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Re-mounting speakers in a vintage flatback?

Discussion in 'Amps and Cabs [BG]' started by morgan138, Jan 9, 2017.


  1. morgan138

    morgan138

    Dec 10, 2007
    Boston
    I recently picked up an early 70s flatback 8x10. It's everything I expected: great to play, terrible to move, you know the drill.

    The one thing is: the speakers are just screwed into the baffle. A few screws are missing (so each speaker has 7-8 holding it in), a few feel like the holes are getting stripped, and a few are at crooked angles so I can't really tighten them down. I've got a suspicion the drivers are slowly loosening themselves as I play (a bunch were super loose when I got the cab) and I want to get them secured. Off the top of my head, I'd either

    1. drill 4 holes per speaker, put in t-nuts, and bolt them in
    2. drill 4 holes per speaker, put in t-nuts, and clamp them down with those external bracket things
    3. same as #2 but just screw the brackets into the baffle
    I should add that I don't care about keeping the cab in original condition (it's already been stripped and truck bed liner-ed, has burly wheels on one side, and very well-mounted Ampeg folding handles -- I actually bet it's passed through Talkbass hands at one point). I'm also not planning on swapping speakers around unless I have to recone or replace one of these old 10s.

    What's gonna be the best way to keep this thing running for another 35+ years?
     
  2. 2saddleslab

    2saddleslab Supporting Member

    May 30, 2003
    Kentucky
    I've recently done with same with a small PB112. Option one worked for me, but I used 8 t-nuts for one speaker. Might as well make it as secure as you can. Not sure what the external bracket things you're talking about in option 2.
     
  3. beans-on-toast

    beans-on-toast Supporting Member

    Aug 7, 2008
    T-nuts are a good way to go. Install them so that the T is against the back of the baffle, the screw will draws them in against thhe baffle and hold them in place.

    It is important when installing a speaker to not overtighten them. This can over compress the gasket and worst case warp the basket. Finger tight plus another half a turn. The pressure around tye basket should be even.

    I was lost on the brackets that you mentioned as well.
     
    Bill Whitehurst likes this.
  4. morgan138

    morgan138

    Dec 10, 2007
    Boston
    I guess they're called "grill clamps"? Basically they clamp the speaker in place without going through the holes in the frame. Here's a really burly example, I'd probably use something smaller for just 10s.

    200x200-1x12.
     
    2saddleslab and beans-on-toast like this.
  5. beans-on-toast

    beans-on-toast Supporting Member

    Aug 7, 2008
    The clamps probably work just as well as T-nuts.

    I think that T-nuts look better in this context. There is also a product called hurricane nuts, see parts-express.com
     
    Last edited: Jan 9, 2017
    morgan138 likes this.
  6. morgan138

    morgan138

    Dec 10, 2007
    Boston
    Yeah, those clamps can be kind of ugly. I think that advantage would be that you don't have to worry about the frame getting warped or bent around the holes. Might be hard to fit them on a crowded 8x10 baffle though, so t-nuts may be my best bet.
     
    beans-on-toast likes this.
  7. basscooker

    basscooker Commercial User

    Apr 11, 2010
    cincy ky
    Owner, ChopShopAmps
    Is it MDF? You may want to consider fabricating some rings to place on the inside surface of the baffle, under the t-nuts. 1/4" ply would do fine. I've found MDF doesn't always cooperate with t-nuts. If it's ply, probably not necessary.
     
  8. Christopher DBG

    Christopher DBG Commercial User

    May 18, 2015
    Westerly, RI
    Luthier/Owner, Christopher Bass Guitar
    Simplest way, and should last more than the next 35 years is rotate the speakers that have stripped holes a few degrees, drill new holes and use the old wood screws again.
     
    bobyoung53 and agedhorse like this.
  9. beans-on-toast

    beans-on-toast Supporting Member

    Aug 7, 2008
    They used ¾" plywood for the baffle in those cabs. Even the later versions that used MDF for the cab stuck with ply for the baffle and the middle shelf. The ply shelf helped structurally back to front.
     
    Last edited: Jan 9, 2017
    bobyoung53 and basscooker like this.
  10. basscooker

    basscooker Commercial User

    Apr 11, 2010
    cincy ky
    Owner, ChopShopAmps
    LOL

    Post#7: moot

    ;)
     
    beans-on-toast likes this.
  11. beans-on-toast

    beans-on-toast Supporting Member

    Aug 7, 2008
    You're right about issues with MDF cracking. I've had casters pop right through the bottom, seen cabinets shatter when dropped. Many are like this. At the same time, I've seen pro EV MDF, what they called RoadWood cabs that were done right and their cabinets have stood the test of time. I guess that it depends on the product.
     
  12. Hey @morgan138 - looking to use the t-nut method in one of my 70s flatbacks. Did you do this? And what is/was your opinion? Thanks!
     
    Last edited: Aug 20, 2019
  13. JimmyM

    JimmyM Supporting Member

    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    T nuts flat out rule. But I'm too lazy for it, so I just did the toothpick/wood glue fix instead in any stripped screw holes.
     
    BasturdBlaster likes this.
  14. @JimmyM - you’ve been on this forum for a minute so maybe you know - what size t-nuts should I get? The 1/4” look WAY too big. And the smaller sizes at my local Lowe’s come in packs of 2 for a couple bucks each. I’m gonna need 64 (8 t-nuts for 8 speakers - AND bolts) so I’m gonna try Amazon. Thanks.
     
    JimmyM likes this.
  15. BasturdBlaster

    BasturdBlaster

    Feb 19, 2012
    Crandon WI
    I'm not sure what the perfect size would be but my local hardware store has a selection and I used some 8-32 t nuts to mount some small rubber feet on a rack case. Funny they had t nuts with "claws" and without.
     
  16. I have two flatbacks with the original screws and they hold the speakers down good, maybe someone fooled with yours.
     
  17. Mine came empty. The hardware is kind of all over the place and piecemeal. I had to buy speakers for it (Jensen MODS for affordability at the moment). There are holes in the wood where the wood screws were so I’m trying to think ahead if any of those become issues and “strip” out.

    Looks like 10-32 was suggested elsewhere. I’ll probably go with those. amazon has 100 packs of the tnuts and machine bolts for pretty cheap.
     
    BasturdBlaster likes this.
  18. Also @bobyoung53 - I don’t have all the original screws. I got these cabs (two of them, both solid wood 70s flat backs) literally off the side of the road for $35 (for BOTH). Going the extra mile here isn’t an issue.
     
    bobyoung53 likes this.
  19. Man, you got a deal! Mine are the same except they came with the original speakers, I bought them both about 20 years ago, one from Daddy's Junky Music and one from a friend.
     
  20. JimmyM

    JimmyM Supporting Member

    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    I am totally clueless, bro. Take a screw to the hardware store, tell them the purpose, and see if they can hook you up for a better price if you buy a bunch.
     

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