He means an SPL meter used to set all your speakers including your sub to the same volume level so you get a balanced output from all speakers (no one speaker will stand out). The analogue version will be fine.
I set mine by having the meter set to 70dB, A weighting and slow reponse and set the volume at 0dB when adjusting the levels. It will improve your setup as accurately set levels sound better than relying on settings adjusted by ear.
It's a good idea as your speakers loosen up to check the levels once every couple of weeks initially then check every few months to be sure everything is set correctly but you can set them as often as you like if you like playing with your new toys - lol!
My Marantz seemed to need adjusting more often but since I changed to a bulleted solid core coaxial this seems to have fixed this anomoly. Go figure!