[Otto]

Hi buzz.

Usually, we use a mic that provides a line-level output signal. Many of us use a RS or Galaxy SPL meter, and many of us use "real" micropohones fed to a preamp and then to the soundcard. Either of those methods results in a line-level signal.

If your mic is not providing a line-level signal, and you are going into the soundcard on the "line-in" port (as I suggested in my previous post), then you'll get really low readings. You should be able to increase the level of the reading by using that mic with the "mic-in" port. However, this may cause a couple problems.

First, you may have trouble with the calibration when using the line-out and mic-in ports. The mic-in path is looking for a much lower signal that what the line-out will generate. You may be able to get a better result by decreasing the output of the soundcard, but it's not the normal way of doing things.

Second, if you use that mic, I presume that you don't know its frequency response. This is a very important part of the measurement, and you will be pretty much guaranteed to have a skewed result if you don't use some type of calibration file with that mic. If that mic was supplied with another program or device that's used for measuring frequency response, I'd think that that program or device knows the frequency response of the mic and accounts for it as part of its measurement process.

If you don't already have an SPL meter, you should get one. Not only can you use it as the mic for these tests, you'll also need it for level calibration. It's a very useful device. I have the Galaxy CM-140 (I think it's the 140, maybe the 130...), and they have been very consistent from one to another (that means that the calibratoin file we use is applicable and accurate for all of these meters). If you can't find the Galaxy, try to get a Radio Shack meter; they are widely available (I see you are in Singapore).

Good luck!