DISCLAIMER(S):

I know about and understand Jim's white paper. Actually I have sat though his array presentation as well as met him. Very nice and smart guy.

I realize the ISD-25 has some design flaws that make the price seem pretty "out there".

I am interested in this project because of the simple design and realtively high performance/cost ratio.

I know this design also needs active EQ for the same reason the IDS does.

I would prefer to build a design from Selah audio (and will eventually) but I do not have time to build the no holds barred enclosure that would go along with it.

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So this is what I had in mind...

http://www.madisound.com/cgi-bin/index.cgi?cart_id=1762089.15690&pid=1757

I need about 50 of these but there is a price break @ 100 pieces. $600 buys 100 of them. If someone is interested I would like to split a 100 piece purchase.

Parts Express has these but it is more pricey ($685/100). The Mad driver looks better though...

http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=299-015

I could not find any info for the PE Part but the Mad part has a PDF here:

http://www.madisound.com/pdf/aurasound/NS3-194-8E%20v2.pdf

I posted here first since it is a line array board (obviously) but also because it is neutral ground for the suppliers mentioned. I would appreciate it if you guys might spread the word as you see approriate. I frequent the PE board and watch the Mad board so if I do not get any interested people I will try those boards next.

Let me know what you think.

Thanks,
AaronD

If you read Jim's paper, and sat through his presentation, why would you deliberately do an expensive line array system when you know up front that serious and clearly audible comb filter distortion will kick in at 2700hz.

For heaven sake, put a dome tweeter in the middle of them and cross at 2700hz.

Marlboro

By doing that, he's able to make the comb filtering distortion appear lessened. I caution you not to try to make his version of the line array unless you are also willing to do considerable measurement, and then use either a 30 slider per channel constant Q equalizer(Rane preferably: looking at about $170 used on ebay), or a digital equalizer( price above $400) to make the comb filtering sound as if its not there.

Marlboro

A pair of arrays using 25 of the Aurasound drivers each will be $300 plus the cost of building the enclosures. Sounds like a fun project for that kind of money, but I doubt they can be used without a subwoofer, so if you don't already have one you have to factor that into the cost.

Go ahead and build a full range line array. You be amazed at the dynamics and power. I think that several 3-3.5" drivers are potential candidates for use in such an array. I like the HI Vi units (either the B3S or B3N available in either a square or round frame) and the Aura units (especially the N3-193-08) as the best compromise for a little bass.

Of course the highs will not be crisp as you'll realize nor should you expect much bass even with heavy equalization. You'll need a good EQ unit with the 31 band analog versions as the low cost EQ leader while a proper digital EQ like the Behringer DEQ2496 would be the entry point to higher fi. A subwoofer (or a stereo pair) will be needed if you wish for real bass. Having the ability to measure the frequency will be really nice so you can tweak to a specific target.

Everyone who wants to do a full range line array really needs to read about Darren Kuzma design in the Parts Express Showcase. It is at the associated link. Pay attention to the unequalized and equalized plots and decide if you like how they look.

Once you are hooked on this array, you want to build a two-way unit with better performance.

Jim

• Darren Kuzma Line Array Project

With a general purpose equalizer a DIY'er can do the same thing when they measure their unit and work to achieve their desired response. All the DIY'er would need to do is to record their set-up to have a 'proprietary' EQ response.

Jim, do you think this would require a 2/3, 1/3 or would require a full digital equalizer to replicate it for the DIYer?

Marlboro

Hard to say without having some data to study. Darren's project with 2" drivers responded well to a 31 band EQ for on axis. A 31 band EQ should be cheap but I like digital equalizers with parametric EQ capability the best.

Note that EQ can clean up the on axis response but look at the 30 degrees off axis plot for Darren's project to understand the shortcoming of a full range driver array. No way to recover this off-axis performance.

Jim

In no certain order:

I am planning on using a sub. In fact I am working on 2 18's that will be powered by a 500 watt Hafler amp. I think I have that covered.

EQ: I am planning on getting a DEQ2496. I have had one on my wish list for quite some time and would like to get one for use the RS8 array eventually. It seems that most agree the 2496 is adequate for this job too.

Lack of bass/highs. Bass is covered. When you buiild an aray for $300 in drivers you will sacrifice something, particularly in off axis response.

Different divers: I picked these Aura's based partly on price but also because they will do the job. I am sure there are better options but they will more likely improve the low end (which I do not really need) more so than the high end. The low end will (assuming) come at the cost of a larger enclosure and a fair amount more cash.

Adding a tweeter: I have considered it as a future option. If I do so I will simply mount it to the side of the existing array as close a possible to the line. I do have a pair of Fountek 3.0's that I got a good deal on that would work great. Definitely worth considering but that is another project for another day...

I want to build a set of nice speakers that will sound great for the small amount of $$ spent.

Now, does anyone want to go in half on 100 Aura drivers?

Thanks,
Aaron

Knowing that you may want better highs eventually, you might consider building it with a 35 inch slot for 30 Dayton Neo 20FA's per side. You can get them for about $3.50 each if you order 60 of them at once. You have to ask though. Then when you want to add crossovers and better highs, you're almost ready to go.

When i bought my Sammi's(3.5 inchers) two years ago, i bought just one, and compared it to my then current system. That consisted of a 1.25 inch audax soft dome tweeter, a Vifa BC-14SG49, and a Goldsound(not goldwood) 12 inch 15 mm x-max woofer. I took the woofer out of the circuit, and put the Sammi in a PVC tube . Without the woofer, the sammi was clearly more detailed than the vifa/audax combination on acoutic guitar. Of course when the volume needed to be turned up it lost, or the music got more complex. And when I connected the woofer and played it, anything with bass below 80hz made the Sammi lose. But i suspect that with 34 of them the story would have been different.

Marlboro