Amplifier for old home theatre speakers


i have a (hopefully simple) question about using one of your amplifier chips, the “Stereo 20W Class D Audio Amplifier - MAX9744”

I’l looking to re-use up some old home theatre speakers. I have four x 3 ohm, 10 watt speakers.

If i connect two speakers in series to each channel, will that give me 6ohms and 20W per channel? and will this amp be suitable?

I also want to include a bluetooth receiver, probably using an arduino board, but will figure this out once i confirm the amp!

Thanks in advance!

Yes, connecting the speakers in series will give you the results you want with that board.

To add a Bluetooth receiver I would have a look at the Raspberry Pi Zero WH or if you something like the ESP32.

Thanks Clinton!

Ill look into your suggestions for the bluetooth recievers.

Hi Clinton,

I had a look at the Raspberry Pi Zero WH, but i have noticed the only input on the amplifier is the headphone jack, and the digital input is only for volume control. Any hints on how i connect the bluetooth receiver?


The Raspberry Pi has a bluetooth receiver built into it, so you do not need to attach a receiver at all.

Sorry I wasn’t clear in my last post, i guess what i am really asking is can i use the bluetooth in the Raspberry Pi to stream music to the amp, or will it only be just for volume control?

I read a few more forums on the adafruit website and it sounds like you can only digitally control the volume. A few people talking about connecting a bluetooth audio adaptor into the 3.5mm jack to stream audio.

Ill give it a go anyway, i’m just starting out in electronics and it will be a good learning project for me!!

Thanks again.

This project may help guide you in the right direction, I’m yet to build a Rpi Speaker so I am not too sure sorry.