Clark Synthesis Update


> How much excursion (Xmax) does your tactile transducer have?
> Is the tactile effect created by shaking a mass on a spring like the Aura
> Bass Shakers, or is the Clark Transducer NOT a constant acceleration device
> like a standard loudspeaker?  Is it more like a pile driver in that it
> transfers its energy by an impact force?  This could create more of a
> tactile effect per pound of mass than the Aura spring on a mass model.

At low frequencies (below 40 Hz) you can see the transducer flexing as much
as a quarter of an inch.  The dome shells act as a dual torsion spring to allow
level in the 90 to 100% range in that the transduction force is transferred
through a single point.  This also allows for easy installation into a small
"footprint" area. 

> Do the 229F and the 329F have the same magnet material?
> What are the other differences between these products?

The 229F has a 20 oz. ceramic magnet structure with an MGO rating of about 3.5.
The 329F has a 20 oz. Neodymium Iron Boride magnet structure with MGO up to
38.9.We also built a 22.5 oz and a 25 oz. mag. structure for our industrial and
Pro models.   The increased mass and magnetic efficiency of these units greatly
increases the force and damping characteristics.  This is all about high
resolution in that the increased gauss in the voice coil gap coupled with the
rigidity of the dual dome structure eliminates overshoot and therefore gives the
"tightest" bass reproduction in the world.  This combination of structural and
magnetic rigidity also allows the transducer to produce higher frequencies (up
to 100 kHz in water).  We have found that there is a lot of tactile information
in these higher frequencies,  most people perceive vibration up to 800 Hz with
some individuals feeling up to3 kHz (particularly the deaf).  This allows us to
recreate the vibratory signature of most if not all musical instruments (wait
till you feel an acoustic guitar)  and sound effects such as the speeders flying
through the forest in Star Wars.

The previous Clark transducers dome shells were vacuum formed from Lucite "L"
acrylic which has a much higher molecular density due to it's crystalline
structure, this resulted in a much higher resonate frequency of 550Hz.

> From the chart, it looks like you are -24dB down from 50Hz to 25Hz.
> With my Aura's and RBH's I EQ this, and it really helps when I play
> some low pipe organ music.  How clean does your transducer create
> sine waves?

Very clean, again due to mechanical rigidity.  The Aura and RBH use phenolic
"spiders" as a support mechanisum for the magnet stucture, this allows the
magnet structure to move up and down within the caseing and allows the magnet
to overshoot null.  We call this distortion or "muddiness".  Also if you inject
enough power into either of these devices the magnet structure will bottom out
on the case, so they both use a small rubber "stopper" to subdue the resulting


Clark Synthesis is advertising a new 229F transducer at $300.
It sounds similar to the old 329F minus the neodymium magnet structure.
The new 329F has more force per watt, stated as > 2 lb/W.
The new 229F has a stated force per watt of > 1.2 /lb/W which is the
same as the old 329F.  The magnet weight of the 329F is up from the old 22.5
ounces to 25 ounces.  The 229F has a 22.5 magnet, but no mention of the
magnetic material used.  Clark's webpage has not been updated recently so
this is all that is known about the new 229F and the changes to the old 329F.

It also looks that the bulk discounts of 3/5/98 is no longer on-line.
Maybe Clark Sythesis was just trying to move some inventory before the
arrival of the new models?   Don't know, this is just speculation.



The prices of the Clark 329F transducers have gone down and you get a
discount if you buy in bulk!

#	total	cost/transducer
-	-----	---------------
1	$489	$489
2	$949	$475
3	$1399	$466
4	$1849	$462
5	$2249	$450



Clarksyn wrote:
> Subject: User Feedback
> Date: Fri Oct 10 13:49:41 US/Eastern 1997
> From: 
> To: clarksyn
> The submitted values are:
> email:  eriko
> comments:  You claim a frequency response of 5 Hz - 800 Hz.
> Could you describe your test setup to me? 
> Could you send me some frequency response charts?
> I have a hard time believing your transducers can really
> be flat down to 5 Hz.
> erik olson


Please forgive the delay in response to your inquiry,  things have been
very busy around here.  To answer your questions, the transducer does
indeed have a frequency response down to 1Hz. and actually spans out to
100 kHz. The bandwith is flat (-7 dB) from 10Hz to 100kHz and drops
about 12dB from 10Hz to 1Hz, part of this drop may be the result of the
sub-sonic filter in the amplifier and we are checking with Peavy to see
if this can be corrected with modification to the amp.  The resonant
frequency is around 550Hz and looks to be about +10dB.

These results were obtained with an HP FFT at the University of Virginia
Commonwealths acoustics lab.  The transducer is loaded by submersion in
a tank of water and a B&K hydrophone is used to measure the output of
the transducer.  I should have the complete test report and graphs in a
week or so.

Please call at 888-797-7509 if I may be of further service.

Thomas Clark Fenner
Clark Synthesis, Inc.

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