In reality, there is no difference. In reality, having the identical same speaker at all positions is ideal. In reality, a vertical speaker is always superior to a horizontal speaker, unless you like watching your movies sideways, lying down.
Having the same speaker at all positions allows for best matching, in timbre, sensitivity, phase, x-over points, yada yada...
So... what's up with the very different looking speakers in any package? The horizontal center is designed that way to more easily fit above or below a display. The smaller surround speakers allow for easier placement, especially to be mounted high enough (well, at least IMO).
Sure, you COULD interchange the speakers. The biggest ones are usually up front since most audio is coming from there. The biggest compromise in a typical package is the center speaker due to horizontal M-T-M layout that provides very poor off-axis response. Ok, you might spared if within 10 degrees of dispersion, maybe even up to 20. However, a typical upright tower or bookshelf gives you about 60 degrees of dispersion. This is quite desired for a wide viewing area. (You will often see me recommending 5 or 6 identical bookshelves to noobies). See, you often can get a superior center speaker, and for less cost, by simply by using an upright bookshelf for center speaker. Problems are 1) do you have space? 2) does it look funny to you?
While a vertical cabinet is also superior, at least a few companies out there put the tweeter on TOP of the mid, such as B&W, Revel, AV123. KEF uses a coaxial setup, and this is just as good, with the added bonus of being not as tall (since no extra space for tweeter is required).
Hmm.. good speakers.... consist of 3 main things: 1) Cabinet 2) Cross-over 3) Drivers. And probably in order of importance as well. You think, huh, the cabinet is most important? Yes. Its hard to find good ones. Actually, all speakers suffer from cabinet resonance. Yes, you can actually hear them, believe it or not, of course you may not be able to distinguish them from the room, or drivers, or x-over, but the total sum of what you hear is distinguishably affected.
There was a recent case of a guy who made a bunch of DIY treatments for his dedicated HT. He is still getting some "bloom" from piano recordings, and its very possible that this bloom is from cabinet resonance. And these are VERY nice Paradigm speakers we are talking about. Pretty much all of us suffer from it.
There are only a couple of speakers that make sure that the existing cabinet resonances are outside of the human hearing range, and those are made be B&W, and they cost as much as an entry/midrange car.
The cross-over. Its the device that gets your drivers acting beautifully in ensemble. If you think about it, a small metal tweeter is going to be pretty different sounding than a polypropelene midrange driver. A lot of R&D goes into this piece, and hopefully a lot of this research is aimed at getting them in phase. People say when you listen to a speaker, you are listening to its cross-over. That's how important it is.
The actual drivers. The most obvious thing one would is linearity. Depending on how linear any driver is, and to which freq points they can keep this linearity up... will very much affect how the x-over is designed. As with cabinets, the actual drivers can suffer from resonances, and this is called "cone resonance".
So, with the above in mind, a great speaker will have these attributes:
- linearity thru much of the human hearing range
- ability to maintain such linearity off-axis, and the better speakers maintain such lineaerity at greater angles
Ah, yes, almost forgot. The acoustics of your room, along with the placement of any speaker in such room, is just as important (IMO) as the speakers chosen. The Absolute Key of what you will hear is the:
Interaction of speakers within any given room. Yes, this is affected by their placement, the room's acoustics, even your listening position. I know this is over everyone's heads, and probably over-kill, but yep... this is what it boils down to.
Im sure that's just the tip of the iceberg. Any other questions?
What exactly is the difference between Center, Front and Surround speakers? What are the important components that should be present in each of these? Can they be interchanged? I know you cannot with the center, but not sure, but what about others?
I think it will be helpful for a lot of newbies like me to understand the home theater concept and guide us for buying good speakers.