Basic Idea
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the idea is to get the most from your speakers (working together) based on a certain focal point, like your couch. Imagine the difference in sound you would here from a speaker pointing at you directly vs on pointing up or down or backwards, thats the basic Idea. Im no expert so all my ideas are kind of conceptual, so I may be wrong in my approach as to how to do things; but I feel my thoughts are still useful so please anyone correct me if im wrong.
Ambient Acoustics
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Since you are in an environment where you can control the ambient acoustics use that to your advantage. The idea is basic, but the concepts are a bit deeper. You just want to hear the original sound wave from your speakers. once the sound waves go past your ears, you want to absorb them as much as your can. So go ahead and hang acoustic absorbing foam everywhere.. lol No just keep that in mind with what direction you point your speakers.
Phase cancellation (in terms of timing and positioning)
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Now, with your placement using 2 speakers to handle the L and R signals in the front and rear, you need to be aware of phase cancellation, which would all be dependent on the placement of the speakers and timing. As far as I know, some high end AVRs/amps have auto tuning that calculates all this and balances it all by adjusting the timing.
Whats happening in phase cancellation is separate sound waves colliding which actually distorts the audio and how we hear it, from what it actually is. So by ensuring that all the sound waves are reaching your sweet spot at the same time, you are going to be in an area that phase cancellation does not exist. If your rear speakers are reaching your couch before your fronts then they will be colliding into your fronts sound waves and they will be distorted before they reach your ears. I believe timing is what you would use to combat this. Timing is ultimately setting your sweet spot, based on distance, using the timing of when the sound reaches the area of desire.
Now that I mention this im sure timing is especially important with surround sound. If your are hearing audio in the back before you hear it in that front thats going to throw off your perception of sound entirely.
Another form of phase cancellation can be seen by using just one speaker. If you are sitting to the center axis of the cone then sound will be reaching your ears at the same time. However, if you are sitting off axis to one side or another of the cone, then sound will have to travel further to reach one ear over the other. Thats why when it comes to placement, logic would tell you to point the center axis of the speaker cone towards your sweet spot.
Now with spacing in between your 2 fronts and 2 backs, keep in mind again phase cancellation, picture sound waves being projected from your cones something like 90 degrees to get an idea of spacing in between each speaker. To close, and you will have overlapping and colliding sound waves from L to R creating phase cancellation, to far and your most likely just moving your speakers further away from your focal point for no reason and would be an excessive waste of space, and id imagine would make dialing in everything else harder. Same goes for the rear L and R. With your sub placement, its much more flexible because of the distance in between sound waves in low frequencies is so vast and because its just a mono signal so no stereo effect is being used. I would suggest placing the sub in a corner wall if available, this will actually boost performance from your sub. Again, timing wont be much of an issue with placement of the sub, however acoustic resonance will be, which is why I would place it in a corner if available.
Getting a Flat Frequency Response
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Each of you speakers will have a frequency response range in which they are designed to work. Its ideal to have a balanced range with an even amount throughout. That range needs to be kept in check by your crossover to make sure they are working in the range they are meant to. Some crossovers though just offer a High, Med, Low type settings, so you might have to do some math to figure out what the actual numbers are.
The other key factor with this is making sure theres even transition between your lows, med, and highs. You do not want to much over lap or any gaps at that matter from your 20-20k range.
However, your F1's being a 2 way are already going to be balanced, from 38-23khz. If you can adjust the built in crossovers on your speakers, then I would cut out the bass of your front F1 towers to the top of your subs response range. From that point and lower will all be left to your sub, which can more efficiently handle those frequencies. This is an area of preference, some people like more heavy bass, some like a more balance bass, so you can tweak it to what you like. You didnt give me any info on your rears or your sub, but check the frequency response of them and adjust them accordingly. The idea here though would to be able to get as much efficiency out of your speakers so you arent wasting any power, and at a set volume it will actually produce higher sound levels than before. Unless you want heavy bass which you would then have wasted overlap between your sub and front towers; its all preference though at that point
