Nearfield Acoustics Pipedreams

Actually, Jflacken, I sold more pairs and spent more time with them than anyone I'm aware of.
Back in 1999 thru 2001, when I was managing Nicholson's Hifi in Nashville, TN, I brought the line in from Craig Oxford who was the owner of Nearfield and a Nashville resident.
Your questions, past 'has anyone heard them':

'What are the problems with line array.'
Great question--typically the problems are 'launch' issues, with multiple drivers stacked...in some cases 42 tweeters and 21 midrange drivers in such close proximity, the cancellation effects are said to create a comb filter.
That means that the response is really uneven 'looking like' a comb, up/down/up/down, in terms of amplitude.
That can be, is always disconcerting. There was 'supposedly' a remedy to this, though the remedy was never explained to me.
I did NOT hear this kind of problem, and I'm very tuned in to frequency response (neutral being my favorite).

'Crossover problem'
You're talking about the external crossover?
Early units did have 60 cycle issues, but that was quickly taken care of.

'What kind of amplification to use'
Pick the 'flavor' of sound that you prefer, (I won't go there). These are very revealing speakers, so the core sound that you pick will be what you hear.
The towers are VERY efficient, as I recall, mid ninties.
Once I used a Gryphon Callisto on the towers and various others on the bass units...the Gryphon bested, Ayre, Mac, Krell, conrad johnson, and it wasn't really close musically. That made me a lifetime Gryphon fan (well, that and the L1 Preamp from back in 1990--another story).

'Are the subs passive or powered'
My last answer made it clear, they're passive.

This is a very, very interesting speaker.
They are the MOST DYNAMIC speaker I've heard including many horns. Maybe not as 'fast dynamic' as some horns, but dynamic as hell!

They stage for me in such a way as to be the imaging champs of all time, placing instruments in a time and place in space--in front of, behind, beside...all over the room, with the towers being incidental to the sound.

They were, in my opinion, fantastic speakers when set up correctly.

Kenyonbm, said, "I might have thought I was on stage." I can't add to that.

Good luck and good listening.

Larry

Philjolet,
I would say that there is a real size differential in the sub diameter, versus the midrange diameters, therefore a possible speed issue...however.
That, and they cross over at 60 Hz as I recall.
Was it a perfect blend, NO, but in my opinion, outboard subs are never as seemless as single unit loudspeakers.
With very careful movement, (parts of an inch) back and forth, one can time/phase the speakers into a very seemless sound.
Not everyone can do it at first, but if one carefully listens, experiments and is dilligent, the work will be worth the effort.
Johnathan Valin, who is a dillitante of the first order, had a love affair with the Pipedreams some years ago. I'm forgetting the actual text quotes, but it was as real as Sandra Bullock and Jesse James, and lasted longer, I'm thinking.

If you trust his ears, (I do some times) read the review and use it as a guide.

These speakers, when set up carefully, correctly, can be magic.

good listening,
Larry

Darkmoebius,
It's funny--one sale inspires another, then another--so much so that it's feast or famine. People, and rightfully so are cautious when multiple 'anythings' appear for sale...I think its only happenstance.
The bulk of units, to my knowledge were sold from 1999 thru 2001 about a three year run. If that's the case, we're ten years down the road, the economy is slowly heating back up and some are looking to move up maybe.

They were well made--beautifully done cabinetry and NA employed really great QC.

I loved those speakers.

Larry

These speakers, IMHO, are some of the best ever created...I agree completely with Beemer's statements regarding 'scale' on large orchestral works.
They do what MBL's do, in terms of dynamics but with fractions of the power.
I'm not comparing them to one another...that's a longer, more detailed post.

Good listening,

Larry