audio system upgrade

Jack, likely bad speakers given the age. Did you rule out a bad fader? Rotate fader knob and see if speakers and see if noise gets better or worse. Are all speakers working?

You have many upgrade options as the W126 has lots of space for speakers and amps.

You are somewhat limited if you want to just replace speakers because the MB system likes to see 2-ohm speakers.

First decide if you want to upgrade your in-dash (head unit) or not.

Also see if your model has an tuner/pre-amp in the trunk (a two piece system).

Do you have front dash speakers (tweeters) and front door speakers (mid bass)?

Scott D

Scott,

Thanks for your input.

Jack

I am not an audio expert but I thought that if an amplifier can handle a 2 ohm load then it can also handle speakers of higher ohms. In other words a 4 or 8 or 16 ohm speaker would be less stress on the amplifier.

If this is so that would mean most any speaker would work because most speakers are 4 or 8 or 16.

If the speakers rattle they are probably blown or there are loose parts in the speaker housing.

If you can get to the speaker easily you can easily test to see if the speaker is any good by taking the speaker wires and attaching then to any half decent speaker you have lying around. If the new speaker does not rattle it is just a bad speaker or loose housing. This should work once again because most speakers have ohm ratings above 2 ohms. Does anybody know if there are any speakers that are less then 2 ohms?

On the other hand if what you really want is more volume than the speaker can deliver someone here a while back pointed out that a cheap solution is an amplifier that takes as inputs the outputs from your existing amp and which therefore is a very easy thing to do.

But like I said I am not a car stereo expert.

If it was me I would just get a pair of JBL 4735 speakers and plop them in the back seat.

But that is because I would be seeking optimal sound quality - volume would be secondary.

You might not even need another amp because the JBLs would be more efficient.

. .

I am surprised there are no rear speakers but....

If your W126 has the two amps mounted behind the seat you really do have a lot of flexibility.

The amp(s) the salesman is talking about are inside the cabin behind the rear seat back, which is easy to get off to check. Two latches on the seat bottom and 3 screws along the bottom of the seat back. There should be two 2-channel amps. One feeds the left F/R and the other feeds the right F/R.

If you can find room for one or two new small amplifiers behind the seat that is best bet because all F/R shielded lines from the fader run in there, and all four output lines are there as well. Then all you may need is an extra fused power line for the amp (current amps combined run off an 8 amp fuse so you decide :^) If not, you could extend the lines into the trunk and mount an amp there. Just note that all the wires running from the head unit to the fader and then to the amps, are shielded so use shielded wire.

Do not get too large an amp or you will end up having to run new speaker wires (35 - 50 watts/channel RMS should be fine). When looking for replacement amps get ones that have both line-level inputs and speaker level inputs in case your MB head-unit signal is too strong.

Some options to minimize wiring and cost:

1 - Easiest: Buy a quality set of coaxial speakers that fit into your front doors. Disconnect dash speakers. Put in a 100-200W 2 channel amp (use speaker specifications), and hook up the Left-Front and Right Front wires. Set fader to front.

2 - A little more work but much better sound: Buy a nice component speaker set (e.g. Rockford Fosgate or similar) that comes with a passive crossover. Mount the tweeters in the dash and the midbass in the front door. It is a little more work because the component set comes with a crossover which separates high and lows. The crossover can be mounted anywhere but you'll need find the separate dash speaker wire and door speaker wire to hook to the outputs of crossover (or run new wires). This may require a bit larger amp than option 1. Set fader to front.

I do not bother with rear speakers - spend the money on high quality front components that make for a nice "sound stage". This also frees up your rear signal lines for sub(s) in the future. 200-400 watts of sub power really improve sound for most music. Just add another 2-channel amp using the L/R rear lines form the fader as input. You can use 6" deck mounted free-air subs, a powered bass "tube", or a small sub box with 8" sub(s). Set fader where you like.

These options compromise some because of the unusal MB fader/signal setup and, using existing wiring but it will sound good. Next step up is to ditch the stock head-unit, run pre-amp coax cables to a fat amps/crossovers in the trunk and run larger gauge speaker wires.

Running wires is fairly easy in the W126 because it has plastic wire guides under the mats. Also try to use RMS power ratings rather than "peak" ratings for the all components you buy.

Search Crutchfield.com site for thier "Car Stereo Installation" guide it is very useful.

Thanks for your input.

Jack

Great feedback, Scott and g_p. Gives me a lot to work with. If you think of anything else, please chme in.

Jack

Thanks, pk. So, by changing out the whold thing there is no need to worry about the 2 ohm / 4 ohm difference? does this mean to leave the original wiring in place and use it. Seems like going to 75wpch doesn't really call for esoteric cables, huh? Fine by me. Do you feel like I need to carefully screen the best buy installers so they dont circumvent the console mounted fader? I'd like to keep it operative where it is. Wouldnt it be tough to buy a BestBuy rig and then take it to a "better grade" shop for install? They would kick me out, no? Just wondrin'

Jack