nickthevoice said:
I view in OLD commercial product many box with 8x 8 inch fullrange speaker. in ¨line array style¨
Yeah. And they didn't work too well either.
For example, let us assume that you have a driver centre-to-centre spacing of 8in. Lobing will begin from approximately 1.7KHz, and this will get progressively worse as frequency increases. That's just the laws of physics I'm afraid, & the reason most arrays have a separate tweeter line -preferably with ribbons, from a convenience point of view.
There are a couple of examples of line arrays using FR drivers. Roger Russel uses 25 3in Vifa drivers per channel in his IDS 25 speakers (lobing will begin at roughly 4.5KHz), and applies massive Eq to flatten the overall response trend. Darren Kuzma used 32 2in Tang Band tweeters in his smaller project -again, massive Eq is required to bring the top-end back up. Unfortunately, this does nothing about the phase problems such designs suffer from. They just have to hope you don't notice.
If you really must use FR drivers, I'd advise using a focused array, rather than a line array, with the front panel curved to focus the energy from the drivers onto a single point. That's about the least compromised thing you can do with FR drivers in a column.
