Measuring room frequency response with different DAC's

[Egoist]

What scale are you using? At the low frequency and amplitude precision of a 15 second frequency sweep of course the measurements look the same.

256 K but then I compare different measurements with the VAR smoothing.

 

[Egoist]

It was probably a bad idea, but the concept was to prove that you can't hear different frequency response from different DACs with your ears if a microphone can't record them (the microphone is capable of recording frequencies that we can't hear).

 

[Blumlein 88]

Right, but it's difficult to set the level exactly the same. Normally I do it playing Pink Noise in order to get something around 75 to 76 dB. If one DAC is at 75 and other at 75.5 dB I guess that it's already a somewhat visible difference (altough it would be across all the frequencies).

You can do a 4 average 256 k FFT using a tone (1 khz is fine). Don't move anything, including yourself (your position changes standing waves). Adjust the tone level in REW until the two match perfectly. You'll see how much change is needed for the 2nd dac to match the 1st. Then go back do the sweep for DAC 1 and adjust the tone level and do a sweep for DAC 2. Also I'd probably do three sweeps with each to get an idea if they are the same or not with nothing changed.

 

[HarmonicTHD]

To the OP: No and No.

 

[MaxwellsEq]

Differences between well designed modern DACs are very, very, very, very small. You need excellent test gear to expose these differences.

A loudspeaker coupled to the air and fabric of a room which is then coupled to a person and their ears or is coupled to a calibrated microphone is an insufficiently resolving facility to measure the differences between well designed modern DACs.