TOTAL HARMONIC DISTORTION: An expression of the amount of distortion or noise created by amplifying the signal. Simply put, distortion is the difference between the sound sent to the speaker and the sound you hear. The amount of Distortion is measured in percentages. An acceptable level of distortion is less than 0.1%. For some CD-quality recording equipment, a common standard is 0.05%, but some speakers have a distortion of 10% or more. Headphones often have a distortion of about 2% or more. WATTS: Usually stated as watts per channel, this is the amount of amplification available to drive the speakers. Check that the company means “per channel” (or RMS) and not the total power. Many audio adapters have built-in amplifiers, providing up to 8 watts per channel (most provide 4 watts). This wattage is not enough to provide rich sound, however, which is why many speakers have built-in amplifiers. With the flick of a switch or the press of a button, these speakers amplify the signals they receive from the audio adapter. If you do not want to amplify the sound, you typically leave the speaker switch set to “direct.” In most cases, you`ll want to amplify the signal. To overcome all these drawbacks an Audio amplifier specialized only for Laptops have been to enhance the sound outcome and also the quality of sound.