setting gains
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=110482
Printed Date: May 21, 2024 at 8:25 AM
Topic: setting gains
Posted By: mike creel
Subject: setting gains
Date Posted: January 08, 2009 at 11:47 PM
I have always been happy with setting the volume control on my deck at 3/4 while setting my amplifier gains as to keep the signal from clipping before it gets to my amp. However, I have aquired a deck without internal power and want to know if I still need to stick to the 3/4 rule or can I bump it up a little?
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reeldeal67
Replies:
Posted By: i am an idiot
Date Posted: January 09, 2009 at 2:07 AM
Just because the radio has no speaker outputs, does not insure clean audio output at any volume. Depending on the brand of deck, you may be able to turn the deck all the way up without any audible distortion. You will have to decide for yourself. If you do turn it all the way up and set gains to that point, the only problem I see is that if you get a CD MP3 or whatever type of track that is recorded low, you will not be able to max out your system. I would stick with what has been working for you.
Posted By: 04nata
Date Posted: January 09, 2009 at 8:38 AM
I also have a question about this, my Clarion head unit has 6volt preouts and my TMA amps say this | Input Sensitivity : | 200mV - 4V
Remote Level Control Included |
based on how I read the gain setting sticky, should I have the gains all the way up to match as close as possible the output of the preouts? this still confuses me, right now my mids/highs amp T2.320.4 is set at about 1/3 and the bass amp T2.500.1 is about 1/2, is sounds good but I am still a bit concerned and the remote level control reads as though is controls the gain, is that true ------------- 2004 Hyundai Sonata
Kenwood KDC-X599 HU
2-Sundown X-18D4
2-SQ Q4500.1
2-SQ Q90.4
1-Massive DBX4
8-Niche 5.25 mids
8-Niche Tweeters
4-Skar 8" mid-bass
OhioGen 220a alt
OhioGen 350a alt
156.0
Posted By: DYohn
Date Posted: January 09, 2009 at 9:52 AM
Not all the way up, most likely most of the way down. ------------- Support the12volt.com
Posted By: 04nata
Date Posted: January 09, 2009 at 2:30 PM
DYohn] wrote:
ot all the way up, most likely most of the way down.
Now I am really confused, on a site called Basic Car Audio (which I found from this forum) it says that turning your gain up is actually turning it down,,,, example: all the way counter clockwise is 200mv and all the way clockwise is 4v, and this is supposed to be set to match the output of your deck so that, say you have 4v preouts, you turn it all the way clockwise so that at 3/4 volume you are at 3/4 power,,,,,,,is that right? because I do not have the equipment to do what is in the stick yet. can someone put this in "simple mind" terms so that those of us "simple minded" people can understand it, what I have done the the past is turn the gain all the way done, turn the volume 3/4 up and then turn the gain up till it sound crappy, then back it off a bit. someone smarter than me please help............... ------------- 2004 Hyundai Sonata
Kenwood KDC-X599 HU
2-Sundown X-18D4
2-SQ Q4500.1
2-SQ Q90.4
1-Massive DBX4
8-Niche 5.25 mids
8-Niche Tweeters
4-Skar 8" mid-bass
OhioGen 220a alt
OhioGen 350a alt
156.0
Posted By: boogeyman
Date Posted: January 09, 2009 at 7:16 PM
Go to radio shack and get a mini audio amplifier w/rca input adaptor.Youll also need an appropriate frequency and recorded level track on the cd , recommend -5 db or -10 db for a 3:1 voltage gain overlap.........First ensure all speakers are unhooked fom HU and amplifier.....2nd set everything flat on hu and amplifier..... 3rd gain settings should be adjusted from the beginning of the signal chain to the end.So start with the hu and work your way down the signal chain using appropriate frequency test tone.....example sub 100 hz ........now to determine at what volume level the hu starts to clip.The mini amp is connected to one of the mid channels. the mini amp is turned on, but the volume should be kept to its minimum to avoid hearing the internal amp clip, as opposed to the incoming signal. With a 1khz test tone playing, the volume of the hu is increased until the pitch of the tone from the mini amp changes. If the hu reaches full volume without this occuring, the hu doesnt clip. if theres a slight change in pitch of the tone from the mini amp, the volume of the hu should be reduced to the point just prior to the change in pitch of the test tone. This is the hu max. unclipped output.setting.........This process is to be repeated down the signal chain...........Once the gains have been set to Max unclipped output setting on the hu and any processors in the signal chain, the amplifier is ready to be adjusted. Since the output of the amplifier is much greater than the pre-amplified signal, its voltage must be reduced prior to feeding it into the mini amplifier. 10:1 high power voltage divider(20:1 if amplifier outputs are over 60v)...........The voltage divider is placed inline, prior to the mini-amp. The inputs of the voltage divider are connected directly to the speaker outputs of the amplifer.The hu is once again set to max. unclipped output setting.The amplifiers gains are adjusted using the appropriate frequency test tone and same method as hu .
Posted By: i am an idiot
Date Posted: January 09, 2009 at 7:35 PM
04nata, let me try and clear up your confusion, when you turn the gain control all the way counterclockwise, this is called turning the gain down. But if you notice the markings surrounding the control, the larger number is at the lowest position. Clockwise is up, but the smaller number is there. Say the gain control has the markings of 4V and (.)2V, with the gain at the lowest setting, it takes 4Volts of signal in order to make the amp reach it's maximum output. With the gain all the way up, it only takes 2 tenths of a volt to reach max output. So turning the gain all the way up is actually turning it to the lowest number on the dial.
Posted By: 04nata
Date Posted: January 09, 2009 at 10:01 PM
thanx for the replies,,,,,,idiot ,that makes sense to me now and since I have 6 volt preouts it looks like my gains should be set pretty low (or high on the number scale) but counterclockwise more than not. Thanx for your help I am gonna do this tomorrow ------------- 2004 Hyundai Sonata
Kenwood KDC-X599 HU
2-Sundown X-18D4
2-SQ Q4500.1
2-SQ Q90.4
1-Massive DBX4
8-Niche 5.25 mids
8-Niche Tweeters
4-Skar 8" mid-bass
OhioGen 220a alt
OhioGen 350a alt
156.0
Posted By: mike creel
Date Posted: January 10, 2009 at 6:46 AM
Boogeyman, could I also use an osscilliscope to find out where my head unit clips? My friend told me that you can by observing where the spikes flatten out.Thanks for the help guys!
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reeldeal67
Posted By: boogeyman
Date Posted: January 10, 2009 at 8:19 AM
yes you can use a scope to determine when the hu clips....your friend is correct.
Posted By: i am an idiot
Date Posted: January 10, 2009 at 5:42 PM
This is not my scope, it is the scope visualization of Windows Media Player. A non clipped audio signal. Not a sinewave 
A moderately clipped audio signal. 
Hope this helps.
Posted By: jmelton86
Date Posted: January 12, 2009 at 10:22 PM
I like how in Windows Media Player you can see clipped signals. It's cool and stuff.
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2013 Kia Rio -90a alternator
DDX470HD GTO14001 GTO1014D (x3)
Big3 in 1/0G
1/0G to GTO14001
Posted By: mike creel
Date Posted: January 13, 2009 at 10:27 AM
This is exactly what he said the sine wave would look like on the osscilliscope. The peaks start flattening out when the signal starts clipping. ------------- reeldeal67
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