Inspired by the great work from @kaykoch you can find here i designed my own take on a satellite case for a raspberry pi 3a+, a Respeaker 2 mic hat and a small mono speaker.
You can find all the files and more pictures here:
Johannes
Very nice case, especially because it’s very compact and only one cable is going out. Thank you for sharing 
Also a nice and compact design. I’m interested in that small speaker you are using. How would you rate its sound quality on a scale from 1 to 10? Could you please provide a link on where to buy it?
They are available from different manufacturers. Adafruit has it but just search on ebay or amazon for 3 watt arduino speaker and you will find it.
Sound quality is like 4/10 but more than enough for feedback.
Wouldn’t want to listen to music with it 
Ok, thank you very much for that information. I think some community members might find them interesting because of the small form factor.
I found these which sound a little better than the other model:
I finished work on both the case for the Pi 4 and the adapter that allows to use the better sounding speaker. I will print a prototype of both and if they are good release the files on Thingiverse.
Looks great 
Thanks for sharing the development process with us.
Where did you find the cad for the mini “iLouder” speaker? Recently purchased some and couldn’t find cad models on the web. If you made them yourself, would you mind sharing?
i made one as I didnt find one either.
You can find it here:
Johannes
Thanks! I would have just used your case, but all I have are 3b+s
I upgraded all mine to 4s a year ago so i cant help there and themore case options there are the better 
After testing I had to redesign the adapter for the mini speaker to hopefully better fit the cables and case. I will make another test print before I publish it on thingiverse.
It fits both the pi 4 and 3a+ case:
Looks nice, what do you use the button for?
When you publish, mind sharing a step file or similar? I’ve recently purchased an expensive amount of pi 4s… however I want to add an isolated air quality sensor location and may toy with isolating the speaker from the mics.
Suppose you couldn’t also make a cut out for one of these?
You would probably need a different lid design too? I guess you would mount an usb sound card internally and connect a electret?
Yep or x2 if you can run 2x KWS at say 180, 135 or 90 degrees its sort of pseudo and cheap beamforming.
Also maybe you could create some electret mounts that also double as isolation from the internal speaker.
Not really sure about the electrets you will get the style of a slotted tube that maybe are external parts that clip / screw onto sides or base?
I fart on about that Boya purely as its prewired but really its too big and overpriced.
What would you use as an amp for the speaker?
I would probably need to buy all the components so that I can actually measure them.
The one I like at the moment but that is by soundbar preference.
But always like these but take wattage ratings with a pinch of salt.
Options use a single channel and have speaker outs on the case?
Also if you could beef up the speaker?
https://uk.rs-online.com/web/p/speaker-drivers/4318686/?
https://uk.rs-online.com/web/p/speaker-drivers/1976441/?
With a silicon pad maybe they could be a great heatsink ? (who knows)
Plus connect a button to the pi run as its a reset but on shutdown will start again even if a different power button to one we know.
I have my fingers crossed we may see a Pi4A+ and price reduction on the 3A+
The class D amps always seem to be a bit ‘hummy’ when idle and like the Sanwu’s I have seen because build quality seems reasonable but also has a standby input that with an alsa hook we could prob hook up to gpio.
For a compact case i might start with a PAM8302 from adafruit as i had good experiences with it combined with small speakers before.
Yeah if that is your thing but 2.5W at 4Ω, 10% THD prob means 1.5watt approx max and for me sort of pointless as would rather just not bother and have an indicator and may be cast audio somewhere.
Always wondered why max is often rated @ 10% THD as who would want to listen to a device being overdriven as that?
The 50watt above means to me yeah approx 30watt.
I think its because of different use cases. I use the speaker only for tts to give feedback, like telling me the weather, how much time is left on my tea timer, what time it is or even the news.
For this i find the PAM8302 more than sufficient even in a bigger room.
Of course if you want to listen to music or other media the bigger amps will be much better suited but will also give you a much bigger form factor and in this case why not cast/trigger/send the audio to a real speaker?
The biggest reason would be to do aec with the output signal.
How warm do those amps get?
Need a 12v 30/40mm fan on 5v prob if enclosed in a case but actually run fairly cool.
You would have to try as the pi when enclosed also quickly builds up heat when passive.
When it comes to mini I like the idea of atomic but rather than witt.ai stream to rhasppy.
https://www.aliexpress.com/item/32819907815.html?
£2.50 and extremely tiny 30x35mm
But we all have different opinion and preference, but when you can get a echo dot / google mini for $20 it questions all of us to what we are actually making.
I have had a look at the code even though my C is non existent it is actually all running on a singular core.
You’re talking about this card, aren’t you ?
Do you get any noise with it. I’m looking for a good way to power a small speaker in a small case. All I’ve tried so far are too much noisy.
Its the ratings Pep as 10% THD @ prob into 2 ohm provides the wattage rating so when your driving this you are driving to hard.
You just need to over spec and lower the volumes on your output.
The above is 3 watt into 4 ohm @ 10% THD and with lower inputs set by output volume it might be OK but overspec even more.
The TPA3118 will run off a 5v supply importantly has a mute switch as they are all buzzy in idle.
Often you need to apply a DC blocking cap to the output but depends on load resistance.
4.7uf - 47uf as a guestimate, or higher as the speakers are not bass capable.
But what you might think is a huge output @5v with a good input level bears no relation to rating.
Also have a look at alsa hooks as you might be able to use so that gpio auto mutes via a 2n2222a transistor.
The 5v input reduces availability and a 12v supply and running the Pi on a 3amp buck might be a better configuration.
Its also the same with ratings on speakers as the reality is usually very different.
If you take the above its 15% THD @ 3watt and 3 watt is maximum and not continuous and the reality is that is not a 3 watt speaker and you need to over spec.
Its only when you get larger and by better manufacturers they actually quote usable ratings.
https://uk.rs-online.com/web/p/speaker-drivers/1345563/
That is a 10watt speaker into 4 ohm.
I find it good for when you are constricted in size and only want to drive a single speaker.
The sound quality especially when used in combination with a usb soundcard is quite good. I have used it in combination with a few different small visaton speakers and was quite suprised by the results.
It also has a shutdown pin to turn the speaker off when your not using it via a gpio pin.
You will have route all the audio to the channel you are connecting the amp to as its only mono but that is easily done in the asound.conf.
But due to power and size it will of course not drive giant speakers.
For example I use it in combination with a 5w 8 ohm speaker and find the quality good for listening to the news or poscasts.
This looks very nice - sturdy and functional. Did you print it yourself or via an online print service? Do you an idea what having it printed would cost?
Thanks for the hint! Collected it today and got superb results. (I’ll not hang it up for the time being…)
Hey Johannes,
any news on this project? I’m ready to put my pi4 + Respeaker v2 using your node-red project in a nice casing!
Best
