One look at the FR tells the story...
...Not one
bit. Frequency response on a baffle changes entirely, and then again with the addition of a floor, and then many times again in a room. You also have to realize, is that after a crossover, response changes altogether. A driver like the Seas Excel W15 does NOT look flat but who cares, if it's going to be crossed over anyways?
You also have to consider how we hear.
We don't hear anechoic frequency response. What anechoic FR tells us, is freedom from resonances, and it has to have high resolution @ 1/12th octave otherwise it's a marketing graph.
When you put yourself in a room, you hear a careful combination of quick arriving response, but also reflected response.
The fact is, to get the same wide horizontal dispersion out of the 6.5" Accuton, that you're getting out of the narrow Neo 8, you need to cross the accuton over near 800-1khz (just guessing here). How many tweeters can play that low? Certainly not a ribbon, so now you've lost your awesome world class RAAL tweeter. And if you're crossing it that low, then what's the point of using ceramic? Why not use a paper driver and get some boost in sensitivity?
Okay, let's talk about the 4.5" accuton. It can play higher with similar horizontal dispersion, but still not
as wide. You probably still want to cross it around 1.5khz or so. How many tweeters can play that low. Still not a RAAL 70-10D. Its big brother the 70-20D can play down to 1.8khz like the Salk Soundscape.
The crossover for the Philharmonics is near 2.8khz to the RAAL 70-10D (I swear the questions in this thread have made me analyze these speakers way more than any other speaker ever
) Either of the above accutons would, as Dennis stated,
in FACT be inferior at this frequency. Just because they're flat, doesn't mean the sound being radiated into the ROOM and then reflected back, is nearly as balanced. The narrower than accuton vertical dispersion of the Neo8 may be beneficial as well at this frequency in many rooms, because the ceiling/floor reflections' intensity is reduced - and those are the strongest and earliest and offensive reflections!
Not to mention that for an open back design, having a giant motor behind the cone can't be great for even response exiting the back of the tube.
You can't look at the price of the accuton and make any conclusion. Make that conclusion with your ears, level matched, in the same room, with the appropriate crossover and preferably with a blind fold on to take away bias. Forget DIYers measured harmonic distortion too. Chances are it'll be masked by the audio content which has its own harmonic content. You can't normally compare world class drivers with harmonic distortion numbers... that's like comparing amplifiers with H.D. numbers.
there's parameters where the accuton is a more desirable driver. It's been discussed in this thread many times. The Neo8 won't mate to a 12" metal woofer. But it's not being mated to one. It's being mated to an 8" pulp woofer.
