What’s the buzz with Line Array?

nick parkin

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greetings!

I was thinking about building a line array setup and wanted to know the benefits and why they seem to sound so good. Can anyone give me some insight or possibly point me to a source about line array speakers?
 
Line arrays put all the drivers in a vertical line (obviously) — it's the closest thing to a point-source, which would be a single full-range driver, or drivers mounted concentrically.

They're more "accurate" than old-fashioned designs where the drivers are in different places on the baffle; on these older designs the sounds come from slightly different locations and don't cohere as well into a single "image".

Line arrays also allow a narrower baffle — this reduces "edge-effects", diffraction, and certain other distortions — and their narrowness makes them less prone to resonate. They also have a taller, thinner appearance which is in vogue these days (Super Models are also tall and thin, and also in Vogue). The woofer(s), which must be bigger to produce deep bass, are usually put on the side(s) of the cabinet. This makes a line-array cabinet deeper. It also defeats the "line source" principle, but it doesn't matter so much with deep bass: they say bass below 100Hz can't be "located" by the ears. Though the smaller baffles are less prone to resonate, the larger sides do resonate, so internal bracing is needed.

Imaging is improved. An analogy would be two sharp eyes (20/20 vision) focusing to define a single image more clearly than two blurry eyes.

These are some of the arguments in favor of a line array. But your statement that they "sound so good" is a subjective opinion.
 
diyaudio has a few good reads on the line source. I've spent countless hours reading over there. I'd say if your thinking about it, it's a good place to start. Some amazing examples too.
 
I believe the best known performance characteristic of a true line-source is the restricted vertical dispersion and the wide horizontal dispersion. Makes for good clarity and yet good coverage, too.
 
I've never seen a line-source with two line arrays on the same baffle, covering the same frequency band. Me thinks that is no longer a line-source at the frequencies covered by the larger drivers.
 
I've never seen a line-source with two line arrays on the same baffle, covering the same frequency band. Me thinks that is no longer a line-source at the frequencies covered by the larger drivers.
Agree. The objective when using multiple drivers is to place them as close as possible to minimize comb filter effects which would clearly be exhibited with the linked design. Spacing of the midranges producing four inch wavelengths appears to be about a foot. I think more of designs like Roger Russell's IDS-25:

ids.jpg

And more exotic Scaenas like this pair that I've heard on several occasions:

scaena.jpg

I've been a line source fancier since I was a teenager. I prefer, however, dipolar flavors that tend to reduce room modes. I see the main advantages being realistic image size, coherence and reduced output variation regardless of distance.
 
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I prefer, however, dipolar flavors that tend to reduce room modes. I see the main advantages being realistic image size, coherence and reduced output variation regardless of distance.
... as your name suggests. I too prefer electrostatics. I've owned four 'static "flavors"; judging from previous posts, you've had more, and more exotic types.

What is your experience with dynamic drivers, arrayed to produce a dipolar effect? A line-array, for instance, could be dipolar if designed that way — and BTW, can you settle my mind once and for all on the difference between di- and bi-polar? Which is in-phase, which is reverse-phase?

I'm currently using box speakers, which reproduce instrumental tone exceptionally well, but I miss the dimensionality of 'statics (though that's not one of their virtues you list). I have matching spare drivers I could put to use. This would no doubt require crossover changes, and I know nothing of crossover design.

Your thinking on this would be valuable.
 
Maggies, ESL's and open baffles are dipolar. The rear wave is 180 degrees out of phase with the front wave.

Bipolar speakers (some Def Techs) are closer to a pulsating sphere as the rear wave is in phase with the front wave
 
Line source sound also doesn't fall off with distance the same as a point source. While this doesn't sound like a very important comment, what it means is it projects into the room differently.

Di-polar means different phase front to the back. Or a driver moving into free air.

Bi-polar is when drivers are moving the opposite directions with the same phase. As in the drivers on the opposite sides of a box driven with the same phase...like a Bose 901 does.

Also, I find the sonics of a line array to differ greatly depending on if it's attempted to be contained within a box...or run open baffle and getting the benefits of di-polar sonics.

EV3
 
What is your experience with dynamic drivers, arrayed to produce a dipolar effect?
Zilch. I've heard dipolar ribbon based speakers like the Infinity Reference System with drivers mounted on both sides of the baffle, but am not aware of a bipolar line array using dynamic drivers. The popular Linkwitz Orion family is a point source design.

and BTW, can you settle my mind once and for all on the difference between di- and bi-polar? Which is in-phase, which is reverse-phase?
Dipoles radiate the same signal at 180 degrees reverse phase. When one side blows, the other sucks. Bipoles are typically used for home theater surrounds with both drivers in phase radiating at different angles and have an AR-LST-like appearance. Here's an example:

focal.jpg

I'm currently using box speakers, which reproduce instrumental tone exceptionally well, but I miss the dimensionality of 'statics (though that's not one of their virtues you list). I have matching spare drivers I could put to use. This would no doubt require crossover changes, and I know nothing of crossover design
One approach would be to adapt them to an open baffle. Some drivers are open backed and inherently are dipolar while you typically need opposing drivers for tweeters. Have you spent any time on the Linkwitz website? There's a lot of good information to be found there.
 
Well I’m buying a lot of vintage Zenith drivers and I figure 6 of thr 12” woofers in each side would do. My room is not super big though. I’m not sure how such a large backwave would do (I’m going open baffle) in a small ish room.
 
6 x 12" woofers per side in a smaller room!? That's a lot of cone area to deal with. I suggest you take a look at the woofer towers for the Infinity IRS-V's.
 
6 x 12" woofers per side in a smaller room!? That's a lot of cone area to deal with. I suggest you take a look at the woofer towers for the Infinity IRS-V's.
I’ve heard all about it im a big fan of Paul from PS audio who tells us all about them on his YouTube channel!
 
The challenge I found with Arnie's IRS and Genesis designs was that of blending the servo woofer towers with the mains. To me, each part sounded exceptional individually but seemed to belong to a different speaker.

Of other large scale mains/tower designs, I found that Carl Marchisotto was more successful with the Nola Grand Reference as was Mark Porzilli with the big Scaena 1.6 (pic above).
 
Line arrays produce a different sound wave compared to other types of speakers. they produce a sound wave in the shape of a cylinder, rather then shaped like a horn. Lessens reflections from floors and ceilings, along with being able to maintain sound db levels further out with less loss and less distortion. Their is a lot positive about them, just google, to read about all the benefits.
 
The challenge I found with Arnie's IRS and Genesis designs was that of blending the servo woofer towers with the mains. To me, each part sounded exceptional individually but seemed to belong to a different speaker.

Of other large scale mains/tower designs, I found that Carl Marchisotto was more successful with the Nola Grand Reference as was Mark Porzilli with the big Scaena 1.6 (pic above).

That is why Arnie's design has the bass drivers in different cabinets than the hi and mid drivers. Being able to have infinite adjustability depending on listening rooms allows the users to find the perfect position to make sure the sound waves arrive at the precise time is imperative. I own the RS-1bs which are basically mini IRS V's and it does take a lot of time and effort to get that time alignment correct. I don't think any speaker can be considered perfect, in that no compromises are made, but really if you have the room, the equipment, and the willingness to spend the time setting it up, not to mention money they sure can be impressive.
 
That is why Arnie's design has the bass drivers in different cabinets than the hi and mid drivers.
Like both the other designs I mentioned.

it does take a lot of time and effort to get that time alignment correct.
I heard them at Sea Cliff where Nudell himself helped with Harry's setup.

I don't think any speaker can be considered perfect
Most definitely agree. As for me, my passion for coherence led me in a different direction. :)
 
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I went down the line array rabbit hole designing a speaker to use the old Pioneer NSB drivers that I came into a pile of. Haven't built em yet due to other things taking up shop time but if you want to read my discovery process, here it is. I'm not saying it's outstanding reference material. :cool: But it does sort of go through the various issues that came up and how I learned about them. There's a lot to it. Comb filtering, baffle step, power tapering, all kinds of stuff.

http://audiokarma.org/forums/index.php?threads/nsb-line-array-project.764445/
 
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