I am a hobbyist at best with no training nor professional experience. I simply enjoy detailed music and feel that without proper sound, watching movies at home is a lackluster experience. I'm also a bit of a gadget-junkie and (as a computer programmer) I like technology. So I attempt to learn through reading - mostly on-line sources, and experimenting - often with used or refurbished equipment. My goal is to understand - at a hobbyist level - the science behind speaker placement and A/V technologies so that I can make appropriate choices for my own home theater and expand my appreciation for the audiophile systems which are out of my reach. So if there is anyone out there who will indulge me in confirming my logic/understandings at this point in time as it relates to 3.1 HDTV home theater setup, I'd appreciate it.
I also would like to know how people measure the "angles" involved in the setups. I just recently discovered the world of Digital Angle Locators and wondered if this was part of an audiophiles tool kit or of you all just approximated angles with your eyes. Not trusting my eyes when it comes to anything other than 45 or 90 degree angles, I'm looking for a way to double-check my eye-ball measurements.
How do you measure the angles in a home theater set up?
And, if you've read this far - then it's onto my statements regarding a 3.1 HDTV Theater Setup:
3.1 Speaker Placement is the same as 5.1 - minus the two surrounds.
Speaker placement should be such that the tweeters are at the same height across the front sound stage. This height should also match the ear-height of the average listener when seated. This is due to the directional sensitivity of the higher frequencies. If the height cannot be matched, then the speakers should be angled and "aimed" at the ear-height of the sweet-spot. Placing 2 front speakers on appropriate height stands and then angling the center channel up-or-down according to it's placement is a common work-around for placement issues across the front sound stage. The three points consisting of the Front Left Speaker placement, Sweet Spot, and Front Right Speaker placement should form an equilateral triangle.
Despite the technological limitations of many center channels, a 3.1 system is still superior to a 2.1 system for home theater use. There are some limits here. The center channel should be at least 3 (or 4) feet away from the mains to avoid disruption and a possible reduction of sound quality. Also, a 3.1 system of "lesser speakers" could perform worse than a 2.1 system with "quality" speakers so the addition of a center channel shouldn't be chosen at the "expense" of good main speakers. But with all things otherwise equal, the addition of a center channel improves dialogue and is a worthy investment.
Sub woofers are more efficient (louder?) as you position them closer to side walls and corners. However Dolby recommends avoiding corner placement, and many sub-woofer recommendations admit you need to move the sub around a bit to get the best spot. One technique I've seen for this is to place the sub in (or as near as possible) the sweet-spot of the listener. And then shuffle around on your knees to various placement options. The place where the bass sounds the best is where you should put the sub. Many THX and Dolby diagrams show the sub-woofer placed between a front speaker and the display screen. Horizontal placement of the sub-woofer seems more important than vertical considerations since the lower frequencies tend to be omni-directional.
THX recommends that the top of the HDTV screen not be above a 15 degree angle from eye-level. It also recommends a 40 degree (or less) horizontal viewing angle, which often results in very large screen size recommendations. They are trying to simulate a cinematic experience after-all; so the horizontal viewing angle can vary. One thing seems certain, in home theater HDTV setups - don't put the screen too high. Not much science here, it's a comfort thing. Raising the screen up to achieve a "flat" horizontal line between the tweeters in the front sound stage is purely personal preference.
So - that's it! How'd I do? Am I on pretty solid ground with those statements/understandings or did I mess something up?