Yes the Yamaha RX-A3000 has YPAO which is Yamaha's own way of calibrating your speakers automatically just like Auddessey does. Its a little different in its processing but the outcome is very much the same. I used to have a Denon that had Auddessey, an HK that had EzEQ & Pioneer that had MCACC. All of them do a good job. In fact, i like what YPAO has done for my speaker the most.
Follow the directions on where to set the mic & then go in after & make sure you set all speakers to small & start off with them crossed over at 80hz. Use your ears to see what sounds best but set it somewhere between 60-100hz.
You dont need the Avia disc really unless you want to calibrate the picture on your TV. Or if your going to fine tune the speaker levels with the slp meter but YPAO gets that almost dead on.
As far as finding the right sub location, the best thing for you to do is the "bass crawl". Look it up on youtube. But to debrief you: place your sub on your main listening seat. Play some bass heavy music or bass tones off a test disc. Then crawl, yes crawl, around the room to the 7 possible locations for the sub. Listen for clean, powerful bass. Not bloated but detailed bass. Whichever of those locations that sounded good when you crawled to them is the place to now set your sub. THEN run YPAO!! This should get you 75% of the way there. There is always fine tuning & possible EQing to do but you can learn about that.
BTW your RX-A3000 has soo much flexability. The YPAO will automatically have your PEQ set to Flat. Copy that to Manual & you can literally tweak each speakers EQ along with being able to adjust each Sub's EQ including Frequency, Band & Q. That what i used on my A2000 to get extremely Flat bass response (along with good placement & proper phase adjustments)
After running YPAO, have your SPL in hand at your seat. Have someone flip the Phase switch on the sub & see which gives you more output. Leave it on the setting that has the higher spl reading.
Theres a lot of info on this stuff. Read up like i did & youll learn how to REALLY get things sounding GREAT!!!!
ENJOY!!