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[Scott Holtzman]

That was an idea, and yes I can measure distances, nothing is active, everything is passive, subwoofers are Void Stasys all.  The array tops are made by me , but I was curious if anyone had tried this placement.

Being passive doesn't bring anything to the table, nor does all being the same.  Home built tops I will reserve judgment on but it's hard to be an acoustic engineer and structural by yourself, then tune the boxes and produce something better than the usual suspects. 

[Steve Eudaly]

I'm going to guess this if for a DJ gig so low-frequency directivity is probably not the highest priority, in which case, I'd say just make a pile with your four subs in the middle (2 over 2). This will give you the most even coverage across the space and eliminate the need for multiple channels of DSP to do a virtual arc delay.

If your other two subs that were being used as risers for your mains are also the same model, then go ahead and throw them in the pile (3 stacks of 2, all touching and in the center) and use something else on stage to get your mains up in the air (stands, scaffolding, stage decks, whatever).

You'll get a lot of LF spill back on to the stage but in my experience that's typically a positive thing for modern DJs (not so good for old-school vinyl setups).

[Ivan Beaver]

At one time (for a long time) a positive voltage in a JBL sub caused the cone to move inward when with almost every other brand sub, a positive voltage caused the cone to move outward.  With two subs side by side, the bass would be mostly canceled due to the 180-degree phase differences.

I learned that the hard way.

Many moons and decades ago, at my first "big gig" I brought out my whole system.  The subs were 4 W bins that half were EV and half were JBL loaded.

When I fired it up there was almost no bass, so I turned it up.  After a little bit I had no subs, they were all blown. 

THe guy doing the lighting (who also had his own sound company) help me swap drivers (I had brought some spares just in case) and he said "did you know your JBL speakers were wired up backwards?"  I said they were wired up correctly (thinking that red meant positive).

He said "when you get them reconed, check the polarity with a battery".

That was an expensive lesson, but it put me on a better path.

Oh what I have learned since those days------------

[Nick Tims]

Being passive doesn't bring anything to the table, nor does all being the same.  Home built tops I will reserve judgment on but it's hard to be an acoustic engineer and structural by yourself, then tune the boxes and produce something better than the usual suspects.

I havWhy do you find it impossible to make line array systems I often see people who comment that it doesn't sound like it doesn't work, before array I used and built various enclosures, I never failed with them, I have over 300 live festivals, only now I started working with line array and studied them,  Special horn deflections etc After all, the line array is not so special compared to classic systems, but you have to have a lot to make the array to be at 100 Hz. So they won't sound unless you put something weak in them and the construction is bad.

[Robert Lunceford]

I havWhy do you find it impossible to make line array systems I often see people who comment that it doesn't sound like it doesn't work, before array I used and built various enclosures, I never failed with them, I have over 300 live festivals, only now I started working with line array and studied them,  Special horn deflections etc After all, the line array is not so special compared to classic systems, but you have to have a lot to make the array to be at 100 Hz. So they won't sound unless you put something weak in them and the construction is bad.

Stacking two speakers, as shown in your drawing, does not make a line array.

[Tim McCulloch]

Stacking two speakers, as shown in your drawing, does not make a line array.

Line? 2 boxes doesn't even make hyphen or a dash, let alone a line array.

[Nick Tims]

Who said that? I said tops are array And yes you need minimum 4 pieces, but how jbl vrx or l acoustics kiva They sell systems like that and nobody complains about the sound. Especially even 2 charts throw more than point source, comparison made with ev Eliminator, Qsc, Jbl, RCF NX etc

[Doug Jane]

Who said that? I said tops are array And yes you need minimum 4 pieces, but how jbl vrx or l acoustics kiva They sell systems like that and nobody complains about the sound. Especially even 2 charts throw more than point source, comparison made with ev Eliminator, Qsc, Jbl, RCF NX etc

You really dont know much about pa do you? You need to do a lot of study, and then maybe come back.
Or hopefully your study will give you the answers you need. Several people here have given you good answers, but no, you dont listen and learn.

[Ivan Beaver]

Especially even 2 charts throw more than point source, comparison made with ev Eliminator, Qsc, Jbl, RCF NX etc

I assume this is a typo-or else I don't understand what you are trying to say.

But multiple boxes will not "throw" (in the classical sense of intelligibility/clarity at a distance) as well as a single box (assuming they both start out at the same level) because of the interference that happens with more than one device covering the same area, ie comb filtering.

The interference of multiple boxes is what causes the sound to fall apart at a distance, NOT add together or "throw" better.

[Nick Tims]

For example, Martin Audio W8VDQ combines line array and differential dispersion technologies to provide an advanced solution to the requirement of even coverage over wide angles and throw distances. Short throw horizontal dispersion is 120º, narrowing to 100º as throw increases. Let's see what you have to say, there is also QSC KLA, L Acoustics Kiva, Jbl VRX etc

[ProSoundWeb Community]