And yes, I took off the grill voiding warranty. But I really like the Play 1's without the grill haha. Would be cool if Sonos let you do that but I can understand why as the speakers can be easily broken without it.
If you wish to criticize, please watch the video.
Testing starts at 3:25, skipping all the disclaimers and introduction. :)
I recorded audio with a Blue Yeti in stereo mode which is capable of capturing audio down to 20Hz.