Allison CD6 speaker problems

saturnfive

saturnfive

New Member
I bought a pair of Allison CD6 speakers used. One speaker works fine. The other does not. When I turn the receiver on I get a pop from the speaker and then it shuts down.

I've connected the working speaker and a known working speaker I've used recently. They both work fine.

I removed the tweeter and the symptoms remained.

I reinstalled the tweeter and removed the woofer and the tweeter plays.

I connected the tweeter directly to a MP3 player and I can hear it play.

I connected the woofer directly to the MP3 player and it plays.

I need advice before I move on because I do not understand the results.
 
Sounds like your crossover then if both drivers are working individually.
Don't forget the cd6 are 4 ohm speakers, make sure your amp is rated for that!
 
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Closely check the two wires where the woofer connects to the crossover, there must be a detachment there. Or a disconnect at the inductor.
 
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on my 110's they are equipped with some kind of safety resistor that heats up when pushed to hard. Then it cools off after a few seconds when the volume is turned down and the volume comes back. If yours has this safety feature it might be bad?
 
I tested the capacitor with a digital VOM and it reads a changing value towards infinite resistance and repeats with each reading. This cap appears to be good.

It's a 8 MFD 50VDC 10% electrolytic non-polarized capacitor.
 
The woofer behaves strangely. When hooked to the amp there is silence then it looks like the cone is pulled all the way down and pops back up to the top. Then nothing. Then it repeats. I suspect something is wrong with voice coil that only appears when the amp is connected, not the very small output of the MP3 player.
 
Allison drivers we made in house and should have a black sticky rubber coating on the speaker cone on the woofers, surrounds and dust caps.. you will never know the joy of the Allison sound with out the originals.
 
I've known the joys of Allison 6. A friend of my brother's had them in a small room paired up with a McIntosh amp. That's why I wanted a pair. I would be okay with the KEF driver, for the time being, if it worked.
 
I reconnected the tweeter and woofer and hooked the output of the MP3 player to the speaker terminals and to my surprise I could faintly hear the music through both. I couldn't hear the vocal so maybe it's being notched out. I plugged the amp back into the terminals and it popped like before. Does this suggest the crossover is the problem?
 
First I'd try swapping the woofers between the two speakers and see if the problem remains. There's a decent chance that the crossovers will need recapping anyway, but the results that you're getting with the woofer on its own suggest there may be something wrong with it as well. Do they both have the Kef woofer? I wouldn't put money into a replacement unless it was the original Allison.
 
swechsler said:
First I'd try swapping the woofers between the two speakers and see if the problem remains. There's a decent chance that the crossovers will need recapping anyway, but the results that you're getting with the woofer on its own suggest there may be something wrong with it as well. Do they both have the Kef woofer? I wouldn't put money into a replacement unless it was the original Allison.
Click to expand...

I replaced the KEF 8" woofer with the woofer from the other speaker. It works fine. There must be something wrong with the KEF driver.

I checked the second speaker for identification. It is definitely not Allison. It has numbers and Made in Canada on it. Paradigm maybe?
 
It is not the crossover. I suspect a short in the voice coil lowering the impedance to where the amp does not like it.
 
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What alternatives are there for replacing the replacement woofers? Are there good quality replacements available through speaker parts suppliers? Perhaps with better bass extension that the originals? Or should I wait until there are Allison woofers available used?
 
Your best bet would be to wait for the correct woofers to come up. Roy Allison (the founder of Allison Acoustics) was a great engineer. He knew what he was doing.

I'm not all that familiar with the smaller Allisons, but there's a pretty good chance that the same woofers were used on other Allison models (even in their heyday, Allison was never a big enough company to use bespoke drivers for a single model; even larger companies generally use the same drivers in multiple designs. The exception is super-expensive models from high end manufacturers, but these weren't that expensive). Figure out which ones and it will make your search a little easier.
 
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He was he was a great engineer. I've always admired Allison designs, especially the small cube bookshelf speakers.

I passed up a pair of Allison 105 speakers with deteriorated surrounds for cheap. I think the woofers would probably fit. I will continue to look for Allison drivers.
 
eBay items #371936832232 and #371936832478 appear to be original, take a look at those to get an idea. Basically you're looking at a dark grey or black cone with some sticky-looking material, plus a paper dust cap (although that could be changed without affecting the sound). As far as I know, all the original iterations used foam surrounds.

Be careful - it does appear that the 8" woofers for the lower number models (e.g. two and four) aren't the same as the one for the CD6.
 
Thanks. I have been watching them. I've asked the seller about markings and they are dated 87 and made in USA. The magnets look different from each other. I've asked about the connector on one because it looks damaged.
 
I just looked up the AL105 woofer size and it is 6.5" not 8" that these use, so I would not have been able to install them in the CD6.

Does the black back of the magnet look original?
 
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