My new Nokia 2710 has a radio. However, the sound is way too loud, even with the headphones that came with the phone. It's also not the only device with this problem: often the volume control doesn't go low enough so that you can listen comfortably in a silent room.
Basic attenuation is simple to achieve with a series resistor on each channel. I chose to go a bit further, adding passive crossfeed. There are also 1nF bypass capacitors so that the attenuator does not affect the radio reception.
I potted the whole thing in epoxy glue. The mold I used was just a piece of baking paper held together with tape.
And here is the mandatory bode plot. I used the actual headphones as the load when I measured it. I assume that explains the peak around 200 Hz. Also notice the rise above 100kHz, caused by the radio frequency bypass.
The response is far from flat, but I'm not a hifist.
– Petteri Aimonen on 1.3.2011