Raspberry Pi BLE and WiFi Internet Radio

My brother who is a wood working enthusiast asked me about electronics for making a BLE speaker box with the form factor of a mid-century table top radio.  His inspiration, which I really like, is this:

He had found a BLE receiver / amp with 2" speakers and wanted some thoughts on adding some electronic bling and 3D printed parts help.  I told him sure, but we could do better.  My suggestion was to add internet radio capability and music storage to the BLE and use a Raspberry Pi (i.e. feature creep).  I found an inexpensive 25W amplifier hat on Amazon which purports to have a Texas Instruments (Burr-Brown) TAS5713 chipset with Nichicon capacitors and two days later it was in my possession.

An unused Raspberry Pi 3B was pressed into service.  The new hat can take anywhere from 12 to 20V as input and will also power the Pi so an old 20V laptop power brick was attached to the hat.  For now a pair of old, but relatively high quality, bookshelf speakers from the junk box were hooked up.  This is what it looks like:

There are a number of apps and resources on line to do this with a Raspberry Pi. Volumio and Moode were selected for further evaluation.  Both have a modified OS that is downloaded and installed on the Pi and web based interfaces.  Volumio has free and paid versions but BLE is only available with the paid version.  A quick look at the github page shows it hasn't had recent updates.

Moode has frequent updates and what appears to be an active forum. It is also open source and free.  I thought the Volumio User Interface was a bit slicker but otherwise Moode was a better fit for this project. 

This is what the Moode web interface looks like running on my iPad:

It sounds great to my tone deaf ears that have high end frequency loss mixed with tinnitus.  The web interface is a bit clunky and some modifications to the software require SSH into a headless Pi which isn't that great for an unsophisticated user.  Hopefully it can be set up beforehand so my brother doesn't have to fool with it.

The next step is to add physical features for installation on the cabinet in addition to the web interface as shown in the clouded section of the block diagram below:

Namely:

• On / off switch
• Manual volume control
• Source control (e.g. internet radio, BLE, loaded files)
• Small display

These capabilities aren't included in the application as downloaded but I've been browsing through the Moode forum and it appears all can be done since the OS is Raspbian based and accessible.

We aren't trying to get audiophile performance.  Nonetheless, I would appreciate any suggestions others might have on both hardware and software as I've not attempted something like this before.