Some of you probably played with some test signals with very high ISP, but they are usually noise-like and the actual clipping is inaudible since a clipped noise is still noise after all.
Here is a test file with -0.004dBFS and +4.x dBTP and when it clips the effect is definitely audible. All you need to do are:
[1] maximize (i.e. no attenuation) your interface/DAC/soundcard's output level*
[2] maximize (i.e. no attenuation) your OS mixer's output level*
*you can't do this test if your headphone is plugged into the interface/DAC/soundcard directly and the only way to adjust volume is doing [1] or [2] digitally.
[3] set your speaker/headphone amp's analog volume at a safe (low) level
[4] make sure your DAW is using ASIO/WASAPI exclusive without resampling (44.1kHz)
[5] make sure your DAW's pan law does not boost or reduce volume
Now play the file in your DAW, the file has a fade in tone and the timbre should not change even at the end. If the timbre changed during playback then it means you encountered intersample clipping. Reduce the master output of your DAW at 0.1dB step until you hear no clipping.
[a] Did you hear any clipping?
[b] If yes, how many dB you need to reduce to eliminate clipping?
[c] Which interface/DAC/soundcard do you have?
You can also use this signal to test your smartphone, TV, CD player etc. Please report if you tried it as well.
Thank you very much!!
https://stash.reaper.fm/32679/intersample.flac