I am checking ISPs in the files I master everyday, the best tools I have for this are Sonoris Meter (not so sensitive), iZotope RX4 Advanced (pretty sensitive and I tend to trust it) and RME Digicheck (specifically the 2 bar level meter).

RX4 and Digicheck used to pretty much concur, with Digicheck perhaps being slightly more sensitive (a good thing), but I have noticed recently that many masters which show no ISPs in RX4 are showing some or even many in Digicheck.

I was just wondering if the algorithm for detecting ISPs/TruePeak level had changed at all in recent versions of Digicheck. I'm having to lower the threshold on my limiter by more than a dB sometimes, to avoid ISPs, while RX4 is showing none, even with the ceiling at 0.0dB (I generally use 8x oversampling in my limiter to avoid all ISPs).

Just wanted to bring it to your intention in case it's a bug or something! Of course, it could also mean that RX4's OS detection is not very good.

Gregg at Hermetech Mastering