Hi @Jetter
That's a little off topic, but 3 different speaker designs. I use all of them in my HT.
2 of these designs are 2-way, one a center (also a 2-way). They're not commercial kits, so no one has the courage to blow cash on the parts. :-)
Plenty of good kits from Parts Express, Madisound and Meniscus. I encourage you to look there for ideas and kits with existing reviews.
Best,
E
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Oh, sorry, nothing that spectacular. I was thinking of using a slot to turn directional drivers into omnis.
While the concept is cool, I'm not convinced that in the living rooms I can afford omnis are going to be all that for me no matter what.
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Now that gives me ideas!! :)
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Oh, so to be clear, the phase angle of the impedance refers to the relationship of the voltage to current.
The phase angle of the output refers to timing.
The only thing they share is that impedance and output are complex numbers. That is, they have a magnitude and phase. None of those four numbers are equivalent. |
Above all, everyone, I want to point out that I’ve made 1 claim. The impedance chart is being misused. There are several great ways to argue that Class D has a lot of phase shift. Show your work. Show the chart. Post specifics. Find a review, or data sheet. Instead we get personal attacks, conflagration of a number of possible Class D issues, but the people (person) who relies on that chart to begin with is completely unable to actually refute my claim. I welcome any and all sources of credible data (public review, manufacturer data sheet, etc.) which expand our knowledge here. |
Here we go, I added similar charts from a speaker simulator. See the bottom. You have both output and impedance for the same speaker charted. Both have phase angles. They are not the same chart. https://inatinear.blogspot.com/2020/02/class-d-amplifiers-do-not-have-horrible.htmlAlso, look at the phase angle for the output? I make damn good speakers. :) Others do too, but I am so proud of how well those two drivers integrated. |
Here's the problem, I have two charts. Both from the same source. Both clearly labelled.
Several people have used the first chart to claim it is the amplifier output phase chart. In fact, the actual amp phase is the second. Then George#3 (or 5?) rolls in and says that charts can't be trusted because (gobbledygook). So... if charts can't be trusted, why is he relying on the first one to make his point????
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Somewhere out there is a person who is so concerned with this thread his digestion is in serious danger of shutting down.
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I meant ,misleading the way someone was trying to use the graph by saying ice 1200 modules had a frequency phase drop at 2khz.
@djones51 You are right. I just meant to say that the geek who put it together never intended it to say what is being claimed. I make a lot of plots, so I feel sympathy for having your data ripped off to mean something you never intended. :) |
Because some of these
comparison modules are measured with/without their output filters insitu, and
the manufacturer has used Audio Precision "very high order" external “test
filtering” instead for the graphs, and/or the frequency knee of the output
filter they use if used, is totally different to the one it's being compared to
by the one doing the comparing, which will directly effect the amount of phase
shift down lower in the audio band as those of us all know.
@jesskerry I only know of one person who could put together such a long sentence that in the end is so convoluted that it cannot be proven or disproven. I would try to answer it, but it is the opposite of building an argument from parts that logically form a whole. Hahahaha. |
@djones51
I don’t think the graph itself is misleading. It’s that is’ so very very rare. I have seen output impedance plots, rarely, but never one with phase also.
It’s truly something for the geeks.
Best,
E
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It may help to think of where the test probes are. For the first chart, the probes are:
Amplifier --> (+) Output Impedance (-) --> Speaker
For the second:
Amplifier --> Output Impedance --> (+) Speaker (-)
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The first graph is the phase response of the impedance the second graph is of the frequency. To be more precise: The second is the graph, both frequency and phase, of the entire amplifier. The first plot measures impedance, the second magnitude of the voltage. It is the difference between measuring a passive component and an active one. :) |
@kijanki
The values were picked at random. They aren't real. :) As I wrote, the point was not the values, but where the parts were. :)
E
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There's no way I would put a 10uF cap in parallel with a speaker!! :)
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It is important to note that output impedance chart varies from 5 milliohms to 50 milliohms, so the effect at worst case of the magnitude and angle of the impedance on the speaker are tiny, so the lower chart with the actual output should give a very good idea of how the amp would perform.
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@imhififan I wrote this: The actual values are irrelevant for the purposes of this discussion. I meant to say that I just picked whatever XSim uses for the defaults. Best, E |
1 mH sounds very very high, isn't it?
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@atmasphere Thanks for the vote of confidence!!
@imhififan Is that typical for a Class D stage??
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@mapman
Ain't that the truth?
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Really, I posted on a very very narrow piece of data regarding Class D and already the anti-Class D people are here.
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the dynamic load of the drivers and crossover will cause massive changes
in the impedance of the speaker system. The drivers shift all over the
map, thousands of times per second.
Not really relevant and also, what does this even mean? |
