iaRIVR Posted September 18, 2020 Share Posted September 18, 2020 Restoring a pair of Chorus IIs and have a couple questions before I get too far. The first one I really don't know, the rest are subjective. 1) Where did the foam go when it left the factory? I thought the consensus for the Forte II was above the woofer (top 2/3 or so). There's foam in there now but a mix of two types, one goes about to the midway point on the woofers, on the other one side goes all the way down on one side and stops above the woofer on the other. Where should the foam go? or does it matter that much? And... subjective ones. These have all been covered before so not expecting answers but if you have thoughts either way please share.Trying to balance doing as much now while I have them apart without going crazy, they sound pretty great as is and no reason to mess with a good thing. 2) Bracing. Considering one between the woofer and the mid, and maybe two up the sides. Straight across, baltic birch ply or solid maple. Seems most say not necessary. 3) Damping. I have a bunch of Kilmat 80 mil. Could line cabinet sides under the foam, or horns and woofer/passive. Also seems not necessary. But I have it already. 4) LMAHL tweeter - very on the fence about doing this now while it will be easy to install, or spending some time with the stock tweeter (w/ crites ti) first. Leaning towards less, but again don't really want to feel the need to take these apart again. Quote Link to comment Share on other sites More sharing options...
jjptkd Posted September 19, 2020 Share Posted September 19, 2020 Foam looks like stock placement I've never felt the need to do any bracing and I've driven them to insane levels for extended periods the de-120 tweeter is very nice upgrade either DaveA's MAHL or if you're handy with a dremel and want to save a few bucks the DPHL works great too. 1 Quote Link to comment Share on other sites More sharing options...
OO1 Posted September 19, 2020 Share Posted September 19, 2020 21 minutes ago, jjptkd said: the DPHL works great too. DPHL ? 1 Quote Link to comment Share on other sites More sharing options...
OO1 Posted September 19, 2020 Share Posted September 19, 2020 9 hours ago, iaRIVR said: Leaning towards less, but again don't really want to feel the need to take these apart again! Make sure to fill in the wood particles that come off from the MDF around the screw holes for the woofer , I see T-Nuts in the holes for the passive woofer , great idea all around - 1 Quote Link to comment Share on other sites More sharing options...
jjptkd Posted September 19, 2020 Share Posted September 19, 2020 7 hours ago, RandyH000 said: DPHL ? "Dremmeled Plastic Horn Lens" these Paudio tweeters on eBay are exactly the same as the Tractrix horns used in the newer Klipsch models 1 Quote Link to comment Share on other sites More sharing options...
iaRIVR Posted September 19, 2020 Author Share Posted September 19, 2020 Cool, and yup need to get old cork residue cleaned off and there are few chipped screw holes that need attention. Quote Link to comment Share on other sites More sharing options...
DizRotus Posted September 19, 2020 Share Posted September 19, 2020 9 hours ago, RandyH000 said: Make sure to fill in the wood particles that come off from the MDF around the screw holes for the woofer , I see T-Nuts in the holes for the passive woofer , great idea all around - I agree with reinforcing the attachment holes. The H2s shown below do not have passive radiators, so no T-nuts needed there. Given the low ply count motorboards, I used toothpicks and Titebond to give all of the mounting screws something to bite into. One of the benefits of DIY is the opportunity to make changes that would be prohibitively expensive during mass production. One example is the 13 ply Baltic birch used to fabricate a pair of “Super Heresy” cabinets compared to the plywood used in these H2s. Another example is four machine screws into T-nuts used to mount La Scala woofers. If I’ve taken the trouble to open the dog house, I’ll use all eight mounting holes to secure the woofers before closing the doghouse. Again, an extra step that is costly at the production stage, but relatively easy to do as DIY. When I refurbished a pair of beater La Scalas, I found loose screws regarding each woofer. OBTW, the plywood in the Chorus II shown above appears to be superior to the plywood in the H2s I repaired. And yes, the grey foam is in there loose, as shown in the photos. 2 Quote Link to comment Share on other sites More sharing options...
jjptkd Posted September 19, 2020 Share Posted September 19, 2020 1 hour ago, DizRotus said: OBTW, the plywood in the Chorus II shown above appears to be superior to the plywood in the H2s I repaired. The chorus line uses a full 1 inch plywood motor board 2 1 Quote Link to comment Share on other sites More sharing options...
OO1 Posted September 19, 2020 Share Posted September 19, 2020 2 hours ago, jjptkd said: The chorus line uses a full 1 inch plywood motor board so , the motorboard is not MDF , but the sides panels , tops and bottoms are MDF Quote Link to comment Share on other sites More sharing options...
jjptkd Posted September 19, 2020 Share Posted September 19, 2020 40 minutes ago, RandyH000 said: so , the motorboard is not MDF , but the sides panels , tops and bottoms are MDF Yes, 3/4 MDF veneered on both sides for the sides back top and bottom with a full 1 inch plywood front probably because of the heavy k-48 woofer. What I find interesting is on the new pro models they use 3/4 plywood everywhere but the front which is 1 inch MDF. Quote Link to comment Share on other sites More sharing options...
DizRotus Posted September 19, 2020 Share Posted September 19, 2020 2 hours ago, jjptkd said: Yes, 3/4 MDF veneered on both sides for the sides back top and bottom with a full 1 inch plywood front probably because of the heavy k-48 woofer. What I find interesting is on the new pro models they use 3/4 plywood everywhere but the front which is 1 inch MDF. Maybe they just got the piles mixed up. 😏 1 Quote Link to comment Share on other sites More sharing options...
Dave A Posted September 19, 2020 Share Posted September 19, 2020 3 hours ago, jjptkd said: Yes, 3/4 MDF veneered on both sides for the sides back top and bottom with a full 1 inch plywood front probably because of the heavy k-48 woofer. What I find interesting is on the new pro models they use 3/4 plywood everywhere but the front which is 1 inch MDF. There is no reason I can see for that except it saves a few dollars per speaker. You just can't substitute MDF for plywood all the way around without having cabinets that may end up failing when suspended or moved around often. Pros have different expectations regarding durability. 1 Quote Link to comment Share on other sites More sharing options...
iaRIVR Posted September 20, 2020 Author Share Posted September 20, 2020 Interesting question, I would assume labor is by far the highest component in the cost of the speaker. Did a quick home depot check: Particle board - 20 MDF 26 Plywood 40 Does make me curious how much they pinched pennies on materials and components, as I wouldn't think they are high enough volume to see huge gains. Guessing they tested mdf, plywood, and a dozen other things and found making the front 1" plywood was necessary, and mdf was good enough for the rest. 1 Quote Link to comment Share on other sites More sharing options...
OO1 Posted September 20, 2020 Share Posted September 20, 2020 3 minutes ago, iaRIVR said: Interesting question, I would assume labor is by far the highest component in the cost of the speaker. Did a quick home depot check: Particle board - 20 MDF 26 Plywood 40 they use BB ------BALTIC BIRCH in speakers , it's more expensive than plywood - Quote Link to comment Share on other sites More sharing options...
iaRIVR Posted September 20, 2020 Author Share Posted September 20, 2020 I'm almost positive the plywood in my chorus is not Baltic birch, not nearly enough layers. I build with both and the difference is easy to spot. The numbers were just a quick and dirty comparison to get a sense of the relative difference. Quote Link to comment Share on other sites More sharing options...
OO1 Posted September 20, 2020 Share Posted September 20, 2020 39 minutes ago, iaRIVR said: I'm almost positive the plywood in my chorus is not Baltic birch, not nearly enough layers. klipsch also used Fur Plywood ----here is what it looked like-it had 1 ply of birch Quote Link to comment Share on other sites More sharing options...
iaRIVR Posted September 20, 2020 Author Share Posted September 20, 2020 That looks more like it 👍 Quote Link to comment Share on other sites More sharing options...
DizRotus Posted September 20, 2020 Share Posted September 20, 2020 10 hours ago, RandyH000 said: they use BB ------BALTIC BIRCH in speakers , it's more expensive than plywood - The Home Depot near me doesn’t know what Baltic birch is. The last 4 x 8 sheet of 3/4 BB I ordered from the local lumberyard cost me just under $100. 1 1 Quote Link to comment Share on other sites More sharing options...
iaRIVR Posted September 21, 2020 Author Share Posted September 21, 2020 Is is much harder to find and way more $$$. Really nice stuff though. Anyway, I am planning to run the foam about 2/3 of the way down both sides and call it good unless anyone thinks that is a terrible idea. Quote Link to comment Share on other sites More sharing options...
001 Posted September 21, 2020 Share Posted September 21, 2020 On 9/18/2020 at 10:45 PM, RandyH000 said: Make sure to fill in the wood particles that come off from the MDF around the screw holes for the woofer , I see T-Nuts in the holes for the passive woofer , great idea all around - chorus 2 use T nuts for the woofers too , you can see them in the holes around the woofer , in his pic- Quote Link to comment Share on other sites More sharing options...
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