easily setting gains using a DMM

[brafferty]

ive been watching youtube tutorials, and no one seems to really break it down and help on how to use it, so im thinking you guys could make it easy. i also keep only finding videos of people doing sub amps and im looking to do both my sub and speaker amp. even a link to videos you guys know break it down nicely i might have missed

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[brafferty]

so ive been looking into this still, but something came to mind, i dont know exactly what my sub amps output wattage is. Every site says something different, between 1400-1800 so what should i do here?

 

[blazian87 10+ year member]

so ive been looking into this still, but something came to mind, i dont know exactly what my sub amps output wattage is. Every site says something different, between 1400-1800 so what should i do here?

It would be safe to say that it does 1500 @ 2 ohms. Some people claim that it does 1800w but there's no bench test to prove it. Even if it did a few hundred watts more than 1500, you wouldn't really hear that much of a difference anyway. You usually need to double your power to hear a 3 db increase if all things equal. The DMM method works well if you know what your rms target is but it doesn't show you where the clipping point is. The real way of getting the most juice from your amp is either a oscilloscope or a SMD DD-1. If you don't wanna spend the money, then just set it at 1500w and call it day. It's not that hard. Just look at the tutorial videos again. Just gotta do a little math then have your dmm read the output as you turn the gain up to your targeted RMS.

Also, for your speakers.. since I'm assuming you are running your speakers passive and using a 4 channel amp for your front and back speakers, then you do the same method as the sub amp. Just look up what your speakers are rated for. Most are usually around 100w. If they are being ran active, then you need to do them by ear.

 

[Jeffdachef 5,000+ posts]

ive been watching youtube tutorials, and no one seems to really break it down and help on how to use it, so im thinking you guys could make it easy. i also keep only finding videos of people doing sub amps and im looking to do both my sub and speaker amp. even a link to videos you guys know break it down nicely i might have missed

practically the same thing but with a 1khz test tone. unplug the negative and stick the dmm prongs in the pos and negative terminals of each channel, set it to AC volts and do your proper voltage calculations and raise to gain to match that. Check the reading for each amp etc..

 

[blazian87 10+ year member]

Here's a good video on breaking down the steps.

 

[maylar 10+ year member]

Main speakers should be set by ear. There are too many variables associated with the install to make power judgments. And the power ratings on speakers aren't standardized, each manufacturer has their own rating methods. We don't know if it's a thermal limit, a mechanical limit, at one frequency or across the whole range.

 

[brafferty]

thanks guys! so ill do my subs at 1500 and see how that goes, as for my door speakers, i have 2 gains, and each has a different rms, my fronts have a 150 and my rears have a 110, so id set this accordingly as if they were 2 separate amps correct? Just trying to get the best performance possible and if my alpines blew from clipping, avoid that this time around with the sundowns