Boxtone, it's sound engineering jargon that describes how some—but not all—analog gear or digital audio software plug-ins (e.g., parametric equalizers, dynamic range compressors, master buss processors, etc) will add unique fairy dust by altering the program material in a pleasurable way (i.e., also referred to as coloring the sound) even though all dials, switches, and knobs are at their factory default settings (i.e., flat or full-reset).

This boxtone mojo often stems from vacuum tubes and transformers found in certain professional audio recording equipment signal paths that add harmonics, giving them a distinctive yet recognizable sound of their own.

Other contributing factors include age (i.e., wear and tear or degraded performance derived from how long the music equipment has been in use), the tolerance of analog circuit components (i.e., random variations or the amount a component's specification is off by—this can affect the balance of L/R channels) and temperature (i.e., how warm or hot the components are at the present moment, especially vacuum tubes, transistors, resistors, and capacitors).

Modern digital audio plugs can also remarkably do quite the same depending on how talented the software developer is because there are lots and lots of snake oil plug-in emulations with a pretty-looking GUI (graphic user interface) but not enough mojo to justify the price in some cases, that is.

Should you add a little bit of "boxtone" in audio mastering?​

Well, if it sounds good why not? If it doesn't then don't. Isn't that a quotable quote? I suppose so.

As always, the golden rule of audio post-production is less is more. You don't wanna deal with angry clients or ruin your mix assuming you are into self-mastering like everybody and their mama is doing these days in their tiny bedrooms with nearfield studio monitors placed right close to the wall—probably with cheap noise-canceling Bluetooth headphones too. That's the DIY mastering starter pack right there mate.

Anyway, sound mixing engineers are the ones who mostly get to have a lot of fun with audio engineering techniques such as this one of utilizing the good ole trick of spicing up a bland record with boxtone.

There usually are several audio tracks in a mixing session to experiment on, unlike the other side of the fence where it's only a printed stereo mix you've got to polish, add a little bit of sheen on, followed by your secret fairy dust, and slam it into a true-peak brickwall mastering limiter!
Top