# formula

Discussion in 'Beginners, General Questions' started by r1c0, Sep 24, 2006.

1. ### r1c0 Auditioning

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how much watts in 6 ohms if the amp produces 100 watts in 8 ohms? what is the formula conversion for these?

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There is no formula. It depends on the design of the amp. Some amps aren't even stable into 6 ohms and will tend to overheat if driven hard, others will give roughly a 40% increase in wattage, and most fall somewhere in the middle.

3. ### Bob McElfresh Producer

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Hi Rico.

The answer for a fixed resistance is around 150 watts for a 6 ohm load.

(if a power source provides 100 watts into 8 ohms, then it would provide 200 watts into 4 ohms. This means:

200 watts into 4 ohms
175 watts into 5 ohms
150 watts into 6 ohms
125 watts into 7 ohms
100 watts into 8 ohms

But these numbers are theoretical MAXIMUMS.

In reality - your receiver is producing 3-7 watts of power on average. But to increase the sound 1 db, takes twice as much power. When a soundtrack has a special effect that jumps in volume - your receiver has to push 90 - 120 watts for a short amount of time. This power draws current which generates heat which damages things.

8 ohm speakers tend to be the safest. But you can run 6 or even 4 ohm speakers. But you need to do a few things:

- Make sure you have lots of ventilation above and around your receiver.

- Check the temperature of the top of your receiver and shut things down if it gets too hot

- Keep the volume control at modest levels if you are running 6 or 4 ohm speakers or if the receiver gets too hot.

- Consider a exteral subwoofer and define the rest of the speakers as "SMALL". This will keep the receiver from trying to drive the power-hungry woofers in your speakers.

Hope this helps.

4. ### JeremyErwin Producer

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Oh shit. This is the newbie forum. Better add a