I don’t have any experience with the 6 mic unfortunately. I have worked with the 4 mic pi hat, the 2 mic pi hat and the usb mic array v2.
The 2 mic is a good entry point for trying it out and development. The 4 mic pi hat is actually quite good performance and distance wise and very easy to work with.
In production I use the usb mic as it has by far the superior performance and far field capabilities but unfortunately also the highest price.
So overall think the 4 mic pi hat gives the best price versus performance balance and if I would start over I might do my whole setup based on it. Only thing to keep in mind is that the 4 mic hat doesn’t have a speaker output like some of the other respeaker mics.
There are several housing models that people designed available on thingiverse. I used some of those in the past and they were quite good. I got them p3d printed via one of the print on demand services like treatstock. Just search for Respeaker on Thingiverse.
There is a really nice one for a pi3 + 4 mic pi hat.
I will work with a pi 3 just fine but you will not get sub real time performance like on a pi 4. So for a 3 second speech command a pi 3 will take about 3 seconds to process it. You could also separate process into parts happening on different machines. This is what I do. I run the wake word and audio capture for the command on some raspberry pi 3s and than send the recorded command over mqtt to a central overclocked pi4 for speech to text and intent processing. This way I only needed one pi 4 and could use pi 3s i still had lying around for the audio capture.
Hope this helped, Johannes
