SQLGuy

Hi folks,

I've been trying to improve my stereo, but on a bit of a budget. So far, I've replaced a couple of big amps and a big subwoofer that were taking up too much space with an Infinity Basslink II sub (nice, relatively small, and built-in amp and crossover), and a Sony 4-channel amp that just fits under the cover where the original amp used to be.

Next step is to upgrade the door speakers. My car came to me with some 3.5" or so Pioneer coaxials in place of the stock mids, and the stock tweeters still in place and wired in parallel with the coaxials. It actually doesn't sound bad, but I am pretty sure there's room for improvement.

Finding a mid-woofer that will fit in place of the original door mid-woofer is tricky. 4 Ohm mid-woofers are hard enough to find, and almost all of them are way too deep to fit in the door. Morel makes one, I think, and so does Focal, but the Morel's are pretty expensive and the Focals are very expensive. I finally found some 100mm Visatons (German brand) that I thought would fit (http://www.visaton.de/en/chassis_zub...n/w100s_4.html), and which were a reasonable price (about US$30 a piece). Unfortunately, they don't seem to be available in the US; but, fortunately, I was in Europe for business a couple of weeks ago and was able to bring back a pair.

In fact, they are about 1/4" too deep to mount directly. They will need a slight bit of spacer/gasket. I think 1/4" is pretty manageable, though.

For the tweeters, I wanted Vifa D25AG's, which I had installed in a previous 928 and been very happy with, but they are very much NLA. Instead I ended up going with some Vifa titanium dome neodymiums. They are cheap ($13) and are just about the same diameter as the the stock ITT's. I am pretty sure I can mount these in the original tweeter mounting rings and keep the original grills.

I bought some 4.5" grills for the Visatons (no-longer having the stock grills), and they should work, but I'm still going to shop around a bit to see if I can find some 4" ones instead. For the crossover, I sort of blindly picked a 2nd order Butterworth at 3.5KHz and guestimated 5dB of attenuation for the tweeter. I measured that with a calibrated mic and function generator, and the 5dB seems to be just about perfect. Hacked together and with the woofer in a box for testing the setup sounds quite good.

Probably over the next week I'll swap these into the car and post an update from there.

Cheers,
Paul

Maleficio

I love the soundstage in my 82. Probably the best sounding interior I've ever experienced.

hans14914

SQLGUY,

Great minds think alike. I am working with the same Visaton drivers to make drop-in kit for the 928. I should have some passive xovers available in a couple weeks as part of the kit.

To try and save you some time, the Visatons will not fit without a spacer, or manipulating the inner sheet metal. I do have some test spacers machined which adapt the 4-bolt pattern for the stock drivers to the 5-bolt on the Visaton. You need a minimum of a 7mm spacer to get the Vistaton to seat properly without pulling on the door. 8mm gets you a bit of flexibility as far a hitting the rear sheet metal with the added weight of an arm on the armrest/leaning passenger... etc.

I am not using that Vifa for my kit, its not a bad driver, but the new NE line of Vifas are a lot nice for not a bunch more money. I have about 15 pairs of ~4" drivers here, and have test fit everything available under $200/driver that comes close to the odd parameters for the 928. I also have a similar number of different tweeters that I have been trying. I have some favorites, and ordered yet another pair yesterday which look very promising.

I would be happy to share some notes with you, but dont want to post too much, as I plan on making this a "commercial" product in the next several weeks, as a kit with custom passive crossovers, and machined spacers/brackets/adapters so you dont have to modify any factory sheet metal or door panels.

Keep up the great work - maybe I will learn something new from you

Thanks
Hans

Pcplod

I have some replacement speakers that are not even on the same levels as the ones that you guys are using, but was wanting to put them in and replace the capacitor (?) that feeds the tweeters. Could you give me any advice or direction on what would work the best?? The speakers that I have to replace the originals are some Blaupunkts and Kenwods.

Thanks, Paul

rixter

the mids can be replaced by the blaupunkt overdrives, they are shallow enough
I put up some pics on this a year or so ago using the stock grills/rings

SQLGuy

Hi Hans,

I called around to try to find some nicer grills than the Madisound 4.5" ones I had orginally bought... I ended up getting a pair of 4" Planet Audio grills.

I didn't really want something with a logo on it, but the logo is relatively subtle, and the fit is PERFECT. Besides being exactly correct diameter, they provide 6.7mm of offset without gaskets. This is going to make the mounting for the Visatons a piece of cake!

Paul, for your crossover changes, please provide some more details about the speakers you want to use. Exact models would be good. If not, then impedance and sensitivity of the two drivers will be needed.

Cheers,
Paul

hagen454

I will be doing the front speakers next also. Here is what I did in the back.

SQLGuy

Can you post a more contextual picture? It's hard to tell what that is. I mean, it looks like a sub, but it's hard to see how it fits into the car.

Mine had a Pioneer sub in the back when I got it, but it was bigger than I wanted. Ideally I'd like a system that replaces the stock parts in the stock places but sounds much better. For most parts, that's possible, but not for a sub, unless you want to lose the spare tire... which I'd rather keep.

As a compromise, I went with this Infinity and added a modular plug for power, so that I can remove it if needed with only three disconnects (the modular plug and the left and right RCA plugs).

This type of a compact, powered, sub is quite common for home use, and works well in the car. I don't understand why there aren't more of them available.

hagen454

I did decide to lose the spare tire, and as it turns out it's a perfect size for the 10" sub. Here are a couple different pictures, hope they help.

mickster

I know there are a lot of MB Quart threads for the front--I can find a new old stock set for under $200; are they any good? I might just splurge for the focals.

Michael

SQLGuy

One side done!

Here are a "before" picture (actually, the left side, which is not yet started), and a picture of the tweeter with the stock mounting ring, which came separated from the ITT tweeter with just a bit of finger pressure. I had to Dremel out about 1mm of ID from the ring in order to fit the new tweeter. Then a bit of super glue and black silicone to ensure it stayed in place and to fill the unneeded screw holes.

The whole right side job took quite some time (about 8 hours) because there was also the WYIT work of removing the door panel, replacing some broken clips, replacing the worn out door support (door now stays open rather than closing by itself), and going through most of a bottle of Weldwood to glue the vinyl and carpet back to the panel.

Now on to the left side...

Cheers,
Paul