LINE ARRAY question ?

Hello :)


I have one question about the number of tweeter for LINE ARRAY.


I don't understand why put the same number of tweeter and woofer in LINE ARRAY loudpseaker.

Why not make SINGLE TWEETER LINE ARRAY with the tweeter at the best Height ?

The tweeter is VERY DIRECTIONAL
For this reason if I put tweeter at seven feet height or at the floor I don't listening


Thanks ! ;)

nicK
 

gtforme00

Member
2004-10-21 4:35 am
The number of tweeters used is chosen as follows:

First, the length of the tweeter array is chosen. If operating in the near field, see Figure 5 in Dr. Griffin's Near Field Line Array White Paper. Then, the number of tweeters is chosen to 1. sufficiently fill that length while maintaining the closest center to center spacing possible and 2. present a load which can be wired for the desired impedance. Thus, one may choose a 42" - 35 tweeter array based on nearfield criterion, but decide to round up the number of tweeters to 36 for wiring purposes.

The arrays using a full length tweeter array to which you seem to be referring do so somewhat unnecessarily, as one could get away with a shorter tweeter array while maintaining the nearfield listening position. That is not to say that they are worse, just that they are more complicated and expensive than need be.

If you have not read the paper linked to above, it would be in your best interest to do so as it is an invaluable resource for practical nearfield arrays.

Regards,
David
 

gtforme00

Member
2004-10-21 4:35 am
How long was the tweeter? Directionality is a function of aperture size. It is possible to have a 48" planar tweeter that would act as a "single" line array tweeter, but it is not possible to have a full bandwidth line array with one 1" dome tweeter as the upper frequency array. The arrays which you have seen with one single tweeter and an array of woofers are not directional in the upper frequencies. Such arrays are hybrids of the line array theory and seek to increase the acoustic efficiency and directionality of the bass frequencies, typically to be compatible with low powered amplification.