This comes up quite often.
All 2in/2out have the same problem: Excruciating drone in the mid-2000's.
Tried the M&K and Dansk and had to change to a 2in/1out because I like my hearing and don't want permanent hearing-loss.
2out on the track for performance but not for the street.
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1980 Carrerarized SC with SS 3.2, LSD & Extras. SOLD!
1995 seafoam-green 993 C2, LSD, Sport seats.

Abstract Darwin Ipso Facto: "Life is evolutionary random and has no meaning as evidenced by 7 Billion paranoid talking monkeys with super-inflated egos and matching vanity worshipping illusionary Gods and Saviors ".