Open Baffle Speakers

[MITsound]

I have indeed experimented with large woofers on panels like this...unfortunately while proponents gush about the "airiness" and other platitudes about open baffles, they don't test well. The locations within the room can be a make or break option....note in this picture, the right side of the panel is very close to a wall...and fully flush with the floor. Those two structures "hook" the woofer so that the rarefied pressure wave can't swing around & cancel out the positive pressure wave.
It seems these creations seem best at home with these big drivers, a plain board....in a small room....those big drivers flailing away.



-------------------------------------------------------------------Rick............

And yet despite not measuring mine, they work as intended. Small open baffles with Tannoy DC drivers.
After a few trials for size and materials, I have folded OB light enough to resonate and fill in low enough to meet a sub rolling off 4th order at 60 hertz.
They sound more spacious and natural than with the factory cabinets I got them in.

 

[phase]

This is making me wish I would’ve taken my Dad’s old Jensen 10” or 12” drivers in the ob cabinets that then went for donation a few years ago. They sounded incredible with guitars.
We’re the speakers I grew up with, using a Scott 299 and a turntable, or Dyna fm tuner.

 

[classicalfan]

...How to widen the front face by 3 mm? Because my front face is 388 mm
what tool to use to simply cut 3 mm...

Here is how to enlarge the cutout by exactly 3 mm.

First purchase the Amana rabbet router bit set #49432. Next use the 1.5 mm rabbet bit, #47663, from that set and use it to cut a recess 1.5 mm deep in 1/2 of the thickness of the baffle. In other words, guide the router against the current opening, but only cut approximately halfway down. Next put a flush trim bit into the router and use the recess you just cut to guide it. Now you will have the opening exactly 3 mm larger than it was before.

Also, make sure that you really want to increase the opening by just 3 mm. Previously you said that you wanted to go from 388 to 393 mm. That's a 5 mm difference, not 3 mm. So, you might need to use a larger bit from the one I specified, which is for a 3 mm increase in hole size only.

Finally, don't trust the driver manufacturer's specs for providing the exact dimensions. Your driver might be a little bigger or smaller than their numbers. So, measure it first and then add a little bit more room to make sure it will fit into the hole. This is particularly true for the driver frame, which will require an additional rabbet in the front of the panel if you are planning to recess it.

 

[GM]

Frankly, it beats any other construction on these pages regardless of price. None of my other speakers even comes close to this. Listening to Niels Henning Ørsted Pedersen on This Is All I Ask, track four, "Just In Time", and you'll know what I mean. The articulation in lower registers is phenomenal and overall dynamics scary. This is close to what an upright bass should sound like. Even the best 10-inch bass in a bass reflex box will never be able to deliver such detail and transient response. Never!"

IME all of this has more to do WRT driver specs as the inverse of an OB is an IB or even a horn, so with it having wide range horn driver specs, his experience mirrors mine.