Gain Setting Tutorial

[TwiZtDBIA 10+ year member]

alright... i thought that you would have unhook em all... just wasn't sure enough... thx for the help

 

[dkguitarist 5,000+ posts]

ok i have another question about setting the gain on my kx1200.1 i'm supposed to set my gain around 38 volts (sqrt(1478*1=38.xx) and on my manual it says input gain control for low level input is 170mV-5v. so i'm confused on where to set it..??? please someone help?

 

[ANeonRider 10+ year member]

Read the tutorial again, becuase you missed some things.

You are supposed to use a DMM, and with a test tone, you set the gain so that the output is 38V (use the DMM to measure this).

 

[dkguitarist 5,000+ posts]

oh right..stupid me //content.invisioncic.com/y282845/emoticons/smash.gif.499e08a4a35ffaf54f4c8194fb8fe8ed.gif need to pay attention more. unfortunately i don't have one..where can i get one and how much do they typically run?

 

[bitwise 10+ year member]

I have a question about setting gains: I was playing a 50Hz test tone to set my monoblock's gain. I noticed my components were playing this frequency even though they are crossed over @ 80Hz with the head unit's high pass filter. I dont need to use the amp's xover too, do I?

Also,

My amp does 175x2 RMS, but my components are 160RMS each. Should I use 160 or 175 when I am measuring the output of one channel?

Thanks

 

[bitwise 10+ year member]

Do you have all speakers running off the head unit, separate amps, or a combination ?

The front components are running off a 175x2 RMS amp. The rear subs are running off the mono block, 750x1 @ 2ohm. The only speakers that are run off the deck are the rears. They were completely faded out when I was setting the gain on the mono amp though.

 

[bitwise 10+ year member]

According to the manufaturer, the speakers are 160RMS, They are the CDT EF-61CFi/25 (560 xover + 1" silk tweet). I will have to readjust to 160 though, that will probably make them sound a little cleaner at higher volumes. They arent as crisp, clear, loud as I was hoping they'd be.

 

[IgnoreMe 5,000+ posts]

anyone got the red dmm from home depot? i recently dropped my old one and it broke...so i went to HD to buy a new one and now my friend wants me to set his gain and i cant get the **** thing to read anything off his amps yet itll read other electrical devices. whats up with that?

 

[ANeonRider 10+ year member]

anyone got the red dmm from home depot? i recently dropped my old one and it broke...so i went to HD to buy a new one and now my friend wants me to set his gain and i cant get the **** thing to read anything off his amps yet itll read other electrical devices. whats up with that?

If it works on other things, but not on the amp, either you are "probing" wrong, or the amp is pooched. Are you sure you are set at AC volts?

 

[IgnoreMe 5,000+ posts]

i can take a picture of it and post it so you can see all the settings on it if you want? is that cool?

edit: this is the one i have

 

[IgnoreMe 5,000+ posts]

anyone use this dmm before?

 

[ANeonRider 10+ year member]

Set it to the V~ and the 200V range.

 

[IgnoreMe 5,000+ posts]

Set it to the V~ and the 200V range.

thats what i had it set to, but it wasnt pickin up anything.

 

[IgnoreMe 5,000+ posts]

Does it read from other AC sources ?

yea. i test it on my wall sockets in the house and i get 120 volts. so i know its working right.

 

[ANeonRider 10+ year member]

Then I suspect the amp pooched.

 

[IgnoreMe 5,000+ posts]

Then I suspect the amp pooched.

how can that be though? its not like there is no signal cause when i hook them up and play the test tone... his **** neighbors come out pissed so i know the amps still working. there is a signal it just wont pick it up.

 

[ANeonRider 10+ year member]

Weird.

 

[IgnoreMe 5,000+ posts]

Weird.

i know. there is no other explanation other than i must be ****in up somewhere. i mean only thing that can be wrong is that i THINK i am doing it right and aren't. oh well when i see him again im gonna give it another go, and then probably another. thanks anyways guys.

 

[ANeonRider 10+ year member]

You have the probe in the V plug right?

 

[IgnoreMe 5,000+ posts]

not sure what 3 phase or 1 phase plugs are jmac

aneonrider: yea when i get 120 volts from the wall i have the black (ground in the com plug like the manual says) and then the red plug in the V part.