Gain Setting Tutorial

[groggy23 10+ year member]

^Actually, I'm not sure if this is the case for most amps but for my Arc 4050xxk, I bridged both for 2-channel output to power my components. So my 1 & 2 (front) channel became the left and the 3 & 4 (rear) became the right. The rear gain became defeatable and the front gain controlled BOTH bridged channels (front AND rear). Hope that helps.

RIP, I'm assuming thats perfectly fine. I also have a 400w rms capable sub but only feeding it 180w rms since thats what my amp can push. So I just set the gain at 180w rms.

Back to my previous post above about the 3 ohm coils, anyone have any insight?

 

[zyklonb 10+ year member]

ok i think i have a general idea of how to do it. i got my dmm and use ac input or something like that. and then unhook the sub and put the things into the amp. but are these the right measurements?

voltage=34.6 (600rmsx2,sqrt)

my box is tuned to 35 hz so i dont know what test tone to use. the links dont work, so anyone know what tones to use, like -3db 50hz or no? and a link would help too =]

i turn the volume up about 60%-70% and turn the gain till it reaches 34.6 correct

and lastly does setting the bass boost have any effect on the output? should i set it to how high i like it before i set the gain or after?

 

[luvinthebass 5,000+ posts]

Perhaps this is a dumb question. I will ask anyway..If setting the amp for lets say..150 watts for a 12" sub with a 150 watt rms 300 watt max. Does that mean that now the amp will never produce above the 150 Watt mark even though the sub is able to handle more.

This confuses me!

So..amp is capable of 250 RMS and 500 Max. I only want 150 rms 300 max.

I hope I am not too confusing!

it still could produce over 150 watts if ya crank the head unit up more then where you set your gain, hell, you could have a 1000 watt amp that does 1000 rms and set it for say a sub that handles 150 rms and despite setting your gain for 150 watts and keepin your volume control and never raising it past where you set your gain at that sub will be fine. does it make more sense to ya now?

ok i think i have a general idea of how to do it. i got my dmm and use ac input or something like that. and then unhook the sub and put the things into the amp. but are these the right measurements?voltage=34.6 (600rmsx2,sqrt)

my box is tuned to 35 hz so i dont know what test tone to use. the links dont work, so anyone know what tones to use, like -3db 50hz or no? and a link would help too =]

i turn the volume up about 60%-70% and turn the gain till it reaches 34.6 correct

and lastly does setting the bass boost have any effect on the output? should i set it to how high i like it before i set the gain or after?

to hell with the bass boost, only if ya wnat to hear distorted bass, ur choice

 

[zyklonb 10+ year member]

haha but i like the extra bass the boost puts out, is that bad or no?

 

[twisztdauthorit 10+ year member]

i got some weird shit going on...

im running a hifonics2006d (2000rms at 1ohm)

AQHD315 sub

playing a song...

the voltage hit up to 52 volts

Test tone

the highest was 21 volts

Im running 4 awg power wire(undersized) with a 3 farad cap...

Im going to upgrade power wire within a week....

should i be seeing around 44.5 volts on a test tone frequency?

 

[tcguy85 10+ year member]

i set my gains using a 0 db 50hz test tone to my desired 39 volts, i then hooked the sub back up and played the 0 db 50hz test tone and it sounds clipped at the volume i set the gains at, it sounds fine a couple notches down. so i turned the gain down and now i get 34 volts at the dmm with the test tone.

whats the deal? i know the 780 watts is at 14.4 and the voltage in my car was just over 13 when i played it and it sounded clipped, i guess it was because the voltage wasn't 14.4 right? would setting it by ear with a -3 db tone be ok?

 

[thch 10+ year member]

clipping is not the only compressive effect. if the woofer overexurts, it will sound similar even though the amp is not a limiting factor.

likewise, certain HU enchancements may push the HU's output into clipping, meaning no gain setting on the amp will be ideal, though the sound may be perceptually worse at some volume settings.

 

[tcguy85 10+ year member]

ok the reason i'm worried is because the dustcap on my sub gets pretty warm. i've never smelled any burning voicecoil or anything but the dust cap gets quite warm.

is it common for a subs dustcap to get warm even if it's getting clean power? i just don't wanna burn it up.

 

[luvinthebass 5,000+ posts]

ok the reason i'm worried is because the dustcap on my sub gets pretty warm. i've never smelled any burning voicecoil or anything but the dust cap gets quite warm.
is it common for a subs dustcap to get warm even if it's getting clean power? i just don't wanna burn it up.

of course it's gonna get warm the sub is movin in and out so it's gonna create some kind of heat, if ya smell a burning smell that's when you turn it down, that's a huge sign that if you keep that smell building up your sub is gonna die

 

[tcguy85 10+ year member]

of course it's gonna get warm the sub is movin in and out so it's gonna create some kind of heat, if ya smell a burning smell that's when you turn it down, that's a huge sign that if you keep that smell building up your sub is gonna die

everyone else agree that it's normal for the dustcap to get quite warm?

 

[Tiger Bass 5,000+ posts]

Is there another link for the test tones?

And I've never set gains myself so I may have a couple really, really stupid questions later, but I'll try and figure this out myself first.

 

[tcguy85 10+ year member]

Yeah, it's normal for the dustcap to get warm. Most speakers are less than 1% efficient, which means 1% of the power is used to move the speaker and 99% of the power is dissipated as heat.

ok, thanks. i can wang away without worrying about burning stuff up now. yay! i have never smelled any burning at all so i guess i'm ok.

 

[Tiger Bass 5,000+ posts]

If my amp's rms rating is lower than my sub's rms, do I really have to worry about setting the gains on my amp? Assuming the level I have it set at does not produce clipping, over-excursion, distortion, etc.

 

[Rochambeau 10+ year member]

If my amp's rms rating is lower than my sub's rms, do I really have to worry about setting the gains on my amp? Assuming the level I have it set at does not produce clipping, over-excursion, distortion, etc.

Well, if you have it set too low, your losing out on some free power.

If you have it set too high (and just can't HEAR the distortion which is hard to hear on subs) you could risk damaging your sub at some point.

Me, I am a big fan of the DMM method. Many, many peeps MUCH prefer the "set it by ear" method because they squeeze out more power that way. I prefer to know that my 'spensive *** subs will survive even the worst pounding my system can give them.

 

[OOBE 10+ year member]

Sorry for the necromancing but I have a doubt. Seems like I understood this stuff years ago and I've been disconnected from this game and now I don't grasp it fully.

1)I have two Coustic CF1244 dual coils rated at 400W RMS. That's per speaker, or per voice coil?

2)Using a Kicker ZR600 which is rated at 150x2 (4 ohm stereo), 300x2 (2 ohm stereo), 600x1 (2.66/3 ohm mono). Now, if I hook up those two CF1244s, which ohm load would it present to the amp?

3)Should I hook each one on a separate channel or both on bridged. I'm just trying to figure out which would be the optimal wiring, so I can adjust the gain. This stuff made sense to me long time ago, and now it's like I never even worked on it. It's like I got dumber over the years. //content.invisioncic.com/y282845/emoticons/blackeye.gif.66a1670f5aaf7f406e783a63e3387dc5.gif