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Posts by Joe Bloggs

If you mean my mention of inaudible ultrasonic frequencies, there are two special considerations: 1. The system needs to be producing only the frequency itself, and not any spurious frequencies below. Thankfully this is easier to achieve than trying to remove higher harmonics. 2. Any test tones need to fade in and fade out smoothly rather than start abruptly--because an abrupt start / stop is a broadband phenomenon and will be heard regardless of the inaudibility of the...
The point is, if earphones have a cliff-face CSD plot if you EQ them to flat, (and I have reason to believe this is the case for IEMs even more so than headphones) then whatever decay you see in a CSD plot of the earphones with their default frequency response, are entirely the result of the earphones having that frequency response. In mathematical terms, we say that the earphones are already "minimum phase" and it is technically impossible to improve on the earphones'...
No, the effect is much more drastic than that, why exactly I can't say (the maths are beyond me) but the effect was demonstrated herehttp://www.head-fi.org/t/566929/headphone-csd-waterfall-plots/735#post_8479175Read up and down a page or two.
And with that, I believe you have done more to promote Fidelizer to me than WindowX himself ever did...
Well I meant that all frequencies would have zero phase shift relative to each other, either in a linear phase filter or an actual zero phase filter combo. Note however that in realtime audio processing the latter option (backward and forward filtering) is not viable.
The bass frequencies of these phones ramp way up in impedance so should be the best electrically damped frequencies for any given driving amp. Besides, given a non-flat frequency response, you will never get a very good looking CSD no matter how good the earphones' time response actually are. Pet peeve of mine--CSDs and impulse responses should be plotted after being compensated to a flat frequency response. The few times I've seen this done for headphones (once,...
1. Note that I was making a 20kHz lowpass filter in a 384kHz upsampled stream. I noticed no magical effects.2. A symmetrical linear phase brickwall filter can ring for all it wants and also be zero phase.3. Trying to make a steep filter that does not ring at the transition band is like trying to pull oneself off the ground by one's shoelaces...
Well sorry! It's just a number I pulled out of my ass with a 9.9% 95% confidence interval (both down and up )
Just checking in.... it's been a while guys. Lost my audio job, coasted around for the better part of a year, got new audio job. New audio job is not having me spend much time on head-fi so far
Ringing would happen as long as there's any sharp transition band. If you notch out the ringing frequency, you're just lowering the transition frequency. What might have happened, is that your notch filter was less sharp than intended and created a slow rolloff filter in combination with the original.To create a non-ringing lowpass filter is simple, it's simply a first order lowpass with Q of 0.5, the Q factor with critical damping:It's just too gentle to be of much use...
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