Audio Asylum Thread Printer

Get a view of an entire thread on one page

FAQ / News / Events

Computer Audio Asylum

RE: This severely compromised system is THE best way to contrast the merits of the software tweaks.

65.19.76.104

In Reply to: RE: This severely compromised system is THE best way to contrast the merits of the software tweaks. posted by Ugly on August 15, 2015 at 11:24:33

You are looking at a different plot than the one I looked at (the noise plot). In the noise plot the hum was at -110 dB and there was no signal, just noise floor from the DAC and the ADC. The hum was in a completely different frequency range than the spikes that I commented upon. It would not have been audible nor did it interfere with the measurements of the spikes.

I agree that the hum is indicative of sloppy test procedures, equipment selection, etc... At the least, there should be explanation of how much of the hum is coming from the DAC and how much from the ADC and other explanation that shows knowledge of and good use of tools. However, the good news is that software changes in the computer are showing up and that with careful testing this method could be used to evaluate software tweaks in the computer (rather than dismissing them as inaudible).

Tony Lauck

"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar

Follow Ups:

RE: This severely compromised system is THE best way to contrast the merits of the software tweaks. - Ugly 12:41:50 08/15/15 (2)
"You are looking at a different plot than the one I looked at (the noise plot)."
LOL! I looked at all of them.
Are you saying you disagree with something I said? The plots I was obviously referring to are the only relevant test worth talking to outside the context of his system, the one with an actual reference signal for comparison, which clearly show a evidence of a hardware problem/s in my opinion. Don't you agree it's a hardware problem?
"In the noise plot the hum was at -110 dB "
Really Tony? -110dB with respect to what exactly?????? Meaningless!

Edits: 08/15/15 08/15/15
- dBfs - Tony Lauck 13:30:40 08/15/15 (1)
  "Really Tony? -110dB with respect to what exactly?????? Meaningless!"
  
  I made the assumption that Archimago used constant settings to record the output of his DAC with his ADC on all of his graphs. So they are dB down below the maximum signal that appears or could appear in any of his tests. I also assumed that he calibrated the gain of his DAC to ADC loop so that it is unity gain. So therefore, all dB would be relative the the maximum output in the 44/24 format, that is to say that -110 dB would be -110 dBfs. with 0 dBFs corresponding to +8388607 or -8388608 integer sample values.
  
  I assume that anyone competent to record digital audio with a PCM recorder would understand how to set up their equipment to get consistent levels and would understand that in PCM recordings dB levels are referenced with respect to full scale, hence the term dBfs. I did not question Archimago's competence in regard to these matters and I assumed that anyone reading and commenting would be equally knowledgeable.
  
  Tony Lauck
  
  "Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
  - https://en.wikipedia.org/wiki/DBFS (Open in New Window)
  - OK, back on topic. - Ugly 13:50:46 08/15/15 (0)
    You keep avoiding my question. Are you disagreeing with my OP or not regarding assertions about hardware problems relation to software tweaks?

Post a Followup:

FAQ

Post a Message!

Forgot Password?

Moniker (Username):
Password (Optional):
	Remember my Moniker & Password (What's this?) Eat Me
E-Mail (Optional):
Subject:

Message:	(Posts are subject to Content Rules)

Optional Link URL:
Optional Link Title:
Optional Image URL:
Upload Image:
E-mail Replies:	Automagically notify you when someone responds.

To view your new posting or follow-up, click on the RELOAD or REFRESH button on your browser.

This post is made possible by the generous support of people like you and our sponsors:

Signature Sound

[ Signature Sound Lounge ]