"bluesjeon" wrote ...
the recording format is "24bit 48 khz wav"

when u record silence in protool with the input is not connected
what is the peak value?

I am using Apogee ad-converter and get -139db in some recording
program but in other recording program the results is not the same

The theoretical noise floor is a simple mathematical function
of the bit depth. Some software may be recording only 16 bits
and not the full 24 bits that are available from the hardware.

The actual noise floor is a function of the design and build
quality of your equipment, and the system/environment in
which you have it deployed (including the software).