How to choose an equalizer
For superior tone control in your car

AudioControl EQL 13-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.
Get Everything You Need
You'll need patch cables to connect an EQ.

JL Audio's TwK 88 8-channel processor includes 10-band EQ on each channel
Wes Jeans from Trinity Texas
Posted on 4/9/2022
I've been out of the game for many years and I am working on putting together a system in my truck. From what I can tell the old style crossovers are a thing of the past. I'm guessing because most of the music these days are digital signals, hence the need for a dsp. So the question is, can I get the same results with just an equalizer or do I need to get a dsp? Thanks.
Buck Pomerantz from Crutchfield
on 4/11/2022
Rey
Posted on 3/29/2020
I have an aftermarket radio connect to T600.4 with some set of t1693 fosgate an t1500.1bdcp but my system doesnt sound as good what kind of eq can I use
Buck Pomerantz from Crutchfield
on 3/30/2020
Lanni Erwin from Worthington
Posted on 2/20/2020
Not sure how to connect my stereo,I have a Kenwood head unit,a soundstream 9 band graphic equalizer and a rf p4004 amplifier,can you tell me how many RCA's I'll need and what hooks up to what please
Buck Pomerantz from Crutchfield
on 2/24/2020
Daniel
Posted on 10/30/2018
Hi, I have a 5 Channel amp connected to my OEM head unit, I use a PAC device to change the from High to Low Outputs. If I want to add an EQ to improve sound quality should I hook it up to the PAC Low Outputs, and then the EQ Outputs to the Amp Inputs? Best Regards
Buck Pomerantz from Crutchfield
on 10/31/2018
Buck Pomerantz from Crutchfield
Posted on 4/26/2018
Brett, There'll be no benefit at all adding a processor to a receiver that already has digital signal processing onboard. In fact you'd penalize yourself if you did because then you'd have to add an amplifier, which your receiver also has built in.
Brett from Daphne
Posted on 4/25/2018
Many aftermarket head units now provide a wide variety of methods to tune the sound in your car. My Kenwood Excelon DDX594 includes HP/LP crossovers, slope, time alignment, 13-band equalizer and several other impressive features that many of these standalone processors provide. What additional benefits would a standalone processor (such as the AudioControl DM-810) provide that my head unit can't handle?
mario from sylmar
Posted on 4/9/2018
I have a 2016 genesis sedan I upgraded the factory speakers to infinity kappa 60csx components and for rear infinity kappa 60.11cs components. Amps alpine pdx f6 4 channel and pdx m12 for sub. I left the double din stock radio as there is no kit to replace this radio the issue is my speakers sound muffled almost as if someone is covering the singers mouth. Would an equalizer fix this issue and what would u suggest? I just want that fixed I sent want to play with settings all the time.
Buck Pomerantz from Crutchfield
Posted on 1/12/2018
Richard, You should never connect outputs of devices together, it could cause damage. Looking at that equalizer's connections and controls lead me to say that you'll probably get the best results using your receiver's front outputs connected to the equalizer's CD inputs. The equalizer then creates the front, rear, and subwoofer signals for your amplifiers to handle, and features front-to-rear fade control and subwoofer level. You set the input gains of the equalizer just like amp gain - turn it up until you hear distortion, then turn it down so it always sounds clean.
Richard Heinrich Ronildo from aruba
Posted on 1/12/2018
hi. mr BUck. i have a few questions. what pre amp outs to use from the HU to the eqaulizer.. front or rear...also can they be combined with a y splitter to the equalizer..and how do i set the gain on the cd in on the equalizer. i have a 7 band equalizer from super iascar
Buck Pomerantz from Crutchfield
Posted on 11/17/2017
Ricky, If you're unsatisfied with your receiver's onboard EQ, maybe an AudioControl LCQ-1 with 11 bands of EQ per channel will work for you.