Tom Danley and Yorkville offer more...

Check out the new offering from Tom by Yorkville. Of special interest is the use of dual comp. drivers in one inch thick wave guides. Very interesting.

I`ve been following this over on PSW for a while...basically taking a few of Danleys current ideas ( Unity and Tapped horns) and adding in the wave guide. Looks good on paper and has some interesting specs.

But prob` never gonna get to hear one in the UK?

.p.

I haven't been able to access the site but the title of the PSW thread mentions line array in its title and the original post mentions dual comp drivers and 1” thick, so here goes at a guess how the thing works.

Presumably from the above description the device is some form of lens/wave guide that transforms the output of two compression drivers into a line array type exit and that it is 1” thick. Given that the device follows the same acoustic principles as every other device it works by equalising the path length between the comp driver exit and the slot (would be very novel if it wasn't) exit. If the device is patented I would guess that the novelty is in the fact it is 1” deep rather than anything else.

Consider a bunch of flexible straws place in front of the comp driver exit. Don't worry about the practicality, just imagine that all the sound goes down the straws. Next arrange the end of the straws away from the comp driver in a line to achieve your line driver. The straws near the centre will bend outwards because the straight line distance from the comp driver exit and the line exit is shorter than the straight line distance to the end straws. The bent path of the straws equalises the path that the sound travels though. This is how most acoustic lenses work. The main difference is how the lens is fabricated. The device Meyer uses in their line arrays works exactly as I have described using 4 pipes. If you search through their patents you should find diagrams that should provide more enlightenment. I experimented with a similar device for a mid range drive unit using garden hose for the tubing. I wrote more details on the Harmony Central line array thread, but the search there doesn't isolate specific posts, so I can't give a link.

Back with the comp driver and straws. Remember that they are flexible. If we push the line end of the straws back to the comp driver the straws bend outwards and the overall depth of the device is reduced. I'm not suggesting that Yorkville design uses straws but the concept should give an idea of the principle involved.

If we now consider a practical device we will start with a typical 1” comp driver with a diameter of say 150mm (approx 6”). To allow multiple drivers to be stacked to form the array the exit slot need to be at least equal in length to the comp driver diameter. Imagine a pipe shaped like a simple periscope. If this is placed vertically with a length equal to the radius of the comp driver it exits from a point on the circumference and slightly in front of the comp driver. A similar pipe going vertically the opposite direction would define the other end of the slot.

Now consider a pipe the same length as the others which travels out horizontally. If at its half way point it is folded back towards the centre of the comp driver the exit can be arranged in the line between the two end exits. By adding additional pipes and adjusting the angles and fold position a complete line can be formed with very little depth.

I think I read somewhere on the PSW thread that the path compensation was continuously variable or something similar. It might be that the device consists of a back plate fixed to the comp driver, 1/2” in front there is an elliptical plate whose vertical dimension is equal to the diameter of the comp driver and whose width is equal to the radius and then 1/2” in front of that is a front plate with a vertical slot in it. Obviously there has to be a path around the edge of the centre plate so for the assumed comp driver the device would be vaguely elliptical, 160mm high by 80mm wide and 25mm (1”) deep.

Of course I could be completely wrong.

Hope it's not to naughty pinching these pics so those who can't view the site can have a look...
Seems you guessed about right Steve, apart from the fact the CDs are mounted with a larger gap than you expected in the vertical plane..










OOps..posted at the same time...




Edited by jethrocker - 13 January 2008 at 4:37pm

Happy birthday and thanks for posting the pictures. I've just set up a new computer (old one died) and running Linux and Opera I haven't sorted the plug in for flash yet so I get an error when I try to access the site. I think it is bad commercial practice to not offer an alternative but web design is a bit off topic.

The vertical spacing of the drive units and slightly longer slot is to keep the spacing equal between different cabinets. The design is a nifty engineering solution if reducing the depth is important but apart from that I can't see any acoustical advantage over the offerings from other manufacturers.

It is very interesting.  I don't think this is any sort of waveguide though - as soon as you start deflecting/bending the wave around, you will get a massive reduction in high frequency response.  The only way I can see this setup working is if the red section in the diagrams is some sort of shaped lightweight diaphram which is being driven from the compression driver output, and re-radiating the sound in an elongated wavefront due to its shape - not the sort of thing that would be DIYable very easily.

I wouldn't imagine that the crossover frequency would be very high, but then again, the synergy/unity horns are strange beasts.

Anyone here going to buy one to pull it apart and report on the workings ????