How to choose an equalizer

AudioControl FOUR.1 in-dash 4-band equalizer

An equalizer (or EQ) lets you tune the sound of your car's audio system by giving you tone adjustment not covered by standard treble, midrange, and bass controls. We carry several types of equalizers, from the traditional in- or under-dash EQs to sophisticated digital equalizers that install in your trunk or cargo area. Some EQs work with any factory or aftermarket stereo, while some are specifically designed to work with one brand.

What to look for:

Besides giving you tight tonal control over your music playback, the equalizers available from Crutchfield also offer you plenty of other useful features.

• Some of our EQs offers a front-to-rear fader for dual-amp balancing, even with a receiver that has only one pair of preamp outputs. The fader is also ideal for dialing in just the right amount of rear-fill.
• You'll also find a "subwoofer output" set of preamp outputs (with a low-pass filter) on many of our EQs. Some models even engage high-pass filters on the front and rear channels whenever the subwoofer output is in use. These crossovers allow only certain frequencies to pass through them (high for your smaller speakers, low for your subwoofers), keeping your speakers and subs from having to try to reproduce sounds they weren't designed to. That's like having a free electronic crossover packaged with your equalizer — a pretty sweet deal.
• Some EQs also feature line drivers that boost the voltage from your receiver to the maximum level accepted by your amp.
• Graphic equalizers use fixed points of adjustment that you can boost or cut. Parametric EQs have equalization bands with adjustable center frequencies. These parametric (variable) bands really let you make exact adjustments within a given frequency range. They give you the maximum tweaking ability.
• Some digital EQs let you program your own EQ curves and store them for repeated use. You can create one curve for rock, another for rap, a third for jazz. After all, each of these musical forms naturally emphasize different tones.
  
  

  Rockford Fosgate's RFPEQU provides treble and bass boost

How an Equalizer Helps Your System

A graphic equalizer gives you ultra-precise tone control. A quality EQ, properly used, can fine-tune even a high-end system. It makes the difference by catering to your listening preferences and allowing you to restore great sound that gets disrupted by your noisiest, most hard-to-handle component — your car.

Vehicle noise, road noise, size and shape of the interior, the reflectivity of glass, and the absorbent nature of seats all affect your system's sound. You can use an equalizer to remedy each one of these ills, boosting the frequencies you're missing and attenuating the ones your vehicle exaggerates.

When you make these adjustments, use a light touch on those knobs and slider switches — a boost of 10 dB works your amplifier ten times harder, and this can introduce distortion. Here's a tip: Try turning down certain frequencies first. For example, before you boost your bass, lower the midrange and high frequencies a little bit.

Of course, an EQ is also a great way to protect your equipment. For example, if your system's bass is provided by a pair of 6-1/2" woofers, use an EQ to cut back all frequencies below 50 Hz. Your amp will work more efficiently and you'll get higher, cleaner volume while protecting your speaker drivers from tones they can't handle.

The best way to find out what an equalizer can do for your system is to try one out for yourself. A little hands-on experience and some trial and error tweaking will help you learn more about shaping up the sound in your car and really bring out the best from your system.

AudioControl EQS 6-channel 13-band equalizer