This is Part Two of a three-part series of reviews of Apple’s HomePod. We published a subjective analysis of the device on Friday. A story tomorrow will test Apple’s claim that the HomePod is unbiased and true to the production values of music.

One of the claims Apple makes about its new HomePod smart speaker is that music played through it sounds pretty much the same, no matter where in the room you happen to be standing or sitting. Apple also says that the HomePod will create pretty much the same sound in the room regardless of where it is placed.

We’ve heard plenty of opinions on the HomePod’s general sound quality, so it’s a good time to measure the consistency of the HomePod’s sound distribution using some professional-grade acoustic analysis tools.

For that we turned to NTi Audio AG, the Liechtenstein-based company that makes all kinds of acoustics testing gear and software. The company was kind enough to loan us a testing device, software, and a special microphone so that we could test the HomePod in a real-life natural habitat–my living room. The company’s Brian MacMillan coached me on how to do the tests, then he and some other NTi people analyzed (and helped me understand) the results after the numbers were uploaded to a cloud server.

Consistency Of Overall Sound

In order to test the consistency of the HomePod’s audio throughout the room, we placed the HomePod on a 30-inch high table by a wall and set it playing a white noise test sound that produces an equal amount of decibels throughout the frequency spectrum.

We recorded this from four locations in the room: 22 inches off the floor and 81 inches off the floor from the middle of the room (13 feet from the HomePod), and 25 inches and 81 inches off the floor 7 feet away on the same wall next to the same wall the HomePod sat near.

After measuring the full frequency spectrum (40Hz through 20,000Hz) of the HomePod’s sound output from each location, we compared each sound profile to see how much they changed from location to location in the room.