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#1
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Old Recording Made with Electret Condenser Mics Sounds Nearly as Good as State of Art Current Digital Recordings?!!
I dug out an old Betamax tape I made in 1986 of a 5-piece jazz ensemble
performing at a night club, just to refresh my memory of what I had in my collection of old tapes. I found the experience downright disturbing. Why? Because it sounds so darned GOOD. It has no right to sound good. It was made with electret condenser mics made around 1982, feeding a Radio Shack mixer, driving a Radio Shack model 22 Beta Hi-Fi VCR. I used a Quasar professional series Newvicon video camera for the visual portion of the recording, which looks simply awful by today's standards. But the sound... I could not believe it. I have some state-of-the-art digital recordings I bought on CD that were made in 2003 and they don't sound that much better. In fact, a lot of my newer recordings have a blanket of hiss in the background. This old recording only suffered from VCR-related problems: tape dropouts and a 30hz purring sound caused by the vertical scan rate of the helical recording heads. Aside from that, the transient response, the s/n ratio on the high end and the smoothness of the frequency spectrum was an unexpected delight. The drums were rousing, very stunning with no dynamic compression. The saxes sounded like they were right in the room and the standup bass had a beautiful detailed clarity and a nice full-bodied bass that didn't boom. The piano sounded smooth with no overhanging notes. And during set breaks, I heard no hiss in this relatively quiet venue. So if my best digital recording of a jazz ensemble is a 10, this recording easily comes in at a 7.5 or better. The think that irks me, is that, with today's digital technology, why are we still getting CDs with very audible hiss on them, when a pair of electrets driving an old RS mixer can produce a recording that is much quieter to the point where any hiss is masked by the ambient noise? What kind of signal routing and planning can cause state of the art recording facilities to turn out such a noisy recording? Now that I have much better recording equipment today, fully digital, I am dying to engage another ensemble recording and see how much better I can do than I did in 1986 with the Betamax VCR. But I still can't believe how enjoyable and natural the sound of that old recording is! -- Take care, Mark & Mary Ann Weiss VIDEO PRODUCTION . FILM SCANNING . DVD MASTERING . AUDIO RESTORATION Hear my Kurzweil Creations at: http://www.dv-clips.com/theater.htm Business sites at: www.dv-clips.com www.mwcomms.com www.adventuresinanimemusic.com - |
#2
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You've given evidence for something that I really wish more people
would realize: if you can put a good enough pair of microphones in a good place in front of a good performance, you'll very likely get a good recording. All that the recorder has to do is not ruin it. I'm not saying that it makes _no_ difference what medium or recorder you use--but just as you've found, a less-than-ideal choice can sometimes be a very good choice for a given situation. So thanks for posting your story. It also shows that an invisible component (the engineer's good sense) is the most important item of equipment for any recording. --best regards |
#3
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#4
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Hey, if the band is playing well, the room and mic placement is
decent, why wouldn't it sound great? Cheaper mics don't automatically mean crap... usually the problem is more acoustics or performance based. Al On Fri, 28 Jan 2005 10:27:08 GMT, "Mark & Mary Ann Weiss" wrote: I dug out an old Betamax tape I made in 1986 of a 5-piece jazz ensemble performing at a night club, just to refresh my memory of what I had in my collection of old tapes. I found the experience downright disturbing. Why? Because it sounds so darned GOOD. It has no right to sound good. It was made with electret condenser mics made around 1982, feeding a Radio Shack mixer, driving a Radio Shack model 22 Beta Hi-Fi VCR. I used a Quasar professional series Newvicon video camera for the visual portion of the recording, which looks simply awful by today's standards. But the sound... I could not believe it. I have some state-of-the-art digital recordings I bought on CD that were made in 2003 and they don't sound that much better. In fact, a lot of my newer recordings have a blanket of hiss in the background. This old recording only suffered from VCR-related problems: tape dropouts and a 30hz purring sound caused by the vertical scan rate of the helical recording heads. Aside from that, the transient response, the s/n ratio on the high end and the smoothness of the frequency spectrum was an unexpected delight. The drums were rousing, very stunning with no dynamic compression. The saxes sounded like they were right in the room and the standup bass had a beautiful detailed clarity and a nice full-bodied bass that didn't boom. The piano sounded smooth with no overhanging notes. And during set breaks, I heard no hiss in this relatively quiet venue. So if my best digital recording of a jazz ensemble is a 10, this recording easily comes in at a 7.5 or better. The think that irks me, is that, with today's digital technology, why are we still getting CDs with very audible hiss on them, when a pair of electrets driving an old RS mixer can produce a recording that is much quieter to the point where any hiss is masked by the ambient noise? What kind of signal routing and planning can cause state of the art recording facilities to turn out such a noisy recording? Now that I have much better recording equipment today, fully digital, I am dying to engage another ensemble recording and see how much better I can do than I did in 1986 with the Betamax VCR. But I still can't believe how enjoyable and natural the sound of that old recording is! |
#5
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"David Satz" wrote in message ups.com... You've given evidence for something that I really wish more people would realize: if you can put a good enough pair of microphones in a good place in front of a good performance, you'll very likely get a good recording. All that the recorder has to do is not ruin it. I'm not saying that it makes _no_ difference what medium or recorder you use--but just as you've found, a less-than-ideal choice can sometimes be a very good choice for a given situation. So thanks for posting your story. It also shows that an invisible component (the engineer's good sense) is the most important item of equipment for any recording. --best regards I'm sure there is (obviously) some truth to this, but what I find disturbing most in this day and age is that $100K and better studio facilities are putting out recordings with very audible hiss. Some newer CDs have one broadband compressor and you can hear it pumping so it sounds like an FM broadcast, not a CD. But with the $3000 mics, $100K consoles, $2500 mic preamps and digital I/O throughout, you would think hiss would be completely banished. This recording probably sounds good because I happened to set an optimal recording level, making the best use of the availabe 45dB s/n ratio of the electret mics (which probably perform a lot better than their spec quotes). When I compare these old mics with my modern new large-diaphragm condenser mics, there is no comparison in hiss levels at all. The difference in sensitivity alone will account for an improvement just on the mic pre not having to provide the extra 21dB of gain. I think that the other factor is that the band didn't utilize an extreme bandwidth from low to high. All that was needed was flat response from 50hz to 15kc to convey the music, since there were no bass notes below 50hz and most people can't hear anything above 15kc anyway, unless they are under 50 years of age. :-) I am theorizing that the program material didn't expose the weaknesses of the system. Had it been an organ that I recorded, I might have noticed a loss of low bass, for instance. But the lack of hiss really amazes me. All I hear is the 30 hz vertical framing noise from the video heads between sets. The venue was VERY quiet--only a few people at some tables far back from the band and behind cardioid mics. I'm going to capture this and put it on a DVD-R so that it is easier to watch. -- Take care, Mark & Mary Ann Weiss VIDEO PRODUCTION . FILM SCANNING . DVD MASTERING . AUDIO RESTORATION Hear my Kurzweil Creations at: http://www.dv-clips.com/theater.htm Business sites at: www.dv-clips.com www.mwcomms.com www.adventuresinanimemusic.com - |
#6
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And maybe it helps to show that some of us may overstate the importance of
very expensive or "state of the art" mics. The difference between a good mic and a better (or different) one may be quite minor, often negligible after mixing and mastering. It ain't the brush; it's the artist. "Uncle Russ" Reinberg WESTLAKE PUBLISHING COMPANY www.finescalerr.com WESTLAKE RECORDS www.westlakerecords.com "Mark & Mary Ann Weiss" wrote in message k.net... "David Satz" wrote in message ups.com... You've given evidence for something that I really wish more people would realize: if you can put a good enough pair of microphones in a good place in front of a good performance, you'll very likely get a good recording. All that the recorder has to do is not ruin it. I'm not saying that it makes _no_ difference what medium or recorder you use--but just as you've found, a less-than-ideal choice can sometimes be a very good choice for a given situation. So thanks for posting your story. It also shows that an invisible component (the engineer's good sense) is the most important item of equipment for any recording. --best regards I'm sure there is (obviously) some truth to this, but what I find disturbing most in this day and age is that $100K and better studio facilities are putting out recordings with very audible hiss. Some newer CDs have one broadband compressor and you can hear it pumping so it sounds like an FM broadcast, not a CD. But with the $3000 mics, $100K consoles, $2500 mic preamps and digital I/O throughout, you would think hiss would be completely banished. This recording probably sounds good because I happened to set an optimal recording level, making the best use of the availabe 45dB s/n ratio of the electret mics (which probably perform a lot better than their spec quotes). When I compare these old mics with my modern new large-diaphragm condenser mics, there is no comparison in hiss levels at all. The difference in sensitivity alone will account for an improvement just on the mic pre not having to provide the extra 21dB of gain. I think that the other factor is that the band didn't utilize an extreme bandwidth from low to high. All that was needed was flat response from 50hz to 15kc to convey the music, since there were no bass notes below 50hz and most people can't hear anything above 15kc anyway, unless they are under 50 years of age. :-) I am theorizing that the program material didn't expose the weaknesses of the system. Had it been an organ that I recorded, I might have noticed a loss of low bass, for instance. But the lack of hiss really amazes me. All I hear is the 30 hz vertical framing noise from the video heads between sets. The venue was VERY quiet--only a few people at some tables far back from the band and behind cardioid mics. I'm going to capture this and put it on a DVD-R so that it is easier to watch. -- Take care, Mark & Mary Ann Weiss VIDEO PRODUCTION . FILM SCANNING . DVD MASTERING . AUDIO RESTORATION Hear my Kurzweil Creations at: http://www.dv-clips.com/theater.htm Business sites at: www.dv-clips.com www.mwcomms.com www.adventuresinanimemusic.com - |
#7
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On Fri, 28 Jan 2005 10:27:08 GMT, "Mark & Mary Ann Weiss"
wrote: I dug out an old Betamax tape I made in 1986 of a 5-piece jazz ensemble performing at a night club, just to refresh my memory of what I had in my collection of old tapes. I found the experience downright disturbing. Why? Because it sounds so darned GOOD. It has no right to sound good. It was made with electret condenser mics made around 1982, feeding a Radio Shack mixer, driving a Radio Shack model 22 Beta Hi-Fi VCR. I used a Quasar professional series Newvicon video camera for the visual portion of the recording, which looks simply awful by today's standards. But the sound... I could not believe it. snip Consumer Beta Hi-Fi, an FM system without the constraints of broadcast FM, was technically superior to JVC's depth recorded VHS Hi-Fi. For a time after the introduction of the Sony SL-5200 in 1984, it rivalled DAT with many users. I have some state-of-the-art digital recordings I bought on CD that were made in 2003 and they don't sound that much better. snip Further proof that digital recording sucks, eh? In fact, a lot of my newer recordings have a blanket of hiss in the background. snip A common fault of noisy codecs. It's not that much better, just "different" than analog tape hiss. This old recording only suffered from VCR-related problems: tape dropouts and a 30hz purring sound caused by the vertical scan rate of the helical recording heads. snip There was a switching adjustment on older Beta Hi-Fi decks that eliminated that, as I remember. The think that irks me, is that, with today's digital technology, why are we still getting CDs with very audible hiss on them snip Because digital recording sucks. People STILL can't figure out how to properly sync that crap! when a pair of electrets driving an old RS mixer can produce a recording that is much quieter to the point where any hiss is masked by the ambient noise? What kind of signal routing and planning can cause state of the art recording facilities to turn out such a noisy recording? snip Don't discount the fact that you MIGHT be listening to CD on a noisy player with a noisy DAC...very common. Computer CD-ROMs are genuinely awful...Sound Platers' crap ranks down at the bottom, in my experience. I use a Sound Plaster CD-ROM as a doorstop. Now that I have much better recording equipment today, fully digital, I am dying to engage another ensemble recording and see how much better I can do than I did in 1986 with the Betamax VCR. But I still can't believe how enjoyable and natural the sound of that old recording is! snip I started making audio reference masters with Beta Hi-Fi in 1985. I was blowing away people with them back then...80 dB s/n with no noise reduction schemes, flat as a board freq response, negligible distortion...it was a really contender to DAT in all areas. VHS Hi-Fi isn't quite as good, but is still better than a lot of the cheap digital crap out there today. dB |
#8
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but what I=AD find disturbing most in this day and age is that $100K
and better studio fac=ADilities are putting out recordings with very audible hiss. You are disturbed by it because you are a mastering engineer. Otherwise you would be listening to the music and not notice the hiss. Mike |
#9
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On Sat, 29 Jan 2005 19:52:49 -0800, "Uncle Russ"
wrote: And maybe it helps to show that some of us may overstate the importance of very expensive or "state of the art" mics. The difference between a good mic and a better (or different) one may be quite minor, often negligible after mixing and mastering. snip The mic is THE weak chain in the system. Next weakest is the mic pre. Everything else is gravy, which is why people can turn out pretty good recordings on unbalanced consumer grade crap, as long as it's fed with a good mic. Skimping on a mic while buying/collecting obscenely expensive digital gear is like buying a new Ford Cobra and ordering it with retreads. dB |
#10
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series Newvicon video camera for the visual portion of the recording,
which looks simply awful by today's standards. But the sound... I could not believe it. snip Consumer Beta Hi-Fi, an FM system without the constraints of broadcast FM, was technically superior to JVC's depth recorded VHS Hi-Fi. For a time after the introduction of the Sony SL-5200 in 1984, it rivalled DAT with many users. Yes, the deep layer recording system on VHS was fragile and prone to dropouts. The Beta was pretty robust with good quality tape stock. I have some state-of-the-art digital recordings I bought on CD that were made in 2003 and they don't sound that much better. snip Further proof that digital recording sucks, eh? I won't go so far as to say that digital sucks, but I think that 16 bits might not be quite enough to convey very soft passages without that 'bumpiness' that happens when there are not enough steps on the waveform to convey it accurately. Low sample rates, such as 44.1, also may be inadequate to convey subtle timing differences between sound arrivals, thus reducing the sense of soundstage depth and breadth. In fact, a lot of my newer recordings have a blanket of hiss in the background. snip A common fault of noisy codecs. It's not that much better, just "different" than analog tape hiss. This sounded worse that noisey A/D conversion. I do have one theory though, after troubleshoot an abyssmally noisey Harris Impulse digital mixing console for broadcast use: all that digital clock noise running around the PCBs was getting into the mic preamps. Taken together, it sounded like hiss. We started getting suspicious about this at installation time, and ran a distortion analyzer set to measure the THD+N. We were coming up with unweighted s/n ratios of just 39dB! Needless to say, Harris had to go back to the drawing board on this new console. The client, a major broadcast conglomerate, was one of the first to purchase the Impulse consoles, and I was the one to install them. So that's my take on the hiss. Could it be that some of these mixing desks are falling prey to bad decoupling? This old recording only suffered from VCR-related problems: tape dropouts and a 30hz purring sound caused by the vertical scan rate of the helical recording heads. snip There was a switching adjustment on older Beta Hi-Fi decks that eliminated that, as I remember. It was a problem that plagued all the beta decks I owned, from the Model 19, to the model 22, to the Sony SL-HF1000, which still serves me today for playing my legacy tapes. Worse, they all have a noise gate, which makes the no-signal noise floor seem unbelievably low. But record a violin solo and hear that ugly purring noise punching on and off. Very annoying. The think that irks me, is that, with today's digital technology, why are we still getting CDs with very audible hiss on them snip Because digital recording sucks. People STILL can't figure out how to properly sync that crap! The modern equipment I use today performs well. Even if I make no effort to optimize levels during recording. Perhaps it is a matter of having too many inputs active and gross misadjustment of levels, or a noisy mixing desk. when a pair of electrets driving an old RS mixer can produce a recording that is much quieter to the point where any hiss is masked by the ambient noise? What kind of signal routing and planning can cause state of the art recording facilities to turn out such a noisy recording? snip Don't discount the fact that you MIGHT be listening to CD on a noisy player with a noisy DAC...very common. Computer CD-ROMs are genuinely awful...Sound Platers' crap ranks down at the bottom, in my experience. I use a Sound Plaster CD-ROM as a doorstop. Not the case here, as I do own a few CDs with zilch in terms of hiss. And I have mastered a few CDs right here that are absolutely free of audible noise. It's not the player in my case. It varies with the recording. I have this beautiful piano solos CD that has as much hiss as non-Dolby reel to reel tape. It ruins the performance for me, as I am constantly reminded that the music is not live. It's like there's a screen between me and the piano. Now that I have much better recording equipment today, fully digital, I am dying to engage another ensemble recording and see how much better I can do than I did in 1986 with the Betamax VCR. But I still can't believe how enjoyable and natural the sound of that old recording is! snip I started making audio reference masters with Beta Hi-Fi in 1985. I was blowing away people with them back then...80 dB s/n with no noise reduction schemes, flat as a board freq response, negligible distortion...it was a really contender to DAT in all areas. VHS Hi-Fi isn't quite as good, but is still better than a lot of the cheap digital crap out there today. dB VHS decks have gotten a lot better in the past 6-8 years. I have a couple of cheap RCA decks that I use as 'loggers' to record multiple radio broadcasts to a single VHS tape. Although the frequency response rolls off on the high end at SLP speed just a bit, the decks don't suffer from the head switching noise, and so they sound quite good. I'm anxious to put my high end digital gear to task in a similar recording situation this spring. I have high expectations. -- Take care, Mark & Mary Ann Weiss VIDEO PRODUCTION . FILM SCANNING . DVD MASTERING . AUDIO RESTORATION Hear my Kurzweil Creations at: http://www.dv-clips.com/theater.htm Business sites at: www.dv-clips.com www.mwcomms.com www.adventuresinanimemusic.com - |
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#13
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Maybe it read as though I was comparing inexpensive mics, such as some of
the early Chinese mics, to cream of the crop stuff. What I should have written was "carefully selected very good mics" (such as a KSM44 or any other mic you prefer in that category and price range) whose price can be a third or less of their more expensive counterparts. Would that make the statement any more palatable? Unc WESTLAKE PUBLISHING COMPANY www.finescalerr.com WESTLAKE RECORDS www.westlakerecords.com "DeserTBoB" wrote in message ... On Sat, 29 Jan 2005 19:52:49 -0800, "Uncle Russ" wrote: And maybe it helps to show that some of us may overstate the importance of very expensive or "state of the art" mics. The difference between a good mic and a better (or different) one may be quite minor, often negligible after mixing and mastering. snip The mic is THE weak chain in the system. Next weakest is the mic pre. Everything else is gravy, which is why people can turn out pretty good recordings on unbalanced consumer grade crap, as long as it's fed with a good mic. Skimping on a mic while buying/collecting obscenely expensive digital gear is like buying a new Ford Cobra and ordering it with retreads. dB |
#14
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Hiss has never really bothered people, and it's sometimes intentionally used as an effect. Compression makes the music sound louder, and pumping makes it sound more exciting (those are "normal" falues, not "recording engineer" values). Compression accentuates hiss. For me it doesn't make things more exciting - it makes me seasick and I loathe it. It is also the lazy man's copout from good mixing. Exactly! Compression is for radio broadcasting. It should not be used on modern recordings as a whole composite. I can see a little bit of compression to smooth out an electric bass to make bad playing more consistent, but on percussion, it ruins the stunning and stirring dynamics that make live music a pleasure to hear--and feel. I have this recent recording of a band that is phenomenal, playing some great music. I wish I could obtain the master tapes and remaster the CD for myself though--the engineer(s) in their great wisdom, put a broadband compressor on the output of the mix! The bass was pumping the rest of the program and it sounded sickening! You're not criticizing modern studios, you're criticizing modern production techniques. There's no accounting for taste. Just stop buying modern recordings. You mean he has taste. Don't knock faithful recording - try it some time. You might even learn to appreciate it. (OK, it sounds like you won't, but it was worth a try). I call it "natural recording" --the technique of using just two microphones (do I hear Bob Fine of Mercury, who did this in '58?) for a modern version of Mercury's "Living Presence" miking technique. My idea? Use a pair of cardioid mics with the flattest response possible. Go into the quietest mic preamp you can afford, sample at the highest bit depth and frequency possible, and set the mics up in O.R.T.F. pattern at the front center row of the audience, or just in front of the stage. It's a simple, old-fashioned concept that is lost on engineers today who believe 'it's not a real recording session unless you've got 40 mics on the stage'. Ba-loney! Oh, and just for the record, hiss bothers me hugely. Rehearse, set levels properly, learn to understand the signal chain and the right way to set various stage gains and hiss will not be a problem. d And I simply cannot believe hiss exists today, but it's there. But oddly enough, with my mic setup, I can't find a space quiet enough to hear the hiss, no matter WHAT the levels. When the mic output is -37dB and the mic pre has a -114dB minimum noise floor, one would have to work really hard to create hiss. I suspect there is still analog tape in use in some studios even today, or some really noisy mixing desks that have untamed digital hash running around the busses. -- Best Regards, Mark A. Weiss, P.E. www.mwcomms.com - |
#15
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On Tue, 01 Feb 2005 05:17:03 GMT, "Mark & Mary Ann Weiss"
wrote: Hiss has never really bothered people, and it's sometimes intentionally used as an effect. Compression makes the music sound louder, and pumping makes it sound more exciting (those are "normal" falues, not "recording engineer" values). Compression accentuates hiss. For me it doesn't make things more exciting - it makes me seasick and I loathe it. It is also the lazy man's copout from good mixing. Exactly! Compression is for radio broadcasting. It should not be used on modern recordings as a whole composite. I can see a little bit of compression to smooth out an electric bass to make bad playing more consistent, but on percussion, it ruins the stunning and stirring dynamics that make live music a pleasure to hear--and feel. I have this recent recording of a band that is phenomenal, playing some great music. I wish I could obtain the master tapes and remaster the CD for myself though--the engineer(s) in their great wisdom, put a broadband compressor on the output of the mix! The bass was pumping the rest of the program and it sounded sickening! You're not criticizing modern studios, you're criticizing modern production techniques. There's no accounting for taste. Just stop buying modern recordings. You mean he has taste. Don't knock faithful recording - try it some time. You might even learn to appreciate it. (OK, it sounds like you won't, but it was worth a try). I call it "natural recording" --the technique of using just two microphones (do I hear Bob Fine of Mercury, who did this in '58?) for a modern version of Mercury's "Living Presence" miking technique. My idea? Use a pair of cardioid mics with the flattest response possible. Go into the quietest mic preamp you can afford, sample at the highest bit depth and frequency possible, and set the mics up in O.R.T.F. pattern at the front center row of the audience, or just in front of the stage. It's a simple, old-fashioned concept that is lost on engineers today who believe 'it's not a real recording session unless you've got 40 mics on the stage'. Ba-loney! Oh, and just for the record, hiss bothers me hugely. Rehearse, set levels properly, learn to understand the signal chain and the right way to set various stage gains and hiss will not be a problem. d And I simply cannot believe hiss exists today, but it's there. But oddly enough, with my mic setup, I can't find a space quiet enough to hear the hiss, no matter WHAT the levels. When the mic output is -37dB and the mic pre has a -114dB minimum noise floor, one would have to work really hard to create hiss. I suspect there is still analog tape in use in some studios even today, or some really noisy mixing desks that have untamed digital hash running around the busses. I wonder if the low hiss levels of the old recordings was due to the very simple signal path, which was really quite difficult to mess up. Maybe modern desks are just too complex for the average recording engineer to understand beyond the "this button does this" level. The problem, I guess, is that they have taken the epithet "engineer" to themselves without the slightest justification, in many cases. d Pearce Consulting http://www.pearce.uk.com |
#16
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"Mark & Mary Ann Weiss" wrote in
k.net: Exactly! Compression is for radio broadcasting. It should not be used on modern recordings as a whole composite. I can see a little bit of compression to smooth out an electric bass to make bad playing more consistent, but on percussion, it ruins the stunning and stirring dynamics that make live music a pleasure to hear--and feel. I have this recent recording of a band that is phenomenal, playing some great music. I wish I could obtain the master tapes and remaster the CD for myself though--the engineer(s) in their great wisdom, put a broadband compressor on the output of the mix! The bass was pumping the rest of the program and it sounded sickening! As a classical guy, I avoid compression 99% of the time. I have found, however, when recording a rock band with heavily distorted guitars, that just about everything (except perhaps percussion) also needs a heavy dose of compression. The gritty guitar sound is achieved by overloading a gain stage (or two) which acts to massively compress the levels. Other more dynamic instruments get buried unless they, too, get compressed. |
#17
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As a classical guy, I avoid compression 99% of the time. I have found, however, when recording a rock band with heavily distorted guitars, that just about everything (except perhaps percussion) also needs a heavy dose of compression. The gritty guitar sound is achieved by overloading a gain stage (or two) which acts to massively compress the levels. Other more dynamic instruments get buried unless they, too, get compressed. And that distortion is part of the accepted character of electric guitars, so I consider that part of the performance. However, with acoustic drums, compression alters the character, sometimes useful to shape the kick drum sound, if multi-miked, but most of the time, I find it reduces the exciting qualities of live drums. I just finished remastering my jazz quintet to a DVD. I used uncompressed PCM audio for the soundtrack, rather than decimate it with Dolby AC3 encoding. The DVD sounds great. -- Best Regards, Mark A. Weiss, P.E. www.mwcomms.com - |
#18
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I wonder if the low hiss levels of the old recordings was due to the very simple signal path, which was really quite difficult to mess up. Maybe modern desks are just too complex for the average recording engineer to understand beyond the "this button does this" level. The problem, I guess, is that they have taken the epithet "engineer" to themselves without the slightest justification, in many cases. d Pearce Consulting http://www.pearce.uk.com That makes some sense. Perhaps recordists today use too many outboard processor chains. But I think there must be more to it than that alone. -- Best Regards, Mark A. Weiss, P.E. www.mwcomms.com - |
#19
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Mark and Mary Ann, when you write, "I think that 16 bits might not be
quite enough to convey very soft passages without that 'bumpiness' that happens when there are not enough steps on the waveform to convey it accurately. Low sample rates, such as 44.1, also may be inadequate to convey subtle timing differences between sound arrivals, thus reducing the sense of soundstage depth and breadth." you are stating an often-expressed viewpoint which accords very well with many people's mental model of how digital recording works, as well as their common sense expectations. Unfortunately the explanations which most people seem to accept about digital audio are greatly simplified and do not fully describe what happens in any actual digital recordings. Thus any projections made from that mental model shouldn't be given much weight unless they can be shown to occur in reality. Such is the case with the two concerns which you mention. They are not, in fact, limitations of 16-bit, 44.1 kHz linear PCM as such. The real, demonstrable (as well as mathematically predictable) limitations of properly dithered 16-bit, 44.1 kHz linear PCM are its dynamic range--about 94 dB--and its bandwidth--less than 22.05 kHz. Sound quality may of course suffer in other ways. But if that were the fault of this bit depth and sampling frequency, then logically, _absolutely_ every CD ever made would sound quite bad, and there could never be a CD--not one, ever--that sounded any good at all. Increasing the number of "steps on the waveform" doesn't convey an analog signal any more accurately unless the noise floor of the analog signal is below that of the A/D converter. You can compare the output to the input and measure (and listen to) the difference--that's the gold standard, no? Adding more "steps" (bits) lowers the noise floor. But it has no other effect on accuracy, i.e. on the difference between input and output. That's why 20-bit and even 24-bit converters are used in professional recording, while 16-bit compact discs appear to have almost too much dynamic range for most consumer requirements. Optimal bit depth is a straightforward engineering decision--you choose it to fit your dynamic range requirements. The more subtle point is that the timing accuracy of analog signals in (for example) a 44.1 kHz sampled system isn't limited by the 44.1 kHz rate as you seem to imagine. Rather, it is limited by the accuracy with which the 44.1 kHz sampling process occurs (i.e. keeping the jitter low enough). If a transient begins to occur between two sampling intervals, it can very well be reconstructed as having begun to occur between them in playback, too. The output of a CD player is a continuous analog signal--not a series of stairstep sample values which are deaf to all the occurrences between them. That misleading image comes from the oversimplified mental model. Consider this: Cedar, the nice British DSP company, has an "azimuth correction" unit that can take a stereo 44.1 kHz digital input and accurately realign the interchannel timing by small fractions of a sampling interval. If your assumptions were correct, that unit couldn't possibly do what it does. Yet, turn the knob and it does it. I hope it is possible to say in a friendly fashion that this accords with decades of actual observation, with practice as well as theory, and is not a matter of mere personal viewpoint or opinion. What you were saying, on the other hand, is conjecture based on your visualization of a process that doesn't actually work in quite the way that you (and a lot of other people, unfortunately) seem to think it does. As a result, the conclusions which you've reached simply aren't correct. --best regards |
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No man, you got the wrong idea. Compression isn't just for broadcasting
and bass. The whole key is to somehow make your finished CDs WAY louder than anyone elses. The person with the LOUDEST finished mix wins! :-) Benj |
#21
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Dave,
I'm glad you typed all that so I didn't have to. :-) I agree. A properly dithered 16 bit 44.1 Ksps digital works as well as an analog system with 94 dB SNR and 20 kHz bandpass. Due to the dithering, there is no crunchiness or stair steps or any of that, there is only noise, just like an analog system. To say it technically, the dithering converts the quantizing non-linearity into random noise. Anyone who does not believe that does not understand the Nyquist theorem and dithering. Digital is the best thing that ever happened to audio. Mark |
#22
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David Satz wrote, in part:
I hope it is possible to say in a friendly fashion that this accords with decades of actual observation, with practice as well as theory, and is not a matter of mere personal viewpoint or opinion. What you were saying, on the other hand, is conjecture based on your visualization of a process that doesn't actually work in quite the way that you (and a lot of other people, unfortunately) seem to think it does. As a result, the conclusions which you've reached simply aren't correct. One of my great joys experienced by participating in rec.audio.pro has been the revelations g so precisely and so nicely iterated as you have above, by you and and several others here, that gently but surely relieved me of my deep misunderstandings about the mechanisms and results of digital audio recording. Thank you, one and all. -- ha |
#23
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David Satz wrote:
Increasing the number of "steps on the waveform" doesn't convey an analog signal any more accurately unless the noise floor of the analog signal is below that of the A/D converter. You can compare the output to the input and measure (and listen to) the difference--that's the gold standard, no? Adding more "steps" (bits) lowers the noise floor. But it has no other effect on accuracy, i.e. on the difference between input and output. That's why 20-bit and even 24-bit converters are used in professional recording, while 16-bit compact discs appear to have almost too much dynamic range for most consumer requirements. Optimal bit depth is a straightforward engineering decision--you choose it to fit your dynamic range requirements. I'm not sure I follow. It seems to me that adding "steps" without changing step size adds dynamic range but does nothing to quantisation noise. A waveform smaller than 90dB peak to peak would be coded the same in 16 and 24 bit audio (+/- a constant). Changing step size, adding steps without changing dynamic range (not commercially available afaik) would change quantisation noise. Is that what you're saying? sincerely Lars -- lars farm // http://www.farm.se lars is also a mail-account on the server farm.se aim: |
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Lars, maybe that wasn't exactly what I meant to say, but what you wrote
is still correct. Many people seem to think of digital samples as integer values. I tend to think of them as binary fractions, and find that scheme more apt. So when I talk about "adding more steps" I really mean the same thing as "adding more decimal places" to a fractional number such as 3.14159... -- the magnitude won't change significantly, but precision is improved to the extent that the additional digits represent valid, actual data. Certainly one can work in the other direction and imagine an integer range which is extended, such that the noise floor (not quantization noise, please--proper dither is an absolute requirement!) becomes less and less when compared to the largest possible sample value. Either way, as you say, more bits simply equals the capability for a wider dynamic range. --best regards |
#25
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David Satz wrote: Lars, maybe that wasn't exactly what I meant to say, but what you wrote is still correct. Many people seem to think of digital samples as integer values. I tend to think of them as binary fractions, and find that scheme more apt. So when I talk about "adding more steps" I really mean the same thing as "adding more decimal places" to a fractional number such as 3.14159... -- the magnitude won't change significantly, but precision is improved to the extent that the additional digits represent valid, actual data. Certainly one can work in the other direction and imagine an integer range which is extended, such that the noise floor (not quantization noise, please--proper dither is an absolute requirement!) becomes less and less when compared to the largest possible sample value. Either way, as you say, more bits simply equals the capability for a wider dynamic range. --best regards Its actally quantization distortion that gets removed by dithering and replaced with random noise. Without dithering, there would be crunchiness, but since the dither that is added before the A/D is larger than the smallest step, the crunchiness is smoothed over and averaged out. So any intermediate value between the digital steps is still conveyed by the duty cycle changes that results from the dither. A crude anlagy is to look at a scene through your spread fingers. Parts are missing. But is you wave your hand back and forth, the missing parts are averaged in. The price for this is added noise but with 16 bits it is still 94 dB down. So dither makes a 16 bit digital system sound just like an anlog system with a 94 dB noise floor. If you have more bits, you need less dither to smooth out the steps so you have less noise. More bits buys you less noise but as long as you have dither you don't get quantization distortion. Mark |
#26
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Mark, thanks for your post; your information is correct down to the
very last bit. --best regards |
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#28
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Mike Rivers wrote:
And more important, why does 24-bit resolution, used in exactly the same way as 16-bit resolution, sound better almost all the time? does it? if it does, then there is something wrong with my model of how things work... Lars -- lars farm // http://www.farm.se lars is also a mail-account on the server farm.se aim: |
#29
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Mike Rivers wrote:
And more important, why does 24-bit resolution, used in exactly the same way as 16-bit resolution, sound better almost all the time? Does it? If it does then there is something wrong with my model of how this works... (still learning...) Lars -- lars farm // http://www.farm.se lars is also a mail-account on the server farm.se aim: |
#31
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Lars Farm wrote: Mike Rivers wrote: And more important, why does 24-bit resolution, used in exactly the same way as 16-bit resolution, sound better almost all the time? Does it? If it does then there is something wrong with my model of how this works... (still learning...) If it does, I have yet to see the blind, level matched testing results (using the same converters but throwing away the extra information) which support the belief. Bob -- "Things should be described as simply as possible, but no simpler." A. Einstein |
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#33
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Mike Rivers wrote: The real trick, though, is that there are no this-generation 16-bit converters, and the comparison is almost always between an older 16-bit converter and its newer and more linear 24-bit replacement. Yes, that is what I think it's about too but many, including some highly respected pros, believe that they can hear differences at 24 bits, after mastering, that are a pure function of those extra bits. Same with the higher sample rates but that's a much harder thing to isolate down to that and only that difference. Bob -- "Things should be described as simply as possible, but no simpler." A. Einstein |
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