Ah, Pano, this is an old trick that you constantly use - unless I can say what test I want you think that invalidates my question to the "experts" in these FFT plots. It's a simple question & has been answered - FFT plots need to be very carefully used & the resulting analysis carefully framed. Something that is maybe lacking in this forum. I used the FFTs that I have experience of as an example but I wonder how many more examples there are within these forum walls?
Yes. FFT is a way of computing DFT, Discrete Fourier Transform, which is the Fourier Transform applied to a limited set of Discrete Time or sampled signals.
When operating on the set of samples from minus infinity to plus infinity the transform employed is the DTFT, Discrete Time Fourier Transform.
Yes, so the DFT is used instead of the DTFT.
Yes. The samples are modified by multiplying with a 'window' (apodization, tapering) function. Different windows produce different inaccuracies. Window function - Wikipedia, the free encyclopedia
Yes.
No. The Fourier transform and DFT (FFT) are not generally used for creating signals. We would take the FFT of the original signal (if necessary using a very low THD amplifier). Then we would take the FFT of the amplified signal to compare. The differences show the co-sines added by the amplifier. This is better information than a simple THD.
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How'm I doing here guys?
I don't get the head clamp thing. I'm sitting here listening to Harry Belafonte and no matter how I bob my head up and down, back and forth, round and round, the image stays the same. All voices and instruments in the same place.
Only by turning my head >80 degrees left or right does the image collapse (quickly) to mono. But it's still in the same place. What's the deal?
Only by turning my head >80 degrees left or right does the image collapse (quickly) to mono. But it's still in the same place. What's the deal?
Audible, But How To Measure It ?......
Ok, question to the experts please.
What is the best measurement methodology (or methods available utilising 96k/24 bit outboard USB soundcard) to discern fine differences in system output - by this the I mean the differences caused by a 'tweak' in an otherwise constant system using a repeatable test signal of any type or an excerpt of any particular musical passage ?.
I am also asking for suggestions on suitable softwares.
Thanks, Eric.
Ok, question to the experts please.
What is the best measurement methodology (or methods available utilising 96k/24 bit outboard USB soundcard) to discern fine differences in system output - by this the I mean the differences caused by a 'tweak' in an otherwise constant system using a repeatable test signal of any type or an excerpt of any particular musical passage ?.
I am also asking for suggestions on suitable softwares.
Thanks, Eric.
It depends on what the tweak is and what it's claimed to do.
That question can't be answered generally- it's like asking, "If I improve my car, how do I measure that?" The main thing is to understand your measurement tools (that means real studying, I'm afraid). A moderately good tool with a skilled brain will get you much further than a great tool with an inadequate brain.
That question can't be answered generally- it's like asking, "If I improve my car, how do I measure that?" The main thing is to understand your measurement tools (that means real studying, I'm afraid). A moderately good tool with a skilled brain will get you much further than a great tool with an inadequate brain.
If you don't know what you might be looking for then all you can do is compare input with output. Unfortunately this will show differences which are of little concern, such as finite bandwidth. Maybe you need to look at the difference between 'before' and 'after' outputs - this assumes that the test is repeatable, which might not be the case if the ambient RF environment is a factor.
Ok so according to this you are only interested in de-bunking claims made rather than any real attempt at testing for a difference. So Steve Eddy is careful to say nothing about his cables other than he likes them & even likes the way they smell. More politics, lest he be tested in any claim?
What are you afraid of? The studying? Maybe you are admitting something here?
And would you say you have a moderately good tool or an skilled brain or a good tool & inadequate brain?
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