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15" death rattle

#21
1. Try to change your polarization, run slowly your power up and observe what's going on with cone and wire.

2. I had the same issue with RCF 18" speaker way back "in the time of long hairs". I just soldered extension wire to existing, glued original for the cone and I was fine. Original wire was short and caused numerous buzz and "stuff". I learned just recently, that RCF is still in use (after 30+) years!!!!
 
#22
yem said:
Perhaps "rattle" is not the best word. It does not sound like something is loose. Describing the noise as a "buzz" might be more accurate but "slight" does not fit - the noise is quite noticeable.
Click to expand...

Can you hum a few bars?

I'm wondering if the whiskers are the problem. That thing cant be touching the cone or the spider, if the darn thing isnt long enough, that would be a problem.

If the things are too tight and the cone has to really move in the there... Maybe you will need to look at the binding posts and see if you can generate a bit more wire by moving it slightly. Making sure the lead stays off the moving parts.

This is definately worth figuring out. This speaker may already be a rebasket job, done by DAVE at 2AM after a gig... If he got things a little short, you could be on it it.

Its worth trying lengthening the lead by 1/2" by soldering on little extensions.

If not you are going to have to find a speaker reconing tech to see if they can for you. BOB
 
#23
Yeah, didn't think that this could already have been a recone job. Hard to believe that this would have been manufactured that way originally. +1 on trying to lengthen and redress those wires if you can determine that the wires are indeed hitting the cone. Doesn't look like there's much to play with there though.

If you have a crap speaker lying around you might be able to cannibalize it for some of the wire to splice in. That would be best but you MIGHT be able to get away with some regular ol' wire from the terminals to the exising voice coild wires IF you're careful about positioning it and there isn't any flexing near the solder splice.
 
#24
Yem, it's a pain in the butt for me, but if you really want, I can pull the (BW) 15" out of my Peavey cab and take some pictures of it for you. It is missing it's dome, but everything else, including the sound, is doing great.
 
#26
gerryjazzman said:
Yeah, didn't think that this could already have been a recone job. Hard to believe that this would have been manufactured that way originally. +1 on trying to lengthen and redress those wires if you can determine that the wires are indeed hitting the cone. Doesn't look like there's much to play with there though.

If you have a crap speaker lying around you might be able to cannibalize it for some of the wire to splice in. That would be best but you MIGHT be able to get away with some regular ol' wire from the terminals to the exising voice coild wires IF you're careful about positioning it and there isn't any flexing near the solder splice.
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I do have a spare laying around. By how much should I lengthen the voice coil wires?
 
#32
Update: I lengthened the voice coil wires and the noise is worse.

It is important to note that I had difficulty adding the extensions. Although I consider myself to have intermediate skills, I found it challenging to get the solder to stick to both the voice coil wires and my extensions. I eventually made all of the connections and replaced the speaker in the cab. When playing low notes at medium volumes, there was a nasty noise. I took the speaker out again and applied some electrician's tape to the solder connections. This had made the nasty noise slightly less abrasive.

So, it seems like the voice coil wires are hitting the inside of the cone. I'm about to remove my extensions unless anyone has some advice. Thanks for all of the help.
 
#34
frankie5string said:
IF the voice coil wire is somehow bashing against the cone beneath the dust cap then it's time to throw it out or have an entirely new cone put on... It's probably flapping all over the place around the magnet... :-(
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Hi Frankie,
My theory is that the voice coil wire is hitting the cone outside of the dust cap - between where the wire comes through the cone and where they are soldered to the connections (which are bolted to the frame). I don't believe anything is hitting the magnet.
 
#36
I just skim very lightly on these tailchasers, but has anyone in the chain of advice yet mention that Black Widows with potential problems are easy to diagnose? The basket removes off the magent assembly and you can usually see if the voice coil has overheated or shorted, or malformed/bent.

Also you can reach down into the magnet gap with doubled-up tape to pull any build-up of crap out of it. Extremely old BWs ferinstance had a foam insert behind the mesh of a cooling vent in center of the motor that would over the decades break down and migrate as detrius into the gap, where it could cause noises that were reminiscient of damage. Once removed, good as new.

The wires clearly were fine by the photos... but no other driver is as easy to check for damage than a BW, which incidentally also is way easier to repair: just order a basket, no reconing needed. On the other hand, sometimes remembering the internet is the world's poorest substitute for actual professional under-the-hooding is the smartest move one can make. Get thee to someone with experience and learn over the shoulder.
 
#37
Well, yeah, these type of problems are hard to diagnose at a distance. Kind of like the Car Talk guys Tom and Ray trying to diagnose a car problem over the phone. I have to admit I have no first hand experience with a BW speaker so I don't know exactly how a properly working one is constructed. Most other speakers that I've seen have much more distance between where the voice coil wires emerge from the back of the cone and the spider. I just took a look at an Eminence Deltalite II 2512 that I have lying around and this distance is about an inch. In Yem's pictures it looks like there is less than 1/4 inch, maybe even like 1/8 inch. Actually I think the wires MIGHT actually be hitting the spider. But, again it's hard to say without first hand observation. Someone who DOES know about BW's check me on this, but it just looks weird to me.
 
#38
OK, gerryjazzman, I read a little more. If it's anything to do with the leads, one can gently bend them so that they aren't close to either spider or the cone further out from the voice coil, try to get any slack bent up away from surfaces. If the leads are TOO LONG it's easier for them to vibrate against cone or spider than if they are shorter... They only need to be long enough to allow full excursion.

rbonner said:
Speakers dont work in free air... All it is then is a rattling cone with the air cancelling the sound in both directions. It wont take any power to speak of and will blow up in short order.
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This is wrong.

One can actually feed a signal (such as music off a CD) at moderate level into the un-enclosed driver and hear plenty of output, and what's more: one can see if the wire leads vibrating against cone or spider are a good bet.
 
#39
ReignBass said:
Peaveys are really easy to dissassemble, Three bolts and you can remove the magnet structure from the basket and coil assembly. The gap can be cleaned out with a piece of folded over masking tape.(sticky side out). The basket assembly can then be inspected for problems. Inspect the coil for burnt spots, or for evidence of binding. Cleaning the gap might not fix the problem. You may have a loose connection on one of your leads to the voice coil, under the dust cap of the cone.That is rather difficult to repair without further damaging the speaker. However replacement basket assemblies are available and easy to install and will repair the speaker to like new condition.The replacement baskets are not overly expensive and are available numerous places. They come with detailed instruction on dissassembly an reassembly.
Click to expand...

OK, someone did show some BW diagnosing smarts - no talk of reconing here, but actual basket removal, and the ease and cost effectiveness if replacement is warranted.
 

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