Audio update on a 123 300D
 

Hello everyone.

I'm planning to do an update to my audio system. This is what I plan to install:

-Front speakers: Blaupunkt 4" 2-way 110 Watts speakers in the original place
-Rear speakers: Blaupunkt 6.5"OS 3-way 150 Watts speakers in the original place using round spacers
- Subwoofer: MA Audio 8" 500 Watts competition subwoofer installed in a spacer I built for the first aid kit compartment (I plan to remove the compartment and use the trunk as baffle) and a MA Audio Monoblock 500 Watts amplifier installed in the deck where the rear speakers sit.

I already have a Pioneer head installed. 45 watts x 4

I have some questions for you guys. First, I still have the original fader control installed (only using 2 channels from the radio) so I'm planning to use the original front speaker cables to plug the front speakers to the radio directly. Will the original cables handle the power requirements?

Second, I plan to use the original rear speaker cables and add the require lenght of cable to plug them directly to the radio, skipping the fader control. Again, will the original cables handle the power requirements?

Third, I'll run RCA cables from the radio outputs to the amplifier following the path of the orginal speaker cables. Which would be a correct path for the power cable for the amp?

Fourht, should I connect the amp directly to the battery or is there a power line inside the car that can handle the power requirements?

Thanks for any advice you can give me.

If you are going through that much trouble - I wouldn't use the original speaker wire (or fader controls). It's quite cheap in comparison to good speaker wire, and you may (probably) hear the difference.

Run the RCA cables and speaker wire down the drivers side of the car; run power wires down the passenger side. Connect your power wires direct to the battery - and use heavy duty wire. Do it right and you won't have to deal with issues down the road...

I'd recommend reading a book before starting this. The work is not hard, but just use it to make sure you don't do something foolish... I read Car Stereo Cookbook (by Rumreich). Took less than a day and it really helped me get comfortable with the job.

thanks bfisher for the advice. what do you think about using the rear trunk as a baffle?

I removed 1st aid kit in my w123 and have a sealed box subwoofer in the trunk. Plenty of bass for me, but I just wanted good sound quality, not booming bass. I think what you are trying to do is going to require a lot of work, but it might work out.

sorry - I missed this until now...

I installed my sub in the spare tire area - so I'm not really using the trunk as a baffle. I've heard of others doing it - but they are using subs designed for this purpose. I don't know enough to give you a real answer... sorry

Thanks for the info guys. I have new updates on my audio system. I just got a Pioneer DEH-6800MP. It has 3 pre-amp outs, so I'll also set up extra front and rear speakers in the doors. About the trunk as baffle, I think I missed some details. I removed the first aid compartment, so this gives me a free path to the trunk. Then I made a flat spacer with 1/2" medium density board that covers the whole space where the compartment was. I made a round hole and putted my subwoofer facing downwards (coils inside the cabin). I haven't pluged it yet. I'll post some pics when I'm done.

What do you think of this guys?

Why is your sub pointed into the trunk?

Thanks for the suggestion
 

I'm going to look for a copy of that. Thanks for mentioning it.

I thought the idea of infinite baffel was to kind of use the trunk as the enclosure and have the sub firing up, but I am no expert. Also, a certain type of sub is required for this type of install I believe.

surprised not to have seen this yet either..
been working on a similar system..

good ideas with the rear deck rebuild, definitely mandatory over the stock fiberboard.
have been slow, but have been working on a .75" 3piece replacement rear deck,
housing alpine 6.5"s and a 10" blaupunkt (odw) overdrive series sub that has a 2" mounting depth. :thumbsup:
it is rated for an infinite baffle application, and the trunk will get a good lining of dynamat.

running wiring just as the good advice that has been given; (stinger) 4gauge from the battery with a 150amp fuse, to a .5 farad (lightning) capacitor, to a power distribution block which will split the power supply back to the alpine head, a blaupunkt amp (200x1), an alpine amp (40x2) for the alpine 6.5"s, and then finally power back to the capacitor.
the alpine 4"s in the dash have to live with the head unit power.

good times. :D keep us posted.

Thanks for your responses. Bfisher, I placed the subwoofer pointing towards the trunk because of the mounting depth it has (5.75"). To mount it the other way, it would need a very very thick spacer and I wanted a quick setup to try the amp, I'm planning to set it up correctly soon. 1stimer, you're right, for IB you need an special sub, which I don't have. :P My sub is a MA Audio MA80XE, as I said, I mounted it that way to try the amp only. Rudolphgreen, sounds your system rocks hard! Any pics of the 3-piece rear deck? I'm still working on mine, but I'm stuck trying to figure out the best way to build it in several pieces in order to mount it easily.

Length of sound waves
 

All I know is that the length of the wave determines its ability to pass through various obstacles. Deeper notes (sub-woofers) have the longest wave lengths and therefore are less critical as far as placement and aiming goes.

Higher notes become increasingly more difficult to aim properly. I hope I'm not stating the obvious here, but the lowest notes can easily penetrate concrete walls. Most of us know this from observation, but the physics that are involved are also good to be aware of when making decisions.

You're right Dee8go, lower frequencies have longer wave lenghts, which allow them to resonate through harder and thicker materials. Rudolphgreen, please post some pics of the 3-piece rear deck?

Thanks guys!

I'm in the process of doing all of this as well, in fact the alternator issue is my hold up now (need juice and lots of it). Looking into what options I may or may not have. Anyway.

I would certainly stay away from the factory speaker wire. The fader, at least in my car, will lower the impedance seen at the deck (or amp) as you fade (or I should say have front/back both at full tilt). So depending on what speakers you have, if you are running at the lowest safe impedance already and use that fader, you may present too low of a load for your source. In low power applications and not pushing it too hard, not a big deal (and blowing fans on your amp can be a great remedy), but there is the chance of putting your amp into protect mode. And the old speaker wire may get hot anyway, with more power flowing through it. So I would say stay away from that in any way possible if putting in a system.

I also agree with rebuilding the rear deck if you are mounting aftermarket speakers. Baffle resonance can give some nasty sounds, so if you can hang that speaker in something like 3/4" material, you'll be much happier in the long run. Same goes for any speaker you mount. The more dense the material you mount the speaker to, the less chance of resonance from that at least.

Personally I'm not so sure that you will be happy with deck power (13 or so watts) to the front speakers and then have 40 watts per going into 6.5's in the back. The rear will definitely overpower and will pull your sound back considerably. Of course, alot of people do not necessarily care about sound stage either, and just want a more "full" sound in their ride.

The cookbook would be a great idea. It will shed alot of light onto cabinet design. IB applications are not for every sub. You'll definitely want to check the T/S parameters of your driver and make sure that it is suitable for that. IB will give you a more "natural" sound, but the trade off is that power handling and output are cut in half at best. Its easier to bottom your sub out and cause damage to it in IB for those reasons. Also, I wouldn't mount the basket up, if you are looking to reverse the phase of your speaker, simply reverse the +/- at the speaker. That will help with cancellation issues if that is the reason why you want the basket up.

the 6.5" will not fit in the rear deck, it uses 5.25" round (have em in my 83 300d-t)

also the 4" on the drivers side wont fit with the cover down, i can barely get the cover down on my drivers side front deck and i have Blaupunkt 3.5"s lol

to answer some of your questions the original lines do handle the sound but not as good as good as it could be, if you have the time def rewire it all.

best path for RCA is down the side of the car under all your carpet. As for the powerwire run it off your battery and through your firewall (one of those rubber plugs will pop off. Also remember to run your power wire and RCA down oppisite side otherwise you'll get nasty static.

any more questions just hit me up.

My car 83' 300d turbo front deck: 3.5" Blaupunkt rear deck: 5.25" Infinity trunk: 2x 12" Xplode and 1000w amp