Distance is completely irrelevant,
thing "actually" being measured is the time
it takes for the signal sent by the avr
to be processed by the amp/processor and produce a sound wave that eventually reaches your mic at the MLP.
The sub channel has a different signal path then the rest of your speakers and room calibration software is designed
to make sure all sounds are time aligned to arrive at your ears at the same time. (IOW, don't mess with it)
From a similar discussion here: https://www.avsforum.com/forum/90-re...l#post58078358
Originally Posted by PioManiac
Calibration Software (YPAO/Audyssey/MCACC etc.)
measures the time it takes for sound signals to travel from the processor, to the speakers, then the sound waves to the mic.
The sub signal also has to pass through it's own amplifier/processor before sending a rather long Low Frequency wave to the mic.
The distance of your powered subwoofer may have been identified by your automatic setup as being further away than it physically is.
This is to compensate for phase matching with your other speakers. Even if the physical distance is closer than the setup microphone identified,
it is not advisable to change the subwoofer distance unless something really doesn’t sound right.
There are also a number of factors and room/furniture influences that will affect the time it takes for those sound waves to reach your MLP.
The "Distance" number is just a reference and should not be used to measure any physical locations of speakers or subs in your room.
What the software is actually doing is measuring delay for how long a sound signal takes to reach your mic, and subsequently your "ears"
Adding More Distance will apply less Delay to the Signal, Reducing the Distance will apply More Delay to the Signal.
After running YPAO, go into manual setup and set all speakers to small (regardless of their physical size)
and set your speaker crossover to 80Hz, Do not re-run calibration after making manual changes.
There is no crossover setting for subs in a Yamaha, (so set your sub output to full range, let the AVR do the rest)
The Sub(s) automatically get all frequencies below the crossover point for speakers set to small
and that gets summed with the LFE channel, in Yamaha's that's automatically <120Hz
Bass Management 101