[dayneger]

The exciting discussions around waveguides and back-firing drivers that have come up discussing Hobb's cool new NX-Bravo design (https://www.audiocircle.com/index.php?topic=190223.0) have gotten me thinking.  Note that that's not always a good thing, but humor me. 

The question:  for a user with sufficient space, could the Studios sound "even better" if built so that the tweeter is fully open straight back toward the wall?

Before someone jumps on me, I'm not criticizing their current design, which obviously was focused on enabling an OB tweeter to be placed close to the back wall, and be usable as monitors.  It's super cool that that works.

I have slightly different constraints--I can often have my speaker baffles 3 feet (but not much more) from the rear wall, and I'd be building them as towers, so would have internal volume to spare.  However, while I'd love to have full OB, I have neither the space nor the budget for Oticas and OB sub stacks.  I did just build a GR/Rythmik-based dual-opposed sealed servo sub to pair with them, though.

What I'm thinking:

- Build the zone behind the tweeter flat or even slightly sloped down (rather than ramped up)
- Taper the sidewalls of the tweeter zone downward at a similar slope to how they currently taper up (or mimic something closer to the asymmetric Otica baffle??)
- Make a ramp/wing module that I could drop into place so that if I did want to push them back against the rear wall, I still could (resulting in geometry basically identical to the current Studio top--in effect, a "near-wall converter")
- Shift the air volume lost behind the tweeter down into the volume of the tower.
- Preferably, make the towers a little shallower than the current 14" depth and shift that volume down as well (would look nicer in my the room and was very successful with my recent conversion of Avinci Studio monitors to towers)

Given my different constraints, could this sound a fraction more like a full OB?  If nothing else, they might look a little shorter visually with the top taper?

[dayneger]

The last idea is probably a horrible one for lots of reasons, but, thinking about the rear driver concept...

Would it be beneficial to add a midwoofer on the back side of the tower... sort of simulate OB in the lower frequencies?  Sorry for not understanding when the back-firing concept is valid/viable.   

The "convertible" aspect in the thread title might be more challenging, but the second driver could be in its own chamber down low on the back, and possibly have a switch to cut it when close to the wall.

If you skipped the convertible part, there could conceivably be a single larger chamber in the tower, with the rear driver aligned with the front driver for force cancellation.  Wired in parallel using the 16 ohm version of the NQs?  Separate network and using the less expensive M-165?

[Danny Richie]

If we were trying those same options, we would have to try each variant to see what it does to the response and make corrections to the filter parts to compensate.

[dayneger]

"Different" would likely be a more apt description, likely sounding more open and spacious than a standard Studio, but losing its near-wall capabilities.
Now if the studio didn't have the ramp or side walls but was more like a mini X-Statik with just the tweeter on a small baffle, overall performance would be very similar between them.

Hobbs seems to have partially answered the question here... thanks for that. 

I wasn't asking for these to be commercialized, but was curious about "directional" feedback to the "what-if" questions...