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View Full Version : how do i measure preout voltages?



Slaugh
06-04-2005, 09:26 PM
hi i have an alpine cda-9815 and im suspicing its preouts are too weak because i have to set gains too high... :eyebrow:

how do i measure the voltage?

jsloan10
06-05-2005, 12:38 AM
No one else seems to be responding, so I'll jump in and keep you company.
As for helping you out, I dont what the procedure is for that, Have you checked Google? Actually I'll go have a look and see if I can find a link.

Nope cant find it, but I did find a **** good FAQ-
http://www.faqs.org/faqs/car-audio/part1/
Why use your brain to help people when you can cut and paste?.

Oh, there seems to be a problem with a bunch of the New Alpine head units these days including eject mechanisms and weak preouts.

cjjackson85
06-05-2005, 12:41 AM
Alpine is notorious for having weak preouts, deal with it...

zachzchw
06-05-2005, 01:23 AM
There was a thread on icix where people were measuring the preout voltage to see how accurate the ratings were.

cjjackson85
06-05-2005, 01:27 AM
There was a thread on icix where people were measuring the preout voltage to see how accurate the ratings were.
Link *****!

zachzchw
06-05-2005, 02:08 AM
Link *****!


Whats that say? "Link, massa"? Alright, since youve asked so nicely.....

http://www.icixsound.com/vb/showthread.php?t=11797&highlight=preout+voltage

squeak9798
06-05-2005, 02:08 AM
Yeah, that year Alpine was pretty famous for weak outputs; atleast on the subwoofer output. Also realize that, on that Alpine, the sub level has to be set to +15 for full output.

Anyways; you'd grab a DMM and set it to volts AC, stick the DMM's red lead on the inside of the RCA preout, the black lead on the outter shield of the RCA preout, play a 0db sine wave and read what the display tells ya. Also keep in mind that, with only a DMM, you won't be able to monitor the point of clipping. I'm not sure if the Alpine's clip and at what volume they do (if they do).

JLCivic
06-05-2005, 06:33 AM
Yeah, that year Alpine was pretty famous for weak outputs; atleast on the subwoofer output. Also realize that, on that Alpine, the sub level has to be set to +15 for full output.

Anyways; you'd grab a DMM and set it to volts AC, stick the DMM's red lead on the inside of the RCA preout, the black lead on the outter shield of the RCA preout, play a 0db sine wave and read what the display tells ya. Also keep in mind that, with only a DMM, you won't be able to monitor the point of clipping. I'm not sure if the Alpine's clip and at what volume they do (if they do).


People were complaining about the weak pre outs for atleast 2 model years.

Raven
06-06-2005, 09:38 PM
I've always figured that a HU's power output increases exponentially. That's just given. I have also measured mine but with a -12db sine wave. Didn't get much output. =\ That's given, too.

audiofx81
06-06-2005, 11:55 PM
Im really upset i got the CDA9855 instead of following my gut to stick with eclipse HU'ss :/ Looks like after only a month ill take a $100+ loss on my Alpine + Sisirus tuner to grab the eclipse :(.