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darkstarjunkie
2005-06-04, 06:00 AM
Hey, here's a show, I know it was rec'd on MD, but i'm terribly worried about a mp3-gen somewhere in the lineage...

freq is cut off at 16khz, and it sounds quite lossy. but it's got those square blocks at the top which afaik is typical for minidisc...

also: i converted one of the flacs to wav, and then converted the wav to mp3 160 kbps, and compared the wav to the mp3, and found basically NO difference - is that a reliable method for determining this? well - frequency analysis of the two show more loss after my mp3 compression than before... i include screens of a 2 second spectral view of both the orig. wav and the mp3.

so, see attachments, and please help me figure this out!

Five
2005-06-04, 06:18 AM
this is a tough one

it looks believeably like pure MD to me at the moment but I'll have to dig up an MD show and double-check in a couple days.

would love some feedback from others on this

Cruzweb
2005-06-04, 09:27 AM
Was the minidisc recording in mp3?

range_hood
2005-06-04, 11:14 AM
The main difference for me is the loss of the noise above 15 kHz. The rest looks quite similar though the mp3 lost some more blocks.
:hmm:
So could this be lp2 (132kbps)? As the codecs ar similar could this be the reason why theres not much more loss when encoding an atrac 132kbps to 160kbps mp3?
What if you go below this 132kps, f. e. 128kbps mp3? Is there much more loss visible?

Iīm missing some examples for lp2 and lp4 as I only have an old MD walkman laying around here thats not capable of doing.

Does anyone have spectrals of known lp2/lp4 sources? Five?

Five
2005-06-04, 04:11 PM
I see you found them, good job!
http://www.thetradersden.org/forums/showthread.php?t=8003

I'm gonna stick that to the top for reference.

this is baffling how converting to mp3 shows no difference on this show in the SA. I think when I get home I'll try converting a couple of tracks from MD sources to mp3 and examining if they typically change.

The real challange here is that MD is lossy and allowed, so with very recent shows of unknown origin we have to really squint and scratch our heads. MD>MP3>lossless is very very challenging to spot for me (and others I'm sure).

range_hood
2005-06-04, 05:43 PM
Yeah, thatīs difficult.

darkstarjunkie, what show is this. What about the lineage do you know.

darkstarjunkie
2005-06-05, 10:36 AM
it's a show by a band called Motorpsycho from Norway. this is a somewhat quiet track, but all tracks seem to show the same frequencies. lineage is uncertain, but something like MD > PC > ? > flac - i'm worried about there being a mp3 somewhere in there, but.... actually, the show is at dimeadozen:
http://www.dimeadozen.org/torrents-details.php?id=44465

i doubt it being LP2, unless the taper ran out of empty minidiscs. he's a quality-concerned taper (without better equpiment than minidisc) so i assume there's no LP2 or such.

darkstarjunkie
2005-06-05, 10:53 AM
hey, i remembered i have some tracks from this show (& source) which definitely has no mp3 gens or anything. i'll do a little comparison and see.

Five
2005-06-05, 05:30 PM
post up some screenshots if you get the chance we'll do our best to help out.

ssamadhi97
2005-06-08, 08:13 PM
spidey senses are telling me that this one's mp3

darkstarjunkie
2005-06-10, 03:36 PM
i'm waiting for more info on the alternate version of the show (some tracks on a compilation, most likely from the same source, but i don't know for sure yet). i'll let you know! thanks for the help!