Early Heresy Uses Electrovoice SP12

[tubav]

Does this Electrovoice have the whizzer cone or not in this application? All of the SP12 I've looked have the whizzer but since the Heresy is a 3-way maybe it didn't use the whizzer.

Thanks.

tubav

[LarryC]

I believe early Heresy's routinely used the SP12B -- that was the standard woof for the "K-Ortho-12" 3-way speaker system.

Not much choice but to "use" it. A passive electro-mechanical crossover propagates frequences above 4000 Hz, extending the SP-12 or 12B to 13,000. No ability to cut it out, as far as I know.

Besides, the early K-Orthos crossed the mid horn at 1000 Hz and the tweet at 5000 Hz, so the extended frequencies would appear to be needed.

[MikeFord]

The crossover is at I think 900 hz, which is below the whizzer mechanical coupling range, so it doesn't whiz. I don't know if the whizzer is present or not, but I "think" so.

[LarryC]

Well, I'm pretty sure the whizzer cone is the shallow horn-like flair surrounding the dust cap, not too hard to miss:

The earliest Heresy's had K-1000 MR horns and I thought the xovers were called the K-1000-5000, but could be wrong.

The whizzer would indeed whizz if the electromechanical crossover was 4,000 Hz and the MR didn't cross until 5,000. Besides, those points are not brick-wall cutoff points -- if 6db/octave, at least an octave above and below would be desirable, and audible if missing.

[MikeFord]

Well, I'm pretty sure the whizzer cone is the shallow horn-like flair surrounding the dust cap, not too hard to miss:

The earliest Heresy's had K-1000 MR horns and I thought the xovers were called the K-1000-5000, but could be wrong.

The whizzer would indeed whizz if the electromechanical crossover was 4,000 Hz and the MR didn't cross until 5,000. Besides, those points are not brick-wall cutoff points -- if 6db/octave, at least an octave above and below would be desirable, and audible if missing.

5k was the squawker to tweeter crossover point, woofer to midrange was the 900 or 1k point.

I was very tempted to buy a pair of the SP12B to replace torn cone woofers in my Heresy I, but I found a nice pair of Speakerlab W1200R, and was feeling a bit nerveous about the EV being so old, and I think close to $200 if you need to recone them. Also many are 16 ohm, not sure how that would work, but some at least appear to be 8 ohm. I haven't learned that much about them except they look very nice.