Nice!
Are the response irregularities around 2.2 kHz and 4.7 kHz due to your measuring rig/environment, or part of the waveguide behavior?
But isn't that always the case with these newer designs? i.e. no significant diffraction from the waveguide. Seems to me that concern would be minimal.
It is the case with the newest axisymmetric designs by they also have tilted power response, i.e. rising DI a bit. It seems that as one tries to make the DI really constant the axial ripple and narrowing and widening start to appear no matter what. My explanation is that the (almost) conical profile needed for the "real" constant directivity is difficult to terminate as smoothly in a resonably finite size - seems logical after all. Once it is curved all the way along, even if only a little, it's much easier but also the DI rises. That said, I'm still not sure that the mildly rising DI with a flat direct response are a bad thing.
Maybe with rectangular waveguides, both the constant DI and smooth listening window are possible, at least it seemed so. I'm so excited that the axisymmetric ones can also be so good that I kind of abandoned the rectangular ones for a while.
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Please bear in mind that these are not anechoic data yet and it may thus be difficult to judge on the real waveguide behaviour.
What irregularities do you mean, BTW? I don't see any at those frequencies.
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Have you ever measured a compression driver? 
What you show are completely common and benign deviations from flat response, handled in crossover/EQ (and it's only +- 2dB). What's of the paramount importance is whether all the polars are the same like this, i.e. if it's really the driver that's the cause. If they are, a simple EQ corrects it all (remind you, both amplitude and time aspects together).
This would be no problem at all.
What you show are completely common and benign deviations from flat response, handled in crossover/EQ (and it's only +- 2dB). What's of the paramount importance is whether all the polars are the same like this, i.e. if it's really the driver that's the cause. If they are, a simple EQ corrects it all (remind you, both amplitude and time aspects together).This would be no problem at all.
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Here we go
This is the small 1" that you designed for me. Actually I was using a 'screw on' adapter - and a bit skeptical as to how well it mates with the driver. I'm going to attach the driver directly and measure again. I'm new to ARTA. This is the Holm plot with phase. What measuring software do you use?
Attachments
Oh, did I? I almost forgot, had to look that up. Indeed, it was only about 11.5" large. Nice.
I still try to use Holm whenever possible. I really like the complete control over the process. In the other programs, I always feel there's something happening "behind the scene", I don't know why. In ARTA this is especially the case with the phase response calculation - I don't consider it very transparent (I have no doubts it can be used reliably). In Holm it couldn't be more open and even with a single channel it works like a charm. Great stuff, really.
I'm only not sure that this is the right thread to consult the measurements issues per se. I'm sure there's a plenty of great help around here.
In Holm all you need now is to select the "Impulse time-window (gating)" option (at this point) and see. The rest is pretty intuitive. Only make sure you have as much free space around the measurement setup as possible.
Yes, but these are first and foremost specifically designed for (treated) studios.
Moreover, it seems fairly constant coverage is most important throughout the midrange and lower treble.
Your best efforts so far, are close to ideal wrt DI.
I would go so far as to state that above a certain DI other factors are more important to the perceived quality, such as low diffraction
One more question about the HF1440 horn: is the intersection of the real and imaginary parts above or below 1000Hz?
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How is that incorporated into the Olive metric?
Only after you tell me what's the use of this information
It's not.
Only after you tell me what's the use of this information
You know why I'm asking
However, I'd be (positively) surprised if it's well below 1000Hz.
But it has the best preference score from all the loudspeakers measured at ASR, whether or not are they "specifically designed for (treated) studios". So this is not really related, is it.
No, I still didn't get it to this dayYou know why I'm asking