Balls. My stupid car can't fit two 15"s. So two 12" or three 10"s

[billy101]

Its better to run at one ohm because you ain't like wasting wattage. Like why get that big of an amp if you aren't going to use at full potential

You are wasting "wattage" when you run at lower resistance. Your amp isn't as efficient, that means you need WAY more power from the source to produce your "wattage"

Example with random numbers.

Amp needs 10 amps from alternator to make 100 watts at 4 ohm

Amp needs 100 amps from alternator to make 100 watts at 1 ohm, the rest is heat, in the wire, in the alternator.

It's like a teenager running at 10 miles an hour vs. a senior citizen running at 10 miles an hour. The teenager can do it for days. he senior citizen is long dead by now. Think of your poor alternator

100 amps to make 100 watts at 1ohm? I think your math is off. based on that math, i am drawing 1500 amps in my set up. (sorry, i see the random numbers comment now)

You are right, efficiency is lower at lower resistances, but it isn't nearly as much as you think it is. If you can't support 3k watts @ 1ohm, you very likely can't support 3k watts @ 4ohms.

I just think it will help out running at 4 ohm because I am powering other things in the car, 30+ speakers and 17 T.Vs

17 T.V's? That's a bit overkill imo.

[monkeyleg]

EVERYTHING on SMD is over kill, lol Trippi's hummer overkill much?

[chrishova]

1 SMD 15"!!!!!!!!!!!!!

[MrSkippyJ]

so just for shits and giggles:

3k @ 1ohm is (55v/1ohm) 55 amps.

3k @ 4ohms is (110v/4) 27.5 amps.

Those are the speaker circuits (numbers are rounded a bit, but close enough), so how much current draw does each amp have?

[monkeyleg]

Way too much power, I can't justify paying close to $1k on just one sub, shipping and duty, and then trying to sell it if I don't like it...Maybe next car. Now I have to decide on three sundown Z's or Fi Q's

[MrSkippyJ]

Can't run at 1 ohm people, not enough power from the alternator. So run like 3k RMS at 4 ohm I can't do a wall because I built panels for the back doors and my middle seat is a console with two 10"s and an amp, way too much work and money to just scrap Wall in my next car for sure.

so three 10"s?

Hold on. Someone correct me if im wrong but power is power. If you are making 2000 watts at 4 ohms or 2000 watts at 1 ohm wont you pull just about the same amount of power?

Yes and no. Not counting efficiency then it should take the same power. However, amps run more efficient the higher the ohm load.

Where this guy is getting confused is he is only considering the output of the 2 amplifiers.

3k at 4ohms is 110 volts (27.5 amps)

3k at 1ohms is 55 volts (55 amps)

yes, 1 ohm is more current, but this is amplifier output.

Since the voltage on the input side of the amp is constant (12v, 14v, 16v, etc....) then current is what varies. The more output your amp has, the more current it uses. To get an amp to increase it's output amperage (3k @1ohm), the input amperage goes up. To get an amp to increase it's output voltage (3k @4ohms), since the input voltage doesn't change, the input current goes up. Yes it will require less current since the amp is running more efficiently, but not much.

For example, a RF T600-4 is 71% at 4ohms and 68% at 2ohms. There would probably be a bigger loss than 3% efficiency IF the amp was 1 ohm stable, but still you are probably looking at about 10% efficiency.

So like I said earlier, if you don't have the power for 3K at 1ohm, you very likely don't have the power for 3k at 4ohms.

This was how my step-dad (a retired skilled trades electrician for GM) explained it to me. He's no electrical engineer but he certainly does know electronics very well.

[Brandonrcm]

Won't pay 1k for a single sub but you'll buy a 9k for 3k watts.....