Jeff928S4

I am currently putting together a system to put in my car (89' S4 - 10-speaker system).

I had some difficulty getting the rear 4" speakers to work after I install a new deck and bypassed the factory amp and wiring direct to the speakers (running the rears and rear woofer in series).

Turns out - the rear 4" DO work.....they are just really hard to hear due to all the hi's being removed at the crossover.

I will eventually be replacing all the 4" speakers/tweeters once the ones are available from Rennlist.

I plan on pulling the current new deck and replacing it with this deck - it has 3 sets of RCA outs (at 4 volts) vs the 1 set I currently have (at 2 volts)...

Pioneer DEH 6000ub



I am going to try and get these 6.5" subwoofers where the original woofers were...crossed over at the amp.

CDT HD M6+



Specs...

Diameter: 6.5"
Sensitivity: 83.8dB
Maximum Power Handling: 240 Watts Peak
Nominal Power Handling: 120 Watts RMS
Frequency Response: 10~4000 Hz
Nominal Impedance: 4 Ohms
Voice Coil Diameter: 1.5"
Peak Xmax: 12mm
Magnet Weight: 30 OZ
Surround Material: Rubber
Frame Type: Cast Alloy
Cone Material: Fiberglass
Mounting Depth: 3.37" (top mount)
Cutout Diameter: 5.812"
Overall Outer Diameter 6.81"


After pulling the old woofers, I am going to add these crossovers in the rear to replace the ones on the back of the old woofer (and will probably use them on the new speakers/tweeters)...

CDT SATNET 456's...




Now, as for an amp.....

I have been looking at mono and 4-channel amps (to combo together to cover the four speakers/2subwoofers), but I found a 5-channel amp that *may* fit in the old factory amp area....

Arc Audio xdi805...



Specs...

Power Output Channel 1 - 4 80 x 4 Watts @ 4 ohms Stereo
Power Output Channel 1 - 4 120 x4 Watts @ 2ohms Stereo
Power Output Channel 5 - 240 x 1 Watts @ 4ohms
Bass Boost 15dB @45 Hz
Crossover (Butterworth) HP (50Hz - 250Hz) / LP (50Hz - 250Hz)
Remote Bass Boost Yes
Fuse Yes
Power Output Channel 1 - 4 240 x 2 Watts (Bridged) @ 4 ohms
Power Output Channel 5 400 x 1 Watts @ 2 ohms


Thing is, the amp measures 6.5 wide (ok) and 2.25 high (ok), but it is 11.25 long - that is 4 inches too long. I was thinking of modifying the amp area cover to make it longer and hope I can squeeze the amp in that spot.

Any suggestions on how to make it fit?

...and, in looking at the specs of the amp, is this a good enough amp to run all four 4"+tweeters and the two subs?

Jeff928S4

I'd like some feedback on the amp specifically because I may need to buy it before the day ends.

StratfordShark

Surely you mean you don't want any feedback on the amp <g>!

Jeff928S4

Yes, that will work also.

I just can get a really good deal on it, but didn't want to pull the trigger until some of the stereo guys chimed in. There is little info on the net regarding the amp (because it is a newer model, I suppose).

I'm thinking I may fabricate a box in the exact same dimensions as the amp and see how it fits in the old amp spot. I know 4 inches longer will place the amp more towards the rear seat foot area, but who puts their feet down there anyway? It looks like I may have to elongate the amp area cover somehow.

Jeff928S4

I have not pulled the old woofers yet, but I am expecting to have to use some sort of spacer.

I'm thinking of perhaps getting a wood-shop to make a wooden version of the speaker surround (save me some cutting) and at the same time make it thick enough to allow the subs to fit.

These woofers are the closest thing to "free air" woofers I could find. I will defiantly be stuffing the empty area behind the woofers with insulation or something like that and perhaps dynomatting over that to form some sort of seal. I guess I'll see once I get in there.

Here is the woofer in action - inside what looks to be a car/truck door. I'm guessing they are not sealed that great....

www.youtube.com/watch?v=f3V1eRVC4BQ
I've been told I can run them full out as a sub, so hopefully I get some bass. I don't want to rattle the mirrors - just enough bass to make it sound nice.

borland

Why don't you buy a head unit that can power the four sets of 4" mid range and tweeters, then use a 2-channel external amp to drive the 6.5" woofers? That's what I'm doing on my 90' S4 with 10 speaker system. There are 6.5" speakers that fit inside the factory housings with some minor modifications.

I have a external amp similar to this that fits in the factory amp location....

http://www.ebay.com/itm/MNX250-1000-...Car_Amplifiers

Jeff928S4

That's a sweet lil' amp for that price, eh? ...and nice power on it too!

I have the head unit right now powering the four factory speakers (and they sound pretty damn good, if I do say so) and have thought of just getting a new mono/2 channel amp - but when I found that 5-channel amp that *might* fit in the old amp spot, I thought into the future and when I get new speakers in the corners.

...but for the price of the amp you posted above, it gets me thinking. I mean, I can always re-sell that amp if I want to go 5-channel down the road......hummmmmm.

Super thanks for that link. I have searched and searched and have only found motorcycle amps and some "audiopipe" brand amp to fit in that location - and none of them had the power of the one you posted above.

borland

Most high end head units have a 5 channel preamp outputs, so with one, it wouldn't be a problem later hooking up a amplified sub-woofer. Some of those sub-woofers are designed to fit under seats.

Jim M.

I've installed 6.5" woofers in the B pillar using the stock speaker grills. You will have to beat the inner fender well out to provide enough room, but it doesn't come anywhere close to the tire.

On an 89, if you want to put the amp in the factory location you will need to re-locate the fan control unit and the round hammer test port. The cover is just pressed board and could easily be duplicated with fiberglass and some new carpet. Be sure to leave some holes in the panel to allow cooling air for the amp.

hans14914

If you are willing to give up your spare tire, I may be able to help with some odds-and-ends I have laying around. If it helps, the smallest decent 5-channel amp I have found is the Kenwood XR-5s.

Hans

Jeff928S4

Thanks Hans. I am trying to avoid using the spare tire area for a sub. If I ever get addicted to making the system big, I know I'll end up with a sub in there or a Sharkwoofer - but for now, I'm just going to go smaller and try the subs in the B-pillers.

That's also a nice amp - the 7 9/16" width pretty much rules it out of going in the old amp location - the seat will defiantly be in the way in that scenario.

After listening to the factory speakers for the past couple weeks, I must say, Porsche did an amazing job with the overall sound. I've had a few big systems back in the day and they were quite loud and VERY bass-filled....and were in a Suzuki Sidekick; so sound quality was never my goal I guess - just volume.

The Porsche system is pretty cool - if you fade the speakers to just the front, it sounds muddy and very, very weak. If you fade to the rear, you can BARELY hear the rear 4", but the tweeters are very bright. Sounds like it would be a crappy thing to listen to, right? But no....once you set the fader back to the middle, it all blends perfectly and sounds like there are speakers everywhere. I've never heard high-hats and certain notes the way I do in the 928.

Mind you, my 6.5" are now just running in series with the rear speakers, so they are running full-range I suspect (and can't seem to handle any low bass or wonky mids - they hummm and rattle).

For the folks who have working 6.5" speakers (either running the original way or off an new amp), just how much highs come through the 6.5" speaker? I know they were originally crossed over at the original amp, but I've never heard them with the highs taken out. Do they usually just focus on bass?

If I go with that 2-channel Lanzar above, I'm going to install it and run the original 6.5" speakers off it first because I want to see what they sound like optimized so I can compare when the new woofer go in.

Ed Scherer

FWIW, when I did my audio system upgrade (can't believe it's been 12 years ago!), I went with component speakers (MB Quart Referenz Premium PSC 210 for the fronts and Referenz Premium PSC 316 for the rear) and all new crossovers. These have been long since discontinued and I have no idea whether or not there are similar replacements (it's not what you were asking about anyway ).

To address the depth issue on the rear 6½ inchers (the MB Quart component speakers were way too deep to flush mount), I wound up using additional MB Quart trim rings (I think MB Quart called them "surface mount spacers") in conjunction with the original speaker mount (with the original speaker cut away). It sticks out a bit, but IMHO, it looks OK. Rear seats aren't used for much anyway. The point, though, is that these kinds of rings can solve a lot of depth issues, while maintaining acceptable aesthetics.

Don't underestimate the importance of getting the crossovers right when changing speakers; there was a weird mix of speaker impedances with the factory speakers. It sounds like you're on top of that, so I'll leave it at that.


Some ancient photos from 12 years ago follow. The spare-tire-well-mounted JL Audio 10W3 sub isn't shown in any of these.

Jeff928S4

Are those tweeters cut into the original grills?

I don't believe the new woofers come with grills, so I'm going to have to figure out a way to use the old grills.

I know all the 4" + tweeters are 4 ohm and the 6.5" are 2 ohm, but the new woofers are also 4 ohm (and will be crossed-over at the amp), so the new cross-overs will be for new 4" + tweeters, so hopefully it's pretty straight forward.

Just found this old-school amp on Ebay that fits in the old spot and many say is one of the best old-school amps made...I guess the built-in crossover is separate from the amp itself?

Audio Art 70.2...





Specs...

2 x 35W @ 4 Ohms
2 x 70W @ 2 Ohms
1 x 140W @ 4 Ohms bridge

Too weak to run the 6.5" speakers???

Ed Scherer

Yup.

Jeff928S4

This is good to know!

I was thinking of cutting the one far left end off the cover; adding an additional 3-4 inches in the form of new press board, gluing the two together and getting the new section covered in carpet to match the rest of the cover - that is if I go with the 5-channel amp that is 11.25" long.