I closed my office door, pulled the vent grille, and remeasured while the AC was running. I saved a mere 2db over just closing the door. I then stuffed a towel in the vent, silencing it completely. I gained another 1-2db. So apparently while quite quiet to my ears, the low rumble of the AC unit is only a few db below the vent flow noise. I’m guessing it’s the difference in frequency that allows me to be more tolerant of the AC unit noise.
However just moving to the far side of the room reduced that noise another 6-8db. So if I rearrange my room and silence the vent, I’m actually getting somewhere.
I’ve been thinking about heavy curtains too. I already have some in my HT room but I’d need to get a wall mount rail to even try them out. Vaulted ceiling means I can’ easily surround the listening station too.
Very expensive and includes a stereo system I don’t want. However it has been reviewed (by Wired), it looks just like the less expesive Aarnio Style Alpha, and there’s a photo of a woman sitting in it that makes it look quite comfy.
If you can access the the AC unit and ducts, pinpoint the loudest rumbles. Audio rubber mats (as uncannily effective versus a towel or pillow) may stop the noise at its source. The air vent may retain the dB of the source rumble but shift it to a different and disturbing frequency. Moving air alone needs not make much noise, but turbulence and constrictions will make noise.
Right. I would say the grille/diffuser is making the most noise, but once it is removed there are all kinds of flat surfaces that could create turbulence which is why I just stuffed a towel in it to seal off the vent entirely - just to see. Once I did that all I could hear was the faint rumble of the AC unit. I think the biggest issue there is that the AC unit is on the roof. If it was on the ground beside the house I probably could not hear it. Something I will definitely keep in mind if/when I buy my next house. Meanwhile I besides your suggestion I’m wondering if there is a way to isolate the unit from the roof better. Like rubber mounts or something.
Isolation mounts will surely have an impact. I got some isolation pads for my recently acquired bookshelf speakers. An inch or two of foam cut the bass bloat (i.e., furniture resonance) entirely.
just update the chiller with a more modern one using inverter, much more quite… or change your windows with more acoustically insulated one… or just sit and listen in quite hot environment leaving air conditioning off
