Remember that Russel is not using just any old equalizer, its a specialized equalizer designed specifically for the speakers that he uses. You can't reproduce his equalizer. When you are done with all the hole cutting and all the work, you'd probably be better off with a point source speaker system with high quality speakers.

I say that if you have all that money to throw away, and all that time to throw away, Heck! go for it. Just don't come back and complain later that there don't seem to be any highs, and that you just don't have any bass.

When I built my three way electronically crossed Tri-amped line array, I turned it on with just the wide range 3.5 inch mid ranges, first. It was fabulous! And then I added the tweeters and then the bass, and discovered how I was deluded by the low distortion in the mid range, the dynamic range, and the giant sound stage. What I didn't have was any highs above 6000 nor any lows below 200.

Good luck.

Marlboro

http://pub48.bravenet.com/photocenter/album.php?usernum=4095425731&album=48032

In many applications you may be very happy with the outcome. Just leave room for the Tweeter, so that you can update the design later. X-overs are not so difficult if you get the Behringer analog x-over.

The problem is that the waves cancel when one driver 1/2 wavelength farther from the ear than the other. At 10k hz this is .67", 5k would be 1.34, 2.5k would be 2.6". Also the sound will drop off faster at the higher Fq.

The applet called "the edge" is great for visualizing diffraction effects. You can see how 2 point sources create a null zone.

If you have a favorite spot that you like to sit in you could focus the array. This will place all the drivers the same distance from the ear.

-Linc

Driver selection will be important. I wouldn't use anything larger than 3" or fewer than 16 drivers per side. As you said, some equalization will be needed, and you should also plan to use a subwoofer with them. If you're on a tight budget the Behringer DEQ2496 might be a good choice for equalization.

If I were building a pair I would shy away from inexpensive drivers. An array reduced the excursion-related distortion of a driver but it doesn't change the sonic signature. Some of the Tang Band drivers with neo magnets like the W3-1346S seem to be good candidates.

Its possible that you have not actually built a line array using dome tweeters so you may be simply parroting Jim's best numbers. The reality is that it is impossible to do a 1/2 wavelength in dome tweeters with any known available tweeters. You can use 3/4 inch ND20A;s and cut the flanges so that the c-to-c distance is .91 or so.

PE's newer 1/2 inch domes were not available when i built the system, and they might work. However their FR and other characteristics are rather inferior to the ND20A .75 inchers, IMO.

I have done this. According to my figures, comb filter distortion doesn't begin to kick in for people in stationary listening positions until above 15Khz. While some people may experience lack of air here I don't. I used 30 ND20A's cut to my specs crossing at 2400hz in each channel(60 total).

Sound is fabulous. I discussed the design with Jim Griffin as I was building it. While I could use tone controls or the system DOD constant Q 1/2 octave equalizer to boost the high frequencies to compensate for any comb filter distortion there is no need to do so. It is important to Tri-amp the system, though, to get full value from your tweeter array.

Marlboro

• Calipso Line Array Speakers

I would have expected the 7" Dayton RS drivers to sound very good in an array. I built an MTM using these drivers and it sounds very good. I wonder if your RS8 array doesn't need more bsc for its placement in your room. Some speakers that sound very warm in my smaller upstairs listening room sound a bit bass shy in the much larger downstairs room with hardwood floors, lots of glass, etc.

Like I suggested, you'll probably like many charactristics of a single driver array, but at some point you my find yourself wishing for a tweeter array to make it perfect. Just my two cents based on my hearing the single driver arrays at the RMAF.