Okay guys I didn't get the request to do the dB reading til after I destroyed the oem moderator. I got my readings in a way that made sense to me at the time. Apologize in advance if this isn't useful.
I had no idea what weights were but I think the dB reader I got only does in A weight so that's good for you who request that. Also another disclaimer is that I only have one moderator with 1/2-20 threads so I just have the one to compare to but more on that later..
Here is the meter I got
Okay so I did 2 positions per configuration. I shot 5 times for each test to get an average (sorry didn't do 10 shots).
1st- since I'm the one shooting I didn't put the meter 10 feet away or anything what I did was hold the gun like normal but with the front on a rest and I used my left hand to wrap under the stock and hold the meter directly by my right ear. I figured this would be like reading the sound I hear. Mic pointed up not at the muzzle cause idk I didn't think about it but that's how all tests were done so it was fair.
2nd was holding Notos like normal with the front in a rest again and I held the meter parallel to the barrel and had the mic next to the muzzle pointing downrange. Figured this would be loudest and also would pick up on if any reduction in dB since it's by the source.
For all tests I was outside so there were birds and wind and stuff but I had the meter going and then I got the Peak readings. For all tests I was shooting FX Atomics 15.9 gr.
First test: I didn't mess with hammer spring jjst shot like out of the box it was about a half turn in from flush out going at 739 FPS for "OEM configuration"
Okay here's OEM results:
By my ear average was 78.76 dB
By the muzzle was 85.16 dB
Next after I tore off the OEM moderator I did not have the bushing in yet but I did install the plenum kit.
Here's with NO LDC, I only shot twice b/c didn't need to bug neighbors
Peak by ear: 83.9 dB
By muzzle: 87.1
Results were weird the Notos was shooting just less than 700 FPS but the HS was in the same spot. Thought I'd gain fps with the plenum but I played with it later.
Anyway here is results I only have a Buck Rail TAPERED LDC so that's what I used going forward. I bought the tapered cause it looked extremely similar to the OEM Notos moderator, thought it would work.
Buck rail tapered no bushing installed, hammer spring same half turn in
By ear: 80.2 dB
By muzzle: 85.7 dB
Then I was playing with the hammer spring and weirdly I couldn't get it to shoot faster than ~740 fps or so but thats about how it shot without the plenum. So I added the bushing to get more spring tension. Then I went up to 755.56 fps average and that was with no HS tension (back out all the way)
With those settings:
By ear: 81.52 dB
Muzzle: 86.36 dB
So if you're keeping track you'll see the same thing I did.... the oem moderator was quieter! I know how you tune can affect how long the valve is open and if open too long it'll put more air out and be louder, so I'm thinking it was not balanced but I did play with it a bit and this is all I could get.
So long story short I just ordered a NON tapered Buck Rail now because that should be quieter since it has more space inside. Tapered looks original but oh well I'd rather have the functionality.