jhoak Posted October 8, 2009 Share Posted October 8, 2009 I'm in the process of reworking a pair of La Scalas. I know that the bass bin can stand some additional bracing. I've seen some who do a single brace centered and some who do a pair of them effectively dividing the opening in to thirds. Is there any distinct advantage to either approach? Obviously one brace per side is a lot less cutting and a lot less work but if two of them is a lot better then it's worth the effort. Input from anyone who has done either (or both)? Quote Link to comment Share on other sites More sharing options...
Guest David H Posted October 8, 2009 Share Posted October 8, 2009 One brace should do nicely. You might want to check out gregs audio pages for ideas. Quote Link to comment Share on other sites More sharing options...
jhoak Posted October 8, 2009 Author Share Posted October 8, 2009 Oh yea... I already have. Absolutely stunning work. I hate it when someone "raises the bar" [] I copied his shape and cut the pattern this evening. My plan is to make grills just like the La Scalas that he did. That's bound to be a world easier than trying to veneer the interiors of the bass bins to match the exteriors. Quote Link to comment Share on other sites More sharing options...
sootshe Posted October 8, 2009 Share Posted October 8, 2009 I also used Greg's ideas...here's a photo of the construction showing the braces....IMO I think 1 brace is more than enough. Quote Link to comment Share on other sites More sharing options...
JohnA Posted October 9, 2009 Share Posted October 9, 2009 Imagine a guitar string. Hold it in the middle and it vibrates in halves at twice the frequency. Being shorter but otherwise the same, it is stifffer and less prone to vibrate from another sound. If you were to hold it off-center the 2 lengths would vibrate at 2 different frequencies and not tend to activate each others natural resonance. So, you can use one brace, but put it above or below the center of the bass horn. Extend it all the way to the front edge of the outer wall because that is the longest unsupported, least stiff length that is most prone to resonate. Put the brace at least 10% of the total length from the center point, about 2 1/2" off center. If you want to build some Belle-style grilles, you could stop an inch short of the front edge to leave room and not lose effectiveness. See the sketch. The dashed lines are optional. Quote Link to comment Share on other sites More sharing options...
Coytee Posted October 9, 2009 Share Posted October 9, 2009 Lemme ask what might be a stupid question. My understanding is the weak spot on a LaScala is the side walls resonating. What if instead of working out the wedgies, someone 'veneered' the LaScala with something like 3/4" oak/rosewood/other choice and essentially, made the sidewalls 1 1/2" thick (much like the LaScala II) Perhaps put some solid wood edging along the front to pretty it up. I've got a third LaScala beater box. I'm debating on trying this since I've nothing to lose with it. I might cut the top section off (not needed if I put a K402 on top) I might also keep the top section, depending on height issues. Anyways... I was thinking on wrapping the bass bin (top and 2 sides) with something like that and seeing how it worked out. Thoughts? Quote Link to comment Share on other sites More sharing options...
sootshe Posted October 9, 2009 Share Posted October 9, 2009 Lemme ask what might be a stupid question. My understanding is the weak spot on a LaScala is the side walls resonating. What if instead of working out the wedgies, someone 'veneered' the LaScala with something like 3/4" oak/rosewood/other choice and essentially, made the sidewalls 1 1/2" thick (much like the LaScala II) Perhaps put some solid wood edging along the front to pretty it up. I've got a third LaScala beater box. I'm debating on trying this since I've nothing to lose with it. I might cut the top section off (not needed if I put a K402 on top) I might also keep the top section, depending on height issues. Anyways... I was thinking on wrapping the bass bin (top and 2 sides) with something like that and seeing how it worked out. Thoughts? From what I've read here I think you'll find that that will do exactly the same thing.I reead here that Klipsch went to the 1 inch side panels to eliminate the resonance in the LS2 because to go the way of the wedgies would involve having to make them individually for each cabinet due to the variations in dimensions for each box. Quote Link to comment Share on other sites More sharing options...
jhoak Posted October 9, 2009 Author Share Posted October 9, 2009 I briefly considered the same process with mine. I thought about laminating 1/2" MDF to the top, bottom, and sides and then veneering the whole mess. I abandoned the idea because (A) it eliminated any possibility of commercially available edge banding, I'd need to find 1 1/4" edge banding or waste an assload of veneer. ( it made the bass bins 1" wider than the tophats. Not a "big deal" but visually that's the kind of stupid thing that makes me crazy (Yes I'm THAT OCD). Since I've already completed and veneered the tophats I was pretty much married to that width dimension. I really didn't want to add another 1/2" all the way around on the tophats and scrap out the that much veneer. I really think (OK... I'm hoping) that simple braces will be just as effective as adding additional panel thickness in taming some of the cabinet resonance. I'll know soon enough... [] What I do find interesting is the comments on brace placement. It would not have ocurred to me to NOT center them in the opening. Especially since every one of the brace installs I've seen have been either centered or in the case of two braces evenly spaced in thirds. The concept makes sense but I'm not yet convinced that 2 1/2" one way or the other will make all that much difference. Quote Link to comment Share on other sites More sharing options...
jwc Posted October 9, 2009 Share Posted October 9, 2009 I went on a factory tour at Hope and got to see the assembly "area" of the LSII's. We were told that Klipsch decided on the 1" thick as it was more effective to control the side panel resonance vs braces. jc Quote Link to comment Share on other sites More sharing options...
JohnA Posted October 12, 2009 Share Posted October 12, 2009 Lemme ask what might be a stupid question. What if instead of working out the wedgies, someone 'veneered' the LaScala with something like 3/4" oak/rosewood/other choice and essentially, made the sidewalls 1 1/2" thick (much like the LaScala II) Perhaps put some solid wood edging along the front to pretty it up. Thoughts? That will work great. The stiffness increases by the cube of thickness (b*h^3)/12 if the second panel is attached very tightly. The extra stiffness reduces deflection (movement) for a given force. There is no reason to modify the top and bottom because the dog house braces them quite well. I didn't do any of that to mine because I didn't diagnose the problem until they were finished and now they are too pretty to screw with. Quote Link to comment Share on other sites More sharing options...
Islander Posted October 12, 2009 Share Posted October 12, 2009 I was thinking on wrapping the bass bin (top and 2 sides) with something like that and seeing how it worked out. I considered doing that with my La Scalas before I did the JubScala conversion. It should improve the sound and the looks. I think the 3/4" sides of the LS bass bin look a bit spindly relative to the boxy HF section, so thicker bass bin walls would look better proportioned, in my opinion anyway.You could run the extra panels all the way to the top, so the change would not even be noticeable at first glance, or stop them at the top of the bass bins and put a bevelled top edge on them, if you can do 45 degree bevels on plywood. I'm no woodworker, so I don't know about that.The top and bottom of the bass bin wouldn't really need bracing, since they're already braced by having the doghouse attached to them. If you rap with a knuckle on various parts of the cabinet, it's easy to tell which parts are most in need of stiffening. Quote Link to comment Share on other sites More sharing options...
JohnA Posted October 12, 2009 Share Posted October 12, 2009 What I do find interesting is the comments on brace placement. It would not have ocurred to me to NOT center them in the opening. Especially since every one of the brace installs I've seen have been either centered or in the case of two braces evenly spaced in thirds. The concept makes sense but I'm not yet convinced that 2 1/2" one way or the other will make all that much difference. Well, I gave you my logic. [] Quote Link to comment Share on other sites More sharing options...
Solly Posted October 13, 2009 Share Posted October 13, 2009 I have just posted an image of my LaScala's with double braces and recently added beveled mirror tops. See posting beveled mirror top on LaScala. I used 2 braces to be different! (and I prefer it asthetically) After installation of the first brace, it was clearly much stiffer, to each his own. Have fun and enjoy! Quote Link to comment Share on other sites More sharing options...
jhoak Posted October 13, 2009 Author Share Posted October 13, 2009 Well, I gave you my logic. And I listened. I'm assuming that you know a whole lot more about such things than I do. A pretty easy assumption actually since you need to know much to know more than me. I wish I had my camera back from Nikon repair so I could post a picture... What I did was a single brace on either side of the bass bin offset from center by 2.5". Where I took a different tack is that one brace is 2.5" below center and the other is 2.5" above center. The cabinets are "mirror" imaged so that depending on how they end up the they match. Of course appearance wise it's pointless as they'll be covered by grills. I should be wrapping up this coming weekend. Nikon tells me that my camera has shipped back to me. I'd have liked to have been taking photo's all along the process. Oh well... I'll document the next project better. Quote Link to comment Share on other sites More sharing options...
JohnA Posted October 13, 2009 Share Posted October 13, 2009 Offset braces should work quite well. The idea is to break up theresonant panels into different sizes that don't try to resonate at thesame time, reinforcing each other. Too much asymmetry disturbs me, but that's my personal burden. Quote Link to comment Share on other sites More sharing options...
Invidiosulus Posted October 13, 2009 Share Posted October 13, 2009 Offset braces should work quite well. The idea is to break up the resonant panels into different sizes that don't try to resonate at the same time, reinforcing each other. Too much asymmetry disturbs me, but that's my personal burden. How about that asymetrical wall in your basement?Although I'm sure it helps prevent standing waves [] Quote Link to comment Share on other sites More sharing options...
JohnA Posted October 13, 2009 Share Posted October 13, 2009 [] Quote Link to comment Share on other sites More sharing options...
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