Explain compressors

[TwilightOdyssey]

Re: Explain compressors

Many people say that a compressor boosts the quiet part of playing and many have also said that a compressor really does not boost the quiet part of playing.

It does the latter, not the former. I made it bold so you can see the correct portion.

Here is my understanding. Correct me if I am wrong. I want to understand if a compressor is going to increase the sustain before I drop $99 on a Boss CS-3. I dont care about the tone. I am a beginner and to my ears good tone or bad tone does not make a difference. I just want longer sustain as the kind of music I play needs a longer sustain. I have to play a lot of successive notes with a single strike and hence I need a longer sustain.

A compressor reduces the louder part of playing by reducing the level higher than the threshold.

Correct.

The quieter parts are untouched if the compressor gain is untouched.

Correct.

Now that the louder parts have been reduced, obviously the sound level is going to be lower than that without the compressor. Now if you did not change the make up gain on the compressor, the quieter part will not change. Right so far?

Correct.

If you increase the make up gain on the compressor, then everything gets louder which is perceived as longer sustain.

Incorrect. You are confusing a compressor with an expander.
Threshold is the point at which the compressor starts pulling down peaks.
Ratio is how aggressive that pulldown is.
Knee is how quickly the compressor starts to act after the initial transient. This is used in conjunction with the Attack and Release.

Not every compressor has discrete control over all of these. Many stomp box compressors have a knob labeled 'sustain'. This knob combines ratio, threshold, and output gain at the same time with a preset knee, attack, and release time. It is not louder than the original signal unless you are applied more make up gain than gain reduction; this is considered an improper way to use a compressor because pumping artefacts will be easily heard this way.

Make Up Gain is used to return the signal back to it's original level after you have pulled it down with the VCA.

There is still a relative difference between the quieter and louder parts, of course.

Incorrect. Depends on how high a ratio you set in relation to the threshold.

You adjust the attack, gain etc such that everything seems to be playing at the same level and this again gives the perception of longer sustain. In other words, the relative difference in loudness between the quieter and louder parts has reduced and the overall gain has increased. Right?

Incorrect. The overall gain is decreased because your dynamic range has decreased. The only setting that affects gain is the output gain of the compressor. What your ears are perceiving as loudness is due to the Haas Effect.

The gain on the amp will also increase the quieter part but it also increases the louder part and so the relative difference between the quieter and louder parts gives a perception of low sustain.

No clue what you mean by this, but if I am understanding you correctly, this is also Incorrect.

I dont understand how a compressor can give that long sustain people are talking about.

Because, as stated above, if you squash the signal enough it becomes very easy to increase the output gain of the entire signal, which will give increased sustain; you are not turning up just the hardest/loudest parts of the frequency spectrum.

If the string has died , there is nothing much anything can do to incease the gain unless you put somethng like a Sustaniac to prevent the string from dying.

Two thoughts:
A - see the note above re: output gain
B - a guitar sustains much longer than you think

A guitar with a Sustanic is like $800 (Schecter Sun Valley). I doubt a $99 Boss CS-3 can beat a Sustaniac. No?

No; you are talking about two totally different technologies. An Ebow or Fernandez Sustainer excites the string so that it is constantly vibrating. This is totally different from compression, which is a psychoacoustic effect.

Hope this helps!

 

[mupi]

Re: Explain compressors

So basically to increase the sustain using a compressor, I have to reduce the louder part a lot so that it comes down to the level of the quieter part and then increase the make up gain to boost the entire signal. Correct?

If for example the note starts to fade after say 4secs without a compressor, then by using a compressor what kind of increase in sustain can I get. Like another 2 secs or another 4secs? In other words what is the delta increase in sustain for any guitar with a compressor?

 

[TwilightOdyssey]

Re: Explain compressors

So basically to increase the sustain using a compressor, I have to reduce the louder part a lot so that it comes down to the level of the quieter part and then increase the make up gain to boost the entire signal. Correct?

Correct. It is MUCH easier to do when you have a compressor with a display so you can see the actual levels you are working with, or a VU meter for the signal you are tying to affect/effect. Doing it by ear is difficult in the extreme for several reasons I won't go into here.

If for example the note starts to fade after say 4secs without a compressor, then by using a compressor what kind of increase in sustain can I get. Like another 2 secs or another 4secs? In other words what is the delta increase in sustain for any guitar with a compressor?

Impossible to predict but with enough squish you can definitely get your guitar to essentially go straight into harmonic feedback which will sustain infinitely.

 

[mupi]

Re: Explain compressors

I presume the Boss CS-3 is a good start for a beginner. My only goal is to increase the sustain as I want to see what is the longest phrase I can play with a single strike of a string. If I break the phrase for a second or third strike, it will not sound right. I dont care much about tone now. I am doing solo on a single string. No chords. I am trying to avoid spending $800 to get a guitar with a Sustaniac if a $99 Boss CS-3 can get me just enough sustain to play a long note/phrase.

 

[dystrust]

Re: Explain compressors

I presume the Boss CS-3 is a good start for a beginner. My only goal is to increase the sustain as I want to see what is the longest phrase I can play with a single strike of a string. If I break the phrase for a second or third strike, it will not sound right. I dont care much about tone now. I am doing solo on a single string. No chords. I am trying to avoid spending $800 to get a guitar with a Sustaniac if a $99 Boss CS-3 can get me just enough sustain to play a long note/phrase.

If you're planning to play legato on a single string, an E-bow will probably work better than a CS-3.

 

[Dave Locher]

Re: Explain compressors

A compressor might help but what you are describing sounds like technique, not equipment. With strong enough finger vibrato you can keep a note going a long, long time with enough volume and/or gain. Develop good hammer on/off fingering and you can drift up and down that string all night if you want to. I used to play a slow solo of about 30 seconds or so, playing notes on three different strings, without striking the strings at all. Right hand at my side. My left fingers did all the work. No compressor, just a very sensitive SG with a Super Distortion pickup running through an EQ pedal for midrange boost into a solid state Randall RG100ES into a 2x12 cabinet with Celestion G12-65 speakers.
I could do it with other equipment but that exact combination made it relatively easy. The mid boost into the gain channel provided enough levelling of the signal to act "compressed" without a compressor.
Prior to that I had a Peavy Studio 50 amp and it took an Arion compressor with all 3 knobs cranked to get the same basic effect.
With both setups the key was to keep the strings moving (vibrato, side-to-side) so the notes would not fade out or devolve into uncontrolled feedback.

You could also try an eBow. I tried one once and found it less responsive than the SG/Randall pairing but it literally allows unlimited sustain on one string for as long as you want.

 

[mupi]

Re: Explain compressors

You say it is not about equipment but you list a lot of equipment. I have a Squier Affinity and a Blackstar Idcore 20 amp! I did try the Epiphone Les Paul Standard as people call it sustain king. Well not really a sustain king. Those who show a long sustain with a Les Paul Standard do use a lot of effects including a compressor. Its natural sustain isn't significantly longer than a Squier. So I returned it. Not worth $500 if the only thing I want is longer sustain.

Also as a beginner I have not perfected pull off. Hammer on is easy. I would need to use more pull off's as I have to go down the neck. It would be many years before I can play for 30secs using hammer on's and pull offs. I dont want to wait for many years

I dont like the ebow. While the long phrases that I have to play are on a single string, I do like to be able to play notes that need another string in the same song and ebow doesnt allow me to make a quick switch between strings.

I am going to try the Boss CS-3. No matter how much I read, ultimately it comes down to trying out something.

 

[Gtrjunior]

Re: Explain compressors

As a beginnner I feel you need to worry more about improving your technique and less about fx. No disrespect intended but that’s the truth. If you can’t do an effective pull off, the last thing you need to be thinking about is compressors.
When I was a beginner, I literally played a Crate G10 practice amp with some no name guitar for YEARS before I upgraded it or thought about fx.
The first pedal I got was a boss delay because another kid in school sold it to me cheap.

 

[Vasshu the humanoid typhoon]

Re: Explain compressors

+1....practise....no electronic gizmo of any kind will help you there....
Just hard work and patience!

 

[TwilightOdyssey]

Re: Explain compressors

+1....practise....no electronic gizmo of any kind will help you there....
Just hard work and patience!

There goes the neighborhood!

 

[devastone]

Re: Explain compressors

I have to agree with the practice statement, if you can't do pull-offs cleanly, then fx aren't going to be a lot of help.

I am a little confused about some earlier statements, compressors do limit the louder parts, but they also boost the gain on quieter parts, that is the point (unless the gain/sustain is set to unity in which case it is being used as a limiter, not a compressor, similar but different).

It's easy to prove, put a distortion pedal in front of a compressor and crank the gain on the distortion,without playing when the compressor off, they will be some hiss/noise coming through, when you turn the compressor on, it will get louder (again, play with the gain), so yes, it can, and usually does, raise the low level signals.

 

[dystrust]

Re: Explain compressors

I have to agree with the practice statement, if you can't do pull-offs cleanly, then fx aren't going to be a lot of help.

I am a little confused about some earlier statements, compressors do limit the louder parts, but they also boost the gain on quieter parts, that is the point (unless the gain/sustain is set to unity in which case it is being used as a limiter, not a compressor, similar but different).

It's easy to prove, put a distortion pedal in front of a compressor and crank the gain on the distortion,without playing when the compressor off, they will be some hiss/noise coming through, when you turn the compressor on, it will get louder (again, play with the gain), so yes, it can, and usually does, raise the low level signals.

+1 on practice, but TO maybe did a better job of explaining compression.

Compressors on their own don't boost anything unless makeup gain is applied; compressing with gain set to unity is NOT limiting. Limiting uses an infinity:1 ratio so that signal level never exceeds the threshold.

 

[devastone]

Re: Explain compressors

Actually TO's explanation was the one I thought could be potentially confusing, generally speaking, if you are using a pedal compressor in a guitar signal chain (which I think was the OP's original question), you are using some gain/sustain to bring up the lower levels, otherwise you aren't getting any increase in perceived sustain.

And yes, rushed explanation of limiting, thanks for the correction.

 

[dystrust]

Re: Explain compressors

Actually TO's explanation was the one I thought could be potentially confusing, generally speaking, if you are using a pedal compressor in a guitar signal chain (which I think was the OP's original question), you are using some gain/sustain to bring up the lower levels, otherwise you aren't getting any increase in perceived sustain.

And yes, rushed explanation of limiting, thanks for the correction.

I can see where it would be confusing. His description is technically correct, but many (maybe most?) pedal compressors kind of hand wave the whole makeup gain thing.

 

[devastone]

Re: Explain compressors

Yet, it is pretty much their main reason for existence.

This is easier than typing.

https://www.practical-music-production.com/audio-compressor.html

https://www.practical-music-production.com/audio-limiter.html (again, thanks for the correction, true limiting is setting a hard ceiling)

Back to the OP, if playing legato on a single string for some specific amount of time is your main goal, get a copy of Troy Stetina's Speed Mechanics for Lead Guitar and camp out in the left hand section (I think it is the 2nd section).

 

[TwilightOdyssey]

Re: Explain compressors

Any compression ratio of 20:1 or greater is considered limiting.

 

[dystrust]

Re: Explain compressors

Any compression ratio of 20:1 or greater is considered limiting.

Did not know that, thanks!

 

[mupi]

Re: Explain compressors

Boss CS-3 is on its way. Will see what it can do for me. If the compressor doesnt get the job done, then I will resort to techniques. If I try too many things as a beginner, I will only get frustrated. I havent even mastered plucking yet. Half the time I am plucking the string below the one I should be plucking. LOL.

As long as I am playing on one or 2 strings I am good. That is why I decided to play this kind of music and not chords. In fact I have put a foam piece near the nut under all 6 strings to eliminate sympathetic vibrations. So I cant play open chords on my guitar anyway. Basically all 6 open strings are muted to eliminate sympathetic vibrations. I know you will say palm and finger muting. Well not there yet. I may never get there as I am not 11 now! So foam to my rescue..

 

[Gtrjunior]

Re: Explain compressors

What you’re doing isn’t going to be good for your playing in the long run.
You’re avoiding all of the most important basics in favor of what is easy and “instantly gratifying “
Guitar playing is hard and takes a TON of practice and work. I’ve been playing 30 years and recently went back to lessons again because....well, guitar is hard and I need to learn more.

But to each his own. Good luck.

 

[Dave Locher]

Re: Explain compressors

You say it is not about equipment but you list a lot of equipment. I have a Squier Affinity and a Blackstar Idcore 20 amp!

I am going to try the Boss CS-3. No matter how much I read, ultimately it comes down to trying out something.

I did say that. What I meant to say is there was no one single magic piece that made it work, it was all those things combined.
You are right that you have to just try things. You might love the Boss. I really like what the Arion did for me but it was very hard to control set that way. But the key was a responsive, resonant guitar that would really vibrate when played. It's not how long a plucked note sustains that matters most, it's the guitar's willingness to vibrate sympathetically to the frequencies the speakers put out. At some point the amp is driving the guitar strings and then you have infinite sustain.
And just to be fair, everyone saying practice more is right. If the compressor pedal makes you like your sound more then that will likely motivate you to practice more. Good luck!