I am thinking about getting one of those speaker systems that have like 5 satelite speakers and one sub woofer. The satelite speakers have a tweater for highs and a 3 1/2 cone for mid range. My current 2 speakers have a 5 1/2 cone for mid range. My question is, if I switch to this new speaker system, am I going to loose mid range sound since the new mid range cones are only 3 1/2?

It's actually more complicated than that. A lot depends on the cabinet design as well as the maximum movement of the speaker cone. If the frequency response IS different then probably the subwoofer makes up for it.

If the satellite speakers are too small, the manufacturers have no choice but to either let the subwoofer play so high that you can easily locate it or leave a big gap between bass and highs.

Example, Logitech X-620 and X-530. The satellites are too small, the subwoofer goes too high in the frequency range. The pic is a small excerpt from c't magazine, buy the article if you want to read the whole review (0.80 Euro, link).

...and it's not just computer speakers that do this - many "hi-fi" satellite/"subwoofer" systems do, as well. It's actually not that difficult to get reasonably flat response down to 80 Hz from a (properly-designed) ~4" driver in a compact enclosure (as long as you have reasonable expectations for its maximum output), but in order to do so, you lose a great deal of efficiency, i.e. acoustic output for a given amount of power (Google "baffle step compensation").

That seems a bit wimpy, but you can only tell by listening. The total cone area is about the same for 5 (or 6*) of the smaller speakers. That won't fully compensate**, but I'll bet the surround-sound set-up will sound better overall, especially if your current set-up doesn't have a subwoofer.

Ideally, all 5 speakers should be full-range. The subwoofer is used for very low frequencies and Low Frequency Effects. (A proper 5.1 channel movie soundtrack is mixed with 5 full-range channels plus one LFE channel.)

But, this isn't practical on most living rooms and it's expensive! In most home-theater set-ups, the bass from the 5 speakers is filtered out of the 5 "full range" channels and all of it mixed together with the LFE and routed to the "subwoofer". (This is usually done with a setting on your receiver.) In the case of 5" or 3" mid-ranges, the "subwoofer" is actually a combination regular-woofer and subwoofer.



*The enter channel might have two mid-range cones.

** Often, the sound is routed to only one or two speakers so you can't take advantage of the combined cone area.

My reciever has crossover options. Would I do best to buy tweeters for on pair of channels, mid cones for another pair of channels, and cones for bass for another pair of channels?

To make this sound right you will have to keep the tweeters, squawkers and woofers together in two groups of three. You will then be right back where you started with standard stereo but your six channel receiver will be doing the job of crossover networks. That's a waste of four channels. The whole point of a surround sound system is to mimic the reverberation you get in a large hall. The sound that comes out of the rear speakers is radically different from what comes out at the front.

The sixth speaker - the sub-woofer - is only there to save money on the other five. As DVDdoug points out, an ideal setup would have five full range speakers. The sub-woofer trick exploits the fact that our ears cannot easily locate the source of the lowest frequencies. By filtering these out of the other channels you can get away with five smaller, lighter and cheaper speakers but such savings can be pushed too far. As CiTay says: