I think it is strongly influenced by the materials you are using.
Going from 3/4" to 1" of bamboo ply is not going to cause serious issues in that regard.
A lot of people are happy using 1.5" of birch or bamboo ply even Dave recommends 1.5" in his excellent Onken cabinets.
Anyway I just like understanding peoples ideas. Sometimes it comes down to looks. Maybe they thought it looks cool. I don't have issues with any of that sought of thing, even I do stuff based on looks if I feel it does not affect the performance audibly
Going from 3/4" to 1" of bamboo ply is not going to cause serious issues in that regard.
A lot of people are happy using 1.5" of birch or bamboo ply even Dave recommends 1.5" in his excellent Onken cabinets.
Anyway I just like understanding peoples ideas. Sometimes it comes down to looks. Maybe they thought it looks cool. I don't have issues with any of that sought of thing, even I do stuff based on looks if I feel it does not affect the performance audibly
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Not an Onken, but a dual SDX7 TL per side
to keep the baffle to which the drivers are mounted as thin as possible - and the 3/4" bamboo matches some of Bud's other speakers - the blonde FE127E shown earlier, as well as a pair of caramel bamboo Alpair7s (in fact this current project is from the same batch of bamboo)
what's not clear in the photos is the 3 layers of spine also provide space to bury the wiring for the two drivers, with access via a strip retained via countersunk neo magnets.
as to the question of reflections - looking closely at backside of the two drivers, I can hardly see that being an issue with the Eminence - the Lowther, hmmm, like I said that remains to be heard - which I probably won't get a chance to do for several months.
to kee
thanks, they were a long time coming
Here are some response curves for the ported 5.6 Cabinet
1/6 octave smoothing.
I will do 1/12 later along with the DIB cabinet response curves
The top pink curve is the ported cabinet with out port tubes (just the cutout for the tubes) and no insulation
The bottom blue curve is the response of cabinet with port tubes and insulation
1/6 octave smoothing.
I will do 1/12 later along with the DIB cabinet response curves
The top pink curve is the ported cabinet with out port tubes (just the cutout for the tubes) and no insulation
The bottom blue curve is the response of cabinet with port tubes and insulation
Attachments
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The Emminenece has the same 3mm xmax as the 15 ohm silver voice coil Lowther PM6A, has the same sensitivity, the same impedance, but will absorb 200 watts. Initial cross will be at 300 hZ with a series crossover, to be driven with a remade AudioPrism Debut amp with our development OPT's installed. The Emminence will be allowed to go as low as it can, though I suspect at least an 80hZ, 6db RL filter will be in the line feeding the amp just for some protection.
Eventually the AudioPtism will go to level three OPT's rather than the level 0.85 they are now. Even more eventually, assuming I live so long and retain my hearing, a hybrid PP SS to SE 300 B with all transformer coupling amp will drive the Lowther's and we will see about the Emminence's. Perhaps a 200 watt off shoot of Gary Kohl's 1700 watt Class D amplifiers. Still only working to 300 Hz but with the cross over duties out in the line level using LR and RL components and perhaps some shaping in the amps themselves.
The spine will cause no particular problems, it will be EnaBL'd and made very slippery. There will be no enclosure or any further extension to the mounting plate, so, very close to nude omni, with both sides of the drivers EnABL'd. If the sound even approaches that of the pair of Lowthers I treated for Jon VerHalen, sitting nude on stands without any bass reinforcement, I will be blissed out for much of the rest of my time, up here where water behaves itself in drains. The Emminenece is there to provide power far beyond what the Lowther can provide, in that midbass region where it is most needed. I have gotten over Bass fever so the TL subs, driven by SS plate amps with phase, level and FR adjustment, starting at 340hz, will be both strong enough down into the high 20's and fast enough to merge seamlessly with the two on their frames.
Those are my thoughts and perhaps my final ones on loudspeakers.
dont rush off too fast. Seems you have much to share. So the eminance will act as a .5 in a 1.5 way, not considerng sdx, of course.
Am a little confused by the 1, 1.5, 2 ,2.5, 3 thing. Sort of like acronyms, with my brain running off to endless possible expanded meanings, except for the one everyone else has already agreed upon. Possibly too much electromagnetism in my life history.... or not enough lead in my life?
The two drivers will be a full range two way as far as the amplifier knows and the crossover frequency may well shift up quite a bit or down some. Thankfully I have a smart friend who has solved series crossover design and I can lean on him for intelligence.
There may even be a RAAHL ribbon at some future point. Alex said he has the perfect one already designed. Not at all averse to multi way speaker systems.
The SDX7's in the TL just have so much textural information that I cannot afford not to use them, and use them as high up as is needed, in parallel with the two frame drivers.
Bud
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