Military grade

I can neither confirm or deny the SR-71 max speed or max altitude. To summarize, mil spec wire or cables has nothing to do with sound quality.

Of course they do. The MIG could blow things up while the Blackbird could only take pictures, but what pictures!

Also, wire from the bathyscaph Trieste went to the bottom of the Mariana's trench, now that's pressure treated! The sonics must be subterranean.