SDA-2A cabinet repair help

cascius

Hi everyone, so I'm pretty much done upgrading my SDA-2As, and have been battling an air leak in the left speaker. I did all the usual things (Armacell, Loctite) and finally found the culprit: it's the cabinet. In the following photo I'm pointing at the area where it's come unglued. It's essentially between the black and wood veneered panels, for about 12 inches on the left side.


The right side also has the same problem, but less serious (probably just 6 to 8 inches unglued).

When pressing on the black wood, it clearly moves back, so it must be unglued. I'm thinking I just need to find a way to insert glue in between the two MDF boards and then keep them tight together until it dries. Does anyone have some tips on how to go with fixing this?

Things just got a bit frustrating I must say... ;P

Thanks in advance,

- Olivier

F1nut

Run a bead of Loctite Power Grab on the inside seams.

ken brydson

F1nut wrote: »

Run a bead of Loctite Power Grab on the inside seams.

Maybe some clamps as well if it's moving back when you apply pressure.

cascius

Thanks guys. I just did the Loctite an hour ago or so, but considering how much it could move I doubt that will cut it on its own.

This morning I played a 15HZ sine wave, and past a certain volume the left MW would go nuts and it sounded as if something was knocking against the wood panel. So at this point I think I'll have to find a way to slightly expand the opening and insert some glue in there. I did find some syringe with wood glue on Amazon, that might be an option. Another idea would be to add some screwed brackets to add extra support, but I'd rather try to avoid that.

- Olivier

westmassguy

Olivier, the front baffle should not move in. There's a slight inset where the front baffle fits into the side and top panels. These were then glued face down at the factory, with industrial "Hot Glue". The rear baffle was glued last. Get a small mirror and a drop light and see what's going on. Normally, the joint between the front baffle, sides and top were slathered heavily with hot glue. Something separated.

cascius

Thanks Dave, i'm not sure what happened to that speaker, but the front panel definitely moves. there is actually a gap of 1 to 2 millimeters between the original glue (inside the cabinet) and the front panel. I believe the knocking noise comes from that panel banging against the glue when rocking back and forth... the good news is that it only happens when playing at ridiculous levels (which I don't). The bad news is that this obviously affects the sound quality at regular levels.

I remember seeing a trick a while back to fix cracks inside butcher cutting blocks:
- put a large amount of wood glue on top of the cutting board,
- use a crappy vaccum to suck in the glue from the other side
- keep pressure on the block until the glue dries up.

Pretty cool right?

I think I will try this, but the wife is going to kill me if I use the brand new vaccum to do that.... lmao.

westmassguy

If you have a heat gun, you may be able to re-melt the hot glue and seal the joints. I use a heat gun to soften the glue for removal when I'm installing Hurricane nuts. They put so much on sometimes, it's right up to the edge of the woofer openings.
Be very careful, you don't want to apply too much heat

F1nut

Ok, it seems joint has suffered damage to the point glue alone will not bond the panels. The butcher block repair will not work. So, what you need to do now is remove the glue along that seam, get some long lengths of 1x1 and a bottle of Titebond wood glue. You will now be adding glue blocks to the inside corner edges. Make the glue blocks as long as possible, coat two sides with glue, press into place and if possible apply weight or some sort of bracing to hold the glue block in place for 24 hours. I guarantee the glue blocks will solve the issue.

cascius

Thanks for all the inputs. Here's what I did so far: I used a very fine paint brush to insert glue into he gap. The gap was actually quite thin at about 1/2 or 1/3 of a mm. I then used a clamp to tighten it and that seems to have worked. I've only done the left side for now, and already the results are much better. when doing the air leak test, it used to take less than a second for the MW to settle. Now it's about 3 seconds. I will fix the other side when I have time and them apply a copious amount of loctite on the inside. If this fix doesn't last I will follow F1nut's advice.

Thanks for all the help guys!

I'm going to run MCACC next and see if I like the resultin eq.

Have a good jight,

Olivier

westmassguy

Olivier, MCACC is fine for matching, as close as possible, all the speakers for Home Theater. When listening to 2 channel, I use pure direct for my 2ATLs. The MCACC seems to suck some of the life out of the SDAs, so it's switched off completely for Music. There's also some debate as to leaving the interconnect connected or disconnected when running the MCACC. I've done it both ways many times. I find that leaving it connected gives the best end result in my room.
Your Crossovers also need a lot more burn-in. You'll most likely be running the MCACC again in a few months.