Setting Gain Perfectly

[wyatt315 10+ year member]

So today i picked up a multi meter but im not quite sure how you use it to set the gain. Looking for some help, Thank you.

Click to read more...

 

[x1le 10+ year member]

SEARCH!!!!!

but to sum it up

take the max RMS you want to run and multiply it by the ohms it will be running at (ie 1200 watts x 2 ohms) Then get the square root of that product.

On your amp, turn off hp, lp, bb, and turn the gain all the way down and make sure your subs are not connected. Turn your head unit volume the absolute loudest you will ever listen to it at.

Put your multimeter on the + and - speaker leads on the amp and make sure your meter is set to AC. Put on a test tone (most use 50hz) and slowly increase the gain until it as at or very close to the square root you got in the first part. Then set your filters and you're good to go.

 

[AlterEgo99 5,000+ posts]

Search...I like it! //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

Yes, concur with x1le, that is what I do.

It is quite important that you should invest in a CD that contains test tones...I have the 5 CD Autosound 2000 set and use them whenever I perform these type of tests. I use the actual CD in the CD player of my Alpine CDA-9887 and have also downloaded them in raw format to my iPod so I can test that source as well.

 

[wyatt315 10+ year member]

any where i can download test tones at?

 

[LGK 10+ year member]

edit woot.

 

[nineball 10+ year member]

keep in mind this method only works if your amp has a regulated power source. the cadence txa line, for example, does not and cannot be set with a dmm. i personally set everything by ear anyways.

 

[DEdwards 10+ year member]

reading is your friend.....

http://www.installer.com/tech/gains.html

 

[TRaGiK 10+ year member]

any where i can download test tones at?

Yes.

http://realmofexcursion.com/

Right click and save as.

 

[AlterEgo99 5,000+ posts]

keep in mind this method only works if your amp has a regulated power source. the cadence txa line, for example, does not and cannot be set with a dmm. i personally set everything by ear anyways.

Dittos but I also like to make sure I don't exceed the amp ratings so I use this test procedure as a safety.

 

[gu_norcal14]

whats a good mutimeter to buy can i just pick up a craftsman at sears?

 

[dur3x 10+ year member]

keep in mind this method only works if your amp has a regulated power source. the cadence txa line, for example, does not and cannot be set with a dmm. i personally set everything by ear anyways.

so if your amp has a unregulated power source.. can i use oscilloscope??

 

[x1le 10+ year member]

whats a good mutimeter to buy can i just pick up a craftsman at sears?

That's what I use. Simple $20 meter gets the job done. I know some who also use the $2 on-sale multimeter from harbor freight with good results //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[audiolife 5,000+ posts]

go by ear as you go pushing it by readings of a dmm you would need an oscope to make sure you are not clipping...over the last 3 years the only peeps i know who blew speakers (not in spl competition) are people who set via a dmm on a test tone only. Better off setting it by ear on matterial you know and listen carefully. One of my friends fried 3 pr of tweeters going active adjusting gains via a DMM only and did this in a period of 2 days LOL

 

[n2audio 5,000+ posts]

keep in mind this method only works if your amp has a regulated power source. the cadence txa line, for example, does not and cannot be set with a dmm. i personally set everything by ear anyways.

All amps are regulated, some just tighter than others.

I don't see why you can't set it with a DMM. Just use a more conservative power number assuming the amp output will fade when/if the voltage fades.

 

[audiolife 5,000+ posts]

All amps are regulated, some just tighter than others.I don't see why you can't set it with a DMM. Just use a more conservative power number assuming the amp output will fade when/if the voltage fades.

conservative would work but most guys try to set it at spec @14.4v or a little over lol