[net.audio] JSE crossovers

wjm@lcuxc.UUCP (B. Mitchell) (04/17/85)

JSE developed their "infinite slope" crossover to prevent the same frequency
range from being sent to more than one driver and causing interference between
the signals from multiple drivers.
I have not examined the crossover networks in my JSE-1's (I don't want to void
the lifetime warranty!!) although I strongly suspect that they are passive
L-C-(and probably R) networks.   JSE claims they have a slope of 100 db/octave
which would require a 17th order filter section (and is effectively "infinite
slope").  They have obtained a patent on the circuit, so one might be able
to determine something about the topology from the patent (however, patents are
noted for their vagueness for two reasons - 1) to cover as much ground as
possible and 2) since they are public documents, to give away as little data
as possible, consistent with the legal requirement that "one skilled in the
art" should be able to reproduce the invention from the patent).
What I can say is that the concept works extremely well - I have not heard ANY
speaker costing less than $5000/pair that has better stereo imaging than the
JSE-1 or JSE-2.  Personally, I think the 1's have better midrange imaging
than the 2's but the 2's provide a bit more low bass response (below 35 Hz).
Frequency response on both models is superb.  The 1's list for $925/pair and
the 2's for about $2200/pair.   If you can't afford these two models, JSE
also has a smaller model, the .06 for $545/pair that sounds better than anything
under $1000/pair except its big brother (the 1's).
Admittedly, JSE speakers aren't discounted, but then they are already an
execptional value at their list price.  If you are looking for speakers for
a stereo system with a system price of $1K or more, I strongly recommend you
listen to the appropriate JSE model.
Regards,
Bill Mitchell ({ihnp4!}lcuxc!wjm)

rfg@hound.UUCP (R.GRANTGES) (04/18/85)

[]
Since JSE's are so raved about, yet are seldom to be seen outside of a
few high end salons (which peasants like me are too poor and lacking
in self-control to allow ourselves to visit), how about describing, say,
the JSE 1. How big, what color, how heavy, where to locate, how loud, etc.
Maybe some would decide they really should see a pair. Don't tell me that
all I need to do is read the XX issue of YY magazine. Those aren't available.

-- 

"It's the thought, if any, that counts!"  Dick Grantges  hound!rfg