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

"DoN. Nichols" wrote in message
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[ ... passive radiator ... ]

An interesting concept. Is it facing the same direction as the
powered speaker, or is it facing out the back? I see how it would
allow
a greater stroke for the voice coil, and with the proper compliance, it
might actually give better sound overall.

They're mounted side by side on the front panel, which is, in turn,
covered
with a wooden grill with a cloth backing. Instinctively you're inclined
to
think that setup would cancel sound, but it doesn't appear to do so. I
can't help but wonder if the ever so slight time delay (compression and
decompression) doesn't just widen the bass somewhat, providing a slightly
sustained sound. Dunno.

Hmm ... is there perhaps some kind of baffle to delay the sound
from the driven speaker to the passive one? But that would likely make
it peak at certain frequencies and cancel at others. (But maybe this
would happen at frequencies that those speaker elements were not fed,
being more the job of the midrange and tweeters.)

No---no baffles of any kind. I've had the woofers out of all of the
speakers to be reconed. They have a foam rim that eventually deteriorates
and must be replaced. Heavy passages can actually tear them apart
completely, although mine have never gone that far.

My first set was purchased way back in '67, new, from a JBL dealership.
It was 9 years later when I noticed the failure of the foam. Believe it or
not, JBL reconed the speakers free of charge, thanks to their then life-time
material and workmanship warranty. They even paid for the return shipping,
California to Utah. Needless to say, that all went away when the high
end home speakers were abandoned. I'm not convinced JBL sells anything
today that's noteworthy.



Mid range is in the center, with the tweeters mounted on the appropriate
top end, right for right, left for left. It's interesting to watch the
woofer work with heavy passages. It's obvious the difference the
passive
radiator makes by the throw one sees. The low end of the JBL speakers
I'm
familiar with are not muddy in the least, so I feel it was a grand
improvement.

Great! I presume that there is no grill cloth mounted in front
of those elements.

There is a very light weight black cloth that is stretched tight and stapled
appropriately. Doesn't seem to create any strange noises, and performs a
fairly important function of masking what's behind the wooden grills. I
think they spent enough time with the design to insure it was a good one,
but I have no way of knowing if it is, or not.


Well ... I'm going to try to describe a Klipshorn from memory,
and there is a good chance that I will be mis-remembering. If anyone
else is still following this thread, they may toss in a correction.

Anyway -- the speaker cabinet was designed to sit in the corner
of the room, using the walls on both sides as an extension of the horn.

The speaker was mounted at the top, directed downwards, and the
front opening started quite narrow at the top and widened in a clean
curve towards the bottom. The back of the cabinet was sloped towards
the front at the bottom, to redirect the sound out towards the listener.

They did not sound like much standing in the middle of a room,
but properly mounted in the corners, with clean walls on each side, they
really came to life.

I recall the speakers, but didn't investigate them at all because of my
partiality to JBL. Your description tells me everything I needed to know,
however. Bose has used that same principle for years, permitting low end
speakers to perform at a much higher level that they otherwise would be
capable. I've run my S8R speakers backwards in a room and the difference
is staggering. They develop a huge low end, still clean, but with my high
end hearing slowly deteriorating, I noticed I was missing some of the highs.
One cut in particular, a Jacques Loussier recording, I often completely lost
the sound on a soft drum solo where there was considerable cymbal work.
Susan could hear it, however. The speakers were used in that fashion by
need, stacked one on top of the other in a small room.

There is another interesting speaker which a friend and neighbor
has. The speakers are capacitive drivers -- big flat things just a bit
smaller than a door. Very nice sound from those, but very expensive
when new. He got both sets used at different times.

I wonder---would that be a planer type speaker?

Yes.

I think that should be a plan*a*r speaker, but I appreciate that you
understood my comment.

I recall a casual
acquaintance bought a set like that some time ago. I heard them only
once,
but he had trouble driving them, lacking enough power to do a good job.
I
seem to recall he was using a Carter amp,

"Carter" or "Carver"? IIRC, the Carver does some strange
processing to try to "improve" the sound. While my Halfer is plain and
straightforward -- pretty much DC from just past the input coupling
capacitor to the speakers. That coupling capacitor was to keep DC from
whatever preamp you used from biasing the speaker cones away from the
central at-rest position.

Blush! Yep, I think it was Carver. I recall that he was interested in
Mc gear, but couldn't come to terms with the cost. He often offered to
store mine for me while we were building the castle. g


And Dolores is similarly cooperative. I keep the computers
running so she can do what she wants on them, and I do the machining
and
whatever in what used to be the garage. :-)

Very, very cool, DoN!

She even searches eBay for tools for me -- and has not yet
learned to not say "this one sounds strange" and attract my attention. :-)

How cool is that? Susan has no clue about tools, but she sure encourages
me.

[ ... burning CDs of your (irreplaceable) vinyl recordings ... ]

The basic principle is to have the CD recorder connected to your
system, and whenever you pull out a record which you have not yet
treated, copy it as you play it. Sometimes you may have to do a bit of
work to set up the index and start points, other times it can be
automatic (if the inter-band gaps are the only really quiet parts).

Maybe I didn't fully understand your comment. I was under the
impression
you did this with the use of a computer, which an elderly friend has been
doing for some time now. Not so?

Not so -- though that is one way to do it. There are small
boxes available which can be connected to your system (typically the
"recorder" output from the preamp, so your adjusting of the volume for
listening won't affect the recording level -- even if you have to turn
the volume all the way down to answer a phone call). It sits there and
captures the audio. You then may wish to interact with the box a
little, to set index points so you can skip to a given cut -- that may
do well on automatic, or you may wish to adjust it. Certainly the
automatic indexing does not work well in a live concert with the
performer talking and introducing the song and telling where it is from.

Thanks for the information. My limited exposure to anything electronics is
really taking a toll on me. The nearest hi fi shop is at least 100 miles
away, so I'll have to do some serious inquiring when it comes time to make
decisions. It's nice to know there's people out there that keep informed.
I'll likely call on you for advice when I get near, DoN.


I wonder. Does the Studer name come connected to precision machine
tools?

It may well be. The machining of the drive is beautifully done.

Studer is (was?) a builder of precision grinders. It would make sense
that
they were somehow connected when you consider the high precision related
to
the feed mechanisms of tape decks.

Especially in these ones. IIRC, the Studer in question is
Swiss.

As are the grinders as far as I know. I've not operated one, but have seen
one. They are reputed to be able to work to .000010" (according to the
shop people at Litton Guidance, where I saw the machine in use), a far
smaller figure than the B&S # 1 universal machines I used to operate. We
routinely held .000050", but anything closer was pretty much hit and miss.
I gathered from the comments at Litton that they were a superb machine.

Harold