Originally Posted by Steve1981
Originally Posted by DS-21
While I haven't seen measurements of the Q300/700,
are a couple rough measurements on the Q700s I took on axis and at 90 degrees off.
I don't know if they're "markedly" inferior to that of the Q100's I had in my bedroom (drivers have been harvested for a custom project, and I didn't measure them),
Then take the measurements.
Also, see what happens over more angles, and you'll "see" what I heard.
What you'll see is a smooth rolloff, rather than a flare-up at the crossover point.
Originally Posted by AcuDefTechGuy
Wow. So you can actually clearly and distinctly hear the polar inferiority of the Q700 just by listening by ear without any kind of measurements.
Change "Q700" to "Q300," and the answer is "yes." Keep it "Q700," and my answer changes to "one can reasonably infer that to be the case, based on my experience with the Q300."
I could also instantly note that Cris Collinsworth was wearing an Isaia jacket in the pregame show last Thursday night, based on the shoulders and lapel sculpting, and lapel stitching. In fact, I only noticed the horribly tacky logo lapel pin marring the jacket only after I ID'ed the jacket as an Isaia in their Argento cut. How could I notice that, or hear the difference between proper directivity matching in the midrange and an excess of midrange energy due to failure to match directivity? It's called combining knowledge with experience. I'm a clotheshorse, and I've listened to a lot of speakers with the goal of seeing what measurements correlation with my subjective perceptions.
Think about it. If the horizontal polars can't be heard, they don't matter. They only matter inasmuch as they can be reliably and repeatably heard to be an issue.
The Q300, especially when A/B'ed against better speakers such as the Q100 and Q900, has a clear "spitty" coloration in the midrange that I always seem to find in sighted and blind listening with speakers that have energy flare-ups in their midrange polars. The Q300 is not as obviously horrible as a typical flush-mounted-tweeter 7" 2-way in that regard* but it has enough spittiness in the midrange that I was very surprised. Especially since I had just heard the Q100 for the first time, and my expectation was that the next model up would be designed to the same standard, but simply be able to play louder/lower/both. Unfortunately, that isn't the case.
Actually in stock form the Q100 (and possibly Q500**) are probably the best of the Q-series. Shortly after the line came out, I heard the Q100, Q300, and Q900 in the same room. I was really impressed with the Q900, and still am every time I hear them. But the Q100 made such a positive impression that I had to buy a set. (I currently have three pairs, one used as surround backs in the living room and two in background systems. Also another set of Q100's concentric drivers is in the Soundfield Audio Monitor 1's in my nearfield/computer system.) The Q300... I was surprised. My listening impression made no sense to me until I saw the specs. Then what I heard made perfect sense to me.
Turns out there are technical reasons that correlate well with that assessment, too. All the Q-series have rudimentary crossovers, frankly too
rudimentary. Especially for metal-cone drivers. All of the current Q-series concentrics seem very well behaved in their passband, but woofer cone breakup starts lower and more pronounced as the midwoofer cone diameter goes up. In the 5" Uni-Qs, woofer breakup is up high enough and suppressed enough by the lossy cone-former collar and other cool design tricks that the crossover works well enough to result in a very impressive speaker.*** The Q300 has the excess midrange energy issue because the tweeter comes in too high, and the woofer breakup is more pronounced.
The Q900 sounds exceptional, but can be fatiguing over time. I suspect that's the sonic penalty from the uncontrolled cone breakup, though if I'm wrong about that I'll know next month.
*In a blind test, I ranked one such example, the Usher Tiny Dancer, far far below the KEF HTS3005SE egg, Behringer Truth, a Zaph DIY design that's very similar in performance to the NHT Absolute Zero, and the Tannoy Arena egg. That was the first time I had heard any of the speakers except for the Tannoy Arena - I supplied them - and the wretched-sounding Usher Tiny Dancer. That experience made me take a new look at KEF, because the HTS3005SE is really, really good.
**I've not heard the Q500 or Q700. I'm not big on 2.5-ways generally, but they have a place in that segment of the market and the Q900 seems to work pretty well as a 2.5-way.
***The upper midrange/lower treble performance of the 5" Uni-Q can be optimized beyond what KEF did in the Q100, as anyone else who has compared the treble performance of the the SAM1 to the Q100 back-to-back will agree. By contrast, the primary sonic difference between the Q100, R100, and LS50 is that the Q100 is voiced basically flat, but the other two are specifically voiced to different notions of perceptual accuracy rather than flat. That the R-series and LS50 drivers also have lower distortion than the Q100 driver due to the shorting rings in their motors and magnet tweaks is a much smaller differentiator than the differences in voicing.
Originally Posted by AcuDefTechGuy
The KEF engineers would disagree as they assure my friend that the sound quality of all the Q speakers were the same, except for the bass and overall dynamic output.
That is what any rational person would expect any employee of KEF to say/write. Anything else would be negligent on her/his part. Doesn't make it true, of course.Edited by DS-21 - 9/7/13 at 10:23am