Re: 2 Speakers one Deck
How are you planning on "sending 4 ohms"?
You're digging deeper..
Do you know what an "ohm" is? "Impedance"? Why it's important and what it all means when you're dealing with audio equipment?
An amplifier is made to only handle a certain amount of flow out of it. If you try and suck too much out of it by lowering the impedance past it's limit, then you will hurt things. Some amps are built to handle more, some less. Class D amps for example can handle down to 1 ohm per channel, and some competition amps down to 1/2 ohm. Most amps these days are made to handle down to 2 ohms and all internal stereo head unit amps (that I've ever seen) have a 4 ohm limit. This is the MAX that you can "suck" out of them. You can suck less.. it doesn't care what you do.. as long as you don't exceed it.
What you have hooked up to that amp in the form of a speaker.. that is what controls how much you draw out of the amp. Speakers are kind of like light bulbs in that they use up what is given to them and some are made to draw more power than others.. kind of like a 60w bulb compared to a 120w bulb. If there's no speaker hooked up.. the amp simply is making the power available but nothing is drawing it out. Just as if you don't have a lightbulb screwed into the base. If you flip the switch to turn it on.. you aren't using any electricity because there's no bulb in the socket. It's available to use, but there's nothing consuming it.
The outlet doesn't care one way or the other though. Same thing with an amp.
This is why you can't "send 4 ohms". You can't "send" ohms. Ohms are a measure of resistance.. not of power. In this case, the resistance level of the speaker connected.. the ohm rating.. is what is throttling the amount of power that it's consuming from the amp.
The only thing that amps really "care" about is that you don't try and draw too much power through them via lowering the impedance via speakers or too many speakers hooked up per channel. It doesn't care if you aren't drawing power to it's full capacity.. say by hooking up an 8 ohm speaker.. as all you're doing is throttling the consumption via a higher impedance. In other words.. all you're doing is not drawing the power that you are able to. The amp doesn't care though.. it's fine by it if you don't use all it's power.. as long as you don't
exceed it.
Same thing with not using a channel. It doesn't care one way or the other. The power is there if you want it.. but if you don't take it.. it's fine by it. Same thing with using a higher impedance speaker than the amp is rated for. The power is there if you want it, but if you don't take it.. it's fine by it.