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Spica TC 50 vibrating

M

mgardner

New Member
This afternoon when I turned on my stereo equipment, I noticed a vibrating sound coming out of the left speaker. I also noticed that my son was playing one of his metal band CD's. With a MAC Mc402 power amp, the Spica TC 50 could easily become toast. He swears that he didn't have it up loud. These speakers are about 22 years old, think vintage, (I am upgrading slowly). I can't see any rips in the cone but when I put my hand on it the vibrating sound stops. These are two way speakers. Do you think I need to replace the six inch speaker that is vibrating or could it be something in the crossover? Does anyone have recommendations for a good place to send it for repair? Thank you for any input you are willing to pass on. :tears:
 
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Sounds like it might be a loose tinsel lead rubbing on the back of the cone or a break in the lead.

Either way, it's repairable. Pull the woofer out and play some music through it whilst gently poking the tinsel leads. If it crackles, there's a break in it which needs to be fixed.

And if the lead is rubbing on the back of the cone...that's your problem!
 
mgardner said:
He swears that he didn't have it up loud.
Click to expand...

That's awfully relative, isn't it?

Have to doubt that the offending vibration has anything to do with the crossover. But this forum abounds with experienced speaker rebuilders and you're already starting to see more sage advice than I can offer.

Good luck with the repair.
 
Check the rubber surrounds on the mids. The glue holding the surround to the frame may have come loose in one or more areas.
 
Spica TC50s are great speakers and there are a few mods to make them even better... I'd love a pair.

There's some great advice above for things to check.. However, I hate to say it, but I'd bet the woofer is toast. If it is, DON'T give up hope...
 
I have the TC-60's with the same size woofer as the TC-50's, 6 1/2 inches. Peerless made the woofer for the TC-60, don't know if they made the one for the TC-50. At any rate both have been out of production for several years.I have someplace information for an accurate drop in replacement. So if all else fails let me know and I'll look for the info.
 
Sometimes the little paper grommet on the rear of the cone where the lead comes through comes loose. I've seen that cause a rattle.
 
Humans tend to percieve distortion as loud, so if a speaker has good headroom as far as distortion goes it will not sound
loud even though they might be in thermal overload. The review in Stereophile noted that they blew many drivers during
the review process.

Where do you live as it would be better not to have to ship them for repair?

I've been interested in the TC-50 for many years, here is some of my more recent work:
http://baselaudiolabs.googlepages.com/MR-TC50-REB.html

http://baselaudiolabs.googlepages.com/BAL_TC50_PLB.html

The 50s are 4 ohm and the 60s are 8 ohm, they do not use the same woofer. The TC-50 uses an Audax that they treated
with a coating of diluted glue. Then the drivers were binned by freq and height of the HF peak. These numbers are called
the service code.

Do your speakers have a square or rectangular opening in the felt around the tweeter?

There is no drop in replacement for the woofer.
 
You may want to visit the spica enthusiasts web site for info on repairs and parts for TC-50s. I hope you haven't blown a driver, because some of these are sort of unabtainum, as Pete mentions above.

Here's the info on replacement drivers from that site
 
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Thank you to every one for your suggustions of things to check. I live in Michigan Pete. That is some extensive testing on the Spica's that you have done. Mine are the earlier version serial number 4466. They have the rectangle felt around the tweeter. These are cosmeticly fawless and did sound nice. So I would like to fix it if possible. Thanks to reneborg for the Spica enthusiasts website. I am getting ready to pull the woofer to check for the things that StarMover, Spkrdtr and MunkeyQ mentioned. I'll post a couple of pics.
 
What is vibrating is the yellow surface behind the cone. I can't see where it has come loose anywhere. Sounds like I have a bad woofer? I'll post another picture. Thanks
 

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How do you know that it is the "yellow surface", I think you mean the spider?

Often, certain types of glues become brittle with age and it is possible that the glue for the spider has come loose. The spider will often rest in the correct position even if the glue is broken, so you have to apply some pressure, are you able to lift the spider at any point from the metal frame? Also, if you apply some pressure can you see if it is loose at the other joint to the cone/voice coil? It is often possible to reglue such a failure.
 
Pete B said:
How do you know that it is the "yellow surface", I think you mean the spider?

Often, certain types of glues become brittle with age and it is possible that the glue for the spider has come loose.
Click to expand...

So that is what it's called. I put my finger on it and I could make the vibrating stop. There is probably a special kind of glue that one would use? I packed it up in the box. I'll get it out and take another look.
 
mgardner said:
So that is what it's called. I put my finger on it and I could make the vibrating stop. There is probably a special kind of glue that one would use? I packed it up in the box. I'll get it out and take another look.
Click to expand...

You probably want to make sure that it is actually a glue problem, and not a voice coil rub, where you are shifting the position slightly to stop the rub. If you press gently with something like a ball point pen, cap on, around the spider under good light you should be able to see movement near a broken joint. Two part epoxy is the best glue, but make sure it does not drip into the gap if you go anywhere near the spider VC joint.

If this is not the problem the next thing is to test for VC rub.
 
Hi Pete,
I checked all around on the spider and could not see any place where it was pulling away from the metal housing or the cone. Is there a place that you could recommend to send just the woofer to have it checked out? Thanks for all you help.
 
archie2 said:
I have the TC-60's with the same size woofer as the TC-50's, 6 1/2 inches. Peerless made the woofer for the TC-60, don't know if they made the one for the TC-50. At any rate both have been out of production for several years.I have someplace information for an accurate drop in replacement. So if all else fails let me know and I'll look for the info.
Click to expand...

I found that info but it's for a drop in tweeter, not woofer as I originally thought.
 
You also might have a cone/voice coil glue failure. I'd try gently (and I mean gently) seeing if there is any motion possible between the inner edge of the spider and the cone. Depending on where the spider attaches (usually to the voice coil) you might be able to figure out if that's where the looseness is. If it is, I'd try experimentally pressing some bluetack or putty around the joint and seeing if it stops the buzzing. If it does, a bead of glue around the joint might solve the problem without adding much mass. I use Ailene's tacky glue for this sort of stuff -- fairly tenacious, but doesn't dissolve stuff, and can be removed if needed, so you haven't committed completely to the experimental procedure.
By the by -- just check that dustcap to make sure its not the culprit (and do this before doing anything else, since its a common failure mode and an easy repair).
 
The Spicas were great speakers, but were not the loudest speaker and if your son tried to play his metal CD's at what might have been satisfying levels to him, then he might have killed a woofer...

Which is a bummer as others have said the original drivers are unobtainium....

With classic gear it is always best to not let anyone fool with it...at least if we break the stuff we have no one to blame but ourselves for our foolhardy actions...

But, I hope it's just a loose spider or dust cap, I hate to see nice examples of classic gear die due to mishaps.....
 
I've had a couple of hopeless looking drivers repaired by Jon Van L of Van L Speakerworks here in Chicago. There are probably a few AKers who can do it as well.

This is Van L's website. Really nice guy...and if you ever hear the speakers he makes himself, you might not repair the Spicas. He makes a pair of some of the best sounding speakers I've ever heard.

http://www.vanlspeakerworks.com/
 
I fried my TC-50s

I fried the voice coil on one of my TC-50s about fifteen years ago.

Was drunk and showing off my gear by pointing the speakers out the window on New Year's Eve so we could listen to Houses of the Holy while drinking in my neighbor's backyard 40 yards away.

Can't remember how much I paid for professional repair/replacement, but I do recall being in deep doo-doo with my wife, the original owner of the Spicas.
 
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