So you own one of the best subs around, musically tight, larger cone area moves more air than a round equivalent but it's making this horrible rattling, flapping sound. So how to remedy this problem?
Step 1: The Problem..
The "retainer" ring becomes unglued and then the surround becomes unglued making a great subwoofer useless. this is a design flaw in the retainer ring which was meant to clamp down on the rubber surround, helping to hold it to the basket. The problem lies in the assembly of the subwoofer, as this particular 06S12L7 (2006 Solobaric 12" L7), its retainer ring which was epoxied in place on the basket. It does not contact the surround at all as i am lead to believe when i turned over the retaining ring. It had a lowered section and comes to within thousandths of an inch of touching under normal mounting, (being glued on). So what to do to make this Asian subwoofer live longer?
Step 2: Step 1: the Solution (hopefully Permanent)
Utilizing the retainer ring to actually retain the surround to the basket, i have chosen to drill and tap (12) 8-32 holes for machine screws to flex the retainer ring down onto the surround, clamping it tightly to the basket. I spaced my holes 1.5" from the mounting holes, using a 1/4" masonry bit to countersink the tops of the screws some. I also lubricated the tap every other hole while using the drill to hold the tap while tapping the holes on slow speed.
Tip: holding the drill with two hands, the trigger hand can also be used to sense torque from the drill. Too much torque or the tap getting snagged creating a torque spike snapping the tap.
Step 3: Step 2: Time for Gluing & Screwin !!
After cleaning up the drilling and tapping opperations, cleaning arround the drilled holes trying to remove as much of the aluminum shavings from the surround area as possible, I glued the surround back to the basket without cleaning the old glue off (seemed to be good still) applying glue to both sides with a brush, immediately centering the cone best I could and then pressing the surround to the basket. I then added the retainer ring back onto the subwoofer and began to install all 12 of my 8-32 screws (not tight, just started).
As i tightened each screw i listened for the first crack sound, thats just tight enough. 8-32 x 3/4" screws did the trick, but left about 1/16" of threads hanging out of the back of the basket which i used a grinder to remove the excess. The finished product is working quite well, 3rd day of HARD Bass!!.. over 2" of cone excursion below 40Hz! All of the products used are available from Lowes or a hardware store.