BillFitzmaurice.info

Keryn O'Shea wrote: ↑Mon Jul 27, 2026 3:06 pm Hoard urge... rising...

Just remember the issue with the crossovers using 16ohm speakers.....Can be done, but have to do a little work to get it right.

Yes mate, true for many of the designs, there's one possibility though, let me get way ahead of myself here..
Two stacks of 3xOT12JA with 16ohm CDs
Bill has provided 8 and 16ohm filter schematics for this model, or bi-amp with the 20uf series HF cap

I love this thread. I felt like I was the only one that was going against the grain here. I know where you’re at Keryn. First, I will say it seems that Bruce is giving very clear wisdom and advice. At the end of the day, you gotta take it in stride and make a decision. Not against it, but on account of it. He’s made some valid points. However, If Otop12s work and the filters are there for it…why not? I’m making my way back around slowly. Just gotta get a few things sorted out. Seems the driver is one of the biggest cost factors in a BFM build. If you can test these and get your hands on them before committing to the purchase it may save you a bit of money in the long run if Otop12s are on the wishlist. Just my 2 cents. I can see it both ways. Hope for the best for you in making a decision.

Keryn O'Shea wrote: ↑Tue Jul 28, 2026 2:51 am Yes mate, true for many of the designs, there's one possibility though, let me get way ahead of myself here..
Two stacks of 3xOT12JA with 16ohm CDs
Bill has provided 8 and 16ohm filter schematics for this model, or bi-amp with the 20uf series HF cap

You are absolutely correct! I haven't looked at the OT12 plans in a long time as I built mine a hundred years ago. I didn't remember the 16 ohm option. The only thing I'd add (for informational purposes) is that the OT12 is kinda' back-heavy even with the Neo drivers. Will be even more so with the heavy ones. However, if you're doing J-Array, that's probably much less of an issue depending on how you are going to deploy them.

I'm not really trying to tell anyone what to do, just make sure they are armed with all the facts before they pull the trigger.

And as an old guy, I'm certainly biased toward the lightest option possible. Only place I want to lift something heavy is at the gym....or getting out of my chair.