The 2 % is not my estimate. I read it somewhere online. I don't disagree with it, because I estimate I have at least 20 and no more than 50 CDs not requiring crossfeed at all, so the 2 % estimate (in my case 30 CDs) is not far off. Even if the number was 10-fold, 80 % of recordings would still benefit from cross-feed. Youtube audio quality isn't top notch, at least not with 360p video. That's why I said that for final judgement CD quality is needed. Wow, you really enjoy splitting hairs! I need to hear it with CD quality to make the final decision. I don't know what Youtube low bitrate coding does to stereo sound. I'm just lazy in reminding you every 3 seconds that what I say is my opinion. You should have learned that by now. I have been around over a month and made over 200 posts. My writing style should be familiar to you considering how much you follow what I write. People around me are friends, working pals etc. People who I connect with in my life face to face. All kind of stuff, 70's rock etc. They listen to what they want and if crossfeed helps it helps. Isn't it great it does? Made it up? I didn't know I am that creative! 1. You're welcome! That's because large channel separation (at low frequencies) is possible only when the sound source is very near one ear. Cross-feed reduces channel separation making it possible for the sound source to have some distance from both ears. The width of soundstage is more complex than just channel separation. The maximum width is achieved with optimal channel separation which is about 3 dB for bass and increases with frequency. 2. Yes, I understand. Linkwitz definition in extremely ambitious. I don't think our audio technology is there yet at least as an affordable form. I think his definition of spatial distortion used to be in the 70's the same as mine, but he has since "developped" it to more ambitious and "3D" direction. That would explain were I got my definition: From his old writings. 3. Pretty straightforward in my opinion, but thanks!