Hugh Robjohns wrote:
The max output level from the ISA2 is +24dBu and by default its metering is calibrated such that 0dBFS on the meter occurs at +22dBu (but the adjusting range spans +16 to +24dBu).
However, this is a bit of a problem since the front line input of the Clarett, with the knob fully anticlockwise expects +26dBu to reach 0dBFS... so the ISA's meters and those in the DAW can never be aligned on tones when using that input with the gain knob fully down.
You could align them with the input gain turned up on the interface, but then you'll need to recalibrate every time you use it which is not practical.
So, you'd be better off using one of the rear panel line inputs to receive the ISA2 since the max level here is +18dBu, and you can definitely match the ISA2 meters to that.
when I switch over to using a microphone the levels are nowhere near being calibrated. My microphone level is way too hot in my DAW compared to what the meter on the ISA 2 is showing me. Any ideas what the problem could be?
Yes... different meter ballistics. We align meters using steady tones because that's the only way we can. Different meters respond very differently with programme material because some are true-peak reading, some are quasi-peak reading, some display the true-RMS level, some a quasi-RMS level, and some now indicate the perceived loudness... They all have different attack (integration) and recovery times, too... so no two different meter types will ever show the same thing on programme audio material.
As a result, you have to be able to recognise and interpret what the different meters are telling you, and use their information accordingly.
Of course, if you're recording with a sensible headroom margin it really doesn't matter anyway -- the meter is only a rough guide to getting the signal sitting somewhere reasonably sensible between the noise floor and the clipping point.
From your description, I'd hazard a guess that the ISA2 is showing something close to the peak levels, while your DAW is showing something more similar to the VU or an RMS meter.
At the end of the day, though, the meter is just an aid. Tweak its calibration knob until you get consistent recording levels, in that what you think you're recording from the ISA2 looks roughly the same on the DAW... Take the pragmatic approach!