Coolermaster HAF 912 sound damping

[f5alcon]

I have the original HAF 912 case, with the unpainted chassis, so the rear and instide wont be changed, but those parts are not seen as I don't have a window on the case. The case is a pretty good basic case and it does have a lot of airflow, and noise.I have a front 200mm intake fan, a top 200mm exhaust fan, a 120mm intake side fan, this makes the most noise as the shape of the built in fan grill causes a whistling noise. There is also a 120mm rear exhuast fan. The CPU cooler is a tuniq tower with a 120mm fan and I have a Gigabyte GTX 970. The CPU cooler makes the most noise and has its own dial fan controller on the rear, but turning it down makes the whistle from the side fan more noticeable and increases CPU temps, so my goal is quieter without having to turn it down. 

 

Using soundmeter on my phone with the phone sitting on top of the case:

Full fans 39db

CPU fan minimum 35db

Covering side fan 32db

 

phone sitting on my desk 31db

 

Stage 1 mods:

Add a fan filter to side fan  change the airflow to stop whistling.

 

 

Use thick sound damping foam on open side of case.

 

Use thin foam on other spots inside case.

 

Full fans on top of case 37db

CPU fan minimum 32db

covering side fan 32db

 

phone sitting on my desk 23db

CPU fan minimum 22db

 

 

Using HWmonitor my CPU temps increased 2 degrees at idle and 4 degrees at load, but still well in safe zones for the processor.

 

 

 

 

 

[blackadder]

i'm not sure i trust my phone's ability to measure db precisely. how much was the foam?

edit nvm you say it at the end of the video..spoilers... 

[f5alcon]

i'm not sure i trust my phone's ability to measure db precisely. how much was the foam?

edit nvm you say it at the end of the video..spoilers... 

Yeah I probably should have added that.

The thick foam was this one http://www.moddiy.com/products/modDIY-Sound-Dampening-Foam-Material-%2810mm%29.html

The thin foam was http://www.moddiy.com/products/modDIY-Sound-Dampening-Foam-Material-%2810mm%29.html

The fan filter http://www.moddiy.com/products/Ultra-Thin-0.45mm-PVC-Fan-Dust-Filter-%284cm-to-14cm%29.html

 

I think the 5mm foam would fit better for behind the motherboard, which I didn't end up doing. I agree that I don't trust the phone for db readings, but it is all I had. It doesn't come across in the video but it is a noticeable difference, mostly do the high pitched whining noise from the stock fan grill being gone. That alone was a big improvement. The foam made the noise from the GPU/CPU fans a lot less and I can't hear coil whine anymore.