Why is getting a great mix on Headphones so tricky?

Mixing on headphones can be tricky because headphones don’t reproduce sound in a natural way, which interferes with the way your brain interprets what you hear, and this can lead to you making some bad mix decisions. That’s not to say don’t mix on headphones though.

Now for the technical details…

Headphones have several advantages and shortcomings over traditional monitor speakers. For starters, a good set of headphones can reproduce tones from 5Hz up to 40kHz. That is some range. Most people with good hearing have a range from 20Hz upto around 20kHz. While speakers can get up to 20kHz, even the big subwoofers at large concerts don’t really go down further than 30-40Hz before tailing off rapidly. This makes judging the bass end of your mix easier on headphones, as you can hear more clearly the sub harmonics and any masking going on between bass instruments.

The shortcomings of headphones are just a function of how they are physically, one speaker exclusively, for each ear. Now when you hear a sound off to one side of you, normally both of your ears hear that sound. One ear will hear it directly, and the other ear, being further away, and on the far side of your head, will hear it differently. The non direct ear, hears the sound later, because it has further to travel, it’s muffled, because your head is in the way casting an acoustic “shadow”, and there will be a phase difference too. Your brain uses the differences between the 2 sounds to work out where the original source of the sound is. With headphones a lot of this information disappears, but with speakers, it’s still there because you can hear both of them with both ears. This can literally skew some of your mix decisions.

Monitor speakers also tend to have a flatter frequency response because they will normally use more than one driver and additional porting, to get a more even response over the full frequency spectrum. Even a good set of headphones will have quite a bumpy frequency response (see below).

This graph is for a set of Beyerdynamic DT880s, (which are somewhat of an industry standard, along with AKGs and Sennheisers). The frequency response varies by more than plus or minus 6dB which is much more than an average to good set of monitors would.

So, what’s the answer?

The take away from all this is it’s important to get to know your headphones well. Know if they are bass light, or too hot in the treble range, for example, so it is important to continually listen to different types of music through them. I will do another post on other available solutions shortly.