Highend64: An amplifier that is bandwidth limited to just above 20 KHz will show "rounding" of the leading edge of a square wave at appr 2 KHz. That is a distortion as far as i'm concerned as it is not replicating the input signal. Passing a sine wave can be "gravy" but square waves are much faster, require greater linearity and are closer to the dynamic impulses that we call "music".
Cdc: Line arrays are like any other speaker i.e. they have some advantages and some disadvantages. If done correctly, they can have some very strong advantages such as increased power handling, lower distortion due to reduced excursion, high spl capacity, sustained spl levels at greater distances, etc... Obviously, this design works best if not sitting right on top of the speakers.
If i can ever get my act together, i've got a very large line array that i'm working on for a friend's system. He is brutal on audio equipment to say the least, so after thinking about it, i decided on a line array for the above reasons. The mains ( this is a combo 2 channel / HT system ) will consist of thirty six tweeters, eighteen 4" mid-woofers and eight 12" woofers per side. This is a "budget" project in terms of the drivers selected, but i'm trying to do the best i can for him and his specific system needs and give him something that sounds pretty decent, will hold up to the chronic abuse that he dishes out and can literally shake the house on demand.
As such, i've had to do some studying on the subject and am learning more as i go along. One thing is for sure though, crossovers need to be done actively OR passively at a very sharp slope rate if you want to avoid comb filter based problems. I've been able to learn quite a bit about this subject courtesy of the "speaker nuts" on Madisound and their own personal websites that they have provided links to.
If i'm lucky, i may be able to get these speakers done in a few months. As you might guess, it is going to be VERY labor intensive in terms of just cutting all of the holes let alone installing and wiring all of the drivers. To top it off, i've got to do a center and two surrounds for him too. Needless to say, the other speakers will NOT be anywhere near as big as the mains but they will all make use of identical multiple drivers in order to maintain consisting "voicing" within the system.
As far as using a transformer between an amp and speakers, i don't like the idea unless it is a necessity. I personally prefer active multi-amping as this allows one to bypass passive components between the amp and individual speaker drivers. It has been my experience that "direct drive" sounds far more natural and dynamic than what you can get out of even the very best passive crossovers. Sean
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