Recently I posted a series of measurements of my N210 - taken using a measurement microphone/loudspeaker testing software - and arrived at the conclusion that shorting C617 on the tone/volume PCB is the best plan. This gives a very flat frequency response, doesn't affect the volume control action, and is easily reversible if required.
I - along with many others - have complained about the bass-heavy nature of these sets many times in the past, but once I got around to properly investigating it, I was pleasantly surprised at how easy it was to tame it, resulting in a set that is now no longer just a display piece.
If you give it a try, I'd appreciate your feedback
