Adjusting Equalizers

Car environment makes it a difficult to achieve better listening as opposed to home environment. It mainly attributes to the curves, edges and the constrained space and also road noise. To achieve a better listening experience is a challenge, and equalizers are the basic element that comes handy to help it.

Simply speaking, equalizers help you to compensate for inaccuracies in the sound response curve. As we already saw in [this article] , Rock setting boosts the high & low frequencies or cuts the mids a bit to compensate for the human ear’s sound dynamics. But, in car environment, there might also be certain inaccuracies that spoil the sound effects. So, the Equalizer’s boost/cut controls increase/decrease emphasis in a specific octave of music. But remember that, EQ is a post processing, and is to be used with care and properly to avoid noise floor.

To operate the Equalizers, one needs to know what sound falls in what frequency range and how it should actually sound. Let’s look into these details for general sounds in any given music:

High-Frequency band: The high frequencies are produced by high notes on percussion instruments and cymbals, snare drums etc. This band can be adjusted to make sure these sounds are not excessively bright and it doesn’t cause any blurring and hissing of human voice.

Mid-Range: Human voice, guitar, percussion and brass instruments fall in this category. Adjust it such that, these instruments sound realistic without harshness & distortion. You can play around a bit, if you want to bring little intelligibility in the voice.

Mid-Bass Range: Bass guitar, piano and synthesizer fall under this range, and they should be reproduced with good details. This is the range you need to pay extra attention to as many cars will have rattles & vibrations that cause peaks in this range. Especially, when you go for sound damping process, watch this band.

Sub Bass Range: Low frequencies produced by drums, bass guitars, drum machines fall under this category. Advised settings are to keep them easily recognizable and not over-exaggerated. If its levels are always higher than the other sounds, it might not sound good and will just give the boom car effect, which is not desired by many listeners.

How to Equalize?

A common mistake that people do while setting the equalizers is to crank up the desired ranges to extreme/very high boost levels. This might often result in undesired sound quality. It often introduces ‘hiss’ in your system.

Recommended procedure:

It is recommended to set the boost/cut controls to the 0 level, i.e. “Flat” position and then use the equalizer to cut certain levels, rather than boost. And see that the boost level differences of neighboring frequencies are kept at minimum, thus making it a smooth curve. While you cut/boost, make sure you don’t cross the 3dB levels. If you are crossing 9dB or more to get a better sound, please look back, for the system design. For sure something has gone wrong there. Check the crossover settings, LPF/HPF settings and the speaker phase.