It is possible but a slim chance..I doubt it.
 
1 - 10 of 10 Posts
Top