Home High Efficiency Speaker Asylum

Need speakers that can rock with just one watt? You found da place.

[ Follow Ups ] Thread: [ Display  All  Email ] [ High Efficiency Speaker Asylum ]
[ Alert Moderator ] [ Edit ] [ Delete ]

Re: Patentable claim

172.133.78.66

Hi Wayne and those following along.

I pointed Tom to take a look at the questions and discussion, which he did an asked me to post the following response for him...
------------------------------------------------
Hi,

Well I guess its not to surprising that a lay person cannot read a patent and determine what the "crux of the biscuit" is to insert a Frank Zappa-ism. Patents are written by lawyers and like other legal documents are not intended to be interpreted by non lawyers. Heck if they spoke plain obvious english lawyers would be unnecessary for the most part so you see the situation... Also, one would have to have a significant grounding in horn theory to see why some things were done the way they were.

I will try to explain what the Unity is as the thoughts come to mind.

The unity is not limited to a pyramidal shape but rather any flare where the expansion rate is variable. The pyramid or conical shape has the advantage that above some frequency set by the mouth size and wall angle, the dispersion is essentially constant with frequency, up to the point that the exit and throat size narrow the pattern. For a 1" exit it is possible to get 80-90 degrees up to about 20 kHz.

It is well known that such conical horns have comparatively poor low frequency response compared to an exponential horn of similar size however, the exponential (and other curved wall types) have narrowing dispersion pattern and as a result of the lower cutoff, also introduce more distortion due to air nom linearity. The Unity began with a joke at the company Christmas party and then the realization of why the conical horn had poor lf response.

The cause of the poor lf response can be seen "if" one looks at the expansion rate of such a flare. One see's that at the compression driver exit, the expansion rate is very rapid at high frequency cutoff) and since the expansion rate acts as a high pass filter, the low frequency energy does not couple to the mouth. Move a few inches toward the mouth and one finds the expansion rate is much slower and suitable for low midrange "if" only that was where the driver was. All one has to do is obtain a mid driver, suitable for efficient horn loading in that frequency band and find the point in the flare where the expansion rate is suitable for that frequency range and couple the sound in at that point. Because the compression driver and each mid driver are less than 1/4 wavelength apart, there output combines fully and coherently, something which cannot happen if the driver were further than bout 1/3 wavelength apart (and how most speakers
are). All that is needed is to have the physical offset (remember if you are in front, the compression driver is furthest away from you) between the upper and lower ranges compensated for by the crossover network phase shift. It is possible to have the crossover from the upper and lower sections be totally seamless with no trace at all even on the TEF machine. It is possible to divide the horn up into several frequency bands not just 2.

In the Unity, the cone drivers for the mid section are loafing in normal operation, they are +2dB more efficient than the compression driver and the group of 4 handle about 3 times the power. In operation they are padded down about -15 dB to match the sensitivity of the LF section on most of our products (typically about 96-101 dB 1w1m). As a result of efficient horn loading and giant headroom, mid range harmonic distortion is typically 1/10 to 1/100 of any speakers I have measured at the same SPL, FAR FAR lower than any 2" compression driver.

Unlike all multi driver multi frequency band speaker systems, there is no self interference between the various ranges at crossover and unlike conventional systems the polar plots are free of lobes and large changes in directivity vs frequency.

In rooms with bad acoustics or where maximum transmission of recorded
information is the goal, a speaker with significant directivty is superior to a wide dispersion source. Once may think of the sound that is direct from the speaker to your ear as the information and the near reflections as interfering noise. As a result, one finds as the directivty increases, so does the speakers direct field (that zone up close where the direct sound is much higher than the reflected sound). Large line sources, large panel and horn speakers are the most common high directivity designs.

Taking a horn for a moment, one can measure the sound radiation in every direction and derive a measurement used in the antenna area, the "front to back ratio". This is the difference between the energy in the desired pattern compared to the energy everywhere else.
A 10X10 inch 60X60 horn and a 20X20 inch 60X60 horn have the same coverage angle but the larger horn has a higher front to back ratio, more of the sound is in the desired pattern and less outside. When one make a multi way horn system, it is a number of different horns with the HF one being the smallest and the lf the largest etc.

With the Unity design a much greater "front to back ratio" is achieved compared to a similar size multi horn system because the hf driver uses the Mid and LF parts of the horn to govern directivity and there are no interference's or lobes sticking out the side or back .

With the most modern DSP one could only "tune" the time of the multi horn source correctly in ONE location, anywhere else side to side and the compensation is wrong as the distance from your ear to each source changes with position. With the Unity the crossover and physical position of the drivers take care of the time issue, the very close driver spacing in the horn eliminates any position
related distance issues so there is no interference, all the drivers combine to be one source in time and space. It is unlike anything else in what it does and how it does it.

Hope this helps.

Tom Danley

This post is made possible by the generous support of people like you and our sponsors:
  Schiit Audio  

Follow Ups Full Thread
Follow Ups
You can not post to an archived thread.

[ Top Top of Page ] [ Contact Us ] [ Support/Wish List ] [ Copyright © 2025, Audio Asylum, all rights reserved ]
[ General ] [ Speakers ] [ Tubes ] [ Vinyl ] [ Digital ] [ Hi-Rez ] [ Video Asylum ] [ Cables ] [ Tweaks/DIY ] [ Music ] [ Films ]