Hi everyone,
I recently got a ZY-2.1BT 2.1 channel Bluetooth digital power amplifier board to test out as part of a DIY audio setup. The idea is to run two bookshelf speakers plus a subwoofer from a single board, mainly for a small home theater project.
Setup Details:
Power supply: 24V 10A DC adapter
Speakers: two 6Ω 50W bookshelf speakers + one 8Ω 80W subwoofer
Inputs: tested both Bluetooth (5.1) and AUX from a laptop
Connected using the provided DC power plug and screw terminals for speakers
Now here are my issues:
At medium to high volumes, I get distortion on the subwoofer even though the speakers sound clean
Bluetooth pairing works fine at first, but sometimes audio cuts out randomly for a second or two
AUX input works, but there’s a noticeable hum when no music is playing
The board gets warm after about 30 minutes of use — not hot enough to shut down, but I’m wondering if I need a heatsink or better airflow
What I’ve tried so far:
Swapped in a different subwoofer (4Ω 60W) — distortion still happens at higher volume
Tried another power supply (19V 6A) — same results, maybe slightly less hum
Moved the board away from other electronics to rule out interference
Checked wiring polarity and connections — all look fine
My questions:
Is it normal for the subwoofer channel on the ZY-2.1BT to distort earlier than the stereo channels?
Would running it at 12V vs 24V change the noise floor or stability?
Any tricks for reducing the AUX hum — like grounding the input or shielding cables?
Should I consider adding a small heatsink to this board, or is passive cooling usually enough?
Thanks in advance. I’m hoping to clean up the sound and make this stable for daily use.
