Equal Loudness Curve.
In 1933 American scientists Harvey Fletcher and Wilden A. Munson came up with the Fletcher-Munson curve.
They were the first guys to measure our perception of loudness at different frequencies using headphones.
The curve represents how much sound pressure dB SPL (energy, amplitude) need to be applied across the frequency spectrum, for a listener to perceive the different frequencies as a constant loudness.
That’s why this is also called an “equal loudness contour”.
Another way of saying this: the ear does not hear all frequencies (vibrations) as equally loud.
The vertical vector represents sound pressure level (dB SPL), the horizontal vector frequency.
The graph shows that it takes much less sound pressure to perceive a 1000Hz frequency at the same level of loudness as a 100Hz frequency, which takes much more amplification to be perceived equally loud.
The curve shows that our ear tends to naturally be the most sensitive in the 1k (means “1 kHz”, which means “1000 vibrations per second) to 5k range.
I never would have known about this, if it had not been for my MP&E (Music Production & Engineering) classes at Berklee College of Music in Boston.
How Can This Knowledge Make You A Better Performer?
Though the Fletcher Munson Curve might seem completely unrelated to being a performer, there is a very useful application of this knowledge which will help your live performances.
Have you ever played a rock show where everybody kept telling you that your guitar playing was awesome, but… that they could not hear your guitar solos?
Have you gone see friend’s shows, where the band’s live mix is pretty good, but the moment your buddy starts soloing, his guitar completely drops out of the mix. You see him gesticulating and rocking out on stage, playing like his life depends on it, but you can’t hear a damn thing.
Then he starts playing rhythm again, and he’s back in the mix again.
The reasons for this happening are pretty obvious.
For one: when you play rhythm guitar you typically hit multiple strings, typically out of your arm with big strong motions, hence louder volume.
When you start improvising however: you switch to playing single note melody lines, only 1 string (or 2 if you solo with intervals) at a time, which means that you play out of your wrist, making much smaller motions because you need more accuracy, hence lower volume.
As a result: the guitar solo disappears in the mix.
Well.. there’s solutions of course:
- You could pay a sound guy to turn up the volume on your solos
- You could buy a volume pedal
- You could use your volume knob on your guitar.
Or… you could use what you now learned about the Fletcher Munson Curve.
Hooray: Everybody Can Now Hear Your Guitar Solo Magic.
If you switch from your neck to your bridge pick up right before a solo, your solo will be perceived as louder in the overall band mix, because the human ear is more sensitive to the higher frequency treble sound produced by the neck pick up.
The human ear hears the guitar as being louder, even though it isn’t, simply because the ear hears better at the frequency range of the bridge pick up.
For those who wonder: “Well, what if I am already strumming on the neck pick up?”
“Why on earth would you want to do that, unless you’re 84 years old and you need to compensate for your hearing loss in the upper frequency range?” 🙂
You prob don’t really want to do that to your listeners.
There’s a reason why on a Les Paul the upper position is called Rhythm (this setting activates the neck pick up) and the lower position is labeled “Lead” or “Treble” (which activates the bridge pick up).
So… No Rhythm Playing On A Bridge Pick Up?
One of the issues with opinions or advice on the internet, is that you get all these conflicting messages because everybody only hits part of the target or misses target completely.
When you Google “rhythm guitar pick up”, you find a billion posts and discussions from guitarists stressing that they play rhythm on their bridge pick up “all the time”.
While it’s hard to not get lost in these seemingly contradictory opinions, the seemingly conflicting messages are merely the result of incomplete information and flawed communication on the part of the people who post these messages.
No one even cares to mention, what style of music or what style of rhythm guitar they usually play, which would explain why they can get away playing rhythm guitar on their bridge pick up without driving their listeners nuts with painful high frequency hell.
All kidding aside: notice that I carefully worded earlier: “Well, what if I am already strumming on the neck pick up?”
Strumming… As opposed to:
- Playing metal in the bass range of the guitar and typically only picking on 1 or 2 strings
- Playing power chords (which is mostly bass range too and only 2 max 3 strings)
- Playing blues rhythm guitar (more often than not this is bass range too and the most 2strings)
In these cases, you won’t wear out the ears (and attention spans) of your audience, because you’re not strumming high frequency treble strings at a painfully brittle, harsh brightness produced by the neck pick up.
The neck pick up in that case adds bite, attitude, clarity and definition to the bass rhythm parts.
In rhythm styles that aren’t strum oriented (metal, the honky tonky 2-string Texas blues rhythm style, power chord oriented rhythm styles…), you typically only play rhythm on 1 or a couple of bass strings at a time.
As the ear is less sensitive to those bass frequencies anyway (yes, Fletcher-Munson again), your solo will appear to be louder regardless of which pick up you played rhythm on before your solo.
After all: guitar solos for the most part are typically played on treble strings, which the Fletcher Munson Curve shows us: our ears hear as being louder.
There you go!
You can fire your sound guy, and sell off your boost and volume pedals for extra cash.
Just switch to your neck pick up if you want your solo to be louder than your rhythm guitar. 🙂
Have fun experimenting.
PS: Of course, I did nowhere say that you can’t play guitar solos on the neck pick up. As a matter of fact: I love playing solos with that nice thick, warm sound on the neck pick up.
However: if nobody can hear you, you’re already maxed out on your guitar, you don’t own a volume or boost pedal, the sound guy is too wasted to know what all the knobs mean, and you’re too tired to walk to your amp… you can simply switch to your neck pick up et voila. 🙂