pre-out voltage

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=32680
Printed Date: May 13, 2025 at 8:07 PM

Topic: pre-out voltage

Posted By: ready247
Subject: pre-out voltage
Date Posted: May 24, 2004 at 7:02 PM

im a noob

i have been looking at head unit specs and i see that the preout voltage goes from about 2-6 volts, why is there diff and why do i need more?

Replies:

Posted By: fastinanaurora
Date Posted: May 24, 2004 at 7:18 PM

I'm pretty sure it has something to do with your amp and the strength in the RCA signal. let me know if this help.

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What makes my car Bang:
Kicker KX 600.1 Mono amp (2004)
Kicker Solobaric L7 10 (2004)
Long Ported Box Single
Kicker 200.4 4 Channel(2004)
Kicker DX 60 6 1/2
Rockford Fosgate FRC3369 6x9

Posted By: stevdart
Date Posted: May 24, 2004 at 8:00 PM

You will see those differences in output voltage because the head unit manufacturer has just a few guidelines to follow, one being to publish specs that have been tested. But you often won't find the frequencies that the output voltage was tested at.

Say you are setting up two amps off that HU, one for the components and one for the subs. The amps have gain controls to adjust the amp's sensitivity to the HU voltage output. The HU may be putting out 4 volts at a frequency of 1 kHz, and you adjust the amp gain to that level. Now, that same HU might also put out 2 volts at 100 Hz, but there again you have another gain adjustment to make on the sub amp for that particular output.

You don't need more (pre-out volts), but the amplifier gain is set lower if you do have more. Which means the signal is amplified less, so any noise that is inherent in that signal is therefore also amplified less.

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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.

Posted By: Velocity Motors
Date Posted: May 24, 2004 at 9:51 PM

Another thing to remember is that the input signal voltage for the amplifier or the EQ has to be kept in mind. In most cases there is a peak voltage input for the amplifiers and EQ's that you have to take into account.

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Jeff
Velocity Custom Home Theater
Mobile Audio/Video Specialist
Morden, Manitoba CANADA

Posted By: mikedawg
Date Posted: June 06, 2004 at 11:21 AM

well the higher the stated pre out voltage the less chance for cable noise and ground loop. right now 8 is about the highest you can get right now. thats eclipse and a company in china. i forget what theyre called but its starts with an "H"

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always looking for new info and willing to give it