"DoN. Nichols" wrote in message
...
In article ,
Harold and Susan Vordos wrote:

"DoN. Nichols" wrote in message
...
..

What came as a real surprise to me was when I inspected the woofers in
the
Paragon. While I've been talking about them as if they have the same
speakers as they S8 system, they are really the next generation of
speakers,
so their identifying numbers are different. Instead of the 375 driver
for
the midrange, they use a 376. As far as I know, the chief difference is
modern magnet technology as opposed to the old Alnico technology. The
375
drivers use a 28 pound magnet, along with a 4" ribbon wound voice coil.

Hmm ... how much were they able to reduce the weight with more
modern magnet materials?

The literature that came with the Paragon indicates the magnet assembly
weighs 10.7 kg (23-1/2 pounds), with a flux density of 15,000 gauss. It
uses a 4" diameter edge wound copper ribbon voice coil. Throat diameter of
the horn is 2".


JBL's literature they make reference to the 375 driver's ability to
handle
explosive passages in stride. My personal experience in having owned
them since 1966 is they were too modest. Until such time that you've
had
the pleasure to play with a set of these giants, I'm not sure you could
understand their capability.

I'd love a chance, but probably won't get it.

The door would be open to your visit were you to find yourself in the other
Washington.

You likely understand that nuts like me enjoy their systems in more than
one way.
Sometimes the music is secondary.

I understand. Sort of like sitting there and watching a shaper
cut away. Relaxing in its own right.

Can't add anything to that.

[ ... ]

You'll have to enlighten me here, DoN. I've never used anything but the
roller type that impresses, and the old school stuff, not even a scissor
type.

O.K. Picture the rollers ground flat on the edges without any
bevel. Mount them at an angle to the direction of cut. And mount them
so the edge, not the center, is at the centerline between the workpiece
and the screw on which the cutter rotates.

This causes the edge of the knurl to actually *cut* material away,
as it is rotated by the workpiece, instead of being embossed into the
workpiece. This produces a much sharper feeling knurl -- and does not
increase the diameter with displaced metal. I'm looking forward to
experiencing the difference once it arrives. (We're in the period
between paying and receiving at the moment.)

Thanks, DoN. I'll be interested in hearing your comments after giving the
setup a test drive. I'd probably really enjoy them, for I'm one of
those nuts that demands a perfect knurl. Even in stainless, I can turn
them out perfectly, every time. I don't like shallow knurls, preferring
them pressed to a sharp point instead. You have to get right after the
thing in stainless to avoid the work hardening potential. I can't help
but think the process of which you speak could make it much easier.


You've probably experienced the principle of these latter two
tools if you have a T-bar knurling tool for your lathe's turret.

No---never have. I've made some quite small items that got knurled, in one
case in 17-4 PH stainless. I've enjoyed success as small as 3/16" diameter.
By making a custom holder for the rolls, getting them to almost make contact
at the centerline, you can knurl very small diameter stuff. Generally the
items are far more fragile than their ability to accept the knurl, so I
start by knurling the material at the desired diameter, then machine
everything from the knurl, insuring concentricity and not damaging fragile
components. My need has always been limited, never for a production job
(I did a lot of tool making), so I always just limped by with what I had.
Makes a good machinist of you to be able to do a job without all the
foxtails and whistles, but it has a cost, too, in that it's often slower.
I've always done my best to stick with the old machining principles, right
down to not even using a DRO. In a strange, perverted sort of way, I
take great pride in that. Sure would like owning one of those scissor type
knurls, though! :-)

Harold