|
Propeller Head Plaza Technical and scientific discussion of amps, cables and other topics. |
|
|
|
Propeller Head Plaza Technical and scientific discussion of amps, cables and other topics. |
|
In Reply to: Re: Human differential localization discussion posted by macaque on June 8, 2005 at 18:14:23:
macaque: ""One comment you make in the DIY thread about 1-2 usec ITD being incongrous with 20 KHz bandwidth. I don't think it is a problem at all since you are talking about measuring the time difference of two different sensors measuring the same signal and this has nothing to do with the frequency of the signal being measured, only the resolution of the system meauring both sensors to detect a _difference_ in the trigger time.""
Yes, I agree with most of that. The one thing I see as an issue is standard measures do not look for 1-2 uSec delays..it might pop up as a result of I/O difference measurements, but are test systems characterized to that level while pushing an 8 or 4 ohm load to hundreds of watts?. Or, to the level of 60 millidB while crankin..As for ITD vs frequency...as stated, no consideration of ears is being done yet..so freq dependence of ITD sensitivity ain't there...too confounding.. The construct is the ideal case, and will define the absolute tightest physically possible coherence. The general equations will provide critera vs "fuzzyness" for image clarity to the nanoinch level if desired..image stability being an input parameter, as well as soundstage depth and width. Output being a time and intensity error boundary, presented as a 3 dimensional surface, the surface height being the allowed parameter error..
macaque:
The other common misconception is that the ITD in a CD signal is limited by the 44.1 Khz sampling rate when in fact it is limited by the 16 bit sample depth for exactly the same reason. The discrete time sampling does not limit the ITD in any way since you are talking about 2 different signals and the time delay between them. You need very high phase resolution to produce very short time delays and the bit depth is what limits the possible phase differences. ""
I can see point to point straight line output reconstruction as having severe time coherence issues, but from discussions with Ted, later generation DAC DSP algorithms are quite a bit deeper in Z, and that affords significant time resolution capability. More details on that would require Ted, who I have no intention of disturbing at this time...Cheers, John
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- Re: Human differential localization discussion - jneutron 07:32:18 06/09/05 (0)
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2025, Audio Asylum, all rights reserved ]
