This process works perfectly for me also… thanks for the details that finally got it working after a few months of fiddling around with this!
One of my biggest frustrations was simply getting the install to work. I found that I had to update my /etc/sources.list file to look like this:
apt-get install libasound2-plugin-equal
BTW, make sure to restart mpd after any changes to asound.conf or mpd.conf:
sudo service mpd restart (ignore the warning about “share” if you get it)
I now have 3 Volumio wireless renderers and a fourth Pi with an external hard drive running Raspian and smb hardwired to my router as NAS. Everything works like a charm, but the equalizer is the final piece that makes it all special!