# Improving thin cabinets Technics SB-A52



## Guest (Jun 3, 2008)

Hi all. Nice forum here. Thanks for letting me join. 

I have a pair of SB-A52, which are fairly large (~4' high) speakers with 2x12" bass drivers each, as well as the mid and tweeter. and I find that the cabinets really resonate at certain frequencies, especially low bass notes. The walls of the cabinets are mostly made from 3/16" MDF or something, aside from the front panel which is 1" MDF. So I am thinking of wrapping the thin sides in another layer of MDF to try and curb these resonances, and possibly bracing the inside, and stuffing it a bit. Just wanted to run the idea past you wise folks here and see if you thought it would be worthwhile. 

Thanks!
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## BoomieMCT (Dec 11, 2006)

Good idea! While you will probably see more benefit from bracing you want to change the internal volume as little as possible (so don't go too crazy). If you don't mine the size / weight, do both!


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## Guest (Jun 3, 2008)

Ｐerhaps stuffing the inside will compensate for the volume reduction by bracing？


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## JCD (Apr 20, 2006)

I think Boomie's got it.. bracing would probably be best, but it changes the internal volume which is very important. Maybe by adding some stuffing, you can make the internal volume "appear" bigger (counter intuititve isn't it) enough that the two balance out somehow. No idea how that works though..

As an experiment, you could cut some boards and clamp them to the sides of the box to see if that helps improve the speaker as well.

JCD


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## Guest (Jun 3, 2008)

Thanks boomie + jcd
Ill do my best to remember to post my results here..


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## Guest (Jun 8, 2008)

So just to let future readers know, I braced and stuffed the cabinets, with good results.

Bracing:
-I put two braces in each cabinet, going from side to side. I put a piece of corrugated cardboard between the brace and the inside of the cabinet so that it wouldnt vibrate at the contact point. I'm sure you're supposed to use some adhesive or something, but thats what I had at hand, and its working just fine. I screwed the braces in from the outside. I made the mistake of using a wood screw at first, which just popped through the thin MDF. Better to use the kind with a rounded head, and flat contact surface. 

Stuffing:
-Stuffed each cabinet with some green "safe n' sound" insulation I had lying around. Basically I covered about 2/3 of the bottom half of the back panel inside each cabinet with stuff thats about 4" thick. Its just held in place by the brace.

Results:
Im glad to report that these mods definately improved the sound and I would recommend it to anyone with these speakers. In a side by side comparison, the bass was definately more even. It's still far from perfect, but good enough. Probably wrapping the cabinet in more MDF would improve it further, but I'm happy with them as they are, so I don't think I'll bother.


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## Owen Bartley (Oct 18, 2006)

good mod, agulha. I wish I'd gotten to you before you put screws through the outside of your speakers to tell you just to cut some bracing to size and glue it in with regular wood glue! But the important thing is that they sound better anyway, so mission accomplished! :T


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## Guest (Jun 12, 2008)

Owen Bartley said:


> good mod, agulha. I wish I'd gotten to you before you put screws through the outside of your speakers to tell you just to cut some bracing to size and glue it in with regular wood glue! But the important thing is that they sound better anyway, so mission accomplished! :T


Woops, wish I put my idea up here before I went ahead with it... can you explain why the screws are a bad idea? It wouldnt be so hard to take them out + glue.
Thanks!


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## Owen Bartley (Oct 18, 2006)

Well they aren't really a bad idea, and I'm sure things will be VERY solid, but unless I'm reading wrong, did you screw right in from the outside of your cabinet? It's more a visual thing. Lots of wood glue would still be nice and solid, but you wouldn't have anything visible on the outside of the speaker. In the end, if that isn't a problem for you, then you're just fine!


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