Protyped the cabinet recently and built a pair. Good response, 134 db 1/2 space from 90 to 200 hz. Size 636x536x700. Uses Celestion 4080fd driver, go on laugh!. Will be producing proper plans shortly. Just one Kicks you in the chest!Two are more than enough for 2x1850 horns loaded with voids and driven with 1000 watts, and 4 1x18 Bass Reflex cabs driven with 2000 watts. Need to get my uploads sorted,with pics and stuff. More Later!.
Hi Deadbeat, cost was the issue and so the celestion was preferable. Will plot the response fo the sd's and see if any improvement, but the celestions are very crisp and tight, sound good and clear even at the upper end.
Design has moved forward, new version is laterally folded making stacking side by side easier and more effective. Throat chamber revised, as a slot rather than half moon, and to answer one question, there is only the single layer of ply forming the throat and external sloped side to the the horn. No added extras inside apart from the rear chamber. Nice and simple!. As soon as revised version is built and tested, then plans available.
Right now where was I?. Oh Driver is ftr154808f not fd.
Fd could be used, about 2.5 db louder!
This horn has really been designed asa pair.
S1: 450 S2: 3000 Hyp 90 T 0.7 Half space 600 w (69.28v) into 8
Two fd's in half spaceare 140db85 to 220hz +/- 1db
Two f's in half space are 138 db 90 to 200hz +/- 1db, lifts after 200 on plot
but as we xover at 200 don't notice it too much.
Here goes for another set of pictures. Sorry for the delay but I've been away, and sidetracked briefly on some other topics. Some drawings:
Drawing of one pair of horns:
Model for the pair:
Plot for one pair 1w / 1mtr:
Plot at full power:
The driver for this is the FTR-15-4080-FD. I decided this was the route to go to gain absolute maximum effect from the smallest array of cabinets. 2000 watt power handling, and about 140 db spl from just two small boxes. In half space!. Xmax across the usable range is well within specs at full power. Word of caution, at 200 hz things will start to get directional, and you will probably start to see a much higher spl at this frequency directly out front. Each cabinet is 248 litres, can be made from less than a sheet of ply, (just less than 3/4), and will weigh 30 odd kilos with the celestion fitted. That is an 1850 sized cabinet producing 140 db. Lowest crossover would be around 65 to 70hz, unless you are indoors. At the moment I'm using the F version which is 600 watts each, and it's still awesomely loud. If a few of you are interested, I'll try to arrange a group buy on this driver. I'll only need four of these on the rig, but I might be persuaded to build a few more. Got to sort out the mid next, and get some plots and drawings up on the other forum. Things are getting interesting as my rig is coming together now. Got to find some decent horns for the top though, might make my own flares for the top end!.
Comments would be appreciated, as always, gentlemen. Until the next visit, happy building!.