I Assembled A Home Audio Thingy

Or, how to use Volumio, an old Raspberry Pi B+ (from 2014!), and an even older Denon stereo receiver+amplifier to pipe my wife’s MP3 collection to wired speakers in my house.

We like ourselves some music in our house. We’re not Hi Fi snobs. We don’t follow bands, really. We just like to have tunes around to help make chores a little less dreary <small>and to fill the gaping void we all hide inside ourselves</small>. Up until getting this house of ours a half decade ago we accomplished this by turning our computer speakers or CD player up to Rather Loud and trying not to spend too much time too close to it.

This “new” house came with a set of speakers in the kitchen and a nest of speaker wires connecting various corners of the main floor to a central location via the drop ceiling in the basement. With a couple of shelf speakers I ripped the proprietary connectors off of, plus two more speakers and a receiver donated by a far-more Hi Fi snobbish (though not really. But he does rather care about the surround, and waxes poetic about Master and Commander and House of the Flying Daggers for their sound fields) friend of ours, I had six speakers in four rooms.

But I had nothing to play on it. No audio source.

For fun I hooked up the PS4 via toslink/spdif/that optical thingy so I could play Uncharted in surround… but it seems Sony’s dream of the PlayStation being the command center of your home entertainment centre never really got off the ground as it can’t even play one of our (many) audio CDs.

(For the youngins: An audio CD is like a Spotify Playlist that is at most an hour long, but doesn’t require an Internet connection to play).

The PS3 was closer to that vision and had the hardware to play CDs, so it got unmothballed and used as a CD Player? Disc Deck? An audio source that did nothing but play audio CDs. The receiver had a 5CH Stereo setting so we had left+right channels in the rooms that had multiple speakers (and the two that only had single speakers I threw on L because Mono)…

Suffice to say we had a “okay” setup, given I spent a grand total of zero dollabux on it.

But my wife and I? We have MP3 collections that far outstrip our CD collections.

(For the youngins: An MP3 is like a stream of audio that you don’t need the Internet to play.)

(I’m ignoring the cassette tape collection, which play only in the basement on the Hi Fi Enthusiast Hardware of the Late Eighties that the previous owners of the house didn’t deign to take with them. It’s delightful.) How was I going to hook those MP3s up so they could play through the house as easily as the Audio CDs?

For a while I tried to get it to work via the Home Theatre PC.

(For the youngins: A Home Theatre PC is a computer which you connect to a TV so you can do computer things on your TV. Like a Smart TV in two pieces, both of which I control. Or like a laptop, but with a much larger screen that has a remote control.)

Unfortunately the HTPC’s dock is acting up when it comes to audio, and even the headphone jack was giving me grief. Plus, the HTPC’s media software stack was based on Kodi which, though lovely and has remote control capabilities over local network via both their web interface Chorus2 and official app Kore, is far more interested in video than audio. (for example: playlists don’t exist in Kore, and can’t really be managed in Chorus2).

But I learned a lot about what I wanted from such a system in trying to squish it into the HTPC which already had a job to do, so I decided to try making the audio player its own thing. Do one thing and do it well, jacks of all trades are masters of none. That sort of thing.

That’s when I remembered I had an old Raspberry Pi B+ in my closet. 700MHz CPU. 512MB RAM. Not the fastest machine in the park… but all it had to do was supply an interface in front of a largish (8k tracks) MP3 collection.

I found this project called Volumio which aimed to catalogue and provide a good, network-aware frontend on an audio collection (and do other stuff). It even had a plugin for playing Audio CDs so I could finally return the PS3 to game playing duty in the basement with the other previous generations of video gaming hardware.

It was a bit fiddly, though. Here’s the process:

1. Install stock Volumio onto a microSD card which you then insert into the Raspberry Pi
   • This was very straightforward except for when I learned that the microsd card I wanted to use actually had bad-sector-ed itself to unusability. Luckily I had a spare.
2. Adjust Volumio’s settings
   • Be sure to change playback to “Single” from “Continuous” or when you press play on a single track in a long list it’ll add every track in that list to the queue… which, on the B+’s anemic processor, takes a goodly while.
3. Install the NanoSound CD Plugin
   • This is where it gets tricky. You could “just” pay for a subscription to Volumio and get first-party audio CD support including upsampling and other Hi Fi things. I’m using the B+’s headphone jack for output so Hi Fi is clearly none of my concern. And I’m too frugal for my own good, so I’m gonna do this myself.
   • Don’t install the plugin from the repository because it won’t work. Install the dependencies as described, then use the install script method. This will take a while as it compiles from source, and my B+ is not fast.
   • I’d like the CD to autoplay when inserted. There are instructions on the support page for how to script this: don’t use them. They have fancy quotation marks and emdashes which confuse both bash and curl when you try. Use instead the instructions on the source comment but don’t reset the volume.
4. Install the Volumio App on your phone for remote control.
   • The “App” appears to be a webview that just loads http://volumio.local/ — for whatever reason my phone won’t resolve that host properly so I can’t just use the browsers I have already installed to access the UI.
5. Move all the MP3s to a computer that is always on
   • You could use a USB drive attached to the Pi if you wanna, but I had space leftover on the Home Theatre PC, so I simply directed Volumio at the network share. Note that it demands credentials even for CIFS/Samba/Windows shares that don’t require credentials, so be prepared to add a straw account.

This was when we learned that our MP3 collection isn’t exactly nicely organized. Like Napster or eDonkey or Limewire or Kazaa, there were multiple slightly-different copies of some tracks or entire albums. Tracks weren’t really clear about what album, artist, and title they had… and the organization was a nightmare.

I’ve turned to Picard to help with the metadata challenges. So far it’s… fine? I dunno, AcoustID isn’t as foolproof as I was expecting it to be, and sometimes it decides to not group tracks into albums… it’s fine. So far.

Also, the gain levels of each track were different. Some were whisper-quiet and some were Cable TV Advertisement Loud. I’d hoped Volumio’s own volume normalization would help, but it seemed to silence already-quiet tracks and amplify high-gain recordings in the exact opposite of what I wanted. So I ran MP3Gain (yes, on sourceforge. Yes it hasn’t had a non-UI-language update since like 2008) for a few hours to get everyone singing at the same level, and turned off Volumio’s volume normalization.

And that’s where we are now. I’m not fully done with Picard (so many tracks to go). I haven’t added my own MP3 collection to the mix, with its additional duplicates and bad gain and whatnot…

…but it’s working. And it’s encouraging my wife and I to discover music we haven’t played in years. Which is wonderful.

If only because it annoys our preteen for her to learn that she kinda likes her parents’ tunes.