Modifications
Car Audio & Video
Replacing the bose system (this is my opinion)
If your mb came w/a Becker radio and a Bose system the replacement is NOT easy to do.
Bose systems are designed for 2 ohm speakers and sub-woofers. Most systems in the regular world are 4-16 ohms.
There are some adaptors that help interface bose systems w/the regular world. It is my belief that those adaptors don't work well. I have never used them.
Bose only works w/bose.
If you want a non-bose system in your car then replace everything
head unit
amplifier
sub-woofer
speakers
You can use the existing stock harness, you will have to get the schematics for the connectors and do some splicing.
If you want to make it easy on you, replace you Bose head unit w/another bose. Buy used Bose components on ebay or on the mb forum.
If you buy used parts from ebay you are playing russian roulette. If you buy new parts you will have a big hole in your pocket.
On page 6 I show how I replaced the Bose system in my 300zx.
On page 37 I show how I repaired a bad Bose speaker in my 500sl.
Other MB forum member comments:
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I had an aftermarket head unit installed with the adapter. I used a radio shop that my local MB dealer recommended. They had installed many aftermarket units in SLs like mine, so they were familiar with the process and had the adapters in stock. They charged me $100.00 for the adapter, but I have no idea who they bought it from or what their cost was on it.
If you're going to start changing speakers to non Bose, etc. then you are going to need to replace the whole sytem.
Do yourself a favor. Go to an installer that has worked on these before. I checked around before getting a reccomendation and got a different story everywhere I went. You're likely to spend more money trying to go the cheap route than you are just paying retail somewhere. I think my whole installation cost was like $200 - $250 including parts.
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Carlos, I love your links and the info you provide. It seems to be an invaluable service to those of us here but in this case you have a slight error in your general info "bose systems are design for two ohms, most systems in the regular world are 8-16 ohms". The reality is that most car audio is 4 ohm and most home is 8ohm. There are many instances of other (2,6, 16, etc) but 4 and 8 are the most common and usually assumed.
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What you need to know, is that Ohm = resistance. A dead short is seen as 0 ohms and an open circuit is Infinity, Thus the lower the number, greater the resistance and the harder your amp works. Also, that speaker will be louder since you're pulling more power (Its just like gearing in a car, the lower the gearing, the more power you get from the RPM band).
Running a 2 ohm load into a slot for a 4 ohm will eventually burn-out the amp if you crank it a lot. If its just easy listening going down the road, its fine. However, do note that it'll be a little louder since you're running that amp, higher than it should be, relative to the other speakers... It may overdrive a little.
Our stock Bose system sux, ok ? They over-crossed the Sub, in the mid-100s range, to give the system bass (sub isn't the same as bass). Bass should never be 'booming', but tight. It should hit, then go, thus the crossover should ALWAYS be less than 100hz (like around 50hz).
The 6 1/2" in the door has the tweeter crossed to low, so the sound is hashy (it also does too much). Then, those little 2" in the rear just sound bad, but have less power and only get the upper Hz band since their supports for the high-end... In other words, its cheaper to make a stereo loud this way because mid-highs takes less power (and less speakers) and is thus cheaper.
Then again, they're just paper cones, so they obviously didn't really care.
I installed 6x9 (2-ways) in the rear, then cut the wiring to the center tweeter. That rear sections gets only highs, so it was pretty bright and too loud. The ohms match was OK, but they're Infinitys and more efficient.
In doing this those 2 ways were rated at 4 ohms, taking one of them out, made it an 8 ohms load... quieter and now its a full range (I couldn't find a good 6x9 full).
Again, its not great for amp to get a lower load either, but it'll work for now.
Remember, when running speakers in parallel its:
(A*B)/(A+B)
where A & B are speakers works like this -
(4 ohm * 4ohms)/ (4 ohms + 4 ohms) = 2 ohms.
When running speakers in series, its the opposite (2 -4ohms become 8 ohms).
This is just a guide since power ratings do change the ohms a bit, but this works...
That's the dealio !
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Posted by: nismo300zx91
05/15/2009, 04:07pm
yo i have a crooked steering wheel cant get it stright i think my alighnment is bad any idea thanks.