During a recent project, we were quite happy with the way our mix of a band sounded through studio monitors, headphones, and home stereo speakers. But since this was a project for TV broadcast, we also ran the mix through small, built-in TV speakers to hear how it translated. Through the TV, the mix had low-frequency build up that was making it sound muddy. Our first nstinct was to check the bass and kick drum for anywhere the mix had excess low frequencies we could cut, but found nothing out of the ordinary.
However, when we looked at the guitar track, we found the culprit. A slight bump at 100Hz was enough to cause the muddiness we were hearing. A quick EQ adjustment dipping the level at 100Hz and boosting the level slightly at 200Hz cleared the muddiness right up. Now the mix translates well on all of our reference devices and is ready for broadcast!
The moral of the story: reference your mixes on as many playback systems as possible, and don’t automatically assume the “obvious” tracks are the source of a problem.