PDA

View Full Version : Is this source lossy or lossless?


calvinist
2009-06-04, 08:33 AM
I would really appreciate any advice about this show. It's supposed to be lossless but I have doubts.

Here are three spectral analyses and one frequency analysis:

http://www.flickr.com/photos/34261432@<hidden>/3592051394/sizes/o/

http://www.flickr.com/photos/34261432@<hidden>/3591244423/sizes/o/

http://www.flickr.com/photos/34261432@<hidden>/3591244551/sizes/o/

http://www.flickr.com/photos/34261432@<hidden>/3591244367/sizes/o/

Any help determining whether this is a lossy or lossless show would be greatly appreciated!

U2Lynne
2009-06-04, 10:02 AM
I'm not an expert, but it all looks fine to me. No blocks in the SA and no sudden drop in the FA. What is it that you see that is making you wonder about it?

rspencer
2009-06-04, 06:05 PM
Looks good. No blocks in the SA, as Lynne said. Peaks all the way to 22K. FA runs clear to 22K as well, no steep drop-off.

I wonder why you would doubt it as well. This looks better than lots of other lossless shows.

calvinist
2009-06-04, 06:11 PM
I'm not an expert, but it all looks fine to me. No blocks in the SA and no sudden drop in the FA. What is it that you see that is making you wonder about it?

Thanks very much for your prompt reply!

This spectral analysis made me uneasy, because of the 'flattening' at 22 kHz:

http://www.flickr.com/photos/34261432@<hidden>/3591244423/sizes/o/

rspencer
2009-06-04, 06:29 PM
22K is the limit of human hearing (in reality, it's often much lower). So the software won't read above that usually. Also, microphones usually have a 22K cap, sometimes lower.

calvinist
2009-06-05, 08:12 PM
22K is the limit of human hearing (in reality, it's often much lower). So the software won't read above that usually. Also, microphones usually have a 22K cap, sometimes lower.

Wow, thanks for that useful info!

May I trouble you to assess the source of another show?

http://www.flickr.com/photos/34261432@<hidden>/3297208420/sizes/l/

http://www.flickr.com/photos/34261432@<hidden>/3296386763/sizes/l/

Is this the 'lego effect' that reveals a lossy source?

Thanks again!

rspencer
2009-06-05, 09:05 PM
Yes. That's it. Notice the steep drop on the FA as well.

calvinist
2009-06-05, 09:38 PM
Yes. That's it. Notice the steep drop on the FA as well.

Thanks again!

I was hoping the fact that it is an old 80s audience recording might account for the 'blocks'. I've tested two sources of the same show with the same result.

This is the original frequency analysis:

http://www.ead666.com/Temp/Out/1986-87/1986-10-14%20Leicester.html