Check speaker phase! The speakers in your system should all be firing in phase — simply put, all the cones should be moving out and in at the same time. If they’re not, you lose bass response, making your system sound anemic and unfocused. It’s important to check all your speakers, even if your system was professionally installed. 

To determine if a pair of speakers in your vehicle are in phase, listen to some bass-heavy music with your stereo’s balance control all the way to one side. Now return the balance control to the center — you should hear significantly more bass. If you don’t, your speakers are out of phase. Switch the positive and negative leads on a single speaker, and try again. If you hear more bass, leave it! Check the front and rear speakers independently in this manner.

Turn on your subwoofer system. Reverse the speaker wires going to your sub and listen for a change in bass response. Again, if it gets louder, leave it! (Make sure that multiple subs are wired in phase with each other.) 

Flatten it out! Especially if you have a sub, it may be tempting to crank up the bass on your receiver. Tune your system first with the receiver EQ set flat — all tone controls at “0″ and no EQ curve engaged. With the subwoofer off, turn some familiar music up to a moderate listening level, then slowly increase the subwoofer output until you hit the “sweet spot” — the place where the bass really kicks in without overwhelming the rest of the music. 

If the bass sounds like it’s coming from behind you, lower the sub amp’s crossover point to “de-localize” the bass. If your amp has a non-adjustable crossover, try moving the subwoofer. For example, if it’s firing toward the rear, turn it around so it fires forward or sideways (remember to check your phase again with the sub in its final position). 

Listen and experiment! Your system should create a “soundstage” — close your eyes and you should hear the instruments in front of you, arranged from far right to far left, with (if you’re listening to rock’n'roll) the kick drum, bass guitar, and lead vocal right dead center. 

Some vehicles make it tough to establish a strong front soundstage:

If your car has small front speakers, install some Bass Blockers. They’ll filter out the low frequencies so your speakers will play louder and clearer, bringing the soundstage back in front of you. If your receiver has built-in crossover capability, use its high-pass filter to remove low bass from smaller speakers for improved performance.

If you have a subwoofer (or larger speakers in the back), use your receiver’s fader to move the music forward and then turn up the overall level to bring the bass back into play.

If your front speakers are mounted low in the doors, some receivers feature independent front/rear tone controls or signal processing that raises the front image. Or, if possible, install a set of tweeters in front.
Instead of cranking the bass way up to increase your system’s impact, raise the bass a little bit and lower the highs and mids. It’s smart to keep equalization to a minimum — pumping up the bass control just robs your system of its effective power.

First rate bass!

1. System sounds dull? Put a set of tweeters up front to strengthen your front image and add liveliness to your sound. Many receivers feature signal processing (BBE, DSO, MediaXpander, etc.) or extensive equalization which can do a lot to improve a dull-sounding system.     

2. Vocals and instruments sound buried? If your receiver has a midrange control, boost it up a little bit; if it includes a parametric EQ, try adding a little bump in the 400-1000 Hz range. Replace your rear full-range speakers with some high-quality midrange speakers to bring out warmth and detail without adding more sizzle. Installing Dynamat (or any sound-absorbing material) in your vehicle will reduce road noise which masks crucial midrange details.     

3. System too bright? If your front speakers have swiveling tweeters, aim them away from you. If you have installed component tweeters, check the crossovers for output level switching — a drop of 3 dB can make a huge difference in the way your tweeters match up to the rest of the system. Experiment with your receiver’s EQ. If that doesn’t nail it, consider a receiver with more equalization control or (for an amplified system) an outboard equalizer.

Think ahead! Once you’ve taken the time to adjust the system, then you’ll know if you’ve made smart purchases. Always buy with an eye to the future — you might be saving 40 bucks on your receiver, but what’s the point if it’s missing some crucial features you’ll be needing when you expand your system? If you plan on adding a sub to your system later, spend a little more on a multi-channel amp (instead of a 2-channel) so you can power your front speakers and subs with one amp. Don’t install 10-gauge power wire if your ultimate goal is a throbbin’ multi-amp system. With the right components and some careful adjustments, your car can be a fantastic place to listen to music.