The much touted review of the HomePod posted by an “audiophile” on Reddit last week – and gleefully tweeted by Apple’s Phil Schiller – turns out to be a long mess of uninformed and poorly made measurements.
This reply on Reddit highlights many of the problems, notably the fact that the HomePod wasn’t measured in an anechoic room, but mainly the fact that the “reviewer” fudged the display of his graphs, making them look better than they were.
Here’s one of the original graphs:
The experimenter seems obsessed with that graph which they claim shows a very flat frequency response. They even say, further down the review, that it’s an “almost perfectly flat speaker”. Mmm. I opened that same measurement in REW and here’s what I get (with the same 1/12 octave smoothing as the above image):
Doesn’t look as nice doesn’t it? That’s because of the scale, you see. It’s the ages-old trick of messing with the vertical scale to make things look flatter than they really are. In the screenshot that the experimenter posted, the interval between ticks is 10 dB. That’s enormous. Almost anything will look almost flat at that scale.
This is why it’s wrong to assume that some random guy who writes 5,000 words and includes a bunch of numbers and graphs knows what he’s doing. Another comment from the comment I linked to above:
I find it absolutely hilarious that the experimenter is specifying conditions like “Room temperature was 72ºF (22.2ºC) and the humidity outside was 97%. Air Pressure was 30.1 inHg (764.54 mmHg)”. It sounds like they’ve done very rigorous measurements in highly controlled conditions, but that’s rendered moot by the overwhelming influence of the specific room in which they made the measurements.
Conclusion: no, these measurements don’t show that “The HomePod is 100% an Audiophile grade Speaker”, far from it. Because the measurements were made in a reverberant room without windowing, the data is mostly meaningless. The linearity, SPL and distortion measurements are usable to some extent, but these are not the most important criteria when assessing the audio quality of a loudspeaker (unless loud bass is really important for you). Many parts of the “review” are misleading, at times egregiously so, leaving the impression that the experimenter is interpreting the data through Apple-colored glasses.
I wonder if Phil Schiller had anyone from Apple’s audio team look at the original “review” before tweeting it. My guess is no; they would have spotted the incorrect measurements, and warned him not to share it. It makes Apple look bad, because of Schiller’s sharing it, now that it has turned out to be quite wrong.