TOPIC:

Hi,

I am trying to calibrate my EARS/REW in terms of absolute SPL. I found the process in the manual confusing and counterintuitive.

The capsules usually are somewhere around 10mV/Pa (94dB) as design centre and the ADC will have a full scale voltage of X (usually 1V RMS to 2V RMS), assuming the ADC is simple single ended 1V RMS setting the gain to 0dB and producing 94dB we should see -40dBFS and should set our SPL meter to 94dB and be done with good enough accuracy.

So Ideally we just know the sensitivity in reference to 1 Pascal (94dB) in 0dB gain mode (and adjust for extra gain if used).

I ultimately calibrated with headphones of known sensitivity fed them a known signal level and set the SPL Meter calibration for that.

But there should be a much easier way to just enter the correct relationship, IF it was known and documented.

Thor

I agree... I tried decoding the calibration method outlined in the manual but found that rather confusing.

Why not simply say that at 18dB gain setting that 94dBSPL = xxxdBFS for example.

From what I gathered from the manual it looks like 40dBFS translates to 80dBSPL when the gain is set to 18dB, but given how the manual is written, I would not wager any money on this.

Can someone at miniDSP please provide a sensitivity spec for this device?

Doug