It's important to a fair degree - the manufacturer makes things the way they are in order to create a time-coherent signal. Having things aligned in the way they were intended means all signals arrive at the same time. Changing that means you are effectively delaying the tweeters by a certain amount. It might give you a wider stereo image, but that's not necessarily a good thing - you want an accurate stereo image.
Perhaps more importantly the dispersion pattern that was in the vertical plane is now in the horizontal plane, and speakers are made with different dispersion patterns. The K+H O300 that I use are made to be mounted horizontally, with a deliberately narrow vertical dispersion pattern. See here at the bottom. This is done in order to minimize reflections off of the mixing desk, and give a good image/representation in all horizontal positions as you slide about in front of your 2000 channel mixing desk Thing is that when you stand up you can very clearly hear things change - mounting them vertically would reduce my sweet spot a lot (unless I was moving up and down instead of fwd/bwd/l/r).
BTW Not all speakers are made to have the tweeters at ear level for similar reasons; PMC make theirs with the tweeters intended to be 13 (? 15?) degrees above the ear. That's where the signals areintended to meet, and so where you shold aim to be.
I had a GREAT diagram that shows all this very clearly, but I can't find it now
I'd always stick with what the manufacturer says, but to be honest it's not a huge concern unless you're pretty anal. Ahem.
Originally Posted by Don Cherry
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