Re: Array driver question

Posted by Jim Griffin [ 12.180.247.169 ] on April 19, 2006 at 21:51:30:

In Reply to: Re: Array driver question posted by Jose on April 19, 2006 at 08:17:50:

Jose,

The Nola design concept puts you into a 4-way speaker design (the Nola tower is a 3-way) if you add external subwoofers. Now you could integrate the subs with external crossovers or a set of plate amps with integral crossovers. What I'm suggesting is a 2-way line array tower which would be augmented by separate subs so it is a 3-way overall design. To me a 3-way would be easier to get sounding correctly vs. a 4-way but to each his own on how much you wish to attempt. With an active crossover you can certainly get closer to perfection vs. a passive crossover.

On the dipolar section akin to the Nola design or a dipolar line array: You would really need the 4-way design if you use the Nola design concept. A dipole line array would take more equalization and such as you realize and the choice of midrange drivers would likely be a concern. By that I mean that you generally need a larger mid-range driver--Linkwitz uses an 8" driver in his Orion model--for a dipolar as you need more augmentation for the lower frequencies. Other people widen the baffle face to help lower the dipolar shortcircuit. Now the Nola concept uses boxed woofers to mitigate this concern so they get by with 4" (or a 4.5") drivers for the mid-ranges. If you add the woofers as they do in their approach, then you could get by with the dipolar mids. But I question what benefit would be to just have a dipole midrange while the rest of the speaker acts as a monopole?

In my case I favor a sealed box for the mids which means that you can expect acceptable bass with a reasonable enclosure size and you have the freedom to use the mids low enough to eliminate the woofers. Sealed mids would integrate very easily with subs. Thus I favor using the mid range drivers down into the 80-100 Hz range with a monopolar enclsoure over the entire frequency band.