What's the rationale for that? I'm not saying it's a good or bad concept. I've just never seen such a placement rule before, and would like to know more about it.
See Genelec's description
here. Page 9. The rationale is that above 60cm or so cancellations will be more noticeable and higher in amplitude. Putting the speaker closer to the wall pushes the cancellation frequency higher, where it would presumably be less noticeable.
That aside, I thought I might share some of my dissenting thoughts on topics in this thread as someone who writes speaker reviews and takes many quasi-anechoic, off-axis measurements.
My case is a little different, as I'm writing for a very mainstream tech publication as opposed to an audio-specific one, so I think it's important to keep some audience context in mind. Nonetheless, I generally believe that speakers should be reviewed as is - as that's the way most buyers will use them. Point out possible improvements where possible, but don't rely on making improvements the consumer is unlikely to make (even if you tell them they should).
On using room correction below Schroeder for reviews (as opposed to for personal listening): I'm on the fence. The best is to try both with and without, which I do. I run room EQ for every speaker I test, and listen both ways.
However, I generally find I get more consistent impressions without, as Room EQ can be inconsistent from speaker to speaker and measurement to measurement. Moreover I know where the peaks and nulls are in my room, and I feel I get a better impression of the speaker's innate performance depending on how the nodes are excited. Bass performance among speakers seems to blend among speakers once I turn on EQ.
For personal listening purposes, of course, I recommend EQ though.
On using a sub for reviews to fill in nulls or 'free up' the woofer: Similar to the above. But perhaps more importantly, I think it's unreasonable to expect readers to have or buy a sub. At least, it certainly is for my audience. I do often recommend subs with bookshelf soeskers, mind you, but I know most won't purchase one. Especially with budget speakers.
On reviewing speakers in a treated room and concerns over differences between rooms:
I do not think this is necessary, as I think room treatment is sometimes a bit overblown in the context of home listening. As Toole points out in his book, we are really really good at adapting to our spaces and being able to hear the sound of a speaker "through" the room (above Schroeder). Having some reflections even seems good.
An audio show, where you're constantly switching between rooms and setups, is a different story. But at home, where I'm used to the sound of my apartment, the differences between speakers positioned roughly similarly are obvious.
On optimal positioning:
I think most pro audio reviewers take the care to tweak placement, but realistically, I'd be willing to bet most are using the same general location for their speakers. In many homes, placement is dictated by furniture. That's certainly the case with me. If I change something, it's toe in angle, but almost all my speakers are tested from the same spots.
A small defense of subjective reviews:
I would prefer every review include on and off axis measurements. But My impression is that experienced subjective reviewers are often quite good at describing a speaker's overall tonality. A bright speaker is called bright. A speaker with good bass extension is described as having good bass extension. A mid-heavy speaker is called so. Etc.
Measurements should correlate with our impressions after all. Rarely have I found a subjective review where descriptions of timbre and tonality are totally off from the measurements. Occasionally, but rarely.
There are also some aspects of sound that are harder to convey and interpret through measurements. Things like dynamics, transient response, soundstage focus. Of course, you can always measure more things, but realistically, only the engineers really have the time and impetus to measure every single little parameter.
The real issue with subjective reviews for me is in how they assess
value. A cheap speaker might measure better than an expensive one, but the more expensive one has to be better because... Well, it's more expensive, right? Reviewers (myself included) rarely have the resources to perform proper sighted A/B tests - let alone blind ones - to reduce the impact of their biases. That's where measurements come in.