Quote:
warrensomebody wrote:
 Anthony - Thanks for your explanation.
I know that this rise in the noise floor doesn't matter when measuring my subs, but I have also done a set of measurements of my tweeters (from a few mm away) using the same mic and cal file, and I see an identical rise in the response. The fact that this rise, in both the noise floor case and the close-mic'd high-frequency case, correlates with the dip in the calibration curve says to me that it really is that the calibration curve isn't correct for my mic.
So I'm tempted to go into the newecm.cal file and flatten out those datapoints so that I don't have to look at the rise anymore... unless this is a bad assumption, and it's really not possible to know whether the rise is real or calibration-related. ? |
If it was me, here's what I would do (you've done some of this already)...
1. Use your setup to measure the noise floor... first with amp off...
2. Then measure again with amp on, and set to reference level, but scan with no input to the amp...
If 1 shows no HF rise, but 2 does, your reading accurately the noise floor of your amp...
If 1 shows an HF rise, I would...
3. Go to another location and run the scan again...
If 3 shows no HF rise, you're accurately reading a rise in the noise in your theater...
If 3 shows the SAME rise, you can be reasonably certain the cal file is not matched to your mic, and you can either manually adjust, or get a file made for your specific mic...
Of course, in this case, I would like to test in my setup again with someone else's mic, just to double check, but I'm funny that way...