I think that more important than the region under discussion is the decline of energy. Look at the blue form and how it forms fewer 'shelves' as the amplitude decreases- it's a smooth loss of energy, as opposed to short duration "pauses" and sudden dips. I'd imagine the "stuttering" of the decaying waveform to be more audible (or more precisely, more difficult to "hear past" (ignore the artifact)) than a smooth decline, purely intuitively based on what I know of our hearing mechanism.
Badman, I have no doubt what you say is correct. I only show the flip comparison as support for the argument that our software and microphones are good enough to display this sort of fine detail, as is found in the portrayal of stepped ringing in the blue plot. The red plot is "smoother", but I think this shows an incoherence in the finely detailed information, as it is received by the microphone. The blue plot does show the resonance as it decays, with a very clear indication of the ringing involved in it's decay. The red plot does not.
In this particular discussion, just what method of allowing the driver to provide the level of coherency, as is found in the blue plot, is not of any importance. In fact, George Soon (soongsc) has already exceeded this level of performance with his own investigations. I am trying to point out to Michael that until the diaphragm coupling to air incoherence as shown by the red plot, is overcome, the level of fine detail that he is concerned with, and it's improvement by providing better control of the problems he is pointing to, may be a moot point.
I do think we are looking at that threshold that Meyer and Bozak have pointed to, when they spoke of an incoherence some 40 db down from signal level that they were finding. Solving emission problems that create the difference in propagation shown between the red and blue plots would also solve their concerns.
Miichael, I do not have any more data than what is shown. John K provided these plots, along with three other comparisons of methods that can be used to change specific characteristics in emitted signals. Frankly, the other three blink comparisons were, in a general sense, much more informative and interesting than this one. However, this is the only one that showed the specific ability of the driver to produce very fine signal structure, once the coupling issues had been removed.
In this particular discussion, just what method of allowing the driver to provide the level of coherency, as is found in the blue plot, is not of any importance. In fact, George Soon (soongsc) has already exceeded this level of performance with his own investigations. I am trying to point out to Michael that until the diaphragm coupling to air incoherence as shown by the red plot, is overcome, the level of fine detail that he is concerned with, and it's improvement by providing better control of the problems he is pointing to, may be a moot point.
I do think we are looking at that threshold that Meyer and Bozak have pointed to, when they spoke of an incoherence some 40 db down from signal level that they were finding. Solving emission problems that create the difference in propagation shown between the red and blue plots would also solve their concerns.
Miichael, I do not have any more data than what is shown. John K provided these plots, along with three other comparisons of methods that can be used to change specific characteristics in emitted signals. Frankly, the other three blink comparisons were, in a general sense, much more informative and interesting than this one. However, this is the only one that showed the specific ability of the driver to produce very fine signal structure, once the coupling issues had been removed.
Any chance of this thread not morphing into just another enabl thread with more pure speculation and misrepresentations of John's measurements? Sheesh.
Dave
Ok, I got your point Bud - and I even agree to some extent - but as said - the discussion about "significance" is a different one.
Also tracing down "looped reflections" behaviour is different to tracing down distortion - in that for the first you most certainly can assume that the mic is perfectly clean whereas this certainly does not apply for the second case.
Its just a question to keep things sorted out as good as it gets.
John, would you mind to post the IR files from that plots over there in the wavelet thread, to allow us for a further look into this ?
Michael
Also tracing down "looped reflections" behaviour is different to tracing down distortion - in that for the first you most certainly can assume that the mic is perfectly clean whereas this certainly does not apply for the second case.
Its just a question to keep things sorted out as good as it gets.
John, would you mind to post the IR files from that plots over there in the wavelet thread, to allow us for a further look into this ?
Michael
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What a pity
I've read some in the enABL thread to see if there is some discussion of your measurements.
I had no success (or possibly not enough investigated) though all in all it was a pretty enlightning reading for an evening ( though not necessarily only for the issues raised).
Michael
I've read some in the enABL thread to see if there is some discussion of your measurements.
I had no success (or possibly not enough investigated) though all in all it was a pretty enlightning reading for an evening ( though not necessarily only for the issues raised).
Michael
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There are many things that difficult to interprete from measurement data. Talking with some doctors, the common breast cancer scan method only has a 60% of detecting it. Since the diagnosis is so unreliable, doctors are becomming to act like lawyers, they tell you all the worst things that can happen, and you have to sign up that you understand. My father just recently went to the hospital and stayed there for about a week, from lots of measurement data, the doctors thought this guy must be almost dead. When they came to see him, and he was eating well crying to get out of bed, it had the doctors scratching their heads for a few days.
I wish I knew where the better elderly (and lively) communities are that's for sure. But it's also a good experience knowing what to expect as we grow older while he stays with us. It's also an opportunity to set an example for our kids as to how we would want them to treate us when we grow old.
With audio, as probably with any science, sometimes you just sit there and look at the differences in the data, and sometimes you suddenly notice somthing that you missed before, and that sometimes might become more obvious once you know it.
With audio, as probably with any science, sometimes you just sit there and look at the differences in the data, and sometimes you suddenly notice somthing that you missed before, and that sometimes might become more obvious once you know it.
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My project is coming along nicely! The sealed TD15M cabinets and the PR-loaded TD15H cabinets are finished. Now I am working on something to support the Azurahorn and A-C ribbon tweeter. My plan is to start with a simple support for just the Azurahorn, and work in the tweeter later on, because the front-to-back alignment of the horn won't be known until the crossover gets worked out.
Grill frames of masonite will be built to fill the inset area around the woofer frames. The whole front of the speaker will be flush with the outer surface of the cabinet.
There's a pretty big stack of Acoustic Elegance shipping cartons sitting in the garage now.
Looking forward to some frequency response measurements!
Gary Dahl
Grill frames of masonite will be built to fill the inset area around the woofer frames. The whole front of the speaker will be flush with the outer surface of the cabinet.
There's a pretty big stack of Acoustic Elegance shipping cartons sitting in the garage now.
Looking forward to some frequency response measurements!
Gary Dahl
Attachments
Simply Awesome. Im kicking myself for not getting the TD15M, I just have the TD12Ms right now. The TD12M doesn't go as low as the TD15M.
You are not only going to love the measurements but the performance is pretty good too
Beautiful finish for a difficult shape !
If you haven't decided for support of your horn yet - why not try some weird idea first ?
http://www.diyaudio.com/forums/multi-way/159731-beautiful-swingin-speaker-3.html#post2110689
Michael
If you haven't decided for support of your horn yet - why not try some weird idea first ?
http://www.diyaudio.com/forums/multi-way/159731-beautiful-swingin-speaker-3.html#post2110689
Michael
Very impressive. Those guys sure know what they're doing. Shame I can't afford a pair, but I have 3 sets of 15"s already and can't expand my comparisons beyond that.