Can I use an 8 ohm load on an amp?

[Umbra]

Can you stick a high impedance load on an amp?

Here's the situation: I have a pair of 4 ohm DVC subs. They're rated 400W RMS each. I have an amp that does 500W @ 4 and 900W @ 2. I've heard mixed things about its 1 ohm stability, so I never tried it and unfortunately I can't wire the pair to 2 ohms, so I've been running them at 4. One of them I need to fix up, so I was wondering if I could wire the remaining sub to 8 ohms and run it safely to get some bass in the mean time.

Is the reason there's no 8 ohm rating is because it's uncommon to see that in car audio and impractical to use a 2 ohm amp at 8 ohms, or is there another reason? If I ran it like this, what could I expect to see the amp put out - roughly? 300W?

I actually have another amp in my possession I'd planned on using for the pair that does 750+ @ 4 and 1. It also does 300+ @ 2 ohms in stereo, so I can use that for the time being if need be, but I'd still like the answer to this question for curiosity sake.

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[csu87 10+ year member]

thats fine. probably see 200-300

 

[phemps 10+ year member]

Absolutely. Just dont try to compensate for less power and output but cranking the gain and clipping your signal

 

[CSCStang]

Totally safe and very stable.

 

[Umbra]

Thanks guys.

Absolutely. Just dont try to compensate for less power and output but cranking the gain and clipping your signal

I've another question. I'm not directing it at you, but you made me recollect it.

When I set my gains I disconnect the speakers from the amp so I don't go deaf/ end up with a headache and then use an oscilloscope (with a test tone). I can see it clip at a certain setting on the gain/input sensitivity. This is based off the input signal, yes? I'd imagine a 1 ohm load on an amp would put more strain on it compared to a 4 or 8 ohm load. Would the impedance the amp sees chance the point it clips, or is the input and output areas of an amp separate?

 

[phemps 10+ year member]

Thanks guys.


I've another question. I'm not directing it at you, but you made me recollect it.

When I set my gains I disconnect the speakers from the amp so I don't go deaf/ end up with a headache and then use an oscilloscope (with a test tone). I can see it clip at a certain setting on the gain/input sensitivity. This is based off the input signal, yes? I'd imagine a 1 ohm load on an amp would put more strain on it compared to a 4 or 8 ohm load. Would the impedance the amp sees chance the point it clips, or is the input and output areas of an amp separate?

Correct, you are matching the voltage of your input (headunit) to that of the amp. It shouldnt affect it really. your subs are not an input, they are a variable load on your amplifier. the cause for concern would be dropping your impedence too low which in turn will ask more than the voltage rails can supply and clip your signal.