Line Array problems *PIC*

[fiddletaker]

This project was started out reading that column speakers had a cylinder shaped sound wave pattern radiating 360. So after making a pair, and installing tweeters in the sides and back, and planning on using them biamped at 300hz up they did'nt turn out as planned, off axis they sound invisible and very nice but out front they turn into monsters that'll cut your ears off. I havn't make grills yet and just maybe thick foam baffles should do the trick. Any suggestions? oh the speakers are mounted in a clear baffle and not just floating in midair.

[thehammer]

I'm not a line array expert but I see a couple of issues. First off, line arrays do not have a 360 degree radiation pattern. What they do have, within some limitations, is a cylindrical 2pi wave front as opposed to a circular or conical wavefront of a point source. The polar (360 degree) pattern of a typical forward facing array is largely a factor of frequency and the diameter of the driver.

Secondly, With the tweeters mounted on the back and side you have no on-axis sound from the tweeters which greatly reduce their apparent output. Additionally, those low end drivers look like NSB's (49 cent PE specials) Correct? If so, those are noted for their "shoutiness" (thanks Dan) that needs to be accounted for in the crossover.

> This project was started out reading that
> column speakers had a cylinder shaped sound
> wave pattern radiating 360. So after making
> a pair, and installing tweeters in the sides
> and back, and planning on using them biamped
> at 300hz up they did'nt turn out as planned,
> off axis they sound invisible and very nice
> but out front they turn into monsters
> that'll cut your ears off. I havn't make
> grills yet and just maybe thick foam baffles
> should do the trick. Any suggestions? oh the
> speakers are mounted in a clear baffle and
> not just floating in midair.

[fiddletaker]

> I'm not a line array expert but I see a
> couple of issues. First off, line arrays do
> not have a 360 degree radiation pattern.
> What they do have, within some limitations,
> is a cylindrical 2pi wave front as opposed
> to a circular or conical wavefront of a
> point source. The polar (360 degree) pattern
> of a typical forward facing array is largely
> a factor of frequency and the diameter of
> the driver.

> Secondly, With the tweeters mounted on the
> back and side you have no on-axis sound from
> the tweeters which greatly reduce their
> apparent output. Additionally, those low end
> drivers look like NSB's (49 cent PE
> specials) Correct? If so, those are noted
> for their "shoutiness" (thanks
> Dan) that needs to be accounted for in the
> crossover.
This speaker is a beamer and not omni as I have been misinformed. It has been suggested to use it up high in a PA system stack were some Line array systems are used.
The drivers are 4" akai with large voice coils and magnets almost as big as the cones, Don't know what were intended for, but they had to mounted from behind hince the plastic baffle ( my hole saws would not cut aluminum plate. and did'nt want to sink them deep in a wood panel)

You have good points, the tweeters will be moved or left out. And the drivers may be a bit peaky.