Ultimate line array

Short and Transmission Line Arrays for Pros
Post Reply
Message
Author
Rich4349
Posts: 776
Joined: Wed Jul 30, 2008 10:18 am
Location: Kankakee, IL

Ultimate line array

#1 Post by Rich4349 »

Other than cost and non-portability, , what would be the pros and cons of building an array that stretched from floor to ceiling? Would you need to power shade the drivers at each end, and what if you didn't?
2 DR250s, 2 27" Lab15 T-60s, 2 30" Neo Titan 39s, 1 Autotuba...and looking for more!

User avatar
Bill Fitzmaurice
Site Admin
Posts: 28197
Joined: Tue May 02, 2006 5:59 pm

Re: Ultimate line array

#2 Post by Bill Fitzmaurice »

Power shading is used in pro sound to send higher levels to the furthest reaches while not being overly loud up close. There's no need for it in a home or even a medium sized club. I don't see any particular advantage to a floor to ceiling array in a home.

Grant Bunter
Posts: 6761
Joined: Mon Nov 28, 2011 11:12 am
Location: Ilfracombe Queensland Australia
Contact:

Re: Ultimate line array

#3 Post by Grant Bunter »

A few things spring to mind, but not by all means exhaustive.

Pros:
As line height increases, pattern control increases and sensitivity rises.
Cons:
The taller the cab, the harder it becomes to keep it structurally stable (especially with torsion).
No one can directly hear the uppermost speakers closest to the ceiling. So are they required?
Manipulating impedance.

Power shading:
So you go to a concert and see a J array flying. If the bottom cab or two, aimed pretty much at the front row(s), were at the same volume as the rest of the cabs pointed further away down the room, the front row(s) audience may have a horrible concert experience, and suffer ear fatigue. Turn those bottom cabs down (ie powershade) and problem solved.

I don't think that applies in a home line array, esp floor to ceiling.
The speakers are in a line, not curved at all. So no need to power shade the lowest (or highest) speakers...
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" BP102 , 2 x 28" 3012lf.
WH8: x 6 with melded array wired series/parallel.
Bunter's Audio and Lighting "like"s would be most appreciated...

Rich4349
Posts: 776
Joined: Wed Jul 30, 2008 10:18 am
Location: Kankakee, IL

Re: Ultimate line array

#4 Post by Rich4349 »

With each doubling of drivers you get greater efficiency, right? With this you demand less of each driver, and of the amp. (Proper, matched impedance assumed.)

Does sound quality increase with less demand? Or just the inverse:
Greater demand, in excess of design parameters, will add distortion. But within the parameters, does less demand cause higher fidelity?

Is there some narrow sweet spot of power consumption for minimum distortion?

Does this vary from design to design or manufacturer to manufacturer?

Maybe this is part of the reason the SLA / TLAH designs don't need very high end drivers?

Maybe I'm asking too many questions? 😆
2 DR250s, 2 27" Lab15 T-60s, 2 30" Neo Titan 39s, 1 Autotuba...and looking for more!

User avatar
Bill Fitzmaurice
Site Admin
Posts: 28197
Joined: Tue May 02, 2006 5:59 pm

Re: Ultimate line array

#5 Post by Bill Fitzmaurice »

As you add drivers you get higher sensitivity along with lower per driver excursion for a given SPL, which lowers the THD sourced from both the amp and the speaker. It also eliminates the need for high power handling and long xmax, which reduces driver cost. But there is a point of diminishing returns. For instance, going from one driver to nine gives a maximum SPL increase of better than 18dB. But going from nine to eighteen only gets an additional 6dB. It would be the unusual living room or HT that would need that 6dB or justify doubling the cost.

Post Reply