I don't know whether some regard this as foo so don't be too harsh. I saw the disc in my local charity shop going cheap, so after a bit of thinking about is it foo or not and wasting my time i decided to go for it. It only takes three minutes to do the job. I sat down to listen my first music disc and i thought well it may have made a slight improvement. This was listening in the afternoon, a time i don't normally listen. Later in the evening, my normal listening time it struck me that the midrange had changed from a warm sound to a more neutral sound. I also noticed the bass was a tad tighter, gelling better with the lower midrange. The highs were cleaner to as if they had a more polished and sweeter sound. So all in all i am pleased for what it has done for a modest outlay as these were something like £20 to £30 (not sure if that is accurate). Would like others opinions who have actually tried it. Jim.