1. Naked plastic cups and baffles
2. Vented with thin felt over the vents
3. Small thick 3/4" tuning felt on bottom of cups
4. Thin white gauze over back of drivers
5. Pressure equalization vent hole in baffle connecting cup volume to outside on ear side
6. Same driver asT40RP MkII (but different max voltage spec??)
7. Cup volumes look the same as T40RP MkII
4. Thicker/denser white gauze over back of drivers (to compensate for lack of venting?)
5. Assume same
6. Same driver as T50RP (but with different max voltage spec??)
7. Same cup volume as T50RP?
1. Stock T50RP needs less damping, therefore, thinner white gauze than Stock T40RP MkII because the T50RP is semi-vented as opposed to non-vented T40RP MkII.
2. Venting Stock T40RP MkII and changing the thick white gauze to thinner material will essentially transform Stock T40RP MkII into a Stock T50RP.
3. Modding with Paxmate or similar damping material in cups, 1 reflex dot on center of driver backs, uncovering 1 of 4 vent slots in T50RP (or opening 4 vent slots in T40RP MkII and covering 3 with felt), and mass loading baffles with plasticine obviates the need for any white gauze on the backs of the drivers; thus accounting for reports of improved SQ after removing the white gauze and making the aforementioned mods. Note: I have not tried any mods on T40RP MkII.