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Assuming you have the same amount of (high) gain, and the same amount of distortion, a palm muted strum gives a higher output than when you hit the same chord with the same amount of energy, non muted. Why is that?

Suppressing the amplitude of vibrations of the strings should adversely affect the amplitude of the output signal but that doesn't appear to be the case. I am assuming this has something to do with reduced harmonic vibrations that might cause destructive interference but I'm not sure about the physics. Could someone explain the physics of this?

By higher output I mean the power or loudness of the signal. Here's the simplest demonstration.

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    I don't agree with the premise of this question -- for me, palm muted is, well, muted.
    – Dave
    May 19, 2014 at 3:18
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    You might need to explain what you mean by higher output. Is this something you measured? If so how? May 19, 2014 at 3:49
  • I've added a video that kinda explains what I'm talking about. Its mostly there when you use high gain sounds.
    – SiddFisher
    May 19, 2014 at 4:21

2 Answers 2

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It's because of the pseudo-compression that using distortion effect gives. The same will be true if you use a clean channel with a compressor, or if your amp has a natural compressing effect, as many do.

What's happening is...

You play a chord normally: You get quite nice mid-range strum of the strings, nothing surprising there.

You play a palm muted chord: you're suppressing mainly the upper frequencies and mid-range, allowing the bass in the notes to poke through more. Also the heavier strings tend to remain ringing longer than the lighter ones, which stop almost immediately so the sound is biased towards bassy and lower strings.

If using distortion or compression, the bassier sound saturates the amp (or effects box) and becomes "dominant" (in terms of volume, not music-theory-dominant .. er .. or any other kind of dominant) and you get a much chunkier sound.

Bassier notes are generally higher output so the overall effect, while it might not really sound louder (or it might), is a higher output.

If you try all this on a straight guitar with no distortion/compression, or an acoustic guitar, then you won't get the saturation and the palm-muted chords will sound quieter.

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  • ps. great question :-) May 19, 2014 at 10:21
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    Yep, I think you nailed it man. I had a feeling this was the case. So is it like when you have natural harmonics, you remove certain harmonics from the harmonic pattern of the not and you get the corresponding harmonic. So in case of a palm mute your hand position is very close to the bridge and most high order harmonics are removed from the signal's harmonic pattern leaving behind the lower frequency harmonics? (Do I make sense?) Ps: Thanks :)
    – SiddFisher
    May 19, 2014 at 10:33
  • Yes, exactly that :-) - with compression (or distortion) I think of it as : the sound wants to be the same volume (owing to the effect), so whatever you take away, what's left kind of rushes in to fill the gap. Gotta say I love this effect and use it a lot May 19, 2014 at 10:40
  • So do I... It just suddenly hit me that I didn't know how it worked exactly.
    – SiddFisher
    May 19, 2014 at 10:44
  • +1 to the question and +1 to the answer. But I get a similar result with a DI box too. Is it possible that my pick-ups have some built-in compression too? (I always feel that's the case but it's not easy to confirm)
    – cyco130
    May 19, 2014 at 19:38
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I imagine when your palm is muting the strings, you are picking them from a different angle or using a different muscle in your arm or wrist that is supplying more energy to the attack.

When you attack with your pick deeper in the strings, it tends to be generally louder because it takes more energy for your hand to pull the pick across.

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  • I agree with the fact that a pick has more attack if you palm mute but try the same picking technique without your palm muting the strings. I'm pretty sure the signal would not clip even if you use more force (don't break the strings). Intuition tells me that this isn't the only factor and that the physics of sound are involved in this phenomenon. Could someone please confirm this?
    – SiddFisher
    May 19, 2014 at 8:06
  • I agree with this too - I think when you palm-mute a string, assuming you're using a pick as well, the point where it hits the strings is a kind of "sweet spot" given they're muted. I suspect it's possible to clunk the strings harder under these circumstances without them doing anything nasty like rattle against the neck etc. May 20, 2014 at 8:32

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