Commercial section is at the bottom of the left hand column on home page - 4 different subsections
Happened to find a handy US source of 1/2 " wool felt at Grainger.
12"x12" for $8.96. P/N 2FHG5
http://www.grainger.com/Grainger/Felt-Sheet-2FHG5?Pid=search
12"x12" for $8.96. P/N 2FHG5
http://www.grainger.com/Grainger/Felt-Sheet-2FHG5?Pid=search
Am I just nit picking again?
The 4th page of the 15mm plans showing the radius and angles show the back as 830mm (32 11/16") and the internal piece as 756mm (29 3/4") which is correct for 18mm build yet the 15mm cut sheets show 815mm (32 3/32") for the back and 741mm (29 5/32") for the internal. I'm trying to be faithful to the plans but...
The 4th page of the 15mm plans showing the radius and angles show the back as 830mm (32 11/16") and the internal piece as 756mm (29 3/4") which is correct for 18mm build yet the 15mm cut sheets show 815mm (32 3/32") for the back and 741mm (29 5/32") for the internal. I'm trying to be faithful to the plans but...
A small fraction of inch or mm or so shouldn't be a problem, but the larger amount that you mention should probably be addressed.
I build mine from CNC machined parts from our flat pack production, and have been working on my own CAD drawings for a couple of years now, and really only looked at the earliest versions of Dave's drawings -obviously something slipped past our joint proof reading, and no, Cal, it's not because we were reading after proofing a joint - well at least not on my part. 😉
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I build mine from CNC machined parts from our flat pack production, and have been working on my own CAD drawings for a couple of years now, and really only looked at the earliest versions of Dave's drawings -obviously something slipped past our joint proof reading, and no, Cal, it's not because we were reading after proofing a joint - well at least not on my part. 😉
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Turns out both are correct (altho misleading). Plan has 2 pieces with round bottom. Cut plan is for the earlier 3-piece version with a block at the bottom.
dave
Thanks, Dave.
Unfortunately, I didn't get to hear 'em this year-- the description is intriguing though.
Don
I'll let the others tell you as I'm not as versed as them in the tech side of things. My impression is more of a more natural uncoloured sound, if that means anything.
Everyone is different. 🙂
Everyone is different. 🙂
So ideally the longer dimensions are correct and I should work both pieces with an add on block since I've cut them to the shorter spec and rounded over already? Will the change in the bottom port size if left as is make an audible difference?
Thanks,
Charlie
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Charlie, round over is only for the longer pieces.You could add 15mm extra at the top as a fudge. Won't be a big deal inside but on the back piece it would be visible. Or cut down the backs to use inside and cut new backs.
The round-overs were a clever trick Chris came up with to eliminate the block.
dave
What is the point of the 45ºchamfer for an A7. How deep should it be in 18mm BB ? Am I just breaking the edge? How about a 1/8" roundover?
Thanks,
Charlie
Thanks,
Charlie
Given the 10mm rebate depth, you want the bevel to be 8mm. A roundover is not as effective, it would need to have an 8mm radius for maximum performance.
http://frugal-phile.com/boxlib/markaudio/Alpair7g3-dimension-230611.pdf
dave
http://frugal-phile.com/boxlib/markaudio/Alpair7g3-dimension-230611.pdf
dave
I'd suggest scalloping the chamfer to leave full thickness "pads" that shadow the basket's mounting frames (see photo - this happens to be one of the removable SB plates for FH3)
When not using the extra bezel ring, and allowing for minor compression of molded gasket and post veneering, a rebate depth of 8mm will still leave a good 10mm of core material on 18mm ply.
I'll be happy to take the flack or saying it, but to be completely honest, considering the operational bandwidth, SPL capabilities and total mass of this driver, I think that's more than enough. Now the 10&12P are a different matter - for those you definitely want thicker core than 10mm - at least a total of 24mm to start with, and you still need to chamfer the back side - so much easier before assembly .
When not using the extra bezel ring, and allowing for minor compression of molded gasket and post veneering, a rebate depth of 8mm will still leave a good 10mm of core material on 18mm ply.
I'll be happy to take the flack or saying it, but to be completely honest, considering the operational bandwidth, SPL capabilities and total mass of this driver, I think that's more than enough. Now the 10&12P are a different matter - for those you definitely want thicker core than 10mm - at least a total of 24mm to start with, and you still need to chamfer the back side - so much easier before assembly .
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The scollops being about 5/16" ?
I was planning to use the extra bezel ring but the prevailing opinion seems to be "why bother?" I just wonder why not?
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As hard as it may be to believe, some details like this don't actually get measured, and I'd have to put a tape on them to be sure - I just set the router so that with the baffle face down, the center of the bearing on the 45dg bit rides on the "bottom" edge of the through hole.
You might not get as heated a debate on that question as with MDF/Plywood 😀, but let's just say opinions vary.
I've built a fair number of enclosures for 7.3s both with and without the extra rings, and it just so happens that my Pensils and center have them, and FH3 and two other enclosures currently in house ( Decware DNA horn, and P10 mFonken) don't. While Mark would probably be happy to explain (again) their purpose, and someone with the right gear and interest could probably measure the difference, I'll be damned if I can hear any - but then my hearing's never been as good as I thought it once was, and certainly isn't so now. That certainly doesn't constitute a prevailing opinion, just mine and perhaps a few others - to be fair, it does constitute second guessing the designer of an excellent series of drivers.