Your music system has a 12-band equaliser, the MP3 player you are going to buy has six-band equaliser, and so on. What does that mean to you?

An equaliser is meant to fine-tune the audio system to the environment where it is placed, and not to change the music itself-though most home users do precisely that. Let us gain an understanding of what frequencies are. The music you hear is composed of frequencies spread from 20 to 20,000 Hz in theory (practically though people hear sounds from 50 to 15,000 Hz). Different instruments and voices give out different frequencies.For example, the drums give low-frequency sounds called the bass, the treble is high frequencies, such as the higher sounds of violin, and the "mids"-the frequencies fall in the middle range-are typically dominated by voice. An equaliser allows you to increase or decrease a particular set of frequencies, thereby altering the levels of various instruments and voices.

When it comes to music, it is the job of the music director to play with the levels of various tones and instruments. He is presumed to be competent enough to choose the best settings for his song, knowing well all the instruments that have gone into its making. When you change the settings on your system, you will be throwing away the sensibilities of the music creator, losing out on the intended experience.

Sometimes, the ambience of the room where a system is placed will affect the way a certain frequencies come across to us. To offset this variation, equalisers are provided so that after careful observation, the user can negate the effect of the environment. Another use that equalisers find is to overcome shortcomings of a system. For example, take the case of a typical entry-level MP3 player that doesnot produce treble at the same level as the bass. When connected to a music system, you can neutralise this effect by sliding the bass control down or the treble control up.

In many cases, simply keeping the equaliser off will provide you with the best sound. Even you need to change the settings, the amount of change should not be more than 20 percent. If you seriously wrong with your speakers or with the player itself.

You might want to move the equaliser settings about if, for example, you love bass and want more of a thumping effect - or, for that matter, for highlighting any particular instrument. But remember that what you'll be listening isn't what the music director intended!