JC, that is a good question! The tubes are each 8" long, the Vb is approx. 4.5 cu. ft, I would guess. The volume is a bit tricky with this stuffing. Might go with longer tubes; I went with the tube size that Chris Munson (popbumper) used as most of the ported La Scala dudes reported that they preferred the shorter tubes. There is a noticable fall-off below the resonance of the tubes, not like a bass horn. It is a very steep cliff - you really notice it, unlike the gentler roll off of the corner horns

I think PWK was right, the measured K33(x) T/S parameters put it outside of the accepted workable horn formulas, so I would agree that it cannot be accurately modelled by most horn programs that I know of. It remains a matter for empirical testing. The Keele formulas, for instance, would predict the optimum efficiency of the K33E at a throat size (St) of 115 sq. in. and a Vb of rather large volume at 9343 cu.in. Not practical, in other words. This all changes when under pressure as in the Khorn and

Got a pair in the house, nasty-looking, but suprizingly sweet sounding. These pups can ROCK! Painted black with that spray epoxy with lumps in it. This will take some practice. Phenolic midrange diaphragm, K33E and a stock ALK crossover. JBL tweets are not going in these, I ordered some Crites tweets for these (hence the offset mid horn). Compared to the V2's (the corner horns), these don't go quite as low, but ran out of that nylon stuffing, so resonance isn't quite where it should be. I ordered

Looks like 1985... (!) However, PWK is absolutely correct in his response, the T/S params of the K33(x) put it way out there into unpredicable territory when under compression such as in a Khorn. DM

Interesting comments above. Let me think about those for awhile... Personally, I think the dynamic range of digital media and low noise level is far better than vinyl, but that's just me. See this letter from PWK posted by Freddyi on the audioasylum forum referring in part to digital technologies. DM

I think the curves are quite useful. They also seem entirely consistant enough for our purposes. The reason I keep coming back to the Jubilee as a comparison is that I think that it acts as a reference, overall size, shape, freq. response, and mouth size, etc., are closer than anything else we could compare it to. It serves to give an ability to determine what portion/element(s) in the curve is likely result of the testing methodology. I think there are 3 portions that are consistant between the

...and the 8 Ohm series curve over the Jubilee clone curve... I really am suprized at the differences in the curves based on impedance alone. DM

Another set of overlays - comparing to the Jubilee clone... Dana

I guess I'll do the series version crossover, then. Between us, we'll get it covered. Is there any T/S difference between the stamped-frame Crites driver and the cast one? Dana

Yes, I'd go with series, too. Perhaps listening would be the best determiner between 4 or 8 Ohm. I really thought that there would be a drop in SPL in series at 8 Ohms, but motors are very strange animals compared to plain old resistance. I wonder what the overall impact is once the mids and tweets/network is also in the loop - could have an influence, too. Dana