Hi Everyone. I'm brand new to the forum and hope someone can help me. I have a 2.2 channel Roon / HQ Player server-based system. The speaker configuration is two satellite speakers and two subwoofers - each with a dedicated DAC channel. I'm currently running 80hz filters in HQ Player between each satellite and sub. My next step is measure each speaker individually so I can time align them (I also intend to EQ the system). Given that I want to measure with the 80hz LP / HP filter in place, I can't do this by connecting REW directly to HQ Player and using REW as a signal generator. I can export a REW signal sweep and run it in HQ Player with an acoustic timing reference. However, as I understand it the acoustic timing reference will only work on my satellites, and not on the subs given the high frequency of the timing sweep. My question is can REW be configured to recognize a stimulus signal to start / perform a measurement if set for loopback timing and the signal is exported and run in HQ Player? If not, does anyone have any suggestions how I can measure all 4 speakers for timing? I have a UMIK-1 and a am EMM-6 / Steinberg UR22 so I can be flexible with my approach. Many thanks!