Multiple Drivers to Increase Efficiency

[SteveG]

oops... sorry. I'll have to turn that back on.
sixtyfive455@netscape.net

Steve

[roddyama]

Dice45,

Here Here, I third that motion.

I too would love to hear a Jordan line array. I have a pair of 10" mid-basses in an over-under arrangement. Just did it recently from a single. The jury is still out on the sound, but it's not bad.

Rodd Yamashita

[roddyama]

SteveG,

Started to read the paper. Absolutely!!

The point I'd like to emphasis is the increase in accuracy you get when using mulitple drivers in a single frequency band. This, to me is the real payoff of multiple driver systems. The difficulty of the task a driver has in trying to follow its driving signal is sorely underestimated. This situation is made worse by the trend toward long excursion drivers.

The driver will always distrort the driving signal. The farther the cone has to travel, the greater will be the distortion. The resistance to the cones motion caused by the surround and spider is non-linear. This will serve to compress the waveform being produced. Each time you double the the number of drivers reproducing a given range, you more then halve the required excursion (more then half because depending on the frequency and distance between the drivers, you get the advantage of some level of mutual coupling of the drivers). This provides the benefits of greater accuracy and dynamics. The difference is readily apparent.

I once bought 24 4" drivers for $2 each from the old Olsuns Electronics just before they gave way to the Shack. I made an 8 driver per side di-pole (open back, baffle only) array from a couple of pieces of plywood. They sounded like Maggies (not many ribbons around back then). It was so cool in my apartment with my subs. I used them for nearly a year. Try it, it easy, cheap, and you'll be amazed.

Or not.

Rodd Yamashita

[Doug]

Mark;

Here is a link that explains comb filtering more accurately.

Doug

http://www.webref.org/acoustics/c/comb_filter.htm