Subwoofer failure


This morning after everyone was awake I put on Fiona Apple's Tidal record. The very first song, Sleep to Dream has a very loud recurrent low synthesizer note. Everytime it stuck there was a belch in the center field of the system. It turned out to be coming from one of the center subwoofers. These are Dayton Titanic III's and have not been made in years. The current version which uses the same basket has different parameters. Sh-t. 
So, I pulled the driver and sat down with a cup of coffee at the kitchen table with the driver. Everything looked fine and the excursion was smooth and quiet. The surround was in perfect shape as was the spider and lead out wires. Out of frustration thinking I would have to replace all four drivers I started tapping on things. When I tapped on the dust cap I got a mini belch! I ran a finger nail under the seam and sure enough it had detached around 1/3rd of the diameter. I ran a bead of medium viscosity cyanoacrylate glue around the detached area and it sucked it right up. Driver reinstalled it was back to normal. 
Subwoofer drivers have a very aggressive lifestyle and they can fail in many ways that can be easily fixed. This is just one example we can store in memory. 
Anybody else have a subwoofer driver failure? 
128x128mijostyn
My very first sub, an M&K, did the same thing.

I wouldn't quite call this a failure, so much as a hiccup though.  I used clear weather sealant, but achieved the same positive result.
I figured someone else would do it erik. The glue used on mine was  black rubbery stuff. Might well have been silicone. My cap was still down and I could not get anything thick under it without possibly damaging either the cone or the cap. So I used cyanoacrylate glue. Capillary effect sucks it right in. You just adding until the capillary effect stops. Then you have a full tank so to speak. Cyanoacrylate is more brittle and it might break down in time. I'm working on MS Tool's Model 4 (when I can use my right arm.) Hopefully they will be done by next spring, up and working.
The Model 3's will be retired. I'm hoping the 4's will be the final version. They are 30 inch long cylinders with a decagon cross section. 10 sides perfectly beveled to 72 degrees made of 1.5" cabinet grade plywood (plywood is stiffer than MDF) The diameter is 15". A 15 inch driver will go in each end (balanced force.) That is #8 15" drivers total in 4 enclosures.
I intend on finishing them in a satin black polyester lacquer. With all that driver I should be able to push 105 dB without pushing them past 1/2 
X max which is 12 mm for this driver keeping them well within their linear zone. Large drivers are not slow contrary to popular opinion as long as their motors are matched properly. But, they do not have to work near as hard to produce the same volume. This means much lower distortion levels, the primary goal in a high end system. By virtue of the design of these encloses distortion should be lower still. 
Anyway, the point of this thread is to let people know this happens and is very easy to fix. If your woofer is belching or burping with aggressive low notes (play some Hip Hop) check the dust cover!!
Wow OP got a little project going... I like it.. I've done folded horns too, mercy, load the slot with a sub standard driver. LOL shred the driver cone
in less than a week. We were kids LEARNING...  I like horns though...
A lot of fun. Very E.. I like the sound, with valve amps doing the lifting...

Regards
oldhvymec, I entertained doing that once but subwoofer horns are HUGE and putting 4 of them in my room would be comical to say the least. Fortunately, today we have high power amps and digital correction so you can make a little subwoofer do anything you like. 
I used to see woofers with dust cap problems on occasion back when I did consumer repair for a living. I repaired them with SealAll, which seemed to work a bit better than crazy glue. I've also glued down loose spiders in this way. I stayed away from replacing the surround though- for those I simply sent the woofer out to a local reconing service (which has been in business for at least the last 60 years).