I've heard talk of the newer HD650 being re-tuned with different drivers to remove the veil associated with the model. I don't know if that's true, since I only have the one pair I bought last year, but to me it doesn't sound veiled at all. There's plenty of treble energy, on par with the HD598, which also are considered fairly bright by Sennheiser standards. That said, neither is anywhere close to the Fostex TH-900 in brightness. Their 7 kHz spike can sometimes feel like an ice pick being jammed in my ear. I like sparkle, but not piercing highs. If the IE800/S has brightness on that level, I dunno... On a different note, in your opinion, do you think the FIIO X5iii is enough to get the most out of the SE846 or IE800/S?