Question about tuning

[Opiate117 10+ year member]

I'm going through this step by step on how to tune your amp using a DMM and I got to this point and have a question

"1) Open your owner’s manuals and find the RMS power output of your head unit’s internal amplifier and the rated RMS input for your speakers. Write down both and use the lower of the two in the next step.

2) Calculate the desired voltage using the formula: Voltage = SQRT(Power*Resistance)"

When it says "sqrt(power*resistance)" does it mean I need to plug in 14 watts for power (HU RMS) and 4 for resistance (Impedance of the speaker) and then find the square root?

Click to read more...

 

[BlactimusCrime 10+ year member]

you only take those steps if youre using an amplifier, not HU power

 

[mast240 10+ year member]

are you using pre outs from your HU to your amp... cuz then you dont need to factor in the wattage off the HU.... just the voltage of the pre out

 

[BlactimusCrime 10+ year member]

are you using pre outs from your HU to your amp... cuz then you dont need to factor in the wattage off the HU.... just the voltage of the pre out

wrong. voltage preout still means nothing. you use the output power of the amp, or speaker

for instance, if youre trying to set gains for 500rms at 4 ohms it would be: V=SQRT(500x4)=44.7volts

and that voltage needs to be measured across the terminals of the amp or sub

 

[sacsking916 5,000+ posts]

theres a gain on the HU??? //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif no wonder i been doin it wrong

 

[whitedragon551 5,000+ posts]

you only take those steps if youre using an amplifier, not HU power

wrong. voltage preout still means nothing. you use the output power of the amp, or speakerfor instance, if youre trying to set gains for 500rms at 4 ohms it would be: V=SQRT(500x4)=44.7volts

and that voltage needs to be measured across the terminals of the amp or sub

This.

 

[Opiate117 10+ year member]

Sorry, I don't have an amp for my speakers lol, which makes the thread seem f'in retarded but I meant the amp for my subs. I was just thrown off because part of the subwoofer tuning steps took a step from that (finding your volume limit) but I realized I didn't need that, I pretty much know my volume limit. But thank you guys, I was mainly concerned I didn't have the resistance part right, but I got it figured out now, thanks.