I believe we all have been there. Spending from minutes to hours, tweaking all of our tones and presets to perfection, experimenting with many different options and listening carefully to every detail until we are 100% satisfied with our tone, only to find that our sound absolutely SUCKS when trying it on stage. It’s a common thing to happen, but why does it happen?
Going from bedroom level to stage level or phrased more correctly in most situations: Going from headphones or (probably small) nearfield speakers to larger PA speakers will deliver a greatly different tone. And it’s actually pretty normal to happen this way. A small headphone driver or a 5-8 inches speaker for mixing is destined to have different characteristics than a 10-15 inches speaker for a PA console. It’s fair to say that the bigger the difference in sizes, the bigger the difference you’ll have from bedroom to stage.
But wait a minute, I use the same FRFR speaker both at home and rehearsals/gigs, does this occur to me too? Unfortunately it does! And that’s where... science comes in! The Fletcher–Munson curves is a research that was conducted in 1933(!). It studied how the ear hears different frequencies at different levels and the concept of equal-loudness contours was later re-determined by Robinson and Dadson in 1956, which became the basis for the 2003 survey by ISO that redefined the curves in a new standard. You can get more info about the studies here:
Basically, the studies have shown that changing the volume of a sound source does not accordingly change the loudness and the way it is perceived by a human ear. So in a few words, when changing the volume, we actually also change the EQ that we perceive. A sound that is mid focused but sounds full to us at a low level would become muddy, with lack of bass and no treble definition when cranked up while a somehow thin sound with a distinct but low volume bass and pronounced highs would actually sound full and round when it goes to high levels.
This is why there are different approaches when it comes to mixing and mastering. It’s fair to say that the music industry nowadays has the headphones mix as a “default”. Most people will hear that song in their headphones using their smartphone so it has to sound good to them. A different approach is to sound decent in headphones or speakers at relatively low volume and sound great when we turn up that volume. Because if the listener is interested, he WILL turn up the volume and it has to sound good then.
It is also why it is normal for a high watt tube amp to sound thin at low levels. They are not supposed to be played at such low levels, they are supposed to be cranked up until you are blown away! And that is where Impulse Responses come in. Even with one cabinet, one speaker and one microphone, you can have unlimited options in creating an IR with them because of the unlimited mic positions and angles. Put a few more mics and combinations (dynamic, condenser and ribbon) and the IRs you can create are endless (and we are not including other factors like room, acoustics, air pressure and so on).
So what’s important when creating an IR is its purpose. Is the IR designed to work at a low volume level with focused mids in order to sit well in a mix or is it designed to work at a high volume level, so it is normal to sound thin if we use it with headphones for example? There are certainly many ways and “tricks” to correct this with EQ as much as possible but choosing a suitable IR will get you there in no time!
Is that all? Wish it was but no. There is another factor that we usually don’t take into consideration and that’s room acoustics (and let's not forget listening positions, how turning the volume up will boost different frequencies depending on the amplifier and the speaker etc). There is vast difference in room acoustics between your home or even rehearsal room and that big (most times untreated) room for gigging or that wide open area outside. Every place is so much different acoustically and it’s bound to impact the way your tone reaches the listener. But this is definitely something we can’t handle easily so the best way to get the best results is to shape your tone within a well-treated room at a volume level as close to your gig level as possible and be prepared for a few adjustments when going to a different place.
You can check out our FREE Custom IR Pack designed to emulate the Live sound of a cab!