Jbl 18" Speaker Question

Dubsly · #1 12-22-2012, 01:26 PM

I just snagged an old Sunn 1-18 cab from a Craigslist ad. The previous owner had done some strange things to try and stop the rear panel from vibrating, so after some weatherstriping tape and decent screws, I've solved that problem. But...

Long story short: It has an 18" Jbl E-155-8 loaded in it, and at first, mostly at lower volumes, it seemed scratchy and almost blown. However, the longer I played through it, it improved gradually and now seems perfectly fine.

Could it be that after sitting around for a long time, (years possibly) that it just needed to get moving again? Or, should I expect problems with it down the road?

audioglenn · #2 12-22-2012, 01:38 PM

Yes, it could be the fact that it sat for so long. The voice coil on any speaker moves back and forth between a gap in the magnet at the center of the speaker. That movement is called "excursion". If that speaker sat for a long time, there could have been dirt and dust that settled in there interfering with the excursion. It could also be that the sound improved from the voice coil heating up after sitting for so long. My guess is that is should be OK. Hope this helps!

audioglenn · #3 12-22-2012, 01:40 PM

One more thing....the E 155 is a very well made speaker, so even if it does fail, I would invest in having it re-coned. It is well worth it!

seamonkey · #4 12-22-2012, 03:22 PM

If it has open ports on the back, sometimes critters move in and build nests. Playing may knock loose the nesting.

Bassmec · #5 12-22-2012, 03:41 PM

Quote:

Originally Posted by seamonkey

If it has open ports on the back, sometimes critters move in and build nests. Playing may knock loose the nesting.

If you got it from certain denominations of Churches you never know what's been in there that might have been causing a rattle:

Great 18 inch speakers them old JBL's she'll be worth evicting a rattler or two for.

will33 · #6 12-22-2012, 04:37 PM

It's entirely dependent on the relationship between rattle and fang. Get it right, and you've got a winner for sure.

chadds · #7 12-23-2012, 01:52 PM

Quote:

Originally Posted by will33

It's entirely dependent on the relationship between rattle and fang. Get it right, and you've got a winner for sure.

Rattle 'n Fang! I knew them mates over in Cornwall!

Dubsly · #8 12-25-2012, 08:46 AM

Thanks for the replies. I got a little worried when I brought it home and gave it a test. But, after it "re-broke itself in" it"s been fine.

I took it to a four hour practice the next day, after letting it sit all night, and it sounded awesome right off the bat.