Parametric Equalizers
Subscribe to Ask Paul Ask a QuestionParametric equalizer, sometimes known as graphic equalizers, are like fancy bass and treble controls. Are they harmful to the purity of the system? Necessary in some cases? Find out what Paul thinks about parametric equalizers and why.
I attended a seminar at an audio show in 2016, where room tuning was the main topic. It was not surprising to me that the best way to tune a system was to get the speakers placed properly in the room, then apply room treatments to solve issues with the sound. A room treatment could be anything from rearranging furniture or putting a blanket over a coffee table, to installing diffusion or absorption panels and bass traps in a room. Only as a last resort was equalization used, when an issue was impossible to overcome by any other means.
What irritates me today is how many owners who set up their audio systems (or home theaters) will immediately whip out a microphone and run their room correction program to instruct their DSP as to how the signal should be manipulated so it sounds “perfect” at the listening position. As the seminar above pointed out, however, this causes two things to happen. First, it could make the sound better at the single seating position. But second, whatever frequency range is cut or boosted for that single point is now thrown completely out of whack at any other position in the room. For instance, a DSP jacking up an 80 Hz dip in response to flatten it at the single position has now introduced a sharp 80 Hz peak everywhere else in the room. (This does not even address the stresses put on an amplifier or speaker if this EQ is forcing the system to boost certain ranges.) Multiply that by the multitude of adjustments that room correction can apply in terms of boosts and cuts, and you begin to understand the flawed concept behind automated room correction. Is this a lazy person’s way of “improving” their system, or just a fancy toy to boast about? I can’t say, as I would prefer to do it the right way with positioning and room treatments first.