Why buy an Add-on Sound Card?

Onboard or Add-On?
By Artiom Bell 2008.03.19 repost here 3.21.08

It's no wonder that the introduction of integrated audio into the market, caused a significant downfall in the sale of add-on sound cards. In fact, why shouldn't it? The average user doesn't need to spend an extra $20 - $40 to hear the windows "beep" better. The newer motherboard models feature the 7.1 surround sound in 3.5 mm jacks, High Definition Audio (HDA) cable, and feature a decent Signal to Noise Ration (SNR) at a decent sampling rate. First, lets find out what exactly the technical terms mean. Signal to Noise Ratio (SNR) is a ratio of signal strength over noise strength and is measured in decibels (dB). A decibel is a measurement of power of intensity. In other words dB is a measure of a power of 10. When saying signal A is 10 dB stronger than signal B, in actuality that means that signal A is 10 times stronger than signal B. If signal A is 20 dB stronger than B the A is B times 100, 30 dB would be B times 1000 and so on. The general idea is that add-on sound cards produce better sound. The first question that comes to mind is what does "better" mean?

Read more here -->Link