# cd2 comp with a weird sound



## req (Aug 4, 2007)

So, 

as most of you know, i have CD2's in my GTi.

The other day i had a problem with my right channel going out, and it turned out that the speaker wire had some how came out of the terminal. dont ask me how, because i dont know. i soldered the wires at the end to make sure they wouldnt fall apart... but they somehow came loose.

so i fixed it up, and got things working again - but i noticed that my right CD2 was sounding weird.

it is almost tinny, like its missing a bunch of midrange. i was listening to 311, and the male vocals were almost gone, like the crossover point is higher on one side than the other. i have done tons of stuff to my 701 and i cant seem to find a problem with any settings.

so could a compression driver go "bad" even though it still plays fine? im about to take the thing out and open the motor up to see if there is some kind of debris in there.

any help on this subject would be appreciated!

ill take pictures tomorrow when i break it open.


and mr. eric stevens, can these things be fixed still? or are parts\diaphragms not available anymore?


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## Eric Stevens (Dec 29, 2007)

. First swap speaker wires at the amp and see it changes sides. Next Inspect it physically if it stayed on the same side. If it changed sides something in the amp or processors etc.

Eric


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## Eric Stevens (Dec 29, 2007)

Yes diaphragms are still available.


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## req (Aug 4, 2007)

thats good news.

ill let you know what i figure out tomorrow.

thanks so much eric.


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## req (Aug 4, 2007)

okay, well i took em out and pulled them apart after i did some diagnoseage.

so each diaphragm reads 6.3 ohms and is not shorted or open. thats good, but there was a bunch of metal shavings and general debris (FOD) in the gap. i did my best at cleaning it all out with some tape and some time.

we are going to swap diaphragms and give them a test run to see if they still have issues.

hopefully cleaning the gaps fixes my problem, but im skeptical.


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## req (Aug 4, 2007)

ok so i slaved them back into the car after i swapped the "softparts" from one motor to the other, and the "bad sound" is less ... bad i guess... i would say its due to taking small debris out of the gap and generally cleaning it all up. but the bad sound did move over to the other motor, telling me that it is indeed a bad diaphragm and not my amplifier or processing. its weird that the resistance is good, and they are fully intact, but still have an audible distortion. but they are 20 years old or so. the cone was not smooth either, it had lots of little dimples in it.


so eric, how much would new parts cost? :sigh:


and do you have any records of sale back then for serial numbers? any way to check how old these things are?

thanks!!


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## Horsemanwill (Jun 1, 2008)

req they cost 118.00 per diaphragm i think u should just upgrade to the Ultras


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## Brian_smith06 (Jan 31, 2008)

Horsemanwill said:


> req they cost 118.00 per diaphragm i think u should just upgrade to the *Ultras*


Nom nom


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## req (Aug 4, 2007)

so it looks likes im caught between a rock and a hard place. i have a "busted thing" and no speakers installed in my car at the moment. im about to put my IDQ8's back in for some sound, but until i figure out what im doing with these CD2 comps i am not going to be reinstalling them until i get things straightend out.

does anyone know if there is another place i could buy the diaphragms at for cheaper? 

i have pictures on my phone, but i have not gotten around to uploading them. ill see if i can get it on here tonight.


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## Brian_smith06 (Jan 31, 2008)

Well yiu could watch for a used set to pop up and have a backup just incase the other goes bad? I think they sell for 200? I paid 340 for my ultras on here


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## Mic10is (Aug 20, 2007)

Id look into getting new drivers. there are so many newer drivers that sound much better and have much better top end response.


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## TREETOP (Feb 11, 2009)

You can get a brand new pair of B&C DE500-8 drivers for $335.26 shipped at PE. 
B&C DE500-8 1" Neo Titanium Horn Driver 8 Ohm 2/3-Bolt | Parts-Express.com
Their replacement diaphragms are $47.36 each.
B & C MMD500-8 Diaphragm For DE500-8 | Parts-Express.com

I've got a pair of DE500-8s I _might_ separate from the CD1e minihorns I have for sale, if that's the route you decide to go and you might be interested, let me know.


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## fish (Jun 30, 2007)

Mic10is said:


> Id look into getting new drivers. there are so many newer drivers that sound much better and have much better top end response.


Examples other than the much talked about B&C DE500's?


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## req (Aug 4, 2007)

because there are some illusion ch-1's for sale. also some CD2Neos. all for around the 300 dollar mark. or i could get a single new diapghram from ID for 120ish.

im not sure if i would want to get a single diaphgram because what if i get the single, and then the one i did not upgrade sounds different than the new one :uhoh:

im keeping my eyes peeled, but i dont have very good hopes. im not saying i couldnt go and buy a brand new set of horns from ID straight up if i wanted to, i have the money - but i am saving for a house and such, so wastefulness is often not something i encourage when i have stuff that works, and 900 dollars is a waste when i already have working motors\lenses. 

also looking at these as well;

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=264-274
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=264-322 &FTR=264-322


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## req (Aug 4, 2007)

also looking at this...

but im not sure if its the same part number, it looks *a little* different than the diaphgrams in the CD2comps...

B&C DE75-8 Diaphragm for EAW LA325 - DM-5001 CD-5001 - eBay (item 360324248582 end time Jan-29-11 12:04:07 PST)


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## req (Aug 4, 2007)

this one looks exactly like it, but i THINK the part number that was stamped on the underside was 8626 im my memory serves me.

B&C MD/DE45-8 8ohm Replacement Diaphragm - eBay (item 380305238762 end time Feb-04-11 09:51:08 PST)


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## req (Aug 4, 2007)

here are some picutres.














































would that kind of diaghpragm damage cause attenuation in the low end (1000hz?) of the frequency spectrum?

i cant find anything else that is wrong with these.


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## ehiunno (Feb 26, 2008)

TREETOP said:


> You can get a brand new pair of B&C DE500-8 drivers for $335.26 shipped at PE.
> B&C DE500-8 1" Neo Titanium Horn Driver 8 Ohm 2/3-Bolt | Parts-Express.com
> Their replacement diaphragms are $47.36 each.
> B & C MMD500-8 Diaphragm For DE500-8 | Parts-Express.com
> ...


Sorry to threadjack, but if you are thinking about separating them I'd probably take the horns from you.


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## Horsemanwill (Jun 1, 2008)

i'm no horn guru but what caused the lil dimples


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## req (Aug 4, 2007)

i dunno.

these things are real old. i got them from audiolife (dave) on caraudio.com like 10 years ago. he is still around, and he used to compete way back in the day. i dont remember them sounding funny when i first got them (i used to have full body lenses btw).

i am guessing they got damaged by debris in the motor?? but i do not know for sure. i know there was some garbage in the gap that i cleaned out with some business cards and masking tape, and after i did this the sound was drastically improved, but i can not be sure they they are 100% working order now because i have no basis for comparison.

but from what i can tell they sound much better.

thats why im still looking for info on this to see if it is the cause of the problem or could be a problem.


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## Eric Stevens (Dec 29, 2007)

The diaphragm with the really bad damage might need to be replaced, it might get break up at high volumes, the better of the two should be just fine. 

So if they both sound the same even the bad one is probably ok and new diaphragms wouldnt improve the sound.

The damage was caused by some garbage in the driver for sure make sure they are all clean before trying to play them again

Eric


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## TREETOP (Feb 11, 2009)

ehiunno said:


> Sorry to threadjack, but if you are thinking about separating them I'd probably take the horns from you.


I did split them up and already sold the horn bodies, sorry! I do have the B&C DE500-8 compression drivers available separately in my sale ad.

req, PM sent.
[edit:] My B&C drivers are sold now too.


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## req (Aug 4, 2007)

Eric Stevens said:


> The diaphragm with the really bad damage might need to be replaced, it might get break up at high volumes, the better of the two should be just fine.
> 
> So if they both sound the same even the bad one is probably ok and new diaphragms wouldnt improve the sound.
> 
> ...


Eric,

the werid thing is the one with the worse looking diaphgram is the one that sounds normal. the one with the better looking diaphgram sounded messed up, but after cleaning the voice coil gap it sounds DRASTICALLY better.

would gunk in the gap cause it to sound like it had a higher highpass filter then its other? 

would dimples in the diaphragm make it sound like it had a higher highpass filter than its other?


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## TREETOP (Feb 11, 2009)

req said:


> ...would gunk in the gap cause it to sound like it had a higher highpass filter then its other?


I'm no expert on these, but I could see gunk in the gap causing restriction of voice coil movement, which could definitely reduce lower frequency response.


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## req (Aug 4, 2007)

i could see that too, as it changed from bad, to it sounds better? after i cleaned it. 

ill take them back out to the car and test them again. i have a video of how it sounded before.. lemme see if i uploaded it.

gimme a few to upload...


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## Eric Stevens (Dec 29, 2007)

req said:


> Eric,
> 
> the werid thing is the one with the worse looking diaphgram is the one that sounds normal. the one with the better looking diaphgram sounded messed up, but after cleaning the voice coil gap it sounds DRASTICALLY better.
> 
> ...


Yes to all of the above. If the diaphragm is restricted in movement it will have many affects most reducing output at the lower octaves of its response. The debris would also cause some distortion.

Listen to them side by side outside the car full range at lower level and see if they sound the same.

Eric


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## req (Aug 4, 2007)

lets hope this works,

this is what it sounded like before i cleaned them. ill take another video of how its sounds now.


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