i thought maybe some fellow MSP5 owners might like to try this trick to "tone down" the highs. just take tissue (preferably something thicker than tissue - like paper towel) and tape it over tweeter. that's it. i think the same thing was done before on the NS-10's. i've found that it's not easy to work with the MSP5's for more than a couple of hours, but with the tissues the problem is quite alleviated. it does a lot more than the HF gain switch. also i tend to notice more midrange material without the highs jabbing mercilessly at my ear. oddly enough it also makes the MSP5's MUCH more suitable for pleasure listening.