Re: Warmest Snare Drum head
Aquarian heads are pretty warm. Warm and dark.
Some good suggestions here and I'll second the "Fiberskyn". A really mellow head. Also, Suedes have a nice round bottom end to them without sounding whumpy.
Personally, when I think of warm I think of full bodied and the Remo Vintage A fits that bill pretty nicely. That was the first head that came to mind.
1) Pearl Masters BRX Vintage Sunburst
2) PDP FS Cherry Fade
Sabian AA, Meinl Byzance, Zildjian K