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procella
2007-09-04, 03:02 PM
Somehow confused with modern day FMs. Almost all of them should be lossy, I know, but sometimes really not easy to tell if it's a good one by accident, at least for a learner like me.

First one is a 2007 BBC 1 broadcast (44.1 Khz). Looks rather good to me. But fa has a drop between 15 and 17 Khz.

procella
2007-09-04, 03:15 PM
Second one is a 2007 KCMP broadcast. Can't see obvious signs for lossyness. But SA looks a little different than the BBC one. And FA takes a deep drop at 16 Khz but it's still at around -60db only.
('sa' is a complete song, 'sa2' 2 secs of it, carrier is at 19 Khz, cutoff at 16 Khz - information missing on the pics, sorry)

procella
2007-09-04, 03:26 PM
Third one is a Spanish broadcast from 2004. FA looks quite similar to the last one. But the skyline in the SA has some strange cuts though they are not black. So I guess this should be lossy.

GRC
2007-09-04, 04:16 PM
Uh-huh.... and your point is what, exactly.........?

Regards, Graham

GIGFY26
2007-09-04, 04:59 PM
My understanding:

Over the air FM received on a normal radio such as in your car is not a compressed signal. It is an analog Frequency Modulated radio wave. Digital data can be sent using Frequency Modulation as well but you wouldn't be receiving that unless you had a digital receiver.

Obviously this is totally independent of the original source that is being broadcast. If you play a mp3 on a FM station you would get a lossy recording and FA. Much the same as taking a mp3 and encoding to flac. Just because a torrent is in a lossless format does not mean it is a lossless recording. That's why FAs are often required and always appreciated.


And to my inexperienced eye, they all three look lossy. There are sharp drops below 15khz and the SAs all have a clear sharp line at the same level. These are often seen in mp3 sourced shows at these levels. This could be true for satellite and digital radio feeds as well depending on the compression ratio they are using.

I believe that if a mp3 source was broadcast over the air, that would account for the signal above the cuts and explain why there isn't more black above the sharp line in the SA.

Just my 2 cents

GIGFY26
2007-09-04, 05:15 PM
Also a quick follow up.
Analog signals can be and often are compressed before they are broadcast. This is different than digital compression used to save space and / or bandwidth.
In broadcasting, analog signals are often routed through compressors / limiters or clippers in order to prevent overmodulation.

procella
2007-09-04, 09:14 PM
Thanks for these replies.

My problem is that I can't really decide often if it's lossy when it comes to FM. FA is clear but I guess not enough to be sure about it. SA cutoff seems to be a problem. Didn't think much about that sharp line. Was looking too much for bricks and holes, probably.
But I have still some questions. How could mixing FM and mp3 result in a signal above the cut when they both cut at around 16 Khz (somewhere 'Five' wrote that FM and TV cut like that)? Or doesn't this count for broadcast over the air?
And would the cutoff line look much different if a DAT and no mp3 was in the lineage?

GIGFY26
2007-09-04, 11:33 PM
ok, this may get a little complicated.

I'm no expert but have worked in tv for a long time.

FM radio and tv audio, which also uses frequency modulation for it's audio, are two different but related things.
Frequency modulation is just a way of transmitting a signal. Think of it as encoding in modern terms. In AM, the amplitude of the radio wave changes to carry the information when compared to a baseline. In FM it's the frequency or the radio wave that is changed compared to a baseline. This is not to be confused with the frequency / channel of the radio or tv signal over the air which is a different thing and is what determines the baseline.

Lossy really just means that all of the original audio is not being reproduced. Mp3 and others, take into account human hearing and try to get rid of the frequencies [again another usage of the same word] that are "beyond the range of the average human hearing"

Answers to your questions to the best of my ability:
Different recording methods have different FA characteristics.
FA cut off just below 15khz is often indicative of mp3 for live recordings. I am not sure of broadcast specifications that cut there, but the info can probably be found at wikipedia or hydrogenaudio. For instance web broadcasts will have different specs than satellite radio which is different from digital radio etc.
The sharp line in the SA indicates to me an electronic clipping of the signal information.
If an original source has no information above 15khz [like a classic mp3] but is broadcast over the air on a signal that has a broader frequency range, there may still be information [ie noise even if you can't hear it] above the 15khz threshold.
Think of it as the broadcast coming down a pipeline. If the water flowing only fills the bottom half of the pipe there is still air and other stuff coming down the pipe above the water line.

I don't know that FM and TV cut at 16khz. I guess I could look it up, but I can pretty much guarantee that it varies around the world. I find it a little hard to believe that FM radio in the US and TV audio use the same thresholds but I could be wrong. Also if it's using compression and not clippers, I wouldn't think it would be such a hard line on the SA.
DATs also produce cutoffs of the frequencies but it varies depending on the mode [ie LP vs SP etc]. Mini Discs have yet another set of characteristics. Generally the DAT and MD recordings have drop offs at higher frequencies. Also variable bit rate mp3s cause even more gray area.

I've been told, and I believe it, that truly recognizing and identifying all the signatures of different recordings is as much an art form as it is science. That's why having as much lineage info as possible is crucial. For instance knowing it was originally a DAT in LP or a MD give you a great jumping off point. FWIW audio ripped from DVDs is a whole different set of specs. Some is lossy but some isn't.

Reading this back I'm not sure I really cleared anything up but it's a very complicated subject and while I am experienced, audio is not my specialty.

Hope this helps. I'm really try to learn to read these myself.

Disclaimer:
This is a limited, general and sometimes not totally technically accurate description of a complicated subject. I'm am not and will not be in a flame war but any constructive input is of course welcome.

Five
2007-09-05, 12:16 AM
the cutoff is more abrupt in recent broadcasts, also the sound is very slurry like a lossy source... still, it would be expected to be able to see some blocky artifacts. I have noticed this with mainstream Toronto radio. If you could share a sample to rapidshare or similar I would like to take a closer look at it. I can also post SA screencaps for recent FM broadcasts I have taped & recieved. I can also contrast this with older (70s and 80s) broadcasts. btw I would be quite happy to discover that there is less lossy material being broadcast than I had previously estimated...

GIGFY26
2007-09-05, 01:16 AM
Thanks for the info Five,

Did a quick google of some products and it does I see things like FM transmitter ranges of 20hz to 15 khz for the Orbands. I have to say that's surprising and a little disappointing. I always thought FM was a higher quality. I would guess and hope however that most stations run compression and not clippers. This would make it so the ratio from quiet to loud would stay intact but reduced and not just throwing info away. I'm not sure that would make a difference but it would make me feel better :D. I checked a few "FM" sources that I have for shows. For some reason EAC would only give me SAs of two and they fell of about 15khz but didn't seem as sharp as I have seen in some mp3s. The one that I could do a FA and SA, the SA still showed a dropoff around 15khz but the FA didn't show any sharp drop off. That seems a little weird.

Thanks guys. I hope we get a bunch of comments. I'm really trying to figure this all out as well, but I do feel it's a bit of a "guesstimate" sometimes. Again, that's where lineage can help so much to point us in the right direction.

Great Topic!!!!

GIGFY26
2007-09-05, 01:19 AM
Five,

What's your take on the FAs and SAs that were posted above?

vladsmythe
2007-09-05, 01:53 AM
Uh-huh.... and your point is what, exactly.........?

Regards, Graham

I'm with Graham on this one. New topic please. :hmm:

procella
2007-09-05, 09:04 AM
the cutoff is more abrupt in recent broadcasts, also the sound is very slurry like a lossy source... still, it would be expected to be able to see some blocky artifacts. I have noticed this with mainstream Toronto radio. If you could share a sample to rapidshare or similar I would like to take a closer look at it. I can also post SA screencaps for recent FM broadcasts I have taped & recieved. I can also contrast this with older (70s and 80s) broadcasts. btw I would be quite happy to discover that there is less lossy material being broadcast than I had previously estimated...

Not much time at the moment. I will try to ul on Rapidshare later. Never done this before though. First example is FooFighters2007-08-17. I grabbed it from ZOMB but a slightly different version is on DaD also.
And I would really like to see your old and modern screencaps. Think this is one of the few things which are missing here. Information about FMs is spread over a lot of different threats.
From what I've seen so far I think you didn't overestimate the degree of lossyness in modern day FM. But I still have a lot of CD-rs to check.

Five
2007-09-05, 12:57 PM
I'll get those up in the next few days, I'm also very busy!

Five,

What's your take on the FAs and SAs that were posted above?
looks lossy but I would like to take a closer look & listen to find some more concrete evidence.

Keep in mind that TTD, DIME and sites in that vein still allow these broadcasts to be shared so long as they are taped from the open air, not from an internet or satellite radio source.

procella
2007-09-05, 01:46 PM
Samples:

http://rapidshare.com/files/53613894/KCMP_sample.wav
http://rapidshare.com/files/53615745/BBC_1_sample.wav

GRC
2007-09-05, 03:52 PM
Again, I say; what's your point? :hmm:

Whether you decide FM is lossy or not, in the absence of a better source, it's all you've got.

All FM broadcasts are 'off-air', 'over the air', or, for want of a better word, 'Post-FM'.

The only way to improve on it, without re-engineering the transmission protocols, is for someone to provide a matching 'Pre-FM' source. In the absence of this, does it really matter whether or not the post-FM is lossy or not? It's the ONLY source.

Regards, Graham

Five
2007-09-05, 04:13 PM
Graham, its just a discussion with lots of techno and babble

Five
2007-09-05, 04:15 PM
ps there's another thread over here:
http://www.thetradersden.org/forums/showthread.php?t=9766

I haven't found blocks in those samples other than the incredibly flat tops. Sound is quite good, better than the sound of the big stations in Toronto.

procella
2007-09-05, 04:21 PM
Thanks for the info Five,

Did a quick google of some products and it does I see things like FM transmitter ranges of 20hz to 15 khz for the Orbands. I have to say that's surprising and a little disappointing. I always thought FM was a higher quality. I would guess and hope however that most stations run compression and not clippers. This would make it so the ratio from quiet to loud would stay intact but reduced and not just throwing info away. I'm not sure that would make a difference but it would make me feel better :D. I checked a few "FM" sources that I have for shows. For some reason EAC would only give me SAs of two and they fell of about 15khz but didn't seem as sharp as I have seen in some mp3s. The one that I could do a FA and SA, the SA still showed a dropoff around 15khz but the FA didn't show any sharp drop off. That seems a little weird.

Thanks guys. I hope we get a bunch of comments. I'm really trying to figure this all out as well, but I do feel it's a bit of a "guesstimate" sometimes. Again, that's where lineage can help so much to point us in the right direction.

Great Topic!!!!

Thanks for your explanations. A little background information is good always.

EAC isn't good. For SA you should get yourself CEP. Trial version is enough. FA and SA still work after it's expired. Check here:
http://www.thetradersden.org/forums/showthread.php?t=4288. I like audacity for FA, at the moment. That's pretty fine for my inexperienced eyes.

You can't decide what it is if you only know the point of the cutoff. There are also mp3s which only cutoff above 20Khz, MDs which cutoff below 16 Khz etc. And it may also have been compressed, pitch changed etc.

I think that a pro will be able to decide correctly in most cases. Basically the problem is that you only may proof lossyness but never losslessness. So that's like in science. You can only proof what's wrong. And the art is to find the right test in difficult cases which proofs lossyness.

procella
2007-09-05, 04:44 PM
ps there's another thread over here:
http://www.thetradersden.org/forums/showthread.php?t=9766

I haven't found blocks in those samples other than the incredibly flat tops. Sound is quite good, better than the sound of the big stations in Toronto.

I know this one. But you didn't explain there why it is lossy. I was thinking about the cutoff at 15 Khz and the sharp cutoff line. But I couldn't be sure that's correct and that's all. So, please, a few words about its lossyness.

Five
2007-09-05, 04:53 PM
well let me dig up some of my FM-sourced shows when I get home and get back to you on that... iirc the older FM broadcasts have a more hazy cutoff, but the new ones look like they've been very abruptly sawed off. In the case of these two broadcasts I couldn't find blocks and they sound decent, so maybe they're not lossy, perhaps they are using a more accurate digital LPF :hmm: I'm not 100% certain, either. However there are other recent FM captures that I am certain about and I can post some SA screencaps from those, as well as some older FM shows from the pre-mp3 days and we can compare.

Five
2007-09-05, 05:03 PM
I'm not even certain why they are lossy encoding broadcasts before sending them to air... here's a bit of relevant recent conversation from the zep board:
audio is really suffering these days... it seems like mostly every hifi cd that's sold doesn't get played, only ripped to mp3 and put on a computer and/or iPod. Its like you're totally out of fashion and a very strange person if you don't listen strictly to mp3/aac as your only source of music. Almost all the radio stations are broadcasting it now as well, which I don't understand. Are they short on HD space or something? I mean the analog broadcasts, of course it has an advantage for xfm
You aren't saying XM or Sirius broadcast CD quality are you? Because there is no way they are.
no I'm saying that since its digital information being sent on XM/Sirius etc the lossy compression allows them to send 1000 stations, which is a tradeoff which you get something for.

what doesn't make sense is that the mainstream local stations are broadcasting the same way they did in the old days, but sending out lossy audio. Some stations in Toronto are worse than others... Q107, which is the Toronto classic rock station sounds like 128kbps cbr mp3, but its just an analog broadcast like it was back in the 80s when it didn't have all that mp3 swish in it. Now I'm listening to mp3s on my same reciever but no extra 1,000 stations wtf
That was the product of Clear Channel/Infinity/and others.....they made every damn rock station in the country have the same lame 40 song playlist....thus taking a DJ and turning him/her into nothing more than an on air personality to lead in songs and repert PSA's and weather. The rest became automated and what easier/more efficiant way than have a computer do it.

procella
2007-09-05, 05:47 PM
well let me dig up some of my FM-sourced shows when I get home and get back to you on that... iirc the older FM broadcasts have a more hazy cutoff, but the new ones look like they've been very abruptly sawed off. In the case of these two broadcasts I couldn't find blocks and they sound decent, so maybe they're not lossy, perhaps they are using a more accurate digital LPF :hmm: I'm not 100% certain, either. However there are other recent FM captures that I am certain about and I can post some SA screencaps from those, as well as some older FM shows from the pre-mp3 days and we can compare.

Thought I try to google a little:

May 4 2005, 16:37 Post #51

The BBC distribute FM around the country in NICAM format, so assuming you can receive a relatively strong FM signal then you're basically hearing NICAM-encoded audio.

NICAM is 14-bit PCM companded to 10-bits using a sampling frequency of 32 kHz (see http://tallyho.bc.nu/~steve/nicam.html). So, not capable of CD-quality, but not too far off it. And although it might appear that its audio bandwidth will be narrower than MPEG audio because of the lower sampling frequency, all digital radio stations in the UK that I'm aware of lowpass filter with a cutoff frequency of about 15.5 KHz anyway, so there's really no difference in that respect.


Not sure if you know about that. 2 years old but NICAM should be a good guess still.

Five
2007-09-05, 07:00 PM
well I'll be... so its a lower sampling frequency LPCM WAV?!?? that makes a hell of a lot of sense. Also slightly more shallow bit depth making it a little more coarse. Sampling at 32kHz gives a hell of an abrupt cutoff at 16kHz (nyquist). So its not mp3 at all!

The lower-grade wav doesn't make the hated swish, that's a hell of a broadcasting system they've got over there. Are you living in the UK? You should be thankful for the BBC :clap:

Source: WWOZ 90.7 FM New Orleans April 27, 2007
the third is a closeup (note frequency scale on right)

procella
2007-09-05, 07:08 PM
I found a page about KCMP. Also over 2 years old. And there someone says that 'The actual broadcast signal quality is roughly equivilant to 96Kbps MP3'. But can't really confirm that this is correct.
It's almost funny. They search for music for their music library in CD quality and a person says: 'there is a quality issue with taking audio that has previously been compressed and putting it on the air. It really wouldn't sound all that great after passing through our web encoders or the digital radio codec'.

Five
2007-09-05, 07:15 PM
^that one the DJ says was taped a couple days previous, perhaps delayed broadcasts are stored as lossy?

LOVE BATTERY @<hidden> HIGH DIVE - SEATTLE,WA. 2006-07-01 KEXP FM

Five
2007-09-05, 07:18 PM
^Lineage: KEXP.org Lossless Stream
(codec of the stream is WMA Lossless - Original bit rate is 1411.2 kb/s.)
Total Recorder-WAV-Wave Splitter-TradersLittleHelper-FLAC(6).

it is not WMA lossless! oh, well. it sounds as awful as it looks, but its the first love battery show ever to be seeded (pretty sure).

Five
2007-09-05, 07:29 PM
I found a page about KCMP. Also over 2 years old. And there someone says that 'The actual broadcast signal quality is roughly equivilant to 96Kbps MP3'. But can't really confirm that this is correct.
yeah, that's about right try encoding a 96kbps vbr mp3 and it will look about equal in quality to that, and a bit of a different 'signature' made from smaller blocks. I wonder what that codec is that they're using? looks a bit like minidisc type-r at the top :hmm:

It's almost funny. They search for music for their music library in CD quality and a person says: 'there is a quality issue with taking audio that has previously been compressed and putting it on the air. It really wouldn't sound all that great after passing through our web encoders or the digital radio codec'.
they have strict control over transcodes... arrgh, its like oink or something.

they used to broadcast records on the radio, with no digital shit in the path, those were the days.

here's some from a talk radio show called Hour 25, scifi/comics talk radio 1986:

Five
2007-09-05, 08:02 PM
^check out the soft cutoff on that! :cool:

Five
2007-09-05, 10:37 PM
Taj Mahal New Orleans Jazz Festival 2007

Five
2007-09-05, 10:53 PM
^lossy *sighs*

The Bruce Springsteen Special (FM 1987)
-this one I would blame the lack of frequency response on taping equipment and media (TDK D90). The carrier isn't even there, and it wasn't removed (I did the transfer)

Five
2007-09-05, 11:06 PM
Billy Joel 1978-03-05 (from 2005 rebroadcast) ... lossy, a little different from the others

GIGFY26
2007-09-06, 12:11 AM
Damn I've learned a lot.
Thanks for this info. I was always more impressed by FM than I should have been. Audio has never been my specialty obviously, but I would guess you guys nailed it with the storage issue. I actually wouldn't be surprised if the library for a local station were stored on a shared server within the network and pulled across as needed. You could almost run a local station with a transmitter and a computer. It seems like accountants run everything now and "good enough" is a company motto.
Learned a ton. Thanks

GIGFY26
2007-09-06, 12:29 AM
What do you guys see in this one?

INXS 1997 04 24 FM show that was uploaded recently on Dime.

No harsh drop on the FA and no straight cutoff in the SA. Based on your comments five, can I assume the SA straight line at 16khz is the subcarrier? No audio above the cutoff but nothing abrupt in either analysis either. Could this be just analog compressed to fit the bandwidth?

GIGFY26
2007-09-06, 12:40 AM
I'll try the attachment again

GIGFY26
2007-09-06, 12:42 AM
Sorry about the size on that one. My first attachment here. I'll scale it down in the future.

Five
2007-09-06, 12:21 PM
EAC isn't the best, really... see how the FA doesn't even show the drop plainly visible in the SA (you could try upping the fft size fwiw). also see here (http://www.thetradersden.org/forums/showthread.php?t=4288).

I'm pretty sure that's not the carrier at 16kHz, seems to me its some other noise. what's the lineage on that? can you post a short track to rapidshare? I'm wondering when the stations started switching over, and I haven't got anything from the late 90s on hand.

the cutoff visible in the SA looks normal for radio, of course.

procella
2007-09-06, 03:35 PM
I dl'ed one track of this INXS show and here are 2sec SA and FA. Guess it's lossy but better you explain that, five.:)
Wanted to up them sooner but I had a car crash. Nothing big and my car just got hit but a lot of trouble.

Five
2007-09-06, 03:45 PM
nah, I don't think that one's lossy from what I can see there... very strange that red stripe being where it is :hmm: what city/station is that?

procella
2007-09-06, 04:02 PM
Torrent info:

Mayan Theatre,
Los Angeles, California - April 24, 1997.

Source: FM Broadcast.
Lineage: Traded cd > EAC > .Wav > Flac Frontend (Level 7).

procella
2007-09-06, 05:16 PM
What's this? The first 2 seconds of the song.

procella
2007-09-06, 05:27 PM
What happened? Had no intention to put this pic into the thread. Thought I just uploaded like the others before.

procella
2007-09-06, 07:32 PM
Thanks for all these examples, Five. Those from the 80s show the difference in the cutoff real nicely.

Is there a way to see the difference between a NICAM - and a mp3 cutoff?
The BBC still seems to keep some quality. But NICAM is lossy also. So good, but could still be better. I am not in Britain but I'm in Europe, in the center of it. Not sure how FM quality is here now but I will check some I downloaded and see if I find interesting ones. I know that Spanish stations lower the quality of live broadcasts sometimes. One I got cuts off at 8 Khz. But doesn't seem to be lossy. And it was announced as a low quality broadcast.

freezer
2007-09-06, 08:37 PM
The Hour 25 shows may not be the best example to use.

The sound was doctored in playback, because I was looking to get the optimum reproduction and on some of those shows, playback was in mono, by either using a mono only deck or by folding the stereo channels into a single monaural source. And in some instances, I ran the signal through a 25 year old equalizer. (And I have no longer have any idea which Hour 25 shows were transferred in mono or stereo.)

Especially since I couldn't discern any stereo seperation in the interview portions of those broadcasts, the many of the original stereo cassettes were transferred to cdr in mono.

GIGFY26
2007-09-07, 08:50 PM
EAC isn't the best, really... see how the FA doesn't even show the drop plainly visible in the SA (you could try upping the fft size fwiw). also see here (http://www.thetradersden.org/forums/showthread.php?t=4288).

I'm pretty sure that's not the carrier at 16kHz, seems to me its some other noise. what's the lineage on that? can you post a short track to rapidshare? I'm wondering when the stations started switching over, and I haven't got anything from the late 90s on hand.

the cutoff visible in the SA looks normal for radio, of course.

Sorry I haven't checked in. I'll try to get it post on rapidshare soon. I've never used it and I'm getting a little slammed right now.

The INXS show was from Dime
Lineage from info file:
Mayan Theatre,
Los Angeles, California - April 24, 1997.

Source: FM Broadcast.
Lineage: Traded cd > EAC > .Wav > Flac Frontend (Level 7).

Thanks for helping me learn this stuff.

Five
2007-09-08, 02:53 AM
sure, whenever you get the chance

What happened? Had no intention to put this pic into the thread. Thought I just uploaded like the others before.
if you attatch only one pic it displays in the thread, if you put 2 or 3 there are just links.

so this pic reveals that the 'red stripe' at 16kHz is not on the tape, it is from the transfer. the beginning black part should be silent since the tape has not started yet (no bias noise).

procella
2007-09-08, 09:14 AM
Just trying to find some good examples for the broadcast of Dutch station VPRO over the years. But will take some time probably.
While looking I stumbled over this one: Sly and the Family Stone - Piknik VPRO 1971FM - 1970-09-10. It is up here on the Den. Looks pretty modern for its age.

Five
2007-09-08, 07:47 PM
VPRO did a bunch of rebroadcasts just a couple years ago... this is probably from that, not from the original 1971 broadcast from what I can gather.

I'm trying to find some pure unaltered broadcasts from that era to post some examples, haven't turned up anything yet...

procella
2007-09-09, 10:41 AM
Hope you find some. But better not try VPROs. Dl'ed one track from 3 or 4 of their old ones now and all looked modern. And the uploaders all stated that this was from 60s or 70s broadcast.
And, well, the other way round. I was asked on DIME to have a look at some BBC sessions from Sleater-Kinney someone wants to upload there. I don't know the date of these shows but this band exists since around 1995 only. And two of those look exactly like a bad 80s FM. Not lossy and not completely dark above cutoff but one cuts off at 8 Khz, the other at 10 Khz. Did you ever see something new which looked bad like that?

pawel
2007-09-10, 05:42 AM
Here are four examples of pure digital captures via a DVB-S card:
1. WDR FM Radio (classic music), AC3 448 kbps
2. same as [1] but MP2 192 kbps
3. WDR Rockpalast TV, AC3 448 kbps
4. same as [3] but MP2 192 kbps

AC3 was imported to Adobe Audition via freeware plugin: http://www.vuplayer.com/audition.php

pawel
2007-09-10, 05:43 AM
#4 Rockpalast TV 192 kbps

procella
2007-09-11, 01:18 PM
Found one fine 70s US broadcast. But not a typical one shurely. Was remastered and released on a boot CD.

Five
2007-09-11, 02:12 PM
that springsteen doesn't look typical at all! maybe its prefm? or somehow a lot of highs have been generated...

another thing that dawned on me is that cassettes can't record the upper highs so that's probably why I'm having trouble finding older fms with the carrier visible.

Pawel, the first three are pretty decent, look to be similar in quality to an MD (atrac) recording. but the 4th is lower-quality than 128kbps cbr mp3.

I don't understand the bitrates... the one that says '192kbps' is not like an mp3 at 192kbps :hmm: I guess its something with the different codec?

I'm not sure how we would go about allowing the kind of captures you're posting... so long as its recorded well and the cutoff it above 16kHz it would be similar or slightly better in quality than some of the modern fm 'open air' broadcasts we've allowed here. Right now we have the advantage of allowing stuff taped from the open air and not allowing stuff that isn't. Its a real can of worms to try to suss out which digital sources are okay and which are not. They usually don't look (or presumably sound) as high quality as the first three you've posted above.

pawel
2007-09-12, 05:36 AM
I don't understand the bitrates... the one that says '192kbps' is not like an mp3 at 192kbps :hmm: I guess its something with the different codec?

I'm not sure how we would go about allowing the kind of captures you're posting


He he, so you would have to ban all DVDs from Rockpalast :D , unless they are DVB captures with secondary AC3 stream. All 192kbps are in MP2 format as filename say.

Five
2007-09-12, 11:56 AM
lol... okay, I see what you mean. those wouldn't be allowed in the audio section, but are okay in the video section.

I meant the audio-only broadcasts.. #1 and #2 are audio-only broadcasts, correct?

procella
2007-09-12, 03:10 PM
[QUOTE=Five]that springsteen doesn't look typical at all! maybe its prefm? or somehow a lot of highs have been generated...

You're right, Five. Pre-FM. Was announced as a broadcast master. But in the discussion it turned out to be the remaster which was sourced from Pre-FM. My mistake. Looked too good to be true, actually.

procella
2007-09-13, 09:17 AM
One of the oldest FMs I have. A Dutch broadcast from 1980. Taped by the same person who uploaded it to DaD.
Source : FM > Cassette > Audacity > CD WAVE Editor > FLAC

procella
2007-09-13, 09:48 AM
Now yesterday it got reupped.

FM (maybe VARA Radio) > Cassette > Audacity > CD WAVE Editor > FLAC > dime > wav > MAGIX cleaning Lab Version 2003 > WAV > FLACs (SBE Level8)

After being asked the uploader stated: 'Yes, i used the dehisser-function from magix and something else'.

Sa and Fa look different now clearly. The result of dehissing? Or was it the 'something else'?
Actually I think it sounds worse now than before when listening to it on my computer. 'Though the difference is not big.

Five
2007-09-13, 10:55 AM
looks like the dehissed version is from a different source, as it has more frequency response in the highs :hmm:

here's an old one with the carrier intact... not sure if its a rebroadcast or taped back in the day.

Herbie Hancock and Headhunters 1974-11-06 Sendesaal, Radio Bremen, Germany (16-bit) (FLAC) (http://www.thetradersden.org/forums/showthread.php?t=45218)

procella
2007-09-14, 01:05 PM
I found this broadcast from 1997. Looks good. But carrier is much weaker. Concert was in Hamburg. Station wasn't mentioned, unfortunately. But probably it was aired by one of those North German stations.

Five
2007-09-14, 01:59 PM
^that doesn't even look like an fm :hmm: seems to be some faint line where the carrier should be and a bit of an 'edge' where the cutoff shold be :hmm: very strange...

procella
2007-09-14, 03:20 PM
[QUOTE=Five]looks like the dehissed version is from a different source, as it has more frequency response in the highs :hmm:

That's the strange thing. According to the lineage and to the words of the uploader it is the same source. I included a 2 sec SA (of the old FM) as it looks like the one I provided doesn't work. But I guess it doesn't change much. Clearly lower response above 16 khz.

procella
2007-09-14, 03:34 PM
Oh well. Same problem as before. But I used a different pic.

procella
2007-09-14, 05:24 PM
^that doesn't even look like an fm :hmm: seems to be some faint line where the carrier should be and a bit of an 'edge' where the cutoff shold be :hmm: very strange...

From the info:

FM - tape - editing ....- cue sheet with EAC - tracks done with cuesplitter - flac8 - md5 - you (no artwork, not cd/r sourced - taper me - )

Den Haag Statenhal 1997-02-21 - approx 49 min.
10 Tracks, last "track" is the mods voice and can be removed

Hamburg Markthalle 1997-02-22 - approx 53 min.
11 Tracks, last song faded out


I have the Hamburg part only. No announcer on that one. So can't prove correctness of information. But would be strange if it was wrong. Still, I always believe that you are right, Five.:)

corsair
2007-09-15, 01:01 AM
Since we're on the topic of FMs...

I've got a show with his lineage:
Digital Radio (over Digital TV Receiver) - Harddisk Recorder (LPCM Mode) - Burn to DVD - Rip Audio to Harddisk with SmartRipper - Normalization to 96%, Fade-In at the Beginning and Fade-Out at the end - Convert from 48kHz to 44.1 kHz

Does the spectral show a normal FM, or its MP3 encoding lossy?

pawel
2007-09-15, 04:31 AM
It's MP2 192 kbps, and of course lossy. You preserve a bit more from the original signal if you don't convert it to WAV but burn it as a fake DVD - blank (black) screen with audio. Such DVD may store almost 20 hours of music in MP2 format.