• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are many reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

An analysis of some tracks, unprocessed, off of CD.

RayDunzl

Grand Contributor
Central Scrutinizer
Joined
Mar 9, 2016
Messages
13,204
Likes
16,986
Location
Riverview FL

DonH56

Master Contributor
Technical Expert
Forum Donor
Joined
Mar 15, 2016
Messages
7,835
Likes
16,498
Location
Monument, CO
Also, if you're using a sine wave, you must use one that hits every level over your analysis window. If, for instance, you use FS/4, you will only get either 2 or 3 levels, depending on sin or cos, or 4 levels using something in between.
<elided>

This is exactly the issue the IEEE Standard (among many others) addresses.
 

DonH56

Master Contributor
Technical Expert
Forum Donor
Joined
Mar 15, 2016
Messages
7,835
Likes
16,498
Location
Monument, CO
Sorry I'm new here. It lists you as a technical expert, which sounds like you are by what you are saying. Who are you if you don't mind me asking?
Also, if anybody can explain in plain english what JJ is talking about, I would much appreciate it. What are missing codes? And how does a CD have incorrect loudness? Does this only happen when the sound is basically at clipping?


https://audiosciencereview.com/forum/index.php?members/j_j.493/#about

JJ is a legend and we are lucky to have him posting here.
 

amirm

Founder/Admin
Staff Member
CFO (Chief Fun Officer)
Joined
Feb 13, 2016
Messages
44,376
Likes
234,540
Location
Seattle Area
That's a pretty impressive resume! I take it he also knows Amir because he worked at MS.
Yes, I hired JJ from Bell Labs as the chief audio architect in my team.
 

restorer-john

Grand Contributor
Joined
Mar 1, 2018
Messages
12,586
Likes
38,285
Location
Gold Coast, Queensland, Australia
Is that because Jason Stoddard and Mike Moffat weren't available? :p

They were available, but Amir's budget couldn't stretch anywhere near enough to secure such luminaries. ;)
 
OP
j_j

j_j

Major Contributor
Audio Luminary
Technical Expert
Joined
Oct 10, 2017
Messages
2,267
Likes
4,759
Location
My kitchen or my listening room.
Sorry I'm new here. It lists you as a technical expert, which sounds like you are by what you are saying. Who are you if you don't mind me asking?
Also, if anybody can explain in plain english what JJ is talking about, I would much appreciate it. What are missing codes? And how does a CD have incorrect loudness? Does this only happen when the sound is basically at clipping?

Missing codes are levels in the 16 bit integer that are not present in the data. Some missing near peaks are ok. Periodic missing codes are indicative of bad production, bad hardware, or thereabouts.

It's the CD Recording that is at fault when loudness or distortion are unpleasant. It's due to production. The CD process isn't the problem, it's the production techniques.

Everyone is welcome to the IEEE/AES talk at Digipen Oct 3 at 7:30 PM, barring some kind of disaster requiring cancellation of the talk.
 

Cosmik

Major Contributor
Joined
Apr 24, 2016
Messages
3,075
Likes
2,180
Location
UK
But has anyone done any listening tests to see if music with missing codes actually sounds better? As long as the conclusions drawn were worded very carefully, that would be science... wouldn't it? :)
 
OP
j_j

j_j

Major Contributor
Audio Luminary
Technical Expert
Joined
Oct 10, 2017
Messages
2,267
Likes
4,759
Location
My kitchen or my listening room.
But has anyone done any listening tests to see if music with missing codes actually sounds better? As long as the conclusions drawn were worded very carefully, that would be science... wouldn't it? :)

Bad quantization rarely sounds better. I could help you out by giving you lots of missing codes (4 bits no dither) and see if you liked it!

(snerk)
 

svart-hvitt

Major Contributor
Joined
Aug 31, 2017
Messages
2,375
Likes
1,253
@j_j ,

is this a MIR project?

https://en.m.wikipedia.org/wiki/Music_information_retrieval

On the theme of loudness and dynamics I had great pleasure of reading these by Emmanuel Deruty et al. (http://emmanuelderuty.com/):

(1) http://emmanuelderuty.com/pages/publications/2015_DerutyPachet_ISMIR.pdf

(2) http://emmanuelderuty.com/pages/publications/2014_DerutyTardieu_JAES.pdf

The «genius» of Deruty was to simply see how a set of factors evolved over time. Would such an historical big data analysis be possible with your metrics as well?
 
Top Bottom