Portable Battery Powered MEH Build

[stoneeh]

What about something like the FaitalPro 6RS140. In my head I have a vision of a version of the solana that goes down to 200hz

For a pure top (mid/high speaker), you'd definitely want to go CB rather than BR. With that, and minimal depth to fit the drivers, the Solana can get to as close as, rough calculation, 12l rear net volume.

Simulated (in WinISD) as a 4th order bandpass, we can get to a result quite similar to the raw measurements; blue 6NDL38, green 6RS140, red the 6ND430 galucha named:



And Max. SPL (@ Xlin and AES power handling):

then crossed with a pair of 12in drivers flanking it similar to how JBL and Lacoustics have their line arrays setup

That would definitely lead to a very controlled horizontal off axis behavior.

the rear port tuning affects air velocity coming out of the front ports inside the waveguide by reducing cone excursion around Fb

That statement definitely hits home. Just very recently, I've printed a part, to test fit a different driver, especially clearance of the membrane to the waveguide at maximum excursion - and I can tell you, with no rear port to limit excursion, at full load at low frequencies, the front ports are basically a fan. Even in the midbass region, it still seemed like somewhat of an issue. Then again, nothing that should be unexpected, given your compression measurements showed up to 2,5 dB compression in the bass area.

 

[galucha]

What about something like the FaitalPro 6RS140. In my head I have a vision of a version of the solana that goes down to 200hz, then crossed with a pair of 12in drivers flanking it similar to how JBL and Lacoustics have their line arrays setup.

That driver wasn't on my radar, but it should be a viable candidate as stoneeh mentioned. I'll make a note to add it to the next update to the guide.

I do think in the future I want to explore more modular, scalable approaches to point sources that can cover 200Hz-upwards. For the work I do in the soundsystems realm, there's a lot of appeal in getting a coherent, controlled directivity top that can cover precisely that range. It lends itself really nicely to crossover to a dedicated bassbin section covering 60-200Hz or somewhere around that. Maybe that will be a further iteration of the Solana that's more purpose built for high output and utilizing a 1.4" comp driver.

 

[ImpuPerf]

I can tell you, with no rear port to limit excursion, at full load at low frequencies, the front ports are basically a fan. Even in the midbass region, it still seemed like somewhat of an issue. Then again, nothing that should be unexpected, given your compression measurements showed up to 2,5 dB compression in the bass area.

Presume that You heard port noise, was the port velocity over 17m/s? I believe Scott Hinson did some measurements on port noise vs velocity.

 

[stoneeh]

That's really not that easy of a question & answer. The amount of noise has to do with not just the air speed, but if the exit has rough edges etc which would disturb the air flow. And the issue of port noise is a completely separate one from that of port compression. As for noise, I may eventually do a video recording of the test I mentioned (driver at max. excursion, front port at full load) to just let everyone see, listen & judge for themselves.