Ha, from my limited time on here I feel that I've already had enough help to warrant a donation, let alone access to the planet-10 plan archive !
These are truly stunning. I've been considering a build of these same speakers as a change from the MarKens I've been enjoying for the past couple of years.
Your baffle does an amazing job of making them look less massive. I'll have to explore a way to do something similar, while not being too derivative. 🙂
Interesting info on the bamboo. I have been considering it for my next build, but didn't realize it was so difficult to work with. What type and brand did you use?
Your baffle does an amazing job of making them look less massive. I'll have to explore a way to do something similar, while not being too derivative. 🙂
Interesting info on the bamboo. I have been considering it for my next build, but didn't realize it was so difficult to work with. What type and brand did you use?
Thanks, Quattrofish. I played around modelling these for weeks before I decided on a final version... Even long after I had the materials...
First of all, getting a perfectly flat sheet of bamboo was impossible... and, it's insanely heavy (90lbs a sheet) and stiff - but of course thats a good thing when you're all done
Also, when birch chips out, the chips are small and easily hidden. When bamboo chips out, it follows the "go big or go home" kind of attitude... at least from my experience.
I got my bamboo from West Wind, but I'm unsure of brand that made the bamboo sheets. The only thing I see is the style is called "Nighthawk"
First of all, getting a perfectly flat sheet of bamboo was impossible... and, it's insanely heavy (90lbs a sheet) and stiff - but of course thats a good thing when you're all done
Also, when birch chips out, the chips are small and easily hidden. When bamboo chips out, it follows the "go big or go home" kind of attitude... at least from my experience.
I got my bamboo from West Wind, but I'm unsure of brand that made the bamboo sheets. The only thing I see is the style is called "Nighthawk"
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Bamboo | West Wind Hardwood
I’m gonna guess from the price that this bamboo is not in the class with the best properties for speakers. When we got the stranded variation (Plyboo, also available in Victoria, Chris?), was closer to $300 for a 4x6 sheet.
It may have decreased in price since we last used it, but not likely that much.
The 3 basic qualities of plywoods lies in the nature of the outer veneers. From poorest to best, a laminate of horizontally arranged pieces of bamboo, a laminate of vertically oriented bamboo, and stranded/fossilized that uses bamboo strands held together by some sort of epoxy, ie akin to composite construction using fibreglass. I imagine that an even better material could be constructed using multiple layers of the outer veneer layer. Hemp fire could also be used as a basic substrate, it has amazing fibres as well.
dave
I’m gonna guess from the price that this bamboo is not in the class with the best properties for speakers. When we got the stranded variation (Plyboo, also available in Victoria, Chris?), was closer to $300 for a 4x6 sheet.
It may have decreased in price since we last used it, but not likely that much.
The 3 basic qualities of plywoods lies in the nature of the outer veneers. From poorest to best, a laminate of horizontally arranged pieces of bamboo, a laminate of vertically oriented bamboo, and stranded/fossilized that uses bamboo strands held together by some sort of epoxy, ie akin to composite construction using fibreglass. I imagine that an even better material could be constructed using multiple layers of the outer veneer layer. Hemp fire could also be used as a basic substrate, it has amazing fibres as well.
dave
I can say with certainty there IS better bamboo out there... but I could not get my hands on any at the time. NO ONE had bamboo sheet goods in stock... even up island. I will say however, I still found the results better than using birch ply. With double thick baffle, cross braced, etc, these sound like knocking on granite.... however, I still will use something less troublesome in the future.
I bit the bullet and ordered two more 12pw last night. Another pair of Alpair MTM will soon be in the world.
I love the look of the stepped baffle on these, and I am wondering if the designers could chime in on whether they expect any impact to the sound?
I will probably stick with BB ply and veneer. Might do the step with hardwood to match. I think I'm entering a walnut phase...
I love the look of the stepped baffle on these, and I am wondering if the designers could chime in on whether they expect any impact to the sound?
I will probably stick with BB ply and veneer. Might do the step with hardwood to match. I think I'm entering a walnut phase...
Oh boy, now this is exciting! Should you feel inclined, feel free to post updates, and especially the final product.
Are you going to do a passive XO or biamp, or?
I found that the walnut phase is a long one... since everything looks good in walnut haha
Good luck, and have fun!
Are you going to do a passive XO or biamp, or?
I found that the walnut phase is a long one... since everything looks good in walnut haha
Good luck, and have fun!
I'll probably start with PLLXO, as I've already got it set up for my 7.3eN/12pw MarKens. My long term goal, however, is definitely to go with the spec'd passive xo so I can more easily swap out amplifiers. I think Chrisb said he liked the sound of it the most of all the crossover options they tried.
Walnut is tough to beat. I like the cherry I used for my MarKens, but a moderately-figured walnut is definitely the way I'll go with these MTMs. Not sure how to integrate solid wood with veneered BB ply, but it'll be fun to play with.
Walnut is tough to beat. I like the cherry I used for my MarKens, but a moderately-figured walnut is definitely the way I'll go with these MTMs. Not sure how to integrate solid wood with veneered BB ply, but it'll be fun to play with.
I really do want to build the passive XO... I don't want to spend the money since I'm back in school, but it's on the to-do list.
Re: walnut. agreed 🙂
Re: walnut. agreed 🙂
Love it, 2x the cone will mean a forth the excursion at low frequencies and move 2x as much air.
If i knew what you meant by “stepped” i might be able to answer :^)
If you are talking about the heavy chamfers, Olson showed that a rectangle with heavy chamfers resembles a sphere in terms of BS transition response (ie smooth). B&W did a lot of work that shows the value of a tear drop for minimim external diffraction. In plan view the trapezoid miniOnkens resemble a teardrop, and at the loe frequencies involved the size of the wavelengths means that it acts like a teardrop leading to decreased diffraction, smooth 2π to 4π transition, still buildable with flat sheets, and, personally, i think they look really cool.
dave
If i knew what you meant by “stepped” i might be able to answer :^)
If you are talking about the heavy chamfers, Olson showed that a rectangle with heavy chamfers resembles a sphere in terms of BS transition response (ie smooth). B&W did a lot of work that shows the value of a tear drop for minimim external diffraction. In plan view the trapezoid miniOnkens resemble a teardrop, and at the loe frequencies involved the size of the wavelengths means that it acts like a teardrop leading to decreased diffraction, smooth 2π to 4π transition, still buildable with flat sheets, and, personally, i think they look really cool.
dave
Chris did a set of walnut bipole towers in port wine stain and it was stunning. Lots of other walnut around here. And cherry & ribbon mahogany.
dave
I love the look of the Onkens too. So much so that I built a set! 🙂
In this case, I mean the way that Danyo layered his baffle. I might do something similar, and am wondering if this departure from the plans might have an impact on the sound. If I understand his design, and assuming 12mm material, the flat face of his baffle is 48mm narrower than the spec due to the chamfering. I'm not sure if the flat face or overall cabinet width is the important dimension for baffle step or other issues.
In this case, I mean the way that Danyo layered his baffle. I might do something similar, and am wondering if this departure from the plans might have an impact on the sound. If I understand his design, and assuming 12mm material, the flat face of his baffle is 48mm narrower than the spec due to the chamfering. I'm not sure if the flat face or overall cabinet width is the important dimension for baffle step or other issues.
Adding to the thickness of the baffle (as long as the driver cutout is properly received) or making the shape more “sphere-like” does not hurt.
dave
dave
Have you done a passive crossover for this build? Absolutely gorgeous build with the bamboo, that big box came out looking dashing.
Yes. The XO works for A7.3, A7p, A7 MAOP. P7HD should as well. May need tweaking for the A7ms.
Would need a redesign foe A5.2/3, A6.2 or any other FR.
dave
Would need a redesign foe A5.2/3, A6.2 or any other FR.
dave
Seeing this reminded me of a conversation I had with JMLC circa '96-7 WRT his 'Onkens' just like yours except with closer to egg shape to a longer depth with the very high aspect ratio vents terminating at the rear to replicate one of the pioneer's corner loading slots in an attempt to completely damp the driver/cab's high Qt without hardly any damping, i.e. like some of us, he was a believer in acoustic solutions to acoustic problems, but ultimately had to 'critically' damp the vents to make it work, losing too much [mid]bass output.