5:12 I think you are right about air speed. Your test setup specifically probably relies a lot on fast the air moves in the center. So fans that blow a lot of air towards the sides would perform worse than a smaller fan that blows the air more concentrated (meaning the air speed in the center is also higher for longer), even if it's significantly less air volume in total. Which one matters in an actual case is debatable. Though I think air volume is more important, because CPU coolers have their own fans and don't rely on case fans blowing through them. They suck the case air themselves, even if the case fans don't blow directly at them. The CPU coolers will mostly depend on how warm the case air temperature is. Which will mostly depend on how much air volume the intake fans can blow into the case.
Somewhere in between these two videos, I redid all the noise measurements. Originally, the 140s on rads were measured in a different spot ( no real reason why ) but the noise-floor was .5db higher over there. At some point I decided to re-do them where all the other fans and case-fans are measured, hence the graph changed slightly for every fan, including the minimum db. The performance (*C) are all still the same, it’s just the noise that slightly shifted. Don’t forget that both graphs also have a different start/stop points, proportions might be different. But still, a different room might yield slightly different results. I compared the two graphs you mentioned, and the bq sw4 pro became slightly better in n-t-p
