Setting amp gain to match head unit voltage.

[Sync45]

Hey guys I had a question about setting my amp gain to match my head unit voltage. I have 2 kicker 12's that are 400 watts rms each at 2 ohms, and a jl audio jx1000.1 that is 1000 watts rms at 2 ohms. So to get target voltage I did 1000*2=2000. Then the square root of 2000 is 44.7 volts.

Now since my subs are rated lower then my amp should I use those numbers instead? So 800*2=1600. Then the square root of 1600 is 40? Also what if the voltage even with my gain all the way up won't reach that?

I have all the settings on the head unit zeroed out, and the lpf down all the way. Also bass boost all the way down. Head unit turned up 3/4 and playing a 50hz 0db test tone. I have true rms dmm, so it should be an accurate reading correct?

I do notice that I can use the bass boost to reach the correct numbers, but I didn't know if that was ideal or if it should be done with just gain.

Thanks for your help.

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[Jeffdachef 5,000+ posts]

3/4 of the way up on the head unit is not enough. try 90% instead. Sub level needs to be raised on the head unit. Bass boost and any kind of bass EQ should be off. Low pass should be 50 to 80hz around there.

On the amp you only use gain, you do not use bass boost at all.

Just pay attention and actually monitor your equipment doing 10-20 minute test sessions keeping an eye on how hot the amp or sub gets. if its too hot, you need to lower it. If its ice cold, you can go up slightly. Room temperature, you are good to go.

 

[Sync45]

Ok, I will try doing that with the volume at 90%. As far as turning the Subwoofer up on the head unit, I don't have a Subwoofer control on it since it's a stock head unit. It has bass, mid, and trebel and that's it. I have all of those set to 0 right now and it actually sounds really good but I have a bandpass box too, and know that it's hard to hear your subs screaming at you in a bandpass box. And I just want to make sure I'm not hurting my subs. What about bass Knob? Half up or off when testing voltage?

 

[Knxwledge]

3/4 of the way up on the head unit is not enough. try 90% instead. Sub level needs to be raised on the head unit. Bass boost and any kind of bass EQ should be off. Low pass should be 50 to 80hz around there.
On the amp you only use gain, you do not use bass boost at all.

Just pay attention and actually monitor your equipment doing 10-20 minute test sessions keeping an eye on how hot the amp or sub gets. if its too hot, you need to lower it. If its ice cold, you can go up slightly. Room temperature, you are good to go.

Can I use an infrared thermometer gun to measure sub temperature? Just point it on the cone?

I’ve always set it using a multi meter but I want to see how much more I can push it.

 

[Jeffdachef 5,000+ posts]

if its the extended bass/gain knob, it should be all the way up when testing voltage.

 

[Jeffdachef 5,000+ posts]

Can I use an infrared thermometer gun to measure sub temperature? Just point it on the cone?
I’ve always set it using a multi meter but I want to see how much more I can push it.

you can just use your hands man. Dont need to get fancy with this. You know the difference between cold, room temperature, warm and hot.

Also your music choice affects the pre-out voltage as well because music all has different bass recording levels.

 

[Sync45]

if its the extended bass/gain knob, it should be all the way up when testing voltage.

Ok. Yes it's the extended bass knob. I'll do those things that you mentioned and see how that goes. That should get me to where I need to be voltage wise. Thanks for your help..

 

[Sync45]

I was just using a 55hz 0 db test tone download that way I got a steady voltage. Does the way that it's played affect voltage. Like using a cd vs download on my phone through Bluetooth or is at all the same?

 

[Knxwledge]

you can just use your hands man. Dont need to get fancy with this. You know the difference between cold, room temperature, warm and hot.
Also your music choice affects the pre-out voltage as well because music all has different bass recording levels.

Alright man, thanks.

So a little clipping is ok? Because if I set my current gain higher then it will keep clipping for sure. But I feel like the sub can handle a lot more. Using 10” icon on Soundqubed 1200 @ 1ohm

 

[Jeffdachef 5,000+ posts]

Alright man, thanks.
So a little clipping is ok? Because if I set my current gain higher then it will keep clipping for sure. But I feel like the sub can handle a lot more. Using 10” icon on Soundqubed 1200 @ 1ohm

soft clip is fine, hard clip is bad. You'll know right away what sounds like a hard clip.