I'm in the market for a new PA and seriously interested in the K-series. I didn't find any retailer in my area able to demo them. I'm quite confident in the people who recommended the system, and in QSC as a brand, so I might eventuallly order a set blindfolded, but need some of my questions answered, and this is indeed one of them: the "throw".
I am familiar (being a sound professional with 30 years of experience (and a broken back, hence my interest in a smooth sounding, lightweight system)) with the basic physics of sound, so the above explanations are ok for me, except that things are quite a bit more complex than that, IHMO. On paper, everything is cool, but the original poster's real-world observation does make sense to me: some speakers "throw" further than others, it's a phenomenon I have observed many times, and it's a main concern for smaller bands with simple PA's that cannot afford to have a separate system for each type of venue.
Still, I'm a bit puzzled: metropaulitan, when you say your K10's don't reach over 40 feet, could you please elaborate? That's amazingly short. The old HK Audio Lucas 1000 I'm planning to replace with a K sytem does exactly that and that's just what my problem is: cool, smooth , non-agressive sound, quite hi-fi really (I hate the agressive mid-highs from most amplified plastic boxes) but is totally lost beyond 30/40 feet. But the Lucas is an older conception, and has a 3/4" HF driver, 8" MF driver, 200 watts tops; a single 600W 15" LF sub, and very agressive limiting which definitely helps to protect the speakers but ruins the sound. What sort of program material are you playing? What are your expectations? I hope I can expect (much) better from this modern, state-of-the art 4000W QSC system? I don't need ear-shattering, ground-shaking volumes at 100ft in open air, I'm looking for well-defined, well-balanced sound with good percussion in the bass for a alround pop-rock pub/function band that does 50/50 open-air/indoors gigs. Typically, outdoors, people dance in the 30-40 feet front area, and sit down an have a drink while listening in an area 40 to 100 feet from the stage. I want the sound to remain clear and well-balanced in that area too. I guess it's a quite standard situation, and expected the K-Series to be just perfect for this. In addition, the system should be confortable for the audience in indoor venues like pubs and bars where we are much closer to the public.
I initially thought that 2 K10's (and 2 KSubs) would cover this all. (I was quite sold on the K8's because of the wide dispersion angle, especially for pub/bar indoors gigs, but thought that for the typical outdoor gig I'd need to crank up the volume a bit to high and risk feedback due to the possible overlap with the stage area) But if what you say is true, and we'd need to add an additional delayed pair of K10's to go comfortably beyond 40 feet, I will need to change my mind.
So, what system to consider now? I'd appreciate your advice!
PS outdoors, I can eventuelly fly speakers up to 4 meters (16 ft) high