BillFitzmaurice.info

The OT12 crossover is 2nd order low pass, 4th order high pass at 2kHz. Never use 2nd order/2nd order, it creates polarity issues.

There are two drivers because the horn is too tall for one to work optimally or keep up with a 600w woofer. They're series wired because they have higher sensitivity than the woofer.

Yes, you'd plane a panel that's too wide but rout or sand the second side to remove any overhang.

Use the smaller side for the initial assembly, make sure all is square, then trim the second side after attaching it to the assembly. A router with a following bit is best for that, though a sander will do in a pinch.

He who dies with the most tools wins. I just used mine for the first time in years, planing a door that was 1/8" too wide for the opening.

If a panel is proud this is what you use to take it down. It's not a tool you'll use very often, but it's invaluable when you need it. https://www.amazon.com/VEVOR-Electric-H ... 15Q1Er8dhZ

You probably won't damage them but they won't work as well as they would with the correct high pass filter.

Looks just a tad bottom heavy.

The high pass for the original compression driver won't work with piezos. They'll function, but the high pass filter isn't doing anything.

The point of trying different positions is to smooth room modes, so that means taking measurements at different listening positions in the room.

It's recommended to use multiple pieces as doing it in one piece wastes a lot of wood.

In that situation placing the mouths close together may not work as well as separating them, so experiment. 15s won't get more extension, only more output via more Vd, and I seriously doubt that more output is required.

This facebook page features our cabs. https://www.facebook.com/groups/495658660544205

I'd say they'd be pretty similar in the lows, with the high frequency advantage going to the three DR250.

The width range for one driver is 15 to 20 inches, so the range for 2x10 is 30 to 40 inches. There's nothing to be gained by using a third driver. There is also nothing to be gained spending big bucks or having to make modifications using auto sound drivers that are optimized for use in a small seal...