Up to speed, or just up...
Haven't posted anything in awhile, so I guess it's time to fling some verbiage about...*G*
Moving forward on V3.5; parts are cut, and it's time to tackle assembly of the 3 way Walsh. Please refer to the attached drawing to see what yours truly has in mind and on the bench.
Ambitious, perhaps. It's certainly has had a long 'gestation period'... And actually more of a test bed for the tweeter and some construction detailing on individual segments.
The tweeter @ top will be able to be removed by just removing 4 nuts. In this way I can apply/try different 'routines', such as suggested by Glo, to see what effects occur. Hopefully this can be done in a non-destructive/'swappable' fashion, as it's made from the 2 mil alum that you graciously donated. That's the idea, anyway...
The 'midrange' at the center is similar to what I've done previously, just adapted to the physical details of the co-opted driver (plastic basket vs. metal). It'll just sit on the woofer's frame with some foam applied to damp any vibrations, as the magnet fits within the mids base. A lucky occurrence...
The lower 'woofer' is an excursion into finding out 'where' the cone transits from a dml to pistonic excitation as frequency descends. The base is made purposely to allow reducing the diameter of the cone by inserting 'shim rings' beneath the cone, which can be reduced in diameter and receive a smaller diameter surround. This obviously will reduce it's height; the posts can be cut down to accommodate this.
The cones will all align vertically, so that more or less addresses 'time alignment'. The cone's profiles are all the same (small up, big down), which hopefully will allow the radiation patterns to more or less 'blend/overlap'. I can't get them any closer together vertically, so I'll see if this works. A 'sonic layer cake', if you will... My earlier test of 'flipping' the top unit (much like the Ikonoklast units) didn't work IMHO, so here's my 'go' at it.
One thing I'm trying to simplify the surround construction is the use of 3M's 77 spray adhesive to apply the EVA foam to the base structure in lieu of the VHB film adhesive I have been using. A test with scraps went well, so I'm reasonably confident it'll hold up. I'll continue to use the 4475 adhesive to bond the EVA to the cones, as it's doing well with all 6 of the units I have now...
...and masking tape is cheap, and the spray is easy to apply. Applying the foam accurately is still a 'hold the breath/focus/steady hands process...*G*
I'm starting to sound like an advert for 3m products. *L* Maybe I can get some corporate support...*L* Yeah, right...
Actually, I've noticed that the 4 units that I've been running consistently are 'breaking in', flaws and all. Certain cuts that I play and the instruments played within them are 'smoothing out', and the occasional 'innocent bystander' that hears them are starting to ask when they could have a pair. They still need a lot of development before I'd consider that. I prefer to keep those around me pleased with what I do and/or subject them to. And it's just good karmic relations. *L*
It is exciting to have 6 speakers underway at once, but it's also 6 speakers in progress at once. I can only dedicate 'snippets' of time, and nibble away at what needs to happen when and what order for what... An obscure bit of multitasking...*G*
Let's see what happens when this jello jells...