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Re: From Wayne Parham - Re: Patentable claim

You wrote:

I'm just not as impressed with the Unity.

Not having heard one, that would seem to be a remarkable call to make.


Are you inferring that Lambda's does not perform properly because it is different

than yours? Why do they need to be
licensed then? Licensing requires a financial relationship; Why would they pay you for something that does not work?

Nick used a crossover of his design and did not choose to use the final version I supplied.
As I explained, I am a DIY'r, this was not about the money. I wanted to give those who were interested a chance to
get something cool for comparatively little money.
As I recall, the license fee was 1$ or something trivial, again, it was not about the money.
A license is needed however as if a company knowingly allowed an infringement and did nothing, that "looks bad"
legally. So far as "work", so far as I know everyone was happy with the sound, don't forget they have several
different strengths.


So does the Lambda speaker require licensing or not? Is it a Unity horn?

The name "unity horn" is the horn design which has multiple ranges in one horn, Lambda sold kits to build one version
of it which was a 16 1/2 inch square mouth horn with a 300 Hz low cutoff.
We sell several versions of the Unity including a 3 way horn.
Two models can be mounted on a physical or acoustic boundary with essentially no interference as well.

One of two conditions must be true in your Unity horn, having a difference in distance between its three subsystems. As Sam
pointed out on this thread, you have an HF subsystem further from the listener and an LF subsystem closer to the listener,
both in relation to the MF subsystem. This means that you must have one of two conditions:

1. Constantly changing phase response, that moves further away from the listener as frequency goes up.
2. Discontinuities in phase response that break rapidly as crossover is made between drivers.

.

I think both Sam and you are off here, I don't know what you know about Richard Heyser but if you know what his
approach was you will get this. If not, it is good reading .

Take a JBL woofer like you use or any other woofer, measure off say 1 meter and set a measurement microphone at
that exact 1 meter distance cone to mic element.
Using a device which can resolve time like Heyser's Time Delay Spectrometry system (as found in the B&K and
TEF)
measure the time interval. One finds that in addition to the delay caused by the acoustic path, one also has a delay
within the driver (in the case of a big woofer it would be on the order of 1-2ms).
Inputting a wide band signal evidences the same intrinsic driver delay once the air path is accounted for..

If one wants to measure the acoustic phase, one has to account for not only the air path delay but the delay within the
driver as well, only when that is done will one get measurements consistent with those predicted by the electrical
equivalent circuit of the driver. Then one see's the mass dominated -90 midband acoustic phase shift which IS what a
direct radiator produces if it has flat amplitude response and is acoustically small.

Now picture you have a crossover where AT crossover, the high and low outputs are shifted by 90 degrees with
respect to each other and the hf output leads the low output.
Lets say the crossover is at 300 Hz, this puts the hf sound ahead of the lf sound by 11.3 inches, add to that the delay
in the woofer and what ever phase lag it has at crossover you have the hf leading by several feet easily.
Yes, one can move the hf source even more foreword and find a spot where the two outputs are temporarily in phase
but the "Time" is skewed and an impulse would still show the hf leading.
Since one is concerned with the sound traveling from the apex to the mouth of the horn, doesn't it make sense to put
the hf driver to the rear by an appropriate amount? Now, at least so far as sound going towards the listener, the time
relationship would be correct, a broad band signal would not be spread out in time as is the case with any other
spatial position.

Think about the time delays, the woofer has a lagging phase response over much of its range, it has the largest internal
delay and is driven with the lagging signal from the crossover, it has to be forward of the hf to make any of that time
up.

Have to run, my kids and I are off to catch some pretty lights and Transient response.


Tom Danley



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