Majestic Beast

I am running a single SXX 10D2 V2 on an SA4000. One thing I have noticed front the SXX 10D4 V1 to the SXX V2 is that there is still motor noise however my question is this, my SXX V2 heats up pretty good on the SA4000 (gained 1/4 and bass boosted 1/4). The coil glue is dark. I never checked my SXX V1 to see if the glue turned colors however I played the SXX V1 very hard, harder than the SXX V2. So much so that the spider separated from the pole. It was repaired and never separated again however with the higher power rating of the V2, why is has the glue changed colors?