How to Set Your Amplifier Gain to RMS Power Using Ohm's Law

In this video, Arthur an engineer from MTX, shows how to properly set the gain on your amplifier using Ohm's law. In this example he knows the RMS power of the amplifier and the impedance (Ω) of the subwoofer enclosure. He uses this information and a multimeter that measure AC current to properly set the gain control on his amplifier to the proper RMS output power.

Category:

Education

Tags:

• MTX
• MTX Audio
• amplifiers
• Ohm
• enclosure
• how to
• audio system
• system
• subwoofer
• sound
• car audio

[shaoweed]

yes i am using a mono and a 4 ch amp...and when i set the volume for the player..the loudness should be off..right? and i dont need the use the loudness function.cause if i use i can break my amps or subs.?( i mean after i set the gains at the level that i normally listen) hope you understand what i meant. TY

[MTXThunderforce]

@shaoweed Yeah you either need to leave it off all of the time or leave it on all of the time. If I were you I would leave it off and yes if you set the amps up with loudness off and then turn it on you will run the risk of damaging your speakers.

[amitkalsi1]

Can I do this using a mp3 device instead of a cd?

[MTXThunderforce]

@amitkalsi1 Yes you could download the test tone to an MP3 device and play it through your head unit to set it up if you have a USB or Apple connection on your head unit.

[cassiskoolio]

hi i have 2 jvc arsenal subs at 600 rms 4/2 ohm subs and a jl jx1000/1 amp mono block. i cant seem to set the amp correct, and the bass sounds muffled (weak). im running them at a 4 ohm load at 500 watss rms so 250 ea. amps only 2 ohm stable. Any tips how to get more power out of it or set it right?

[MTXThunderforce]

@cassiskoolio Did you follow the steps to use the multimeter to match the voltage? You should be showing 44.72 volts if it is doing 500W RMS @ 4Ω. Is it set like this? Do you have it in a sealed or vented enclosure? What do you have the low pass filter set at?

[snipwow]

I Think "Meade916" won't be happy after this, cause we now know how to set our gain correctely without buying the expensive "SMD DISTORTION DETECTOR DD-1"

Thumb-UP :D

[Yuneitee]

@goatskindreams someone needs to introduce you to DD-eeznuts! MTX ruuules!! ......snoogins

[WirelessVault]

i got a piece of paper an quickly calculated the required voltage rating and after I tuned my amp the sound had an amazing 150% improvement over what my buddy ghetto tuned. I have an Alpine CDE-126BT connected to a Kicker DX200.4 hooked up to a Kicker KS650.2 component speakers. I used the 1khz test tone and used 14.14v, just in case someone had the same equipment. I actually have to go back because the actual RMS rating for my amp is tested @ 244watts, so the actual V = 15.62.THANKS

[shaoweed]

thx MTXThunderforce

[mtxjt08]

@shaoweed Are you using a 4 channel and a mono block amplifier? For the 4 channel you would want to use the 1kHz test tone and you would want to measure for the RMS power of a single channel. You would need to set the front and rear gains independently. For the mono block you would do it just like the video shows with the 50Hz test tone. I would set the volume at the level you normally listen to the radio at when setting it up.

[shaoweed]

hi.i have a question.i have a player that has 1 pair of rca's.and i wanna use 2 amplifiers(the rca from the output of the first amp to the input of the second

so how should i set up the gains for the 2 amps.after i connect the 2 together? is there any problem then i would need to know about?

and one more thing..when i setup the gains..the volume of the player how up should it be...it has 60 max .it starts clipping at 50..or 45 i cant remember..but if i enable loudness it starts clipping at 30