Question in regards to hook up

[superchad]

In the cable hook up thread this is stated :

"A microphone input on the soundcard is not suitable (many laptops only have mic-in)."
I am trying to keep cost down and not purchase an external soundcard so help me answer...........

Why is this? please help me understand......thanks

[brucek]

Why is this?

There are several reasons.

SPL meters (such as the Radio Shack meter) output a line-level voltage signal. The microphone input jack offers high gain since actual microphone signals are quite low in relation to a line level signal.

This extra gain at the mic inputs front end usually results in increased noise.

Mic inputs usually enjoy a very limited bandwidth that is designed to comply with a narrow voice frequency range that a cheap microphone would supply. The port often supplies a 5 volts bias signal also.

You require a line-in to use REW.

brucek