Gain Setting Tutorial

[progz]

Ok soo let me get this straight...

I have a..

(1) JL Audio A1800 http://www.crutchfield.com/S-J8aylaHy1Oy/App/Product/Item/Main.aspx?I=136A1800

(2) JL Audio w3 12 inch (bridged to 2 ohm) http://www.crutchfield.com/App/Product/Item/Main.aspx?g=520&i=13612W3V34&c=3&tp=111&avf=N

If Im correct the voltage should be near... 44?

 

[Casey K]

What would be a recommended volume level on a Pioneer DEH-P3900MP for setting the gain?

For that matter, what would you guys recommend I set the bass levels and such at?

 

[95BlazerLT4wd 10+ year member]

i have a kicker zx750.1, and a kicker cvx 12. what should my gain voltage at? thanks.

 

[bad03ranger 10+ year member]

im running a AP 1200 bridgd @ 4ohm so....sqrt(600*4)=48.98 (49~V) right?

 

[moneybags 10+ year member]

I have a sundown 100.4 pusing my hybrid audio L4 (4ohm) and L1pro (4 ohm),a 100.4 bridged to push my L8 (4 ohm) and 2 sundown 1500 strapped to 1 ohm (1/2 per amp)

What would my voltages be for all of them?

 

[bad03ranger 10+ year member]

I have a sundown 100.4 pusing my hybrid audio L4 (4ohm) and L1pro (4 ohm),a 100.4 bridged to push my L8 (4 ohm) and 2 sundown 1500 strapped to 1 ohm (1/2 per amp)What would my voltages be for all of them?

start an new thread in the amp section u tend not to get answeres here

 

[bearser18]

You also dont get any help in the amp section either. Atleast I cant anyways.

 

[AudioJunkie73 10+ year member]

ok I have a question. I have a Kicker 700.5 amp. I am adjusting my woofer on the mono channel. I figured everything out. ON my bass boost, should I turn that all the way down or all the way up? then adjust the gain.

 

[SocialStealth]

I have the input for both sets of speakers at half way up (hu @ 100% volume)

The infinity speakers can go up to 3/4 input until they distort, but when I turn the JL Audios input up past 1/2, the amp shuts off? (protective mode?)

I read the trouble shooting manual that came with the amp, and it said it may be because of a short in the wiring.

What is a short? And what could possibly be the problem? (if it even is a problem...shouldn't the JL audios imput be 2x higher than the infinities though?)

btw, I soldered the terminals onto the speakers (because they were slightly too big) but they're tight to the pull now. I also put bare wire into the amp itself because the spade terminals I got didnt fit in it.

Amp puts out 75 watts rms

JL's handle 80 RMS

Infinities handle 60 RMS

 

[drpeeb 10+ year member]

Using a DMM seems most likely to be pointless to me:

When audiophiles arbitrarily choose* a test tone's attenuation level, whether it be 0dB, -3dB, -6dB, etc., it's really just a guess, or an estimate ... Then they're instructed to use a DMM to take a very accurate measurement of a system that includes a major variable that was a guess.

* even though they've done their best to choose a test tone level

... which is probably the main reason amp manufacturers don't tell you to use a DMM; From my Alpine PDX-5 manual:

Set the PDX-5 input gain to the minimum position. Using a dynamic CD as a source, increase the head unit volume until the output distorts. Then, reduce the volume 1 step (or until the output is no longer distorted). Now, increase the amplifier gain until the sound from the speakers becomes distorted. Reduce the gain slightly so the sound is no longer distorted to achieve the optimum gain setting.


From my Kicker MX700.5 manual:

The input gain control is not a volume control. It matches the output of the source unit to the input level of the amplifier. Turn the source unit up to about 3/4 volume (if the source unit goes to 30, turn it to 25). Next, slowly turn (clockwise) the gain on the amplifier up until you can hear audible distortion, then turn it down a little. Adjust AMP 1, then proceed to AMP 2 and finally the Subwoofer Channel input gain control.
I dunno ... It all seems like a "Make your best guess, and hope you don't burn it up" to me. I just wanna be able to crank it and know I'm not hurting anything.

 

[badvlvo 10+ year member]

That's where an oscilloscope is useful, you can see amp clipping. You can still damage things but it's the best tool in my box for setting amps.

It's all voodoo science anyway, there is no hard rule as to how to set things up. It all depends on the individual pieces and how they work together, no 2 systems will be the same unless they use identical components in identical cars.

 

[jharijan 10+ year member]

I'm probably gonna get chewed out for asking this but I'm still a little confused at the equation. I have a 600 watt rms 2 ohm mono amp and am going to connect two 12" 4 ohm subs to equal a 2 ohm load right, what would my desired voltage be when setting with a dmm? would it be the square root of 600x4 or the square root of 600x2 since I would be wiring them to equal to 2ohms?

 

[tinmanchris217 10+ year member]

Assuming your amp really puts out the RMS wattage you say, you should have 34.6 V AC at the speaker terminals. sqrt(600*2)...

Wire your subs in parallel to get 2 ohms.

As always, go 3/4 HU volume, 60 Hz tone, and steer clear of the bass boost. Listen for distortion carefully (from outside of the car), and check to make sure nothing gets hot/smokes/smells/etc.

 

[jharijan 10+ year member]

That's what the box and mtx website says it puts out.

http://www.mtx.com/caraudio/products/amplifiers/xthunder600XD.cfm

thanks for the info...so whenever you are calculating for voltage you always multiply by the impedence that the speakers are wired to create?

 

[tinmanchris217 10+ year member]

Yep. sqrt(power*impedance) = voltage

That amp may be capable of a little more than rated if you electrical system is good. Set it at 35V and use your ears from there. You should be able to tell a difference in sound quality as the distortion ramps up.

Also, if you are using the bass remote, max it when gain setting, so you won't risk trashing anything when you "crank it up"