"Line source" vs. "point source" speakers.

Can anybody explain the advantages and disadvantages of each? I've been intrugued by the Dali line of speakers. They claim that line source speakers remove room reflections from the sonic equation. I'd be interested in hearing what people have to think, particularly if they use this type of spaeker.

David Shapiro
I have Maggie 3.5's which are line source. They don't totally "remove room reflrctions from the equation", but they do take care of some of it. There are very little vertical reflections from floor and ceiling, which is nice. They do however throw sound to the side, just less than point source. The consequence of this however is a generally smaller sweet spot. But it is SWEET.
David, you need to clarify if you are looking for input stricly about "front firing line arrays" ( like the Dali primarily is ) or "full range dipolar line sources" as they are VERY different beasts. After all, the Dali is "front firing" for the lows and a good portion of the mids. It only becomes "dipolar" at frequencies above 1.2KHz.

I also think you need to clarify what you mean by "point source" i.e. single driver full range speakers or "standard" front firing multi-ways that are designed to work as a point source due to limited dispersion characteristics. A point source to me is a single driver or possibly a co-axial / tri-axial type driver. Others may think differently, but greater specificity would clear the air : ) Sean

PS... Someone from these forums asked me to check these speakers out for them a few months back. You should be aware that even though they use an active crossover between the cones and the ribbon, the ribbons are NOT "direct drive" from the amp. That is, everything above 1.2 KHz is fed to the ribbons courtesy of a capacitor. To me, this is a drastic mistake. I'm sure that they did this as a measure of protecton i.e. trying to keep DC voltages from a "leaky" amp from damaging the ribbons. These speakers are also of a rear ported design, so keep that in mind too.
Hi Sean,
You raise good points that truly didn't even occur to me. I guess that by "line source" I am referring to the Dali setup, while point source seems to be the ""standard" front firing multi-ways that are designed to work as a point source due to limited dispersion characteristics" that you mention. My info, so far, is derived from the Dali website, a pehaps somewhat biased source.

Deshapiro, sorry for the non related question but I'm curious about the sound of the Avalon Osiris: if I well remember you had a pair of these, right ? Why you decided to sell such beautiful speakers ? I have a pair of Radian hc now and I couldn't be more happy... Thanks.
I sold the Osiris speakers for a variety of reasons. The most compelling is that I'm moving to a smaller room, and they just wouldn't fit well, with the massive external crossover. Secondly, they are excellent speakers, but kind of laid back. While I'm not interested in horns, I'm gravitating to a more dynamic sound, as far as my taste is conc erned. So I'm investigating other options.

Thanks for your kind reply.