Subwoofer maintenance

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Bruce Weldy
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Joined: Fri Nov 27, 2009 11:37 am
Location: New Braunfels, TX

Subwoofer maintenance

#1 Post by Bruce Weldy » Sun May 29, 2016 3:36 pm

Began the process of getting my rig ready for the summer - as I'm sure many of you are doing also.

I decided to check the drivers in all the subs - every one needed tightening. Some as much as a full turn. My three pairs of subs were built at different times using three different types of fasteners. They were all about the same as far as how much they needed to be tightened.

While I hate to ever break the seal on the access covers, it was definitely time to do it and I'm glad I did.

So, if you haven't tightened those drivers since you built 'em - time to do it.

Now, off to check the limiters to make sure they are still where they belong.....yeah, I know they can't change inside the driverack - but, I'm still gonna' check 'em.

6 - T39 4-25" 2-22" 3012LF
4 - OT12 2512 Melded/NSD2005
1 - T24
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

laits
Posts: 140
Joined: Mon Mar 22, 2010 6:01 pm

Re: Subwoofer maintenance

#2 Post by laits » Sun May 29, 2016 4:46 pm

Wow, I have not rechecked my subs since I built them about 4 years ago. Added to this week's to do list.

Did you also need to replace the access cover gasket?
Built 2-OT12 (3012HO); 2-T39 22" (3012LF); 2-T39 16" (3012LF);
2-J12 (DL2512); 2-W8 (Beta 8A)

Bruce Weldy
Posts: 6148
Joined: Fri Nov 27, 2009 11:37 am
Location: New Braunfels, TX

Re: Subwoofer maintenance

#3 Post by Bruce Weldy » Sun May 29, 2016 6:02 pm

laits wrote:
Did you also need to replace the access cover gasket?
No, the 4 I built were still good.

The pair I bought only had one width of w/s all the way around....I always do two, so I added another width all the way around.

The sad thing I found was that the two I bought (from a really nice guy who had them made by an authorized builder - who is no longer around) had some build issues. The driver compartment was filthy. Sawdust and crap all over. On both of them the middle screw on the access cover was broken off - when I backed it out there was only half a screw. The problem was that they centered the screw right in the middle and it was hitting the driver frame - but they didn't even fix it. You know when you spin a screw...no excuse for that.

The other issue was the finish - the duratex comes off of these two too easily. My other four have been around longer and had more abuse and look better than these two. I guess I'll have to do some painting after this year's shows are over.

Oh well, enough complaining.....

Check your drivers if they've been in there a couple of years.

6 - T39 4-25" 2-22" 3012LF
4 - OT12 2512 Melded/NSD2005
1 - T24
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

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J_Dunavin
Posts: 745
Joined: Sun Jul 09, 2006 3:13 pm
Location: Appleton WI

Re: Subwoofer maintenance

#4 Post by J_Dunavin » Sun May 29, 2016 6:49 pm

Thought i had better chime in as well.
Ive been going through my DR200s, repainting, adding a grill and fixing parts on the array. I had to tighten all the fastners around all four of my beta 8s, more than two turns. And those have star lock washers on them.

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Chris_Allen
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Joined: Wed Jul 11, 2007 2:43 pm
Location: Huddersfield, UK

Re: Subwoofer maintenance

#5 Post by Chris_Allen » Mon May 30, 2016 4:16 am

I had to retighten the BP102's in my T39's a couple of years ago, I'll check them again next weekend. I've not had a look at the drivers in my DR's yet.
Built:
6xDR200, 2xT39, 2xT48, 2xJack110, 1xOmni10.5, 1xAutotuba, 1xT18, 1xSLA Pro, 1xW8, 1xW10

NukePooch
Posts: 275
Joined: Mon Jun 30, 2014 8:07 pm
Location: Berea, Kentucky

Re: Subwoofer maintenance

#6 Post by NukePooch » Mon May 30, 2016 4:53 am

Ya, I had the screws on my AutoTuba back out enough that I lost SPL and started hearing noises...thought I blew the driver....

Good tip!
4 Jack 112L- 3012HO, melded array
2 Jack 112 (bought), straight array
17.5 wide AutoTuba with Infinity 860w
6 Wedgehorn W6 w/ Panel Mount Piezos
2 T48 Slims (15" wide) with 3012LF

jimbo7
Posts: 494
Joined: Fri Dec 28, 2012 10:45 am
Location: St. Louis

Re: Subwoofer maintenance

#7 Post by jimbo7 » Mon May 30, 2016 1:57 pm

Could we also add how much use they've had? I'm sure some here use certain models less than others. :conf:
BFM builds:
XF212
T24 BP102 24"
2x SLA's 6-5" mids, 9-gt-302's
2x AT 14" MCM 55-2421
TrT 5" MCM 55-2421
AT 18" JBL GTO804
OT12 flat array

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Bill Fitzmaurice
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Joined: Tue May 02, 2006 5:59 pm

Re: Subwoofer maintenance

#8 Post by Bill Fitzmaurice » Mon May 30, 2016 3:53 pm

jimbo7 wrote:Could we also add how much use they've had?
Driver gaskets will compress even with no usage. When you mount the driver it's a good idea to let the cab sit a day or two before you button it up and re-torque the screws, as most of the gasket compression will occur early on.

jimbo7
Posts: 494
Joined: Fri Dec 28, 2012 10:45 am
Location: St. Louis

Re: Subwoofer maintenance

#9 Post by jimbo7 » Mon May 30, 2016 11:45 pm

Bill Fitzmaurice wrote:
jimbo7 wrote:Could we also add how much use they've had?
Driver gaskets will compress even with no usage. When you mount the driver it's a good idea to let the cab sit a day or two before you button it up and re-torque the screws, as most of the gasket compression will occur early on.
that should be added in the plans :ugeek:
BFM builds:
XF212
T24 BP102 24"
2x SLA's 6-5" mids, 9-gt-302's
2x AT 14" MCM 55-2421
TrT 5" MCM 55-2421
AT 18" JBL GTO804
OT12 flat array

Grant Bunter
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Location: Ilfracombe Queensland Australia
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Re: Subwoofer maintenance

#10 Post by Grant Bunter » Tue May 31, 2016 4:15 am

jimbo7 wrote: that should be added in the plans :ugeek:
You reckon anyone going to take any notice at that stage?
Everyone wants to fire them up, not wait another day...

Bruce,
Good on you for starting this thread off!
A few minutes of work can return performance you never even knew you had lost...
Built:
DR 250: x 2 (melded array) with March 2012 plans.
T39's: 4 x 20" BP102 , 2 x 28" 3012lf.
WH8: x 3 with melded array.
Bunter's Audio and Lighting "like"s would be most appreciated...

jimbo7
Posts: 494
Joined: Fri Dec 28, 2012 10:45 am
Location: St. Louis

Re: Subwoofer maintenance

#11 Post by jimbo7 » Tue May 31, 2016 7:19 pm

Grant Bunter wrote:Bruce,
Good on you for starting this thread off!
A few minutes of work can return performance you never even knew you had lost...
Adding a few stickers will add horsepower :chainsaw:
BFM builds:
XF212
T24 BP102 24"
2x SLA's 6-5" mids, 9-gt-302's
2x AT 14" MCM 55-2421
TrT 5" MCM 55-2421
AT 18" JBL GTO804
OT12 flat array

chris_c_
Posts: 192
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Location: Hartford, CT, US
Contact:

Re: Subwoofer maintenance

#12 Post by chris_c_ » Fri Aug 12, 2016 11:09 pm

It'd be a good idea to put some type of hot glue or whatever suitable temporary craft adhesive, to connect the sides of the bolts to the woofer frame. These driver mounting bolts, no matter how much you tighten them, they can back out just as easily, due to many hours of vibration which loosens them up. The hot glue prevents them from turning - sort of. You can still get the bolts out with an allen wrench or whatever is needed for the head they have.
Newest mix 8) https://facebook.com/BEATJACKERmusic "Like" appreciated :D

Rich4349
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Location: Kankakee, IL

Re: Subwoofer maintenance

#13 Post by Rich4349 » Sat Aug 13, 2016 5:30 am

I've had the same issue, and noticed they last time I cracked open my t-60s that the speaker gasket had compressed- to essentially nothing, maybe 1 mm! So one at a time I removed the bolts and put a tiny dab of blue (weaker) loctite on the last 3 or so threads, then tightened them down. I guess I'll see how that worked the next time I crack em open.
2 DR250s, 2 27" Lab15 T-60s, 2 30" Neo Titan 39s, 1 Autotuba...and looking for more!

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Bill Fitzmaurice
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Re: Subwoofer maintenance

#14 Post by Bill Fitzmaurice » Sat Aug 13, 2016 9:14 am

Rich4349 wrote:put a tiny dab of blue (weaker) loctite on the last 3 or so threads, then tightened them down.
Loctite will keep them from backing out, but it also makes it difficult to screw them tighter should the need arise. Screws don't back out, that's one of the reasons that they're recommended and bolts/tnuts are not.

MA043HA
Posts: 60
Joined: Mon Jul 11, 2016 11:17 am
Location: Mass

Re: Subwoofer maintenance

#15 Post by MA043HA » Sat Aug 13, 2016 9:47 am

Bill Fitzmaurice wrote:
Rich4349 wrote:put a tiny dab of blue (weaker) loctite on the last 3 or so threads, then tightened them down.
Loctite will keep them from backing out, but it also makes it difficult to screw them tighter should the need arise. Screws don't back out, that's one of the reasons that they're recommended and bolts/tnuts are not.
On page 16 of my THTLP plans it says "Install and wire the driver; lock washers are a must, or the screws will vibrate loose"

Now I'm the confused noob again. Do screws (not bolts/nuts) vibrate loose (back out) or not? And if they do, ARE lock washers a must? If so what kind? What if anything else can i do to ensure my driver stays sealed in place?

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