I'm assuming I'm the Jim that you paged.

You did not say what you had in mind with the Fostex Fe87. Are you thinking of a full range line array with this driver used without tweeters? Or is this a 'woofer' line candidate with a line of tweeters to cover the high end?

I generally don't recommend a full range driver line array because of the issues with comb lines (worst effect is the loss of directivity or sensitivity as frequency increases). This means the only way to get there is to use heavy equalization (see the November 2005 AudioExpress Roger Russell article on his full range driver line array) or go read about Darren Kuzma's array at:
http://www.partsexpress.com/projectshowcase/Kuze3201/Kuze3201.html

Notice the performance plots with and without equalization.

As a woofer the FE87 isn't much help. The Xmax is 0.4 mm while fs is 140 Hz. You not likely to get much (if any) low frequency out of this driver.

A better way to go is to use a two-way array with a small 4-7 inch diameter woofer and a tweeter line of planar or ribbons.

Any thoughts from you on what you have in mind?

Jim

• Near Field Line Array White Paper