Originally Posted by aarons915
I've used that test and others and that is part of what got me curious because honestly even at 200Hz, bass seems hard to localize. ...
Human hearing is most sensitive to midrange frequencies, and it is those that are easiest to localize. (It turns out, one could have one super-tweeter for all channels for very high treble, without people localizing that, too, but that is not done because it is easy and cheap to just put in a proper tweeter in all channels and it does not take up a lot of space, unlike the situation with deep bass.) And different people are more sensitive to localization than others.
Also, as already discussed above, different setups allow for different crossover points (as, for example, the subwoofer located between the front left and right speakers, versus putting the subwoofer behind you, etc.).
So, yes, 200Hz may not be overly easy to localize. Especially if we are not talking about a pure tone, but are listening to music in which there is some 200Hz content as well as many other frequencies at the same time.
As a practical matter, it is good to have a standard that people can use, instead of trying out complicated testing in their rooms. Most people seem to have enough trouble setting up their systems without adding more difficulties. This is where something like the THX standard comes in handy, as it is a reasonable choice for most cases, and allows one to have reasonably small main speakers (though I would not want to go with smaller than 5" woofers with it).
Of course, using a higher crossover has some advantages, as it will allow one to use even smaller speakers, or allow for higher volumes (since the woofer in the main speakers is no longer reproducing those frequencies sent to the subwoofer).
I get the impression that what you are looking for is validation in using a higher crossover frequency than 80Hz. Well, with the KEF LS50 and with careful positioning of the subwoofer(s) and careful setup, setting it higher may work out better, particularly at higher volume levels. In other words, if it works better in your system to set the crossover higher, go ahead and do so. Don't worry if you are using a higher than the norm frequency, because your system is unique and, if carefully set up, a higher frequency is fine (as you should realize from the research you have done). And, presumably, after you set it up, you are not going to be spending a lot of time listening to test tones but are instead going to be listening to music, and so what matters is what you can localize with music, not test tones. Which means that one can generally set the crossover higher than would work with test tones without being able to localize the subwoofer from the sound.
But for people who are not going to carefully measure things, I recommend that they get speakers suitable for an 80Hz crossover and go with that. Notice, this recommendation is not an absolute requirement, but is one to make things work well for people who are unable or unwilling to go to the trouble of taking careful measurements and taking great care in setting things up.
When I first added a subwoofer to my current main 2 channel system, I spent a few hours playing with a meter and test tones and adjusted the phase and the crossover frequency and level for the subwoofer. (Most people are not going to do that or go to such trouble to get things right, so simple rules of thumb are useful for getting good sound, which may not be ideal but are still quite good.) I ended up with something I would not have guessed would be best beforehand, though looking at the measured frequency response of my speakers helps explain why I ended up with an unusual situation. If you are carefully measuring in your room with your speakers, then you may well end up with unique settings for what works best. Don't let that worry you, that it may be quite different from what people typically do.
If you are worried about what other people think about it, you don't have to tell them what crossover setting you have selected. You have done due diligence in looking at the research on the question such that you should know that a higher crossover setting can be fine. If people who are ignorant of these studies think your crossover is too high, don't worry about their opinions. The easiest way, generally, is to just not tell them about your particular settings.