BillFitzmaurice.info

Hi Folks,

I've started making sawdust on an O15, with plans to follow with an J15, Otop15 and a T39.

I have many speakers sitting on shelves looking for boxes. Speakers are expensive in Australia and resale is terrible, so while I acknowledge finding a box for a speaker is not as good as deciding on a box and finding speakers to put in it, that is not practical for me.

I have some Beyma 2" compression drivers and some large horns to go with them. Beyma says they are good down to 500hz at 12db/oct crossover.

Being that the flares are quite big, I assume that they would mess with the mouth of a J15 or Otop15. Do I gain anything by using them on the diffraction horns in the plans and crossing over at 1200hz?

Alternatively (and I think this might be a long shot), could I raise the high pass of the woofer section of the O15 to 500hz and use the 2 inch driver and flare as the mid highs (with the help of DSP/active crossovers)?

They're great drivers that I would love to put in a BFM box.

Specs here

https://www.beyma.com/speakers/Fichas_T ... P850Nd.pdf

Those are too deep. Check your plans. Bill will have to weigh in, but I doubt the horn on the OT15 is designed to go that low.

Plus the width at the back of the horn isn't wide enough to use a 2" driver.


Just realized that you reference OT15, O15, and Jack 15. My comments are regarding the OT15. Be a little more specific on which box the questions are about and we'll get you better answers.

Bruce Weldy wrote: ↑Fri Oct 29, 2021 5:25 am Just realized that you reference OT15, O15, and Jack 15. My comments are regarding the OT15. Be a little more specific on which box the questions are about and we'll get you better answers.

Hi Bruce,

Thanks for your reply.

I deliberately mentioned three different cabs as I intend to build all over the next few months. I would like to make use of the 2" drivers in something, and was hoping for a suggestion.

I might not have worded my query well, but I am asking if these drivers can be used in an Omni 15, Omni top 15 OR a Jack 15. In the case of the Omni 15, specifically whether they could replace the mid and tweeter.

I had not considered the size being too big for the Otop15 - that rules them out of that design.

Cheerio
Alex

The only reasons to use a 2" HF driver is when you have to because the LF section won't go high enough to use a 1" HF driver, or because the LF section sensitivity is so low that you need to cross over to a horn loaded HF section as low as possible. That's not the case with any of our designs.

You could sell those two Beyma drivers at 50% of the new cost and totally finance a couple of cabinets.