I don't know what "timbre" in a sub is; its just alot of fluffy adjectives the audio world has because the world of mathematics is beyond these forums, its not practical that's for sure. A loudspeaker driver just moves in-and-out to a series of electrical impulses and any non-linearity in that movement is called distortion. The sunfire has quite a bit more than alot of high-end subwoofers, 10% pushing its max. However since its small, it can use the corner of the room as a "horn" and operate more in the 3% range. Its an innovative sub, but giving no consideration to its design, strictly its performance; its just an average high-end sub; i.e. its not that accurate. Not to discredit you question, but I wouldn't worry about the issue of "timbre." You'll know a better sub from another when you here two. Timbre isn't an "attribute of a sub" to sort of use your wording, or any loudspeaker for that matter. All speakers do is reproduce the signal they get. My wording may not be the best. Put maybe another way, What kind of timbre would you want in a sub? None, you'd just want it to reproduce the signal its given. Technically, a phrase like musical accuracy (which I have caught myself typing in other parts of this and having to omit it, so I am guilty too) is redundant- accuracy is musicality so there's no reason to make distinctions in accuracy. Maybe it helped???