This is my '89 GT's rear speaker crossover. The rectangular things are resistors.

I think the pink thing is a capacitor. Right?

What are the black tape-wrapped cylinders?

 

The round objects are wound coils usually called chokes or inductors.

 

Those coils make up a tuned tank circuit that is used to separate the frequencies and send them to the correct speakers. The tank circuit is tuned to about 1.2 Khz where frquencies below that are sent to the woofers(bog ones) and the frequencies above that are sent to the mid-range and tweeters. The speakers provide a semblance of tuning by the nature of the coil windings at the voice coil, and the natural resistance of the winding.

The Porsche amp/speaker system is truely crap. If you are working on this in an attempt to get nice sound from the factory setup, give up and replace the whole thing with good stuff from an audio shop. The GT is notoriously noisy also, due to the limited insulation. A car audiophile would spend a lot on insulation, head, amp, changer, Sirius, speakers, etc. The factory speakers are 2 ohm junk, the amp is a noisy, cheap POS, and the head is just okay.

 

OK, I'll join in by saying I've given up trying to find replacements for the MY89 6.5 inch "woofers". When they worked I thought they had decent output, so I guess that knocks me out of the audiophile class. Anyway, mine gave up and I'd like to replace EVERYTHING, BUT I do not want to build some big amp deck in the rear hatch area or give up the spare tire well. Ideally the components would be hidden in the dash, where the existing amp is, in door space or under the front seats.

I found a subwoofer that is ALMOST small enough to hide. (Clarion SRV303). Subaru WRX systems have one hidden under the froint seat that is small enough and provides reasonable sub levels. I'm not trying to rattle windows down the block, but looking for balanced sound, and these small subs will provide that.

The problem is a small multi-channel amp that can be hidden and then speaker selection. I see other refering to various Infinity or MB Quart. Anybody want to give a rundown on specifdic speaker models? How about an amp or headunit-amp combo?

Thanks,

 

I put in MB Quart 216s and 210s with no external amp. I'm driving all eight from a Kenwood Exelceon 50x4 headunit. It doesn't go to ear-drum busting levels and the bass is mediocre at best. But, the sound is far better than the (working) factory system.

 

Bill,

Instead of a small hideable multi-channel amp, how about several hideable single- or two-channel amps? Maybe one for the fronts, one for the rears, and one for a subwoofer.

 

Doc,

It appears to me that the output from the amp (or, in my case, the head unit, since the amp is gone) goes directly to the woofer, and the crossover has an output for the tweeter and an output for the midrange. I don't know what the cutoffs are for those two speakers, but I'm sure an audio engineer could look at the wiring diagram of the crossover and tell me.

I am definitely not an audiophile, but I'd like decent quality at volumes that can be heard over the V8 symphony.

 

I think you really need to get all new stuff. Look around several car stereo shops and see what they can do for you. Theres a lot of choices out there. You should start out with a new am/fm/cd which has decent power (at least 50 wpc) and have them replace the speakers with a good quality component speaker system. If you want to expand later, you can add amps and sub woofers.
There are many speaker manufacturers with speakers that can replace those. I use boston acoustic pro. You can also downsize the drivers behind your grilles with reducing mounting brackets so you can use more common 5, 5 1/4, 5 1/2 , 6 , 6 1/4 inch woofers. And you can also make a good subwoofer enclosure in the spare tire compartment.

 

Bill, two thin amps should fit under the front seats (one each side). Another norrow one under the glove box in the map tray.

 

T_MaX, did you have a specific model of amplifier in mind for under the seats?

I was thinking maybe a couple (or more) of these Rumble Road RAW40s for amplification.

 

OK, I like the multiple, small two-channel amps. I do have a 50x4 headnit and it is not adequate. The small Clarion sub I bought has its own amp. If I can hide it, that may contribute enough that I can stick with the current headunit and put mid-range 6.5s in the bolsters. I probably should replace most of the other speakers with stuff of known impeadance.

 

Infinity makes a nice powered sub called the baselink which I'm hopeing will fit in the spare tire area. I'm not ready to do this so I havent done any measuring. I'm using a Alpine CD player that is rated at 50Wx4. but realisticaly it not. I also put in Alpine 4x6 in the doors. It sounds pretty good but definitly needs a sub.

Good luck

 

If anyone really understood the relationship between what a Db per mV into 4 ohms@ 1 meter was, the world would be a much nicer place. A watt of audio power @ 1000Hz, properly delivered to a high efficiency audio speaker at 1 meter distance is very, very loud. All the hype about 50 watts, 250 watts, even 1000 watts is just so much hot air (almost literally). Amplifier specs have gotten out of control in the last 25 years, to the point that it's nearly meaningless.

I don't want to give a primer on electrical stuff here but there's been all kinds of measurements thrown around. Watts Peak, Peak to Peak, RMS, Ave, Input, Output, even a Surge & Punch number. None of it means ANYTHING without the proper context. I would recommend not shopping by power ratings, but shop by somthing much more primative. Namely your hearing!

For example. In a home system I use a 40 year old McIntosh amp, with tubes that 'only' puts out 40 Watts per channel (there I go). Here's the point: When McIntosh says 40, it means: "at least 40 Watts RMS output, into 8 ohms continuious, from 25-18,000Hz @ less than 0.25 Total Harmonic Distortion". So, in effect I could set the volume all the way up all day, and it would sound as good as the source information provided(big caveat coming) I had the speakers that will dissipate that power.

So, for an auto system, where space is limited I would start with the speakers, as they are the limiting factor in the space provided. Now, speakers have naturally gotten larger in cars throughout the decades. With kickers, boom tubes, and the like, we've made real advances in audio quality recently. Still, there's a limit to what can be done in the chassis of a GT car. If you want to work within the confines of the existing speaker cutouts, this will limit your choices even more. Several of our bretheren have put a nice size kicker for bass reflex in the tub of the spare tire, with a lattice cover to protect the speaker. Sounds like a good plan!

Next we'll have to deal with the mid range. This speaker, more than the bass reflex will determine the true quality of the sound. It's where the predominant vocal, and instrumental tones are generated, and not surprisingly, where our audible hearing is the finest. In the stock trim, we are limited to a 6.5" round opening. I had a car that was set up on the outside for a 6.5", but if the panel were removed, it would clearly fit an 8" speaker which would be a huge improvement. (A = pi*R^2). I haven't been in the 928 panel yet, but I would bet an 8" would shoehorn in there.

Next, the tweeter. Stay away from 'disk' or metal cone tweeters. It would make sense that they sound 'tinney' and they do. A good tweeter will have a polymer cone, or perhaps paper, and a good size voice coil with a response at least to 20,000Hz.

Now the amp. In short, an external amp is a marketing thing. It's there to get you to buy more stuff for your car. Unfortunately, many source MFG are going along with the trend and and putting really crappy integrated amps in their product. What a shame. I guess the silver lining is that you get more choices. Also, the higher wattage amps mounted to the back chassis of the intergrated units were starting to run pretty warm, leading to component failure. If you find a reciever/CD/MP3 unit with an intergrated 50 Watt RMS per channel into 4 ohms, this should be sufficient for almost all applications. That will be hard to find. Even Alpine's CDA-9826 integrated unit that raves about it's "45W X 4" power capacity, admits in it's specs that it's really only 18W per channel, with 1% distortion, measured at only ONE WATT! The truth, lies and Damn lies. So, I guess get a reciever/changer head with pre-out and then shop for a separate amp. Same rules for the amp, don't shop wattage, shop sound quality. More than 50 Watts per channel X 4 channels(that's 200 watts, marketing speak, or 500 Watts 'peak') is unusable.

The reciever/head units have a vast array of gadgets. Decide what you are really going to use, and get any of the top brands.

In closing, the bigger the mid range, with at least 100oz magnet, and a big kicker in the wheel well,with a big magnet will probably sound as good as it will get in a car. There's room in the pocket on the side of the pass seat for an amp, also could be under the pass seat, and possibly under the rear seats, although it needs some cooling air. I'm going back to bone stock, as that is what my car aim is. But, I wish I could get a better system, and just leave the stock speaker covers on, and the stock head in the console.

 

Wow!!
I know who I am going to get to help me on my incar audio.

 

So, Doc, wouldn't you be better off with different speakers under the stock speaker covers?