Calibration help?

[Thared33]

I haven't even gotten as far as calibration, so there's no telling how bad I'll get stuck when I actually measure

I'm using a Presonus Firebox. Do I connect a main out (1/2) to a line in (3/4)? There are line outs that I can use, but I think the 'main outs' and 'line outs' are the same thing, it's just a matter of selecting it.

When I was testing it, only the left side was moving, and I take it that that's correct because I'm using a single side (main out 1 to line in 3 which is the left side)... or do I actually have to use both the main outs 1/2 to both the line ins 3/4

I went into my Firebox's mixer and turned the level all the way up, then turned the Vista volume all the way up, and then turned the volume knob on my Firebox all the way up so I had everything going at 100% full blast, but I was still falling short by a few db. The sound was playing at -12 or so and I got maybe as high as -13 or -14, but remember that's at 100% FULL BLAST. Is that normal?

[brucek]

Do I connect a main out (1/2) to a line in (3/4)?

You want a single line-out to a single line-in. You also need to select that channel in REW as right or left, so you'll have to associate that with a 1/2 (i.e. 1=left and 2-right).

There are soundcards that have to be at full volume to get the required levels to do the soundcard routine, so I wouldn't worry.

Once you get a good soundcard cal file, then do a measure the loopback cable to be sure it returns a flat response.

brucek

[Thared33]

Thanks for the reply Bruce, appreciated. What I came up with is attached. I think the calibration test looks just fine. When I left the loopback connection just as in calibrating though, and I hit Measure - just look at the result. Judging from what it's supposed to be in the guide, the Measure with the loopback connection isn't quite right for some reason as it has a steady decline starting at 50hz or so and I think it's supposed to be basically straight all the way through.... or do I have it backwards and everything looks fine? :P

[brucek]

or do I have it backwards and everything looks fine?

The blue line that is sloping down in graph 2 is the target line for setting filters.

Play with the checkboxes below the graph to show yourself which is which.

Everything looks fine.
You can remove the loopback and now use that channel for measuring now.
Be sure to load your meter/mic calibration file.

When posting measurement graphs be sure to use (for subwoofers), the standard Vertical graph axis of (45dB - 105dB) and the Horizontal graph axis of (15Hz - 200Hz) using the Graph Limits button in the top right corner of REW.

brucek