Multiple bluetooth speakers setup for Pi's, MPD & snapcast

I’ve been looking round for a few weeks on an effective way to do this. I have read most of the 14 previous posts here in regard to this topic.

At this stage I can get one speaker working through the desktop or with the bluetoothctl as well as playing the audio from the 3.5mm jack. I can get another to connect but the audio comes through.

I have about 10 BT speakers I’d like to add into the mix of my setup. I can use most with a line in but a few don’t have that option. Ideally I’d like to run 3 or 4 of them from each Pi.

The mpd.conf I am trying to replicate or use looks something like

I don’t know what the bluealsa:DEV or bluez_card should be

aplay -D bluealsa:DEV=00:42:79:91:2D:A7 /usr/share/sounds/alsa/Front_Center.wav

audio_output {
type “alsa”
name “Bluetooth Speaker 1”
device “bluez_card=00:42:79:91:2D:A7”

When I run pactl list

pa_context_connect() failed: Connection refused

It does that or works the first time.

Is using a BT dongle an easy way to add another speaker into the mix?

Is blue alsa the right option or should i be trying pulse audio? I have Raspberry 3 and 4 with latest dietpi on both. I am asking for help with this as when I try and play around with things I generally end up breaking things pretty fast.

I am looking for any scripts or programs to make this job as easy as possible. My tech skills are pretty limited.

How do I check what sound drivers I have installed? I’ve tried to use both blue alsa and pulse audio and the closest I can get it to work with MPD is getting errors about the device being wrong.

Thanks heaps!!