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Re: Close, but not the same [message #53275 is a reply to message #53272] |
Sun, 01 March 2009 22:10 |
Psychoacoustic
Messages: 75 Registered: May 2009
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Viscount |
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Wayne, thanks again for the response and plans. Getting closer to the build... couple more questions. I understand that this has been done to death, but one more time please... In Japan, I can only source 10mm ply. The plans call for 20mm (3/4"). For the Pi7 specifically, would gluing two 10mm ply sheets together or one 10mm ply and one 10mm MDF be better, or no difference? Recently, there was some discussion of crossover value changes. Do you have these updated, populated crossovers ready to go? PaulW, who has built the Pi7, mentioned enlarging the mid-horn flare dimensions. Any thoughts on this? Thanks again.
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Re: Close, but not the same [message #53278 is a reply to message #53275] |
Mon, 02 March 2009 00:18 |
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Wayne Parham
Messages: 18786 Registered: January 2001
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Illuminati (33rd Degree) |
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For plywood, I'd use 18mm which is very close to 3/4". It's about 0.7"About crossovers, we stock assembled circuit boards using a variety of optional components. You can choose from Jantzen, Auricap, Mills, etc. We also sell unpopulated crossover PCB's if you'd rather assemble your own. About the midhorn, PaulW wrote to me some time ago when he was assembling his. He was concerned about how to mount them in the box, wondering how to trim them out. I suggested a hardwood trim that serves as a sort of edge band. The idea is to cut it to have the same angle as the flare. It is attractive and it extends the flare slightly, which isn't a bad thing. I think that's probably what you're talking about. The midhorn is designed to be as small as possible without sacrificing sound quality. Even still, they're fairly large. Making a horn larger isn't generally a problem, it's making it smaller where you'll run into complications. You could make them larger, if you wanted, but when used in the corner, the walls tend to act as flare extensions anyway.
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Oh, my mid-horn mkII idea [message #53281 is a reply to message #53278] |
Mon, 02 March 2009 17:05 |
PaulW
Messages: 71 Registered: May 2009 Location: UK
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Viscount |
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Child art added to give an idea of what I'm thinking of. Indeed that was the context the mid-horn size got raised - and I never did use the edging method. But it was mentioned that the flare would benefit from being slightly bigger so, when I get round to remaking it I was going to increase the throat to corner distance by 1 inch with the top and bottom faces slightly curved to the middle with a 2 inch increase. The 'drum' holding the driver would be made from flexible MDF (MDF sheet with slots cut 2/3's the way through the thickness at regular intervals) formed over disc of ply. Well that's the plan, but then again, there's the power-amp upgrade, the preamp upgrade...... Paul
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Re: You may now graduate to finger-painting [message #53286 is a reply to message #53284] |
Tue, 03 March 2009 05:00 |
PaulW
Messages: 71 Registered: May 2009 Location: UK
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Viscount |
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To mount the HF horn I would use a "T" shaped platform attached to the front/top of the horn in-line with the original dimensions, supported by the triangular brace. A similar method below to support the mid on the bass unit. Still all a bit academic at the moment as these are just ideas in my head and on the doodle pad! Don't remember any posts about altering crossover points TBH, the end result with mine is impressively cohesive as it stands - I certainly can't hear the joins ;¬) Paul
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