Great video

Your guess of "NR 4" was pretty close to the mark. Another 'Tube' set up a measurement concept and -- although he used 'sand' instead of foam, the other conditions were the same. His improvement was measured at "4.5". So your guess was pretty good. For my modification, I will attempt to insert additional material to the battery compartment as it wasn't really mentioned in either video. Good job nevertheless and thanks for the guide.

I done the upgrade gell ear cups was 10 quid and earbids used around 15 big tip cut the earbuds in to small bits much easier to fill the spaces

do u need to double up to max your NRR or can u just use the howards in an open range? i forgot which but ive seen E-ear pro as low as 19? or 18 nrr

what do you use to charge these headphones?

I wonder if that air space that you just sealed up was to keep the electronics cool. I wonder what the failure rate for the electronic portion of the heads it will be now that the heat dissipation is hindered. Very interesting

the packing doesn't do anything. I crammed a shit ton of those in there. Still doesn't compare to proper hearing protection.