Setting gain *yes I read the sticky*

[Flex68 10+ year member]

That's what I would do, guy....plenty of time later for "tweaking" if you want to use a clamp-on AC meter to test and make adjustments for box-rise, and etc, ad nauseum.

Assuming your speakers are able to handle the amp at max, then 55.1V should be a nice, safe initial setting to get you bumping

 

[bruceg 10+ year member]

Gotcha. Thanks man!

 

[southpoleman69 10+ year member]

so then if you set it to the voltage how do you account for tuning the deck and subsonic filter? won't that make the voltage go up, in which case now your clipping the signal?

 

[bubbagumper6 5,000+ posts]

OP, setting your gains via the DMM and formula you used is easiest way, even if the least accurate.
To wit: You calculate for your amp's max output of 760WRMS, set your gains to make your amp output the 55.1V, and all is kosher, yes?

Not really!

This is based solely upon rated speaker impedance....but but what about box-rise?

Theoretically, say your enclosure presents an additional load of 0.85 ohms. Well, that would mean you need an additional 11.7V added to your earlier calculation of 55.1V.

BUT, since the load seen by the amp is reactive versus purely resistive, anyway....then there's temp variation, voltage drops across speaker wiring and terminal connections, and several other variables to be taken into account.

Anyone got a non-linear equations book handy.....? //content.invisioncic.com/y282845/emoticons/suicide.gif.a649d21efc0d1fd4890a6428166586c1.gif

Ah, well. Maybe you should just set it up for 55.1V without subs connected.

At least for now!

Actually yes I believe I still have my differential equations book around here somewhere....lulz

 

[bruceg 10+ year member]

I went up to 48 volts and the bass was about to phuckin deafen me...sooo I just left it there...

Edit: I may d/c the speakers and set it up to 55, but it's beating HARDD at 48 volts.

 

[Flex68 10+ year member]

Actually yes I believe I still have my differential equations book around here somewhere....lulz

Hope yours isn't as old as my college textbook: Basic Differential Equations.... Author = de Fermat, and dated 1711

lmao

 

[southpoleman69 10+ year member]

not to thread jack here but, the just is set the gains to the voltage output of the amp. so, my rubicon is rated at 1600x1, so 1600x1 sq rt = 40 volts. but thats at max output. that amp will never put out 1600 actual watts. so wouldn't this cause a clipped signal? another example, my cousin has an autotek 4000, they rate it at 4000x1 which would be 63.24 volts, but it'll never do 4000 watts, which in turn would result in clipping to the woofers. right? if not why?

 

[dooski 10+ year member]

I'm not sure if im to tired to read this thread atm or what but im getting confused lol, dont you set your gains to match your subs max rms?

 

[southpoleman69 10+ year member]

I'm not sure if im to tired to read this thread atm or what but im getting confused lol, dont you set your gains to match your subs max rms?

from what i understand, no. you take ur amps out put, times it by the desired ohm and sq root that.

 

[dooski 10+ year member]

from what i understand, no. you take ur amps out put, times it by the desired ohm and sq root that.

Yea but if you do that it just shows how much voltage your amp can put out at max. But if your sub cant handle the max output of your amp then you would still blow your sub.

For ex. if my sub can handle 500rms and is a dual 4ohm voice coil i would wire it to 2ohms and use the equation (500x2)sqrt= ~31.62v

and set the gains till i get that voltage.

Thats what i got after reading the stickies.

 

[dooski 10+ year member]

dbl post...

 

[southpoleman69 10+ year member]

Yea but if you do that it just shows how much voltage your amp can put out at max. But if your sub cant handle the max output of your amp then you would still blow your sub.
For ex. if my sub can handle 500rms and is a dual 4ohm voice coil i would wire it to 2ohms and use the equation (500x2)sqrt= ~31.62v

and set the gains till i get that voltage.

Thats what i got after reading the stickies.

hmm, so for a lvl 4, u go on rms or max. would it be 1400x1 sq rt=37.4 or 2400x1 sq rt=48.9

 

[southpoleman69 10+ year member]

or say I'm setting a 4 channel amp. my front components can do 50 rms at 4 ohms, but my rears can do 100@4, so then the gains for each channel on a 4 channel are set differently?

 

[southpoleman69 10+ year member]

Originally Posted by Jmac

Here's something I hope you can will all use to your benefits. As you may or may not have noticed, most equipment dies for one simple reason : Most people push their equipment beyond its limits. Whether its the amplifier or subwoofer or speakers, clipping is the number one cause of failure that I see. To prevent clipping, I've made this tutorial (Well, JL Audio did, but I've been doing this for years before they put it on their site).

Okay, before I post the links, there's just one problem that I have with the following guide. It says to use 75% of max volume. I don't agree with this at all because, with some head units, you can crank it up to full without distortion and with others, it may only be 60% ... To set your gains, use the MAX settings you'd NORMALLY use ... If the loudest you listen to your music at on a regular basis is 22/35 with bass @ +3 and treble @ 0 with MX on, by all means use those settings. Also remember to have the car on It should also be noted that if you want to use bass boost, set it prior to the gains and use the center frequency of the bass boost (45 Hz for most amps) as your test tone ... Please remember that if you have a subwoofer volume control, set it to full before you set the gains on the sub amp ...

Here's the formula you'll need ...

Sqrt(Power*Resistance) = Voltage

(i.e. If you bridge a 4 ohm subwoofer to your amplifier that is rated to produce 100 RMS @ 4 ohms in bridged mode, you would want Sqrt(4*100) = 20 volts)

Gain Setting tutorial ...

JL Audio: Car Stereo, Speakers, Amps, Home Theater

Test Tones ...

http://www.teamtreo.com/view.php?showme=Free_Test_Tones

Hopefully, this will all result in greater longevity of your products and cleaner bass. Some people still insist on cranking the gains after using this tutorial because it's "not as loud as it was." If you choose to do so, you may be putting your equipment at risk. If you find that you find the output is too much, feel free to turn the gains down.

from this i have gathered, take the output of your amp*resistance woofer will be wired to and sq rt it. in my case, 1600*1= 40 volts on the amp. correct or is dooski's explanation correct. I thought i had this down, now I'm all confused again

 

[Colossus281 10+ year member]

How do you set for a amp at .5ohms? My next amp will be a Lanzar opti3201d. Its rated at 3200 at .5ohm