Can you really over-tighten speaker bolts...

jbert58

Silver Supporting Member
Messages
452
...if you tighten them by hand? I've been reading info on speaker replacement in this forum and from other sources, and there is some very helpful advice to be found, such as using the "star" pattern when tightening the bolts to ensure even distribution of pressure around the frame.

My question relates to how much to tighten - do you tighten as snugly as you can by hand to ensure that the gasket is fully compressed, or do you leave some "play" in the gasket by not screwing the bolts in as far as you can get them in by hand.

The concern seems to be with warping the speaker frame, but from what I can tell, these frames (at least on newly manufactured speakers) are very rigid and I doubt that they can actually be warped without bearing down with alot of torque from a power drill.

Your thoughts are appreciated.

Jbert
 

Scumback Speakers

Platinum Supporting Member
Messages
10,849
Yes, you can over-tighten them. This is my advice to all Scumback buyers.

Mounting your speakers. Use caution. Vintage style frames (thinner) require that you mount the speakers using the following X pattern method.

A) Tighten all bolts/screws hand tight till the bolt or screw meets the back of speaker frame.

B) Turn your bolts/screws 1/2 to 3/4 turn after bolt/screw meets back of frame.

C) Tighten in a cross frame or X pattern. DO NOT TIGHTEN in a circular fashion as you can warp the frame. Tighten 1/4 turn on each bolt in an X pattern in one pass, then the other 1/4 to 1/2 successive turns in successive passes. This will compress the gasket sufficiently to ensure a proper seal, and without warping the frame. Failure to do this could result in a damaged cone, bent frame, or unusually high shrill noises from over-tightening. DO NOT USE AN ELECTRIC DRILL SET TO A TORQUE SETTING UNLESS YOU KNOW THE DRILL REAL WELL!

I've got some old Celestions that were original to a cab, and you can see the frame dip down where the speaker bolts are.
 

rockon1

Platinum Supporting Member
Messages
12,981
Im sure you can but I havent been able to cause damage.Ive repeatedly swapped the same speakers (Celestions and Eminence) and overtightened them with no ill affects that I can hear. Sad but true Ive always been a cronic overtightener! That said I'd stick with the above post's recommendations! Bob
 

bosstone

Member
Messages
3,396
I read on the Lansing Heritage site (cover JBL questions etc.) that JBL continuously received JBL D120s back for warranty because of voice coil rub caused by the speakers being over tightened by Fender and repeatedly warned Fender about the problem. I am sure over tightening problems are worse with those speakers because of their very tight voice coil clearances.
 

seajay

Member
Messages
2,670
Yes, you can over-tighten them. This is my advice to all Scumback buyers.

Mounting your speakers. Use caution. Vintage style frames (thinner) require that you mount the speakers using the following X pattern method.

A) Tighten all bolts/screws hand tight till the bolt or screw meets the back of speaker frame.

B) Turn your bolts/screws 1/2 to 3/4 turn after bolt/screw meets back of frame.

C) Tighten in a cross frame or X pattern. DO NOT TIGHTEN in a circular fashion as you can warp the frame. Tighten 1/4 turn on each bolt in an X pattern in one pass, then the other 1/4 to 1/2 successive turns in successive passes. This will compress the gasket sufficiently to ensure a proper seal, and without warping the frame. Failure to do this could result in a damaged cone, bent frame, or unusually high shrill noises from over-tightening. DO NOT USE AN ELECTRIC DRILL SET TO A TORQUE SETTING UNLESS YOU KNOW THE DRILL REAL WELL!

I've got some old Celestions that were original to a cab, and you can see the frame dip down where the speaker bolts are.
Jim - In step C, how many 1/4-turn passes do you recommend?
 

Scumback Speakers

Platinum Supporting Member
Messages
10,849
Jim - In step C, how many 1/4-turn passes do you recommend?
A total of three 1/4 turn passes, just enough to compress the gasket (having it act like a lock washer, if you will) and not bend the frame. Does that make sense, or is it clear enough?
 

Scumback Speakers

Platinum Supporting Member
Messages
10,849
I read on the Lansing Heritage site (cover JBL questions etc.) that JBL continuously received JBL D120s back for warranty because of voice coil rub caused by the speakers being over tightened by Fender and repeatedly warned Fender about the problem. I am sure over tightening problems are worse with those speakers because of their very tight voice coil clearances.
One of the things that Ted improved in my speakers over the originals is the voice coil gap. It's tighter and they sound better because of it, among other things, of course.

And that's one reason he recommended I start advertising this tightening technique, so that he didn't get any warranty repair issues because of it. Seemed logical to me, so I did it.
 

rockon1

Platinum Supporting Member
Messages
12,981
One of the things that Ted improved in my speakers over the originals is the voice coil gap. It's tighter and they sound better because of it, among other things, of course.

And that's one reason he recommended I start advertising this tightening technique, so that he didn't get any warranty repair issues because of it. Seemed logical to me, so I did it.

Makes sense. If I ever get around to buying some of yours I'll have to control my "hamfistedness" as we say in the automotive industry. Very bad habit. Tighter isnt better,correct torque is-sadly I know this.Bob
 




Trending Topics

Top