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Wagner
11-24-2009, 03:34 PM
Should the LE14A and similar drivers with the same mounting flanges or ears be tightened down?

It concerns me that even when modestly "snugged" down, and then given a 1/4 turn (as suggested here in another thread), the rate of compression at the screw flanges is such that the frame actually touches the baffle at those 4 points and does not in the areas in between.

What is the correct amount of torque? I've read elsewhere that with the really old drivers like the 130A they should be little more than a bit beyond finger tight to avoid damage?

I try to use common sense, but I wonder every time I remove and install a JBL driver. Like Goldilocks, what's too tight, what's too loose and what's "just right"!

Thanks to all,
Thomas

Harvey Gerst
11-24-2009, 11:14 PM
At JBL, we snugged the speakers down just enough that the cork surround made contact, and we'd only tighten the screws using two fingers (thumb and first finger, or thumb and middle finger). The speakers would seat themselves nicely that way.

Wagner
11-24-2009, 11:32 PM
At JBL, we snugged the speakers down just enough that the cork surround made contact, and we'd only tighten the screws using two fingers (thumb and first finger, or thumb and middle finger). The speakers would seat themselves nicely that way.


Thank you Mr. Gerst. I believe it was one of your posts where I learned of your suggested method for the older round drivers.
I'm feeling a little uncertain however over what is right for the "squircles" with the o-ring seals on the back side of the basket flange.
Warm regards,
Thomas

Harvey Gerst
11-24-2009, 11:36 PM
Same idea; just tight enough to slightly "squash" the O-ring, but not tight enough to warp the frame.

ROSSO
11-29-2009, 03:32 PM
Should the LE14A and similar drivers with the same mounting flanges or ears be tightened down?

It concerns me that even when modestly "snugged" down, and then given a 1/4 turn (as suggested here in another thread), the rate of compression at the screw flanges is such that the frame actually touches the baffle at those 4 points and does not in the areas in between.

What is the correct amount of torque? I've read elsewhere that with the really old drivers like the 130A they should be little more than a bit beyond finger tight to avoid damage?

I try to use common sense, but I wonder every time I remove and install a JBL driver. Like Goldilocks, what's too tight, what's too loose and what's "just right"!

Thanks to all,
ThomasIs this a JBL factory cabinet or a DIY? The LE series of woofers have very little tolerence for mis-sized baffle openings. Anything bigger than the specified opening won't seal the o-ring and anything smaller won't allow the flange to pull up flat. The white o-ring on the back is the gasket, and the whole works is a pretty close-tolerance fit. If the hole is the right size the whole frame should mount flat to the baffle. If the ears are bending something is really VERY wrong.

Wagner
12-07-2009, 01:40 PM
Is this a JBL factory cabinet or a DIY? The LE series of woofers have very little tolerence for mis-sized baffle openings. Anything bigger than the specified opening won't seal the o-ring and anything smaller won't allow the flange to pull up flat. The white o-ring on the back is the gasket, and the whole works is a pretty close-tolerance fit. If the hole is the right size the whole frame should mount flat to the baffle. If the ears are bending something is really VERY wrong.


L55s: 100% JBL
Front baffle is flat (checked with a straight edge used for checking heads and block decks)
I didn't say or use the word "bending".
Every JBL box I own, or have ever owned, has had extremely close tolerance and fine fit for the driver openings.
I understand how the O-ring thing works, thanks! :D

Thomas