Subwoofer failure

Hello oldhvymec,

     I respect and applaud your efforts of experimenting with bass reproduction systems in your room and system in order to optimize bass performance. 
     As I believe you're aware, I also utilize the DBA concept in my room and system, but employ it in a more basic manner through an Audio Kinesis Debra 4-sub complete kit DBA system.  My main speakers only go down to 35 Hz so my simple application of the DBA concept is to just have the 4 DBA subs reproduce bass below 40 Hz and down to their combined rated bass extension of 20 Hz,  
     This combination, of my mains reproducing all the bass down to 35 Hz and the 4-sub DBA reproducing bass below 40 Hz along with a slight overlap and redundancy between 35-40 Hz, has been perceived by myself as providing very good and well integrated bass at my main listening position.  I perceive no need for supplementing the bass in the 60-300 Hz range that I'm assuming the use of your 'bass bins' are providing. I also have no difficulty setting up the A K Debra 4-sub DBA and dialing in the bass in a matter of a few hours, not years.
     Just to be perfectly clear, I have absolutely no doubts that you are perceiving very good and well integrated bass at your main listening position with the combination 'bass bins' and subs bass system you've built and utilize. 
     My primary reasons for posting are curiosity and a better understanding of why and how you perceived a need for these 'bass bins' initially.  For example, do your main speakers lack the ability to provide good perceived bass performance in the 60-300 Hz range at your main listening position? 
      Or do you perceive the enhancement of bass in the 60-300 Hz range at your main listening position, resulting from the deployment of these 'bass bins', as being beneficial in some ways to your system's overall sound quality or listening experience? 
      I'm just curious about whether you use them to achieve bass accuracy or bass enhancement?  And if you use them for bass enhancement, what benefits do you perceive?  I'm suspecting that using your 'bass bins' may result in improved bass detail and sound stage imaging.

Thanks,
   Tim
     

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.