Gain Setting Tutorial

[Meh! 10+ year member]

Ok, sorry for the dumb newb question and i read this but i may of overlooked it or it was called something different..I need to adjust my gain but my amp has a Gain knob and a Level knob, what do i set the level knob to when I adjust the gain? I understand the rest of the tutorial though and it is very well put together.

I have been lurking around here and it looks like a sweet place..I am getting very interested in this hobby..

 

[Warren G 10+ year member]

Question, I have some 6ohm and 4 ohm speakers. If I used a 75x4 amp, should I use this calculation sqrt(75*6) or should it be sqrt(56.25*6) for the 6ohm speakers? Also, if I was to use both 6ohm and 4ohm speakers, say 6ohms front and 4ohms rear, do I need to set the gains evenly per channel or should they be set accordingly to the impedance of the speakers?

 

[joeboxer5876 10+ year member]

i have a question about setting the gain when the amp is overrated. i have the brutus and if i try to set the gain and i set it for 1500 watts, will it cause the amp to clip. should i set my amp for around 1300 to make sure it wont clip

 

[Harrison486 10+ year member]

Ok... heres my take on it (I may be wrong so wait for someone like Jmac to respond or something)

Anyway, to get the 1500 watts that the brutus supposedly does, you would have to get a reading of about 38.7 volts from a multimeter.

Now lets say your highest normal listening volume is 30.

Set your headunit to 30, put on all your normal settings. Put in the test tone CD and mesure the voltage. If you can adjust to voltage to around 38.7, then you will be fine, granted that you dont go over a volume of 30 or mess with your settings too much. However, if you can't get a reading anywhere near 38.7, then you know the Brutus is overated...

I may be an idiot, and I am sorry if this whole post was pointless...

 

[joeboxer5876 10+ year member]

right. i understand all of the gain setting. i have done that with my voltmeter. im just not sure if im going to be clipping. i just want to know if setting the amp for 1500 watts, is going to clip since it probably can put out the full 1500 watts. if its putting out the volts that the voltmeter reads, does that mean it is putting out that exact amount of power weather it is clean or unclean?

 

[mastadulog 10+ year member]

i just did this this morning and the voltage i got from my formula was 48.1. i had the hu level flattened out except i had the fade on full rear because i couldnt stand the buzzing noise. am i supposed to put the leads the same way my sub is wiring. for instance, my subs are wired so that one speaker wire is connected to - from one channel and + from the other channel so its in bridged mode. am i supposed to put the leads the same way? because i was getting some crazy readings around the 80 range. if i put the leads in on just channel i would get readings in the 40s

 

[mastadulog 10+ year member]

**** i keep getting reads around 80 volts using the bridged leads. if i do seperate channels i get readings around 35 volts. should i double the number i got from the formula since im bridging my amp?

 

[kramonut 10+ year member]

Just followed this tutorial tonight & it worked pretty well for me, went real easy.

Had a couple questions though. Does an adjustable line-out converter have an effect on the gain setting?

For instance right now I'm running a 4-channel amp (Clarion APA450) off the F&R outputs of my H/U (Pioneer DEH4600MP) for 4 speakers.

When I add a sub & subwoofer amp in a couple months I will be moving the rear RCA outputs to a loc seen here: LOC & using the rear off the headunit for the sub.

Will this affect my gain setting at all? Do I need to fool w/ the LOC adjustments?

Thx!

 

[joeboxer5876 10+ year member]

i dont think anyone understood my question. i dont blame anyone for that cause it may have been hard to follow. but to restate it... i have the brutus 1500 watt amp. i want to max it out and this amp does 1300 max. when setting the gain sould i do the math part of the equation using 1500 or 1300 watts?

thanks

 

[joeboxer5876 10+ year member]

thanks. jmac... i'll probably just set it for 1300, if i crave a tiny bit more ill set it for 1500. when you set an amp with a voltmeter assuming you do everything correct, it is giving you the exact wattage you set it to right? ex. i set my amp to 60 watts for my comps, even though its a little over rated, its still putting out 60 watts since its 110x2. right?

 

[mastadulog 10+ year member]

Your gains are full counter-clockwise, right ? Bass boost is off ?
What are the specs on your amplifier ?

i turned bass boost all the way down, and my gains are full counterclockwise. i set the hu to all neutral levels and turned off the lpf. at normal listening levels, i can get the voltage around the 40 range but when i crank it up to halfway it jumps up to 80.

my amp puts out 560 @ 4 ohms bridged.

 

[Harrison486 10+ year member]

Is This multimeter going to work for what I need?

Also, am I measuring in AC or DC?

 

[TooLowTooGo 10+ year member]

dc... ac is in home

 

[Harrison486 10+ year member]

So will that multimeter be fine or no?

 

[Harrison486 10+ year member]

Im asking because it says "• AC voltage (two ranges): 200V/500V"

will it measure in the range i need?