What's the best setting for the EQ controls - My...

While many people do like to boost the low and high frequencies, this setting may not sound the best in your system. The best way to determine the most appropriate EQ settings is trial and error. Your speakers and the inside of your car both come into play, as well as the type of music you typically listen to.
Start with all the sliders set flat, so that the EQ is not affecting your sound. Then make minor adjustments to the appropriate frequencies that are missing or are too strong. For example, if your vocals are not coming through clearly, boost some of the middle frequencies a little.
Or maybe the vocals aren't clear because the highs are too piercing. In this case, attenuate some of the higher frequency bands a little. And instead of boosting the low frequencies all the way up (and we've all been tempted), try bringing them up just a little bit, while lowering the mids and highs a touch ? you'll get more effective gain out of your system that way (and you won't fry your speakers). The great thing about having an equalizer is that you can change the sound of your music quickly and easily to match your mood.