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Hey,

I just want to see if you peeps can help me out. I am wondering if you peeps know how many volt is coming out of the stock HU cd player for 2002 civic. I don't care about the watts, just the voltage. thanks.

 
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its a different type of output, there are no rca outputs on the stock hu, you have to use a high to low level converter and convert it to rca's, and even then, the signal wont be nearly as clean as an aftermarket unit. if i had to guess, youd probably get 2 volts maybe, but it's a hwole different type of voltage and signal

 
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LudlamTheory, I see that you make many great contributions to these threads but I have to disagree with you on this one.

When you use a converter, you actually get the differential signal between the + and - speaker wire. This will create a geat CMRR (Common mode rejection ratio) thus filtering out any common mode noise induced on the speaker wire.

Second, the voltage produced by the high-level wire is greater than the low-level signal created from RCA's. Many of today's decks claim to put out higher and higher voltages to get better SNR.

Now, distortion is another matter. Many stock decks distort the signal at high volumes so I still prefer to use an aftermarket deck for this reason.

Hope this helps.

 
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I see what youre saying, but i was trying to dumb it down.
the only people on this site that understood that statement you could count on your hands.
I assume he was trying to find out if there was a sort of rca output on the stock deck in order to compare the voltage to an aftermarket in order to compare cleanliness of signal. Both me and you know voltage isnt everything, but not everyone does.
People ask about mounting their speakers, I could tell them all about a point source install based on all that blah blah blah, but its unnecessary. I see where youre coming from though. it's nice to see some people on here can hold their own.

 
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well thets think this through....

lets posit that the stock radio puts out about 11 watt rms.

so we make that a nice round number and convert that to 25 watts peak. we are still positing, not basing this on any sort of reality, but just thinking about the possibilities.

so now we know through ohms law that power = voltage suared divided by resistance. we know the factory speakers are 4 ohm? yes? am i wrong?

so with a little figuring, id guess our civic stock radios are putting out about 10 volts or so. but why take my word for it? grab a multi meter!

take yrou multimeter to your rear deck in the trunk. unplug one of the speakers and hook the multimeter to it. now pop in a cd with a test tone, and max out the volume. a 50 Hzish test tone is probably best, but music will work somewhat ok.

test tone is really best. whatever you cna read as yoru AC voltage is yoru voltage rating.

 
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OK, don't rely on your AC function of your DMM. This is NOT THE REAL POWER. The resistance of a speaker is a function of its frequency. The nominal impedance of a 4-OHM driver is less than 4-OHMS (I dunno the exact value, will vary by each driver) You can buy a driver tester and get a plot of the real resistance vs freq and do your calculation. To get real power, you need to measure the voltage and current P=V*I (P=V^2/r and P=I^2 * R work too but R isn't a constant)

As for using music, music ~ 1/8th the power content of a pure sine wave. This is not a very good way to measure it.

 
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hey tbone, your absolutely right, did you see the way i ballparked the voltage? same way as if used a dmm to test it!

but was the question here power out? nope! it was what VOLTAGE teh radio is putting out! how else could you POSSIBLY do it other than a DMM? =D

and i would have expected you of all people to realize that i used a best gueasstimate of PEAK power to figure out theoretical voltage from teh radio?

dont tell me that you reply to messages too without reading the full post! *cries*

 
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my bad, you are correct in checkin the voltage. I wouldn't use music tho, you mentioned a test CD, which is a much better idea.

~Tbone