How do these compare to th-900 mk 2?
Bass?
Soundstage?
Mids?
Thanks
Well, I haven't had my TH900 in quite some time, and it was the first version, but bass will always go to the Fostex without a doubt. That said, the Monitor 5 has very tuneful bass with plenty of snap and detail so depending on what is more important to you about bass, impact versus speed and detail. It isn't like the Monitor 5 has no impact, but it most certainly has less impact than the TH900. I have to date only heard the Monitor 5 with the velour pads and as a bass head (although I like quality over raw quantity) I still think the Pioneer is very good in that department and I suspect most people would be pleased. Soundstage, going by memory they are comparable, but the Fostex has more depth which would be an area of weakness with the M5, in my opinion. Now weakness isn't to say fatal flaw, however, there is room to improve in that area.
The mids are most certainly more prominent with the Pioneer, and quite good, but I do at times feel there can be some glare, but frankly as I have been listening to them for longer now, I think I either notice it less, or it bothers me less. It is at the point where I think I can say I enjoy the mids very much, and same with the treble. The M5 is a pretty balanced performer. I think it is well worth an audition. It is no doubt closer toward a detailed signature and as I seem to have been becoming more attracted to slight warmth it can at times throw me. I am happy to say that it isn't fatiguing which at first I thought it might be for me, but that isn't the case, and I listen very loud which would emphasize that trait if anything.
For me I am still on the fence, but not because I don't think the Monitor 5 is quite a solid headphone because it is, it hedges more on personal preference as opposed to any technical anomalies or wonky sound signature concerns. The Monitor 5 sounds in many ways like a closed but more revealing version of an HD600. If you can audition it and return it I would seriously say try it out, and it is really beautiful, comfortable and extremely well made so taken as a whole package, with todays high prices, it is actually a solid value if it matches your preferences.