Interesting viewpoints on what compression is, some of which I agree with, some of which I strongly disagree with or are just incorrect:
1. This is incorrect. Compression isn't just applied according to end use. In the mixing phase it's applied for creative, positional, tonal, etc., reasons. IE., It's about the music itself rather than the end use.
2. Actually, compression lowers the level (of the peaks exceeding a user defined threshold). Of course, lowering the level of the peaks provides headroom to add more gain, should one wish to do so.
3. I agree entirely. Except that it's obviously far better applied by those mastering the recording than by some dumb device in the playback chain which has no idea of the musical intentions!
4. This is completely incorrect! In some genres, acoustic genres like most classical music, you would be correct, except in the case of #3 as you mentioned. However, in virtually all popular music genres it's use is essential ingredient in the expected sound. Many genres would be almost a laughable parody without it!
5. True, it can do, if so desired. A point you seem to be entirely missing is what happens in the case of someone wanting to create "grungy and edgy" music? Surely then such compression is the absolute perfect tool? Some vintage compressors are extremely highly prized for their pleasing/desired distortion.
6. Ducking and other effects such as pumping are a musical decision, applied to create impact or otherwise improve the listener experience of certain genres, EDM being a good example of such a genre.
7. That's a rather bizarre statement. Popular genres of music deliberately moved away from the "normal acoustic life" in the 1960's. That's largely what defines the difference between, acoustic genres such as classical/jazz and genres such as rock and most of those which followed. Sure compression is a form of distortion, so is an electric guitar amp! Take the distortion (inc. compression distortion) out of popular genres and make them "natural" and you kill the genre! Ever heard an electric guitar without distortion? The natural sound of an electric guitar is unrecognisable as an electric guitar. The same is largely true of a rock drum kit and to a lesser extent of the live un-compressed/unprocessed vox recorded in the studio.
8. Again, that's a bizarre thing to say. Energetic and dense is exactly the aim with many genres of music. I can appreciate that you personally might not like heavy metal, EDM and most other popular genres and find them "mostly uncomfortable" but far larger numbers of people like and purchase music of those genres than of the acoustic "natural" genres.
9. Brickwall limiting can look similar to clipping distortion when looking at a graphical representation of a waveform but usually sounds completely different.
10. This is incorrect. Sure it's possible to over-apply compression/brickwall limiting so that it sounds unnatural and distorted (and often that's desirable, as mentioned above) but it certainly doesn't have to and the vast majority of the time it's largely transparent.
11. This is blatantly incorrect, in fact the exact opposite is true. Virtually without exception, ALL TV and radio is compressed and brickwall limited, by law in many countries (inc. the USA). You appear to be arguing against yourself as this point contracts your point #3?! The only time your statement has been demonstrated to be true is when all the following conditions are met: In critical listening situations, with good quality playback equipment being used in a decently quiet listening environment and when the audio being listened too has been over-processed in the first place.
1. EDM as an example, uses very different sound sources than acoustic genres such as most classical music. The bass drum sounds used and indeed most of the sounds do not exist in the natural world, they are manufactured and only exist in the studio (hence the term EDM!), and compression is an essential tool used in the manufacture of those sounds. Commonly, the only relatively natural sound in an EDM mix is the lead vocal but even that has to be significantly compressed (and processed in other ways) in order to be successfully integrated into the mix. Additionally, as the name also implies, EDM is primarily designed for use in extremely noisy listening environments (clubs, arenas, etc.) and therefore requires a small dynamic range. Although there are some genre exceptions, a small dynamic range is not generally perceived as very exciting, so heavy compression is often used as it reduces the energy level differences while still maintaining some of the key indicators the brain uses to differentiate dynamic range. To take full advantage of this, the music has to be composed and orchestrated with this in mind. Obviously the vast majority of classical music isn't, it's designed for acoustic instrument performance, whereas EDM is specifically created/designed for this type of processing.
2. Generally it wouldn't necessarily be uncomfortable as such, you could just turn your amp down if it were too loud. Most of the energy in music mixes is in the lower frequencies. When applying broadband compression it's therefore these lower frequencies which get more compressed (lowered/attenuated), resulting in the mix having relatively more mid and high frequency content, which makes it sound louder and more present but also potentially harsh (and therefore potentially uncomfortable).
G
"Interesting viewpoints on what compression is, some of which I agree with, some of which I strongly disagree with or are just incorrect:
1. This is incorrect. Compression isn't just applied according to end use. In the mixing phase it's applied for creative, positional, tonal, etc., reasons. IE., It's about the music itself rather than the end use."
Actually, not incorrect, but we are both correct. These are not opposing concepts, both occur. But compression on a per-track or per-source basis is not responsible for the overall loudness of a piece. Yes, per-track compression is about the music. Mastering loudness compression is more about the impression the piece has up against other competitors.
2. Actually, compression lowers the level (of the peaks exceeding a user defined threshold). Of course, lowering the level of the peaks provides headroom to add more gain, should one wish to do so.
I never said otherwise, but the type of compression you're referring to is specifically peak limiting, fast attack and recovery, infinite slope or close to it. It controls peak maximum, as you say, but that permits the total volume to be pushed up to close to 0dBFS, as much as 12dB or so closer than it would without peak limiting.
3. I agree entirely. Except that it's obviously far better applied by those mastering the recording than by some dumb device in the playback chain which has no idea of the musical intentions!
Not so obviously...some mastering compression may be beneficial, but its not tuned to specific listener environments. The needs for compression in forground vs background applications are vastly different. Background systems I design and install all include some form of general music compression so levels can be consistent. The average level in background music is very touchy, a little variation is percieved as wrong. Very different demands for compression. However, if it's over-done in mastering, there's no way to un-do it for any application.
4. This is completely incorrect! In some genres, acoustic genres like most classical music, you would be correct, except in the case of #3 as you mentioned. However, in virtually all popular music genres it's use is essential ingredient in the expected sound. Many genres would be almost a laughable parody without it!
This is a matter of opinion, so "incorrect" would be a bit of an over-statement. The drive to heavily processed popular music is well documented in the loudness war. It's not about listener preference or artistic expression at all. There is so much about the loudness war published, I don't feel compelled to detail it here.
5. True, it can do, if so desired. A point you seem to be entirely missing is what happens in the case of someone wanting to create "grungy and edgy" music? Surely then such compression is the absolute perfect tool? Some vintage compressors are extremely highly prized for their pleasing/desired distortion.
IMHO, the desire for moderate grunge may be artistic expression, over use of compression is simply misguided. I'm intimately familiar with what the popular vintage compressors do having used them personally before they were "vintage". In many cases they aren't responsible for the objectionable effects I'm referring to.
6. Ducking and other effects such as pumping are a musical decision, applied to create impact or otherwise improve the listener experience of certain genres, EDM being a good example of such a genre.
The examples I hear I find objectionable. I actually like and listen to some of the newest music, but have even tried to remove some of that effect with very limited success (pardon...). Again, this is a matter of opinion, though I firmly believe that most listeners, if given the choice of ducking or not in a level matched test would prefer the not.
7. That's a rather bizarre statement. Popular genres of music deliberately moved away from the "normal acoustic life" in the 1960's. That's largely what defines the difference between, acoustic genres such as classical/jazz and genres such as rock and most of those which followed. Sure compression is a form of distortion, so is an electric guitar amp! Take the distortion (inc. compression distortion) out of popular genres and make them "natural" and you kill the genre!
Not at all. Acoustic life is all around us. It's the reference, like it or not. Genres have adopted certain styles, that's true, but I don't think severe loudness processing defines the style. It could be backed of 6dB or more without affecting the style or genre while vastly improving the clarity and impact of the piece.
Ever heard an electric guitar without distortion? The natural sound of an electric guitar is unrecognisable as an electric guitar. The same is largely true of a rock drum kit and to a lesser extent of the live un-compressed/unprocessed vox recorded in the studio.
You're confusing compression as applied as an (abused) loudness tool with processes that define an instrumental sound. The are not at all the same nor comparable.
8. Again, that's a bizarre thing to say. Energetic and dense is exactly the aim with many genres of music. I can appreciate that you personally might not like heavy metal, EDM and most other popular genres and find them "mostly uncomfortable" but far larger numbers of people like and purchase music of those genres than of the acoustic "natural" genres.
How would you or anyone else know that? Those that buy music have no choice of the final processing. They buy it for what it is, processing is beside the point.
In radio we've experimented for many decades with different types and amounts of processing, and yes, there's been a loudness war on radio for 50 years. What the evidence of audience ratings has shown is audience preference is for the content, and processing and loudness doesn't matter. That's why an AM talk station in a major market can beat all of the FM music stations, processed or not. The AM signal has issues, it's lower quality, and this particular station (yes, it's a real example) was actually one of the least processed, less loud AM stations on the dial. They still won the ratings. You wouldn't know what music buyers would choose, because they don't have any choice in the matter. However, there is research to show that less compression is generally preferred. That research has prompted the development of highly sophisticated broadcast processors that do what they do with less compression artifact.
If you combine that with the admittedly grass-roots movement against the loudness war in recorded music, to me, that confirms that less compression is the preferred version.
9. Brickwall limiting can look similar to clipping distortion when looking at a graphical representation of a waveform but usually sounds completely different.
Yes, but the point is moot. Both are used to varying degrees in recorded music. Both add distortion of several kinds.
10. This is incorrect. Sure it's possible to over-apply compression/brickwall limiting so that it sounds unnatural and distorted (and often that's desirable, as mentioned above) but it certainly doesn't have to and the vast majority of the time it's largely transparent.
Respectfully have to disagree that the majority of the time it's transparent. The popular music I hear is all way over processed, easily heard.
11. This is blatantly incorrect, in fact the exact opposite is true. Virtually without exception, ALL TV and radio is compressed and brickwall limited, by law in many countries (inc. the USA).
What makes you think that the choices made by broadcasters reflect listener preference? I've been a broadcast engineer for 45 years, I can tell you all about broadcast processing. I've designed broadcast processors. Your concept of a brick-wall limiter is also blatantly incorrect. Pre-emphasis and assymetrical modulation limits (AM) preclude the typical brick wall limiter from being effective. True, at the final transmitter input there must be absolute peak control, but with pre-emphasis and de-emphasis involved, it doesn't come out that way at the receiver audio outputs.
A broadcast processor includes absolute peak protection as the final process in a complex chain of other processes. This is generally some form of clipping, but must act on the final pre-emphasised and bandwidth-limited signal. To over-simplify a bit, that clipper is preceded by a fast peak limiter and in the case of analog AM and FM, a high frequency limiter that response to the specific pre-emphasis curve in use. That's preceded typically by a multi-band limiter, at minimum two band, at maximum 8, but typically 4 or 5. Each band is handled by a complex gain control algorithm that includes variable attack and release, several different composite time constants, bandwidth controls, re-mix controls, threshold controls and release-time gating. That's typically preceded by a broadband compressor, again with variable attack and release, but fairly slow, and with release time gating. All of it is so incredibly adjustable and variable that no two stations are likely to be processed identically. TV and radio are processed differently too, as is each radio format. The goals fundamentally are to sound as loud as the competition without sounding bad, and that translates to sounding as loud as possible without sounding too bad, all the while keeping within legal modulation limits. But "brick wall" doesn't even scratch the surface, nor does it describe the same sort of thing as used in music mastering.
Yet in the development of audio processors, has been plenty of research that proves that listeners, if given the choice, prefer less processing and compression. Again, that's why over the last 40 years broadcast processing has become less damaging for the same comparative loudness. The problem is that when the tools got better, there was also more opportunity to abuse them.
You appear to be arguing against yourself as this point contracts your point #3?! The only time your statement has been demonstrated to be true is when all the following conditions are met: In critical listening situations, with good quality playback equipment being used in a decently quiet listening environment and when the audio being listened too has been over-processed in the first place.
Actually, I'm not arguing against myself at all. My statements in point #3 are specific to an end-use situation. My statements are not based on the conditions you outline, in fact, the conditions that make classical music difficult or impossible to listen to most often are found in a moving car with high background noise and medium quality equipment. Those are conditions where processing is necessary and beneficial.
Actually, my point was that if the end use is well understood, then the proper processing can be applied. To over-process generally creates a signal that has no opportunity for ever being played with any better dynamics, and is actually mastered for the lowest common denominator. That, I feel, is a mistake.