the photo of the plans should help.
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They're sounding great, The driver is a Beyma 15XA38Nd with the matching Beyma crossover. I've taken 1.5db out of the compression driver, as it was a bit too blight/loud (the crossover has this adjustment build-in). I've played everything from classical to rock to dub and back again, and I very pleased with their big sound.
Great looking pair of cabs - I'd really like to hear these to be able to compare with Tannoy drivers.
Interesting on the tweeter attenuation too.
They are great for all sorts of music listening, and I bet you find yourself doing just that - listening to the music...
Did you consider a tear drop baffle thingy in the throat? I put one in to a pair of BTH 18" dual backloaded horn cabs (ala GRF-R's) only bigger and it worked well.
There is talk about it on the Tannoy hilberink site I think it is.
Just had a look online at those Beyma dual concentric drivers. Very interesting, sensible prices too. One of the 8" units looks good for a project I have in mind.
Thanks for the reply Speedy.Steve. It was some of your boxes that inspired, and helped me decide to do this style of horn.
I'm not sure if this built would benefit too much from the 'teardrop'. The start of the horn mouth is only 40mm wide. The horn length is still similar to the GRF-R, but I cut down the actual volume of the horn, I didn't want too much colouration, or phase issues with upper bass through the horn. The speaker's bass response is pretty tight, but still extended and deep, which I'm happy with. I think some bassheads would benefit from a box with a slightly deeper dimension to accommodate a larger horn passage... but that said it's still a large folded horn (for home use) and I didn't want a box that was too boomy...
I'm happy to make to plans available, if anyone wants to build them...
Very nice Maarten, I love the exposed ply edges on the front. Just a very nice looking design, I am sure the sound is just as nice! Enjoy! Tim