TimoJ

Yes, but for example Trinnov needs low gain amps (or amps with gain adjustments or inline attenuators) because of this.

There is also idle noise (noise floor) of the preamp/avp that is rarely (never?) measured but it also should be taken into account when...

@JohnPM I'm still wondering this, could you please explain. If I select linear sweep and set it to start from 7Hz, it starts from 7Hz...

Why does it start from DC instead of half of 15Hz i.e. 7.5Hz?

But if I select 15Hz as the start frequency, REW sweep seems to start from DC instead of 7.5Hz. Is that correct? This near DC part...

When measurement range starts below 20Hz, REW sweep always includes linear sweep from DC to 10Hz. This is a documented feature, but why...

Yes.

I use ART with two setups in two rooms, smaller room with 2 speakers. Subwoofer (LFE channel) is supported by all speakers so it's not...

I have L-shaped living room where all speakers are symmetrically setup. Subwoofer1 is near left front corner and sub2 is center of rear...