whats the difference between channels?

[robert325is]

im a total noob at audio. so, what is the difference between the number of channels on a amp? say the difference between a 1 and 2 channel amp is...?

[natorious]

outputs.. for example a 3 channel is usually left, right, and subwoofer

[DSchultz325e]

If you are wanting to run stereo to all speakers in the cabin, pick up a 4 channel amplifier. It sounds like you are looking at subwoofer amps, though. Either way, unless you are actually "trying" to run them in stereo, all you'll need is a monoblock (1 channel) amp. If you do get a 2 channel (stereo), you will have to bridge the channels into one and create a mono signal.

It's not uncommon at all to run a 2 channel amp for one subwoofer. Depending on your speakers impedance, you might consider it. However, most companies are producing dedicated monoblock subwoofer amplifiers so it's all up to you.

[StereoInstaller1]

ok, since you are an admitted noob to this, I will give a quick tutorial.

Imagine what a freaky world this would be if you could tow a trailer with your e30 and make it go faster...weird, huh?
That is how electronics work. More load makes more power. HOWEVER, there are drawbacks...more heat, more distortion. Too much load and all the smoke comes out.

Impedance IS load....impedance cannot be changed. A single voice coil 4 ohm woofer is 4 ohms, no matter what. A Dual voice coil speaker is just that, 2 voice coils. Assume we are talking about a dual 4 ohm woof here.They can be wired in series to cut the load in half (8 ohms) or in paralell, to double the load (2 ohms). Multiple woofers can be combined in several ways, but cannot change their own individual impedance.

If the amp can do it with stability, double the load means double the power

Now for channels and such.

Stereo means left and right. You have stereo ears, unless you are WAY more of a freak than I would guess. Midrange and treble should always be in stereo pairs, unless surround sound is involved, but we are not gonna go there from here.

You need 2 channels minimum to power your mids and highs, whether that comes from an amplifier, or the amplifier in your deck.

So, now for subwoofing...Bass is omnidirectional, meaning your ears can't really hear where bass comes from in the lowest frequencies, thus the single woofer sub. Bass is also generally recorded in mono, thus again no need for stereo bass.

Now we get to the whole channel thing.

Most car amplifiers make the best mix of power and stability at 2 ohms. Yes there are exceptions, but screw that....for the most part, 2 ohms PER CHANNEL!

So, for a 2 channel amp to see 2 ohms per channel, you need to show it a 4 ohm mono load (AKA "bridged, an incorrect term. All car amps are already bridged, so we simply wire them in mono) This is accomplished by whatever means nesessary, wheter that means 1) 4 ohm woof, 2) 8 ohm woofs, 3) 12 ohm woofs, 16) 32 ohm woofs, whatever. I have run 22 speakers off of an old punch 45, WAY back in the day.
If you were to run 3) 8 ohm woofs, divide the impedance by the number of woofs, thus 8/3=2.6. Not gonna make as much power as a proper 4 ohm load.

If the amp can do it with stability, double the load means double the power.

Monoblock amps are just that, a one channel amp. No "Bridging", nothing to bridge.

So, what is better? Proper design....I would rather hear 2 cheap ass jensen amps running a kick ass woofer that some mix and match bullshit with poor engeneering, regardless of whatever brand name is on it.

I hope all of this makes sense to you. If not, print it out and take it to a stereo shop, see if they can help. This is all very general, by the way. Box design, vehicle interior, lots of other variables make a difference here, but we are trying to keep it simple. You may have noticed that the whole "channel" thing is a small part of the answer here, not a simple topic when discussing a system.

Good Luck!
Luke