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Topic: "Led Zeppelin - BBC Sessions (1997)" (WPRCR-11756/7) from lo (Read 4479 times) previous topic - next topic
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"Led Zeppelin - BBC Sessions (1997)" (WPRCR-11756/7) from lo

A few days ago I bought double cd album "Led Zeppelin - BBC Sessions (1997)" (WPRCR-11756/7). The first CD is OK. But spectrum of the second looks that way (a part of the whole picture):

Seem like some lossy format. Although it doesn't looks like mp3...
Is there anyone who has the same cd, please tell me does your spectrum looks that way. If that disk was copied from lossy I will bring it back to store.

"Led Zeppelin - BBC Sessions (1997)" (WPRCR-11756/7) from lo

Reply #1
Nobody has this disc?

"Led Zeppelin - BBC Sessions (1997)" (WPRCR-11756/7) from lo

Reply #2
waiting

"Led Zeppelin - BBC Sessions (1997)" (WPRCR-11756/7) from lo

Reply #3
BBC Sessions... hm... TV... hm... don't they make noise at 16kHz...? Yeeah...

Well, don't worry. Possible explanation for the 16kHz noise (I'm pretty sure that line is at 16kHz, although you cut off the scale): cathode ray tube. It's a BBC Session recording, so chances are nearly 1, that it was caused by the studio equiptment.

About the cutoff at a somehwat lower frequency, I'd guess that that's caused by the the recording equiptment. Either some sort of filter or bad tapes.

And yeah, it doesn't look like a typical MP3 spectrum, those only have a single freq. cutoff at 16/17/18 kHz and the remaining signal above that also looks different.

"Led Zeppelin - BBC Sessions (1997)" (WPRCR-11756/7) from lo

Reply #4
A few things. A spectrum graph without a scale is useless. What you see could be caused by any number of things. I doubt lossy compression is one of them. I have no idea when this recording was made, but it could be caused by dated recording equipment, filtering or a clueless mastering engineer. As usual, spectrum analysis is a poor gauge of audio quality. Does the disc sound good or bad?

Lastly, don't post useless bumps to your own threads. And certainly don't bump it multiple times within hours. It accomplishes nothing.

"Led Zeppelin - BBC Sessions (1997)" (WPRCR-11756/7) from lo

Reply #5
Here's a screenshot showing the scale for the spectral frequency display. This is a later part of track 4 "Black Dog" on Disc 2. My copy of "BBC Sessions" is an Atlantic/Warner release, catalog # 830612-2, but it looks like it's pretty much the same as the WPRCR-11756/7 release. Is the WPRCR a Japan release?



All of the tracks on Disc 1, which came from several different recording sessions, appear normal visually. All of the tracks on Disc 2 look basically like the screenshot. The narrow bandwidth component is at about 19.2 kiloHertz. I can't hear it even in the quiet parts, but I'm wearing my cheap headphones right now anyway so that's not surprising. The frequency band that seems to have substantial filtering is centered at 14.8 kiloHertz and is about +/- 400 hertz. I'm not sure why filtering was done in this frequency band. It does look like you can see a signal component at about 15650 Hertz, which I think is a deflection frequency used by televisions in the UK.

The CD booklet says that all of the Disc 2 tracks were recorded at the Paris Theatre in London on April 1, 1971, and broadcast on April 4th. The thing you have to consider here is that the show was recorded for the purpose of the BBC broadcasting it on RADIO. So, I'd guess that the recording equipment they used didn't need to be studio quality for producing records, and it wasn't. Radio wouldn't be able to broadcast anything over about 15 kiloHertz at best, so they didn't need to worry about recording the higher frequencies.

It definitely does not look like this material was sourced from a lossy digital compression format, it's just from a relatively poorly recorded analog tape source. IMO it doesn't sound great for sure, but it's OK for a live performance put on 36 years ago and only recorded for the purpose of radio broadcast. I seriously doubt if anyone ever remotely considered that this might be released directly to the public at some point in the future. Hey, I'm just glad I get hear what LZ sounded like in those early years of their career.

"Led Zeppelin - BBC Sessions (1997)" (WPRCR-11756/7) from lo

Reply #6
I guess I'll throw my guess into the ring:

Some mastering engineer left his graphical eq settings messed up on the final mix, and that band got cut.

"Led Zeppelin - BBC Sessions (1997)" (WPRCR-11756/7) from lo

Reply #7
I wonder if it could be recorded from the radio broadcast. The peak at ~19 kHz could be a residue of the pilot tone.

Here is a wiki page that explains the pilot tone: http://en.wikipedia.org/wiki/Pilot_tone
The linked image in that page shows quite similar frequency spectrum (except the ~15-16 kHz peak, which could be for example high-pitched noise).

Edit

... or could it be possible that the pilot tone has leaked somehow into the recording if it was captured from the final edit during the actual broadcast at BBC?

"Led Zeppelin - BBC Sessions (1997)" (WPRCR-11756/7) from lo

Reply #8
I have this album but didn't bother checking the wave form. One thing I know. Those recordings were not originally intended to be released as a CD.

"Led Zeppelin - BBC Sessions (1997)" (WPRCR-11756/7) from lo

Reply #9
It's a 19khz pilot tone.  Possibly sourced from an FM broadcast.  My disc looks the same.

http://en.wikipedia.org/wiki/Pilot_tone
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"Led Zeppelin - BBC Sessions (1997)" (WPRCR-11756/7) from lo

Reply #10
The CD booklet says that all of the Disc 2 tracks were recorded at the Paris Theatre in London on April 1, 1971, and broadcast on April 4th. The thing you have to consider here is that the show was recorded for the purpose of the BBC broadcasting it on RADIO. So, I'd guess that the recording equipment they used didn't need to be studio quality for producing records, and it wasn't. Radio wouldn't be able to broadcast anything over about 15 kiloHertz at best, so they didn't need to worry about recording the higher frequencies.

This can mean two things. Either the booklet is wrong about the source of the CD material, i.e. it is not from the April 1st, but a radio capture from the 4th.

Or the BBC crew at the theatre actually did all the pre-processing needed for broadcast right during the show and this signal was recored directly onto tape, which was then broadcast three days later without any real-tim processing (or maybe even redundant processing?). Then a few decades later this tape with the pre-processed audio signal was also the source for this CD...

"Led Zeppelin - BBC Sessions (1997)" (WPRCR-11756/7) from lo

Reply #11
Thanks for evryone for replies.  Yes it's japanese release. I'm living in Russia and sometimes I meet CDs recorded from lossy. I'm not shure that this is not pirate double-cd. it costs only 10$  . But looks very like original. 2 big booklets and cover...

"Led Zeppelin - BBC Sessions (1997)" (WPRCR-11756/7) from lo

Reply #12
In the United States it was a 3cd set.  Disk 3 was interviews.
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