Daystate Reflex shroud

Modified Daystate Airstream MK4 Reflex moderator and installed inside the shroud of Stealth 2000. I also installed my sound reduction plates in combination with Daystate.


Seller of Daystate Airstream MK4 indicated as tested at just 61.3dB.
http://www.guns-n-stuff.co.uk/silencers.htm

But I tested my Stealth after mod, my sound level meter showed 64 – 65dB.
Is it lower noise level or not so low?

Currently, I am making the copy of Sparrow22 for rimfire (manufacturer indicated as sound reduction: 40dB)
to fit in my shroud of Stealth, and the slim dimension is 27mm dia x 156mm long.