How can I help my LA with short tweeter array?

[GuyPanico]

I got my NSB line array up and working just yesterday. So far i'm pleased. My only problem is when I move above or below my tweeter line, the sound turns dull. Unfortunantly my tweeter line is only about 18" long. So I'm thinking of shortening and/or power tapering the mids.

I'm using a 2nd order LW @ ~3425hz. Perhaps crossing higher might help the situation as well.

I'm just happy I finally got this tall beasts working finally!

[ralph-bway]

Hi,

I built an array with 9 NSBs and 4 Onkyos per side. I let the NSBs run full and filtered the Onkyos to run above 8500hz (1st order).

I treated the cones of the NSB's with puzzle coat & cut a 1/4 hole in the center of the dustcap. From listening alone they sound fine. The high end is crisp without being shrilly.

A lot of people here know more than me and hopefully they'll chime in, but IMO one of two things will help your problem

1. Change your XO to something much higher.

2. I see you have 9 tweeters, add 7 tweeters (6 above and 1 below the 9 that are there) to get the same ohm load.

I relly like how you back mounted the NSBs, that's exactly how I'm going to mount my next NSB project.

Best,
Ralph

[Scottmoose]

The only true fix is to add more tweeters. Power tapering won't help much -that's just to fix the fractional time delay problem caused by the drivers toward the ends of the line being slightly further away from the listening position than those in the centre. Applied to the mids you might get a fractional improvement, and it's always worth trying anyway, as it costs nothing except time. But more tweeters is, really, you're only genuine solution. Agreed though -they look excellent so far.

Best
Scott

[thylantyr]

Originally posted by GuyPanico
I got my NSB line array up and working just yesterday. So far i'm pleased. My only problem is when I move above or below my tweeter line, the sound turns dull. Unfortunantly my tweeter line is only about 18" long. So I'm thinking of shortening and/or power tapering the mids.

I'm using a 2nd order LW @ ~3425hz. Perhaps crossing higher might help the situation as well.

I'm just happy I finally got this tall beasts working finally!

My line array experiments I find the tweeter to be the
heart and soul of the sound system. If you compromised the
tweeter solution too much the sound suffers. If you do less
compromises on the tweeter solution, the sound quality improves
and there is less focus on the NSB's. For example, if you substitute
those tweeters with a full PT2 planar line and lower your crossover,
the sound quality improves as the tweeter line defines the SQ
and the NSB only plays the support role.

I found the best crossover settings to be;
PT2/NSB - 1.7khz LR 8th order.

Second choice;
PT2/NSB - 2.5khz LR 4th order.

{+/-250hz}

Different between the LR 4th and LR 8th order was better SQ
and imaging and the steeper slope helps reduce distortion when
you push the system to higher SPL levels.

If I raise the crossover frequency on this system the sound quality
becomes bland and imaging degrades. It's not bad, but it's not
as sweet.

Your findings support what I said. You are realizing that your
partial line of tweeters is the bottleneck and not
your NSB's.

NSB's are very good in an array but you can't skimp on the
tweeter solutions, they are very important too!

Going active with the steep slope using a DCX2496 takes the
array to new heights in performance.

Sum of all parts[tm]