Compressor Settings for Mastering, Vocals and Instruments

OK, so I'm really trying to get my head around compressor settings - along with my rudimentary practical knowledge about what the settings do. I am just beginning to be able to HEAR changes that are made and the pros/cons of them.

I've actually found a pretty useful resource, albeit general, in "Home Recording for Musicians for DUMMIES" It provides some general settings for compressors for different instruments/voice. For instance:

ELECTRIC GUITAR T: -1dB; R: (Betw.) 2:1 and 3:1; A: 25ms to 30ms; R ~200ms; G adjust I/O equally
ELECTRIC BASS T: -4dB; R: (Betw.) 2.5:1 and 3:1; A: 40ms to 50ms; R ~180ms; G adjust I/O equally
ACOUSTIC GUITAR T: -6dB; R: (Betw.) 3:1 and 4:1; A: 150ms; R ~400ms; G adjust I/O equally

VOCALS
(to even out vocal performance)
T: -8dB; R: (Betw.) 1.5:1 and 2:1; A: <1ms; R ~40ms; G adjust I/O equally
(to bring vox way out front in mix)
T: -2dB; R: (Betw.) 4:1 and 6:1; A: <1ms; R ~40ms; G adjust I/O equally

. . . so . . .

Surprisingly there's nothing about mastering and what tweaking certain levels do like there is briefly in the vocals department.

I'm not really looking for a magic bullet, but just a starting point. There MUST be a resource somewhere that's a bit more thorough than this. I have tried some of these settings, particularly the VOCALS and have noticed favorable results.

As far as mastering; I've used SONITIS FX "complete mix" and have lowered the RATIO to about 1.5; I've found that much above that produces discernable changes and squashing. I guess my objective with the mastering compression is to get things to even out and make as loud as possible, though not ridiculously so as to squash dynamics (i.e., Metallica's new album).

So anyway, that's pretty much my question. Is there a guide somewhere that anyone knows about that has these settings or an experienced producer/engineer here that uses tried-and-true settings as starting points? That's really all I'm looking for is STARTING POINTS, as I know that most music (even for the same artist) varies from song-to-song, but there must be some "rules-of-thumb" to begin with. Examples with "HOW & WHY & WHAT they DO" would be especially useful.

Thanks in advance!

I believe there are two basic reasons for using a compressor. The first and most well known is to even out the dynamics of the material, reducing the spikes that occur here and there so that the material has more of a consistent playback volume. This could be so a certain instrument does not fall in and out of a mix in the song, or to master a song and make it louder overall. The second way to use a compressor is to make the tracks have more punch. This is done by using very low threshold settings and slow attacks. If you are doing this to a single track then I would guess you are using a very low threshold setting (maybe -18dB) but if you are mastering I assume you would probably not use such a low setting, maybe only -5dB or less. Attack and release are going to be HIGHLY dependent on your tempo as very slight changes is going to increase pumping. The attack settings would also affect the release settings when using this technique I do believe.

I think one of the reasons there are no starting points for numbers really is that it entirely depends on what you are wanting to use the compressor for (the two techniques mentioned above have entirely different compressor settings from one side of the scale to the other). One instrument could really use any number of threshold, attack and release settings depending on so many things. At best, one can really only say 'fast or slow release/attack' or 'high or low threshold' and that would mainly depend on what you are trying to do. If it were possible to give some rough starting points for settings, they would be out there already.

I think the best way to start is to set it to something moderate. Lets say we have a track of some instrument, who cares what it is. Now, we set our threshold to -10, ratio to 2, attack to 20, release to 100. Now, play it back and see how it sounds. Now, pull your threshold slowly down to -25 and listen to how the audio changes. Now set your ratio to 10, and do the same thing. Listen to the differences it makes. Now, set your threshold to -20, ratio to 10, and now move your attack from 1 to 40 and listen to how it affects the audio. Do the same for the release. When I am setting my compressors, I do this. Really move your dials to the max and see how it affects the particular audio. Play around with this until you find out how to get the sound you want. This is all with respect to single instruments in the mix. As for mastering, I know even less. I usually work with using a multiband compressor with three bands - any more and it gets too difficult to sound transparent. I listen to where my bass really breaks away from the rest of the music, and place my first point there. I then listen up through the vocals to find where the high end really starts in the audio and set my second point. I now have roughly my bass, mids and highs. I then tend to solo the bass and just play around like before, maxing the settings here and there to see how it sounds, switching in and out of solo to see how it sounds in context. Important to really make sure that your I and O are volume matched when doing this.

So that's about as much as I know about how I use my compressor. Most of what I have said is from reading and about a year or two of practical experience. I am certainly no pro when it comes to using a compressor, but that's my take on it at this stage in my recording learning. Hope something there was useful!

Beagle,
THANKS FOR THAT LINK!!! What I did was go through and compile a "manual" from Yep's post. The guy needs to write a book. Actually, I bet if someone just went through a copied his posts, they could publish a book themselves!! Albeit, on the sly! That thread should be a sticky for sure.

Matt,
Thank you for that. Your suggestions make sense to me, and I like the way you explained the workflow. I'll give it a try.

Now, off to the SOS forums. I love going there, but the problem is, there is so much information out there, it's hard to weed through and know what's good and what's bad. Usually SOS gets it right, I think.

Time to study!!! If anyone else has any ideas, I'm all for more suggestions on this topic. I think it's kind of an important subject; as it can really make something fantastic, or ruin it completely!!!

Cheers!