Could be good, but I am not everyone. I use specs, but even more, sophisticated/proprietary listening tests, that no one else uses. I have also "worked" with some exemplary individuals if I may.
Jneutron and I communicated and posted together some years ago. Jneutron worked at FermiLab, then Cern when they were designing and building it, last I heard J is at Brookhaven National Laboratory. He has "professored" other scientists in the classroom, and been an audiophile/music lover for some two decades now.
Decades ago, when fussing over parts quality, I spent some time conversing with Jenalabs. Michael worked as a sub-contractor on the probes that ventured outside our solar system and Jennifer worked on some "minor" government research projects. They gave me clues which parts were the most accurate, thus saving me valuable time.
By the way, I personally checked out their suggestions for myself.
I ran the lab in college, then my own lab for some decades. I have had students and professors consult me, not often, concerning audio projects etc.
One of the flags I look for when checking out a speaker is what electronic components are used to evaluate said speaker design. Using DHT is yesterdays news, and indicates what their "reference" is. DHTs have inherent limitations/flaws that limit the musical quality. Everything follows laws, whether it is room acoustics, parts quality, the design, or listening tests, in otherwards true Physics, not personal theories.
One of the major barriers that is occurring is that NOS tubes are fleeting, prices are rising; so the challenge is to produce a component that is superior without them. It Can be done.
That is where the 10A and 11A preamplifiers come in. Both preamplifiers are designed around new production tubes.
Both models consistently beat the competition, which use expensive NOS tubes, regardless of price.
That is why you won't find a used 11A for sale. The question is, who will continue the legacy when I am gone?
Sorry for the rant but my string has the goal of informing what is possible in audio vs what others are preaching dooms day with newly manufactured tubes.
I like the Heils, but the crossover point dictates a three way system imo. I would not use one with a xover at 800hz or lower as one would have to address Mr. Doppler, which degrades the sound. I would also not like one higher, say 1.6-2khz either.
I hope you can see my goal more clearly, I have been in uncharted territory for well over 20 years.
cheers
steve
re: the accutons; well, while not having heard mr blume's top creations, all i can say is i've never heard anyone who has, say anything less than they're one of the best speakers they've ever heard.
interesting you should mention the heil amt's. their largest driver - 6" tall - is rated 800hz to 20khz and 96db efficient. i've always wondered how a stack (8, 9 or 12 drivers per side) would sound. retail for 24 of them would be $4800 - not chump change, but within the realm of affordability. ( and if you wanted to buy 24, i suspect the mfr might provide a bit of a price break.) i wonder how low you could cross them, if running that many. 12 drivers would be something like ~106-107db efficient; i bet you could cross them over quite a bit lower and be successful, w/eq...
best,
doug s.
Hi Doug,
Yes, he picked some of the better drivers which is good. There are still some questions I would ask myself though.
The tweeter looks pretty good, although I would like to check out the off axis response. Does it beam? I take it he minimized that
effect. If I had a choice, and gobs of money etc I would go for the Heils air motion transformers, maybe even the ionized helium, requiring tanks. Nah, the tanks are too much bother.
But so far so good.
The midrange is another matter between 2-4khz, within the most sensitive portion of the ear. I still don't like the 5khz and above
either as there is not a gentle, linear downward slope from 1.8khz to 8khz. That 5db "roughness in response" is going to show an unevenness when combined with the tweeters overlaping response. The worst part is the dip covers a whole octave, well above
the 1/3 octave width Rane claims is the minimum width necessary for being perceivable. Less than 1/3 octave is generally not perceivable.
Forgot to mention DB spikes and dips are directly added. For instance, if we have a spike of 5db, then the overlap will show the
5db spike. If we have a dip of 5db, then the overlap will dip 5db.
Not to worry Doug, I have had the same problem whenever I look at any 3 way design. Overlapping always occurs, worse with lower order crossover designs. That is why I went with a two way design, just one overlap to deal with, and at a much lower frequency.
Cheers
steve