line array

[simpleacoustic]

I have just started reading a bit about line arrays.So I'm curious to know whether it is possible to have mid-range compression drivers in in a waveguide similar to that of the hf instead of using cone woofers.Might sound stupid to those who understand line arrays well enough.
I use mid compression drivers with round 12" metal pa horns in my present 3-way tops and is very pleased with how they fill in,so this is what raised the thought.

[GM]

I've seen patents of several different compression driven line arrays and IIRC there's a prosound Co. or two using them, but haven't saved any info or links.

GM

[dirkwright]

Originally Posted by simpleacoustic

I have just started reading a bit about line arrays.So I'm curious to know whether it is possible to have mid-range compression drivers in in a waveguide similar to that of the hf instead of using cone woofers.Might sound stupid to those who understand line arrays well enough.
I use mid compression drivers with round 12" metal pa horns in my present 3-way tops and is very pleased with how they fill in,so this is what raised the thought.

I have read that the waveguides or horns have to have a very narrow vertical dispersion, like less than 10 degrees or so, depending on how many you are going to use:
"Practical line array systems act as line sources only in the low- and mid- frequencies. For the high frequencies, some other method must be employed to attain directional characteristics that match those of the lows and mids. The most practical method for reinforcement systems is to use wave guides (horns) coupled to compression drivers. Each horn must have a very narrow vertical and a very wide horizontal dispersion.
Rather than using constructive and destructive interference, horns achieve directionality by reflecting sound into a specified coverage pattern. In a properly designed line array system, that pattern should closely match the low-frequency directional characteristic of the array. If the array's vertical dispersion is 60 degrees and there are 12 boxes, then each horn would need to have 5 degree vertical coverage. (Narrow vertical coverage has the benefit that it minimizes multiple arrivals, which would harm intelligibility.) If this is achieved, then the wave guide elements can be integrated into the line array and, with proper equalization and crossovers, the beam from the high frequencies and the constructive interference of the low frequencies can be made to align so that the resulting arrayed system provides consistent coverage." from Wikipedia on Line Array.

Here's some information on using a full range driver in a full height linear array:
The Murphy Corner-Line-Array Home Page

I don't completely agree that sound behaves like light and therefore the laws and theories of light apply to sound. So, I have no opinion about line arrays in general. (Murphy uses light characteristics as analogous to sound and sound sources.)
"Sound waves are longitudinal mechanical waves, while light waves are transverse electromagnetic waves, and sound requires a medium through which to travel, but light does not.


A brief outline of key differences between light waves and sound waves:

Sound requires a medium (gas, liquid, air) to travel through. Light does not.
Light can also be treated as a particle, sound cannot.
How you calculate the energy of a sound, or light wave is also different. Light energy is related to the frequency (or wavelength, these two values are closely related) - "E=hf". The energy of a sound wave is related to it's amplitude (|a|2)and frequency.
The speed of sound is relative to the speed of the observer, while the speed of light is constant, regardless of the speed of the observer.
Sound is a pressure wave, a region of higher and lower densities in a material, moving through the material. Light is an oscillation in the strength of electrical and magnetic fields moving through space.
They are different types of waves, sound is a compression or longitudinal wave, light is a transverse wave."

[simpleacoustic]

Some nice info there @dirkwright,been very busy ,my reason for not replying earlier..
I've seen pa ,bms,faital pro,and beyma waveguides and they use a somewhat similar "lens shape"not sure if that's the right term but is a bit baffelled by the jbl's "waveformer" as it looks much simpler .I'm tryin to figure out why?
horn.jpg Waveformerp10.jpg