Hi John,
Yes, the easiest way to reduce the noise is to use a 30- or 75-ohm impedance adapter, in a 3.5 jack casing.
In general, a higher impedance value results in less noise. However, please note that higher values also lead to a greater reduction in maximum volume.
If you’re comfortable with soldering, an even better solution is to add 50-ohm resistors in series with the positive terminals of the speakers. This approach doesn’t require any extra space in the helmet, and the resulting volume drop is less.
Traditional impedance adapters (that you can buy in stores) typically use series resistors along with an additional 15-ohm shunt resistor to ground. In our case, that shunt resistor isn’t necessary and would only make the sound quieter. That’s why the DIY version even better.
Happy holidays!
Best Regards,
Alex
