How to use a DMM to set gains?

[James Bang 5,000+ posts]

ok, i hear a lot about people say they set their gains using a DMM (digital multi meter).

I myself do not have a DMM and wondering how exactly would i set my gains if I were to get one because i would like to have my gains set correctly. I wouldn't want to harm my irreplaceable IDQ8s and 6s.

I assume i would have to know how to convert volts into watts? if so, how? *i'm new to electrical terms and formulas*

thanks in advance for any replies.

-James

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[dalucifer 10+ year member]

Best tutorial for this is on jlaudio's website..tells u exactly how to do it..

//content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[jeepintn 10+ year member]

//content.invisioncic.com/y282845/emoticons/search.gif.e79a63b2b580b39b282dff402646b704.gif

 

[Calikid 5,000+ posts]

i was about to say use the //content.invisioncic.com/y282845/emoticons/search.gif.e79a63b2b580b39b282dff402646b704.gif button but the i saw the name "james bang".

but anyways heres what^^^ was talking about http://mobile.jlaudio.com/support_pages.php?page_id=127

 

[PhatTonyDeMarco 5,000+ posts]

Read the stickies, n00b......

 

[James Bang 5,000+ posts]

ok, i jsut gone through the tutorial on the JL site, and the only part that throws me off is the voltage chart for their amps. since i dont' use 'their' amps, how would i know what voltage to look for.

and yes i've searched, then i got burnt out reading the many pages. what I mainly need to know is what voltage i need to get certain watts. yeah i'm a noob in this area. electrical terms > me.

i just found this site for it: http://www.sengpielaudio.com/calculator-ohm.htm

would this work? can i use their calculator and input my desired watts and ohms of my speaker and get the voltage i need?

 

[XaznKewLguyX 10+ year member]

//content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif lol i've always wanted to set gains correctly but i get stumped with the terms too

 

[luvinthebass 5,000+ posts]

Take an hour to familiarize yourself with the terms then set your gain and it's no sweat, it' s not that hard at all, just the calculations

 

[Rich B 5,000+ posts]

ok, i jsut gone through the tutorial on the JL site, and the only part that throws me off is the voltage chart for their amps. since i dont' use 'their' amps, how would i know what voltage to look for.
and yes i've searched, then i got burnt out reading the many pages. what I mainly need to know is what voltage i need to get certain watts. yeah i'm a noob in this area. electrical terms > me.

i just found this site for it: http://www.sengpielaudio.com/calculator-ohm.htm

would this work? can i use their calculator and input my desired watts and ohms of my speaker and get the voltage i need?

Try this voltage calculator, its far simpler-

http://www.caraudio911.com/tutorials/GainSet/voltage.htm

 

[James Bang 5,000+ posts]

Try this voltage calculator, its far simpler-
http://www.caraudio911.com/tutorials/GainSet/voltage.htm

sweet. i believe i'm set now..

time to go out and buy a DMM. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[nauc 10+ year member]

if your deck is clipping or your amp is clipping, setting to whatever V you need can still ruin your sub/s

thats why i bought this

http://www.amazon.com/Oscilloscope-Velleman-Personal-Scope-Hps10/dp/B0007ZPNH8/ref=sr_11_1/002-0343779-7693625

 

[IamDeMan 5,000+ posts]

ok, i jsut gone through the tutorial on the JL site, and the only part that throws me off is the voltage chart for their amps. since i dont' use 'their' amps, how would i know what voltage to look for.
and yes i've searched, then i got burnt out reading the many pages. what I mainly need to know is what voltage i need to get certain watts. yeah i'm a noob in this area. electrical terms > me.

i just found this site for it: http://www.sengpielaudio.com/calculator-ohm.htm

would this work? can i use their calculator and input my desired watts and ohms of my speaker and get the voltage i need?

It's easy.

Sq root of Watts X ohms = the voltage

Say your speaker load is 4ohms and you want to set your amp to feed them 100 watts

100 X 4 = 400 then the sq root of 400 = 20

20 volts is what you are loking to set that channel to using a 0db reference test tone. or -3db test tone to some peoples logic that music will never be at a 0db referencve point. Aslo if you are using a high end HU, more than likely you should be safe setting the gains with the HU at full volume.

 

[IamDeMan 5,000+ posts]

if your deck is clipping or your amp is clipping, setting to whatever V you need can still ruin your sub/s
thats why i bought this

http://www.amazon.com/Oscilloscope-Velleman-Personal-Scope-Hps10/dp/B0007ZPNH8/ref=sr_11_1/002-0343779-7693625

Interesting. By far using a O=scope is the best, but you can still get reasonbly good results with a DMM as opposed to ear tuning. Thanks for that link though. At that price using it is tempting.

 

[nauc 10+ year member]

i freakin love it, push one button to turn it on, then another to do its thing and thats it

if it ever stops workin, im buyin another one

 

[dvrmstrng 5,000+ posts]

is ever bad that setting the gains correctly for me is too much and i set the gains lower then when they are correctly set?