I'm building some silbury's for A10P's, and I'm getting close to doing the final panels. Because of the way I happened to fit up the front panel and side panel, there's not really a practical way to mock up the speaker with clamps. So I kind of just have to wing it with any dampening material inside the horn. Since I haven't nailed down what amplifier (and thus source impedance) I'm going to be using anyway, I'll need to adjust things. My assumption is I'll leave the interior unreachable channels totally empty.
1) Am I going to be OK with just whatever dampening material I can place in the rear openings? I can reach arm length up to the first bend, and that's about it. Obviously I could reach a little bit behind the driver, but I'm pretty sure those openings are supposed to be kept clear anyway. Anybody have a preference for sheet dampening material I could cut to friction fit if I'm stuffing the open end of the horn at all?
2) Any advice on the overall strategy for tuning the dampening, or a source for further reading? I would need a microphone with flat low frequency response, or do my own calibration with REW outdoors or something, I suppose? But I'm not sure where to start with 'Ok a bump at X frequency means add/remove/shift material.'
1) Am I going to be OK with just whatever dampening material I can place in the rear openings? I can reach arm length up to the first bend, and that's about it. Obviously I could reach a little bit behind the driver, but I'm pretty sure those openings are supposed to be kept clear anyway. Anybody have a preference for sheet dampening material I could cut to friction fit if I'm stuffing the open end of the horn at all?
2) Any advice on the overall strategy for tuning the dampening, or a source for further reading? I would need a microphone with flat low frequency response, or do my own calibration with REW outdoors or something, I suppose? But I'm not sure where to start with 'Ok a bump at X frequency means add/remove/shift material.'
Well, you can always email to ask. As I try to [remember to 😉 ] mention to every client, it's what we're here for -Dave & I don't just vanish & leave people to it if they have any questions. While we're not perfect, we do try our best to help our builders.
Aside from what's specified in the plans & slightly expanded on in this post, you should be, yes. The driver chamber is lagged on all internal faces apart from the inside of the front baffle, ensuring the throats are kept clear. You can also add a layer of the same material [see the pdf planset] to the uppermost / lowermost internal horizontal surfaces, i.e. around the 180 degree bends of manifold 1 & 2. No other material should be needed in the main expansion path of the horn with Alpair 10P; final adjustments to suit the amplifier output impedance & room acoustic can be achieved by damping around the termini; optimally loaded Silbury is by design a high-gain design to ensure a reasonable amount of flexibility for end-users.
Hope that helps & remember we aren't the Great Houdini: ye olde email is available, so don't be afraid to get in touch if you have any queries. We'd always rather people did that than guessed!
Aside from what's specified in the plans & slightly expanded on in this post, you should be, yes. The driver chamber is lagged on all internal faces apart from the inside of the front baffle, ensuring the throats are kept clear. You can also add a layer of the same material [see the pdf planset] to the uppermost / lowermost internal horizontal surfaces, i.e. around the 180 degree bends of manifold 1 & 2. No other material should be needed in the main expansion path of the horn with Alpair 10P; final adjustments to suit the amplifier output impedance & room acoustic can be achieved by damping around the termini; optimally loaded Silbury is by design a high-gain design to ensure a reasonable amount of flexibility for end-users.
Hope that helps & remember we aren't the Great Houdini: ye olde email is available, so don't be afraid to get in touch if you have any queries. We'd always rather people did that than guessed!
Hey Scott, thanks for the response. I had emailed you a couple times actually and I just figured you were busy with Life, but maybe one of us is having email problems. And you have your direct messages closed on the forum here.
I am still curious if anyone has a source of flat batting material rather than just the loose polyfill. I think I've seen a couple pictures of people using kind of sheets of 2" thick material cut to squares to friction fit inside horns, but I don't seem to see it at any of the usual parts express or madisound or the like, if anyone knows where I can find that stuff in the US.
I am still curious if anyone has a source of flat batting material rather than just the loose polyfill. I think I've seen a couple pictures of people using kind of sheets of 2" thick material cut to squares to friction fit inside horns, but I don't seem to see it at any of the usual parts express or madisound or the like, if anyone knows where I can find that stuff in the US.
Look up soft wool felt (SAE-F10 is preferable but not cheap), denim insulation (recycled or otherwise), OC-703 rigid fibreglass board, 'speaker wadding' (usually rolls of bonded polyester / BAF) etc.
Solen, Madisound, Parts-Express etc. all sell variations -you can pick up polyester wadding almost anywhere, from eBay to craft-stores, haberdasheries etc.; HVAC rated fibreglass damping like OC-703 (which is usually over-thick but can be used with some creativity) is usually available all over the place, even on Amazon. Just don't necessarily spend a fortune on branded materials -most are good, but they're often relabelled generics with a price to match, or simply don't do much more than generic alternatives.
Solen, Madisound, Parts-Express etc. all sell variations -you can pick up polyester wadding almost anywhere, from eBay to craft-stores, haberdasheries etc.; HVAC rated fibreglass damping like OC-703 (which is usually over-thick but can be used with some creativity) is usually available all over the place, even on Amazon. Just don't necessarily spend a fortune on branded materials -most are good, but they're often relabelled generics with a price to match, or simply don't do much more than generic alternatives.