Honestly still undecided, the extra 10hz of the Red back compared to the Black doesn't seem to give more bass but rather it actually tames the treble just a bit. Very weird.
Try out the Black Back with the blue nozzle and let me know what you think
Interesting, I found when I had Black/b and Red/f, the bass was little less punchy than the Red back. Could have been tip related as well
By the way, with your JVC spiral dots how did you choose size?
I love my spinfits with a large diameter, which is maybe a little to big (real nice isolation and does add bit of bass and high end over any other silicon tip I have used. Bass is comparable to comply/foam tips).
I am hesitant to get medium size Spiral dots as I read a review where the person thought the medium spiral dot was slightly smaller than medium spinfit(even though diameter size is the same). Not sure if I should go Medium/large.
These tips are pricey (sort-of) and I hate buy the wrong size.