@hardisj
Is that speaker the same width on the front as the Salk Sound? Do you have any more info on that build, maybe the builder has a build thread somewhere? Maybe it's a visual trick due to proportions, black or more rounded edge front baffle, but it looks a little skinnier than the current Salk Sound BMR.
This would probably work if it weren't for the port - it's nearly as long as the speaker is deep. If you can make a custom curved port with the same length as the precision one used, it would probably be fine. Or maybe put the port on the bottom of the tower and make sure to raise up the bottom with feet or a plinth or something crazy.
That is really good info, I had not seen the port was that long. I gather it is 2"x8"?
How about a slotted port on the front bottom of the speaker? I think at the depth of the speaker I'm targeting it would need to 'bend' up the back a little. I'm fairly competent at woodworking, I would be able to make this. I'm imagining creating curves on any transition points and maybe even in the corners of the port (looking at the cross section), square edges seem like a bad idea on any ports. My image is to make the same cross section and length as the current port. Another idea is the use the 'diagonal' space in the base and I might not even need to turn it up the back. I don't like this as much due to aesthetics and symmetry, but
could be easier to construct. My image about front port would be better since I plan to place them close to the wall.
The cabinet is also super damped behind the woofer, with not much space between the magnet and the damping material.
Any good images that you know of for the damping? I can't seem to find any to understand or come up with an idea for a solution? If it's what I'm imagining, maybe carve our a place in the damping for the speaker? It doesn't seem ideal, but from a damping standpoint the best I can think of for a shallower cabinet depth. Depending on the specifics I could see this causing some heat rejection issues for the speaker (magnet) when driven hard for long periods.
Those towers would have to be super tall and skinny though I'd think. Front width is non negotiable because of baffle edge stuff, so that's fixed at appx 8 inches. Looks like my cab is 12" x 8" x 20" for an internal volume of ~ 1920 in^3. I'm too lazy to use the internal dimensions, note. So if you wanted it 48" tall, it would only be 5" deep...
It's also pretty easy to calculate internal and talk about reasonable speaker heights for a speaker this size. I think both of these are pretty important even if we are just in paper napkin world at this point. My image is usually 48" talk speakers are semi-monsters with much more driver area, higher output like the Revel Salon 2's. Any of the smaller towers I can find are usually in the 40-42" tall range. This probably still gets the tweeter at a reasonable (ear) height.
External (for the Salk Sound BMR) are 8" x 20" x 12.5" (WxDxH), so 2,000 in^3. So assuming 3/4" sides we get 6.5" x 18.5" x 11" =1322 in^3. That's a huge difference.
If we keep the 8" width but go to an 8" depth we get 33.5" tall. Probably needs to be a bit taller.
If we go to 40" tall we get about 6.75" deep, that actually doesn't seem bad to me.
Another idea I had was to 'separate' out the tweeter and BMR into a smaller (footprint) upper enclosure. Would probably be about 10" tall, leaving 30" for the woofer enclosure. My rough calculations are about an 8" square footprint for the woofer enclosure. I think at this point I would want to look up the woofer displacement and do some actual calculations/drawings. I'm really liking this idea. My image is the front baffle, back, top (twetter/BMR) enclosure in black with lower woofer enclosure sides and top finished. I think the smaller top enclosure in black would also shrink the visual footprint too as well as possible have some beneficial acoustic side effects (smaller baffle for mid/BMR).
I would probably make a plinth or some 'feet' that extend past the base an inch or an inch and a half bigger to give it some stability, this will also add some height possibly reducing the cabinet height above by an inch or two.