bellutta@irst.it (Paolo Bellutta) (08/21/90)
I've seen some messages from people working in recording studios and in TV/Radio stations. This message is mainly for them. I always wondered why compressors and limiters are so widely used during the recording. I can understand that the dynamic range of certain instruments must be compressed to fit into a TV speaker dynamic range. Recording Studios: But if the source tape must be mixed to sound good on poor quality reproduction systems, why should I pay $15 to $20 (that's the price here...) for a CD with a dynamic range that has been killed to a few dBs? Some CDs has been recorded "direct from microphone" but only classical or jazz music (I know that rock music is considered "low level" but there are people that like that!). I can understand that voice for example sounds better when a limiter is used, but why *everything* must be limited and/or compressed? TV/Radio Stations: When a record is transmitted I can understand that the microphone *must* be compressed *and* limited so that the transmitted signal fits the FCC specifications, but why compress and limit the music also? Is that for the fact that different records have different recording levels? If that is the reason, are the level controls on the mixers used just to collect dust? All this may sound a bit rude but I think that what high-end people are really missing is the dynamic range of the original sound. Since the people I'm asking this question *work* with audio I'd like to know what is the *real* reason. Paolo Bellutta I.R.S.T. vox: +39 461 814417 loc. Pante' di Povo fax: +39 461 810851 38050 POVO (TN) e-mail: bellutta@irst.uucp ITALY bellutta%irst@uunet.uu.net
lshaw@walt.cc.utexas.edu (logan shaw) (08/22/90)
In article <5834@uwm.edu> bellutta@irst.it (Paolo Bellutta) writes: >TV/Radio Stations: >When a record is transmitted I can understand that the microphone *must* be >compressed *and* limited so that the transmitted signal fits the FCC >specifications, but why compress and limit the music also? Is that for the >fact that different records have different recording levels? If that is the >reason, are the level controls on the mixers used just to collect dust? Basically, they're greedy. They want to be able to reach the most people they can with their music (and advertisements). If they compress everything, the people in the fringe areas can hear them over the noise. Since they can't raise the highest level (because of the FCC), they raise the _average_ level. >Paolo Bellutta >I.R.S.T. vox: +39 461 814417 >loc. Pante' di Povo fax: +39 461 810851 >38050 POVO (TN) e-mail: bellutta@irst.uucp >ITALY bellutta%irst@uunet.uu.net And now for my question... How many people out there are annoyed more than words can describe that commercials on TV are noticeably louder than the TV shows? (almost as if the TV shows are being limited to some level less than the level the commercials are being limited to). Is this as annoying to other people as it is to me? Is there anything we can _do_ about this? (write letters to the TV stations, etc) ============================================================================ "The beauty queen, clevely clad, Logan Shaw admires herself in a cigarette ad. lshaw@ccwf.cc.utexas.edu Will she admit that all was in vain ======================== when the face in her mirror cracks like a windowpane?" -Elim Hall, _Things_Break_
urban@harvard.harvard.edu (Mark Urban-Lurain) (08/23/90)
In article <5862@uwm.edu> lshaw@walt.cc.utexas.edu (logan shaw) writes: > >How many people out there are annoyed more than words can describe that >commercials on TV are noticeably louder than the TV shows? (almost as if >the TV shows are being limited to some level less than the level the >commercials are being limited to). Is this as annoying to other people >as it is to me? Is there anything we can _do_ about this? (write >letters to the TV stations, etc) Yes it is annoying, but no, they are not louder, just more compressed. It is only partly the fault of the stations. The commercials come to them VERY compressed specifically to make their average level louder so that they stand out (hard to do with 10 or more 10 second commercials in a break). If you have the ability to monitor the broadcast levels (with a VCR or tape recorder with meters) watch. Set your maximum level during the "loudest" commercial. Then, during the program, watch the levels. There will be some peaks at the maximum level, but the average modulation will have a wider dynamic range, and lower average level. What to do? Sure, write letters to the stations (kill a tree). You might write to the specific advertisers and tell them you will NOT buy their product as long as their commercials are annoying. A TV with a MUTE button on the remote control helps. Record all programs on your VCR then nuke the commercials with the FF button. Just remember, the program is filler to string between commercials. Stations don't make money on programs, only on the commercials. -- Mark Urban-Lurain urban@cpswh.cps.msu.edu Computer Science Dept. urbanluraimg@clvax1.cl.msu.edu Michigan State University (517) 353-0682 A-714 Wells Hall, East Lansing, MI 48824
urban@harvard.harvard.edu (Mark Urban-Lurain) (08/23/90)
In article <5834@uwm.edu> bellutta@irst.it (Paolo Bellutta) writes: > >Recording Studios: > I can understand that voice for example sounds better when a >limiter is used, but why *everything* must be limited and/or compressed? As a former audio engineer in various public radio and TV stations, here's my perspective. Use of compression is a production decision in the recording studio. It is just one more tool (like EQ) available to the producer. Unfortunately, many (rock) artists and producers like the compressed sound, it seems "louder" and "denser". In addition, although CD's have wide dynamic range, cassette is still the dominant medium for popular music (played on mid-fi equipment in most cases) so many producers feel that they must target this audience. >TV/Radio Stations: >When a record is transmitted I can understand that the microphone *must* be >compressed *and* limited so that the transmitted signal fits the FCC >specifications, but why compress and limit the music also? Is that for the >fact that different records have different recording levels? Nope, it is because maximum modulation is 100%. Now, it makes no difference to the FCC what the average modulation level is, so to sound "louder" than the competition, stations compress / limit (they are two different processes) so that their average level is as high as possible without being over 100%. There are a number of companies who do nothing but make "signal processing" equipment for broadcast use that does just this. Many of them compress different frequency bands individually (like a limiter on each equalizer control) to allow "shaping" of the final sound. It's all fairly gross, but management usually pressures engineering to "make it louder" after the program director scans all the stations on his car radio and finds one louder than his. One reason I prefered working as an engineer in public broadcasting was that they were more concerned with quality than quantity. However, in recent years, with fund raising being a big part of public broadcasting, management was adopting similar attitudes there. You CAN write a letter to the stations, telling them that you think their sound is lousy. Best to point out the best sounding station in the market (they'll know it too, but don't think the audience can tell). It won't do much good, but it may help the engineers resist moron program directors. -- Mark Urban-Lurain urban@cpswh.cps.msu.edu Computer Science Dept. urbanluraimg@clvax1.cl.msu.edu Michigan State University (517) 353-0682 A-714 Wells Hall, East Lansing, MI 48824
pozar@uunet.UU.NET (Tim Pozar) (08/23/90)
In article <5834@uwm.edu> bellutta@irst.it (Paolo Bellutta) writes: >I've seen some messages from people working in recording studios and in >TV/Radio stations. This message is mainly for them. > >TV/Radio Stations: >When a record is transmitted I can understand that the microphone *must* be >compressed *and* limited so that the transmitted signal fits the FCC >specifications, but why compress and limit the music also? Actually, the FCC asks that all the programme material be within a specified limit. Not too low, nor too high. (Kinda silly about a low limit with all the talk about market-place regulation...) Some station programme directors (and sometimes engineers) feel that the 'louder' the station, the better. With 'loud' or dense audio the station 'jumps out' on the dial. Also, by creative processing the PD can colour the sound so as to provide some idenity to the station. This is called 'positioning'. The argument to this is listener fatigue, and preservation of dynamic range. Also, some stations use the lack of processing as a way to 'position' themselves. The station I am the Chief Engineer for (KKSF-FM / San Francisco), uses the lack of processing for exactly that. I pride the station on being very audiophile. (My little plug.) >Is that for the fact that different records have different recording >levels? No but records have different "loudness densities". Compression and limiting for the stations that feel that they need it, is used to homoginize the density as well as increase the loudness. The latter being the most important task for audio processing. >All this may sound a bit rude but I think that what high-end people are >really missing is the dynamic range of the original sound. True, but you are a very small minority. And that may sound a bit rude too, but that is the way you are seen by most of the programme directors out there. If you are upset by this, pick your favorite over-processed radio station and address your letter to the 'Program Director' and the 'Chief Engineer'. You may get a letter back, but it is unlikely you will change any minds. >Since the people I'm asking this question *work* with audio I'd like to know >what is the *real* reason. You got a very striped down version of what goes on behind the scenes in radio. For further discussions, you can drop me a line or give me a call. Since you are in Italy, you may just want to drop me a line :-). Tim -- Tim Pozar Try also... uunet!hoptoad!kumr!pozar Fido: 1:125/555 PaBell: (415) 788-3904 USNail: KKSF-FM / 77 Maiden Lane / San Francisco CA 94108
ttak@uhura.cc.rochester.edu (Timothy Takahashi) (08/24/90)
In article <5870@uwm.edu> hoptoad!kumr!pozar@uunet.UU.NET (Tim Pozar) writes: >In article <5834@uwm.edu> bellutta@irst.it (Paolo Bellutta) writes: >>When a record is transmitted I can understand that the microphone *must* be >>compressed *and* limited so that the transmitted signal fits the FCC >>specifications, but why compress and limit the music also? > Actually, the FCC asks that all the programme material be within >a specified limit. I'd like to share my experiences working in a College station (WTJU - Charlottesville, Va). I DJed a Classical show there during the fall and winter of 1988 when I was attending the University of Virginia. Our station had (still has?) a particular problem with variable sound quality - a problem due to the volunteer nature of a college station itself. Most individuals who DJ for a college station do so for musical rather than technical interests, in fact I found the technical background of many of the DJs rather limited. The non-technical types do not understand the calibration of the VU meters on the console with respect to the transmitter. Several individuals regularly drove the needles far into the red when playing music - the fact that the transmitters limiters were kicking in preventing the 150% modulation requested of them was lost to those listening over the monitor speakers. I was particularly careful to watch the modulation meter when setting levels for a disk - as a result my programs tended to be 3 to 6 db quieter than those following or preceeding (something that I was repremanded about once - for the low levels, that is). The hypothetical station manager who demands that his station be "the loudest" probably wouldn't appreciate dynamic range if it hit him over the head. Tim Takahashi
KLUDGE@AGCB1.LARC.NASA.GOV (08/24/90)
Radio stations overcompress things: 1. So the level controls on the mixer do collect dust. DJ's are usually not too good at gain riding. Most stations have things set up so you just bring the slider up to the mark and leave it there. 2. To increase range. If the overall modulation level (the effective loudness of the signal) is lower than the noise floor, you'll hear noise. By keeping the peak modulation level as high as possible, your signal will be above the noise floor even when the noise is higher. This is important in fringe areas, and in cities where reflection is a major problem. (In actuality, reducing power down an order of magnitude or two will eliminate reflection problems in\ cities and not really reduce the range in the downtown area much at all... but stations seem to think that more power is better). 3. To increase the perceived loudness of the station. Since people only listen to one station for 2.3 minutes on the average anyway, and since as they flip across the dial, they tend to stop on the loudest stations, it's important to make your signal louder than anybody else's. Some stations (like KPRT, Los Angeles) add deliberate second-harmonic distortion to give their station a 'characteristic sound' so that people can identify it as they turn by. Much like the horrible reverb chamber that Radio Moscow uses. Commercial radio and high fidelity are not even remotely related. Big money and commercial radio are much more tightly connected. --scott