# Watts Going On?



## Brent (Aug 17, 2004)

Ok well I really want to understand this whole stereo/watt thing. I have a HU (that what you call a radio around here?) and some speakers. Anyways the HU is rated at 200w, or 50wx4 as it says. It's a Sanyo EDC-T1550 if it matters. Now when it works, is it sending out 50 watts to each speaker constantly or does the amount of watts depend on the volume? 
Now lets say I put all the fade in the back or the front. So whats usually 50w per speaker (4), would it now double to 100w per speaker since the output is on only 2?
Or how about the speakers. They have a Peak power of 180 watts, and a Rated power of 40 watts. Does that mean that my HU will blow the speakers since its 50wx4 on a 40w rated power speaker?

Watts watts everywhere and I don't have an answer. Thanks for any help!


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## sr20dem0n (Mar 19, 2003)

*Anyways the HU is rated at 200w, or 50wx4 as it says*
that's peak power, if you read the fine print you'll find it's closer to 20rms or so per channel

*is it sending out 50 watts to each speaker constantly or does the amount of watts depend on the volume?*
it varies with the volume, full power only occurs at a very high volume, most of the time you're only using 1-2 watts per speaker

*Now lets say I put all the fade in the back or the front. So whats usually 50w per speaker (4), would it now double to 100w per speaker since the output is on only 2?*
it'd be nice if that were the case, but no, the power going to the rear speakers would stay the same, the fronts would just fade out, so your 20x4 amp is now a 20x2 amp

*Or how about the speakers. They have a Peak power of 180 watts, and a Rated power of 40 watts. Does that mean that my HU will blow the speakers since its 50wx4 on a 40w rated power speaker?*
if your headunit actually put out 50 watts, and if you played a sine wave (just a solid tone) at full power and left it running for a while, and if your 40rms speakers could really only handle 40rms and not any more, then yes after a few minutes of a solid tone you might fry them. But your amp only puts out about 20rms per channel, it only does this at max volume, and music is dynamic which means that even at max volume you would only get 20rms for small instants like kick drums, the rest of the time it would be much less, so no you aren't going to blow your speakers thermally. You could still blow them mechanically though, this happens when you send the speaker too much power at too low of a frequency and it bottoms out, I'm sure you've heard that sound before, that could blow a speaker pretty easily even if you're only sending it 10 watts and it's rated at 40 watts, because that 40 watt rating is thermal only, it has nothing to do with mechanical power handling.


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## Brent (Aug 17, 2004)

Hey man you answered it all! Thank you! :fluffy:


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