Hi Grindstone, I am planning the ARU one. I haven’t seen a BR design from Goodman for Axiom 80. Saw it for some of their other drivers.
They seem to have a box design specific to each of their driver. For the 301, they specify minimum of 7/8. For 80, they have specified minimum 3/4 inch.
I don’t have corners in the room. Hence they will be pulled out. Also I have not seen a corner reflex design specifically for Axiom 80.
Hari has been helping me with simulations, basis the TS numbers available on net. I don’t think there are any officially published numbers.
Between ARU box and OB, would you have any preference. And also if you could share any graphs or numbers or box designs, that would be helpful.
OK, sounds like you guys have it covered; didn't know anyone had posted TS numbers but just found more than I have on
diyA. Modeling the highly-resistive things is a crapshoot w/o real pressure-flowrate data on the ARUs and even then you end-up measuring to verify models so it's not worth it for one-off diy stuff IMO, but there's enough on that page for some sim-diving in case you guys missed it. I'll help if I can. What the simple sims will show is that the driver and ARU both might be nudged down a bit for slightly smoother response and a different distribution of "pipe organ" resonances inside the cab, but it gets dicey when resistivity increases that much and the driver needs to be up in the air that high anyway so that compromise has already been made. The alternative to that is to tilt the baffle to allow the moves and still fire higher but then that's a different design.
I like what you are doing (i.e., try them how they're supposed to be). Getting your hands on the right ARUs is a big deal that makes it worth it to try that. My hunch is the corner reflex cab is ~'54-ish because the artwork matches the other stuff from that year (ie, pre-ARU). Noteworthy that those disappeared after the ARUs showed.
Nothing wrong with trying OB (or even just raw drivers for a while), but my thinking is that it's a disservice to the magical unicorn drivers to not try the factory cab if it's convenient to try it. This is based on my situation where a cheap prototype cab to be thrown-away isn't a big deal. If it's a pain to get anything built and only one can happen, well perhaps that's a different decision. If you don't have the ARUs or if they are too dear to obtain, well then you can revisit the whole idea of alternatives and look harder at detailed sims for a best-effort cab, etc.
Big hunks of solid wood scare the life outta me, but I defer to you guys. Where I live, everything that's not laminated pieces cracks and breaks no matter what heroics people attempt because the humidity varies so much. And just to say it out loud, speakers have to be airtight--things can't just be left to move. I'd use whatever decent ply makes economic sense and maybe you can dress it up with a pretty facing piece that's not structural (?). I know that's not Art or a statement of passion, but it's safe and wood is a fortune anymore. Who knows, maybe you will hate them instantly and wont need to make furniture-grade things. My own preferences do not tend toward tone-wood cabs but rather the opposite, however, I can appreciate that not everyone agrees. It's just that box loss (panel movement, leaks) reduced output comes right off the bottom of the bottom--the bit we all work so hard to achieve. Set aside that it's distributed sources acting at different delays with different reflections (themselves extra sources), it's just a tough pill to swallow when already on single driver and tube amp.
I'd vote for building the thing stiff as can be, braced so a tank could drive over it. Then seal it, line it, do the curtains, gasket everything and let the magical unicorns sing
My guess is that, with a tube amp and 195X Goodmans Axiom drivers, you should not need much cabinet "warmth". My fear is that you may experience dynamics-withdrawal, or at least that's what happens to me when I go from bigs to 1-bangers. The best and worst thing a person can do is live with big sensitive speakers...
