General Question About Watts to Subs

[Workin for DBs 10+ year member]

Is it true that your gain does not control the amount of watts to your sub? In other words if you have a 1000 watt rms amp hooked up to a 500 rms sub you will blow that thing fast even if your gain is all the way down? I'm very confused and had never heard of this until a few days ago from a car audio shop. I always thought as long as your subs are not distorting you were fine.

Thanks

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[j&b4ever 10+ year member]

no its not true if you set your gains you hould be fine

 

[>>SQL<< 10+ year member]

Another shop giving BS info - not shocking at all.

 

[akheathen Premium Member]

no, it's not true. you can use a dmm to set the output voltage, and your wattage will stay in range. believe it or not, most stand the chance to blow a sub by not giving it enough power, since it takes a little more experience to pick up on when the amp is clipping. obviously, you can overpower the sub if you turn the gain up too far, or if you clip it on any amp.

 

[bgowdy 5,000+ posts]

ok. im curious i know theres no real way of telling if one is clipping. What is a dmm? so i can set mine for futer reference

 

[disturbed471985 5,000+ posts]

who said u cant tell if ur clipping??? Never listen to him again

 

[bgowdy 5,000+ posts]

oh. well maybe you can. from my knowledge(not much) you cant i didnt know you could. i mean i know distortion is a sign but my hdc318 (1000rms) never sound bad on my sundown 2000d or smelled. and i take it back some one did say you cant tell its clipping

 

[disturbed471985 5,000+ posts]

like i said never listen to that person again cause u can most defiantly tell if ur clipping a speaker.

 

[bgowdy 5,000+ posts]

ok. so what is dmm? so i can set my gain correctly

 

[dipitydoo 10+ year member]

gain control isn't made to control the wattage necessarily, its for you to match the source output voltage with the amp's input. that being said, it is possible to 'control' the wattage out of the amp, depending on the amp and the source output voltage. for example, if an amp requires 5v input at its minimum setting for full power, and the head unit produces a maximum of 2v, then you will not get full power out of the amp with the gains all the way down.

 

[disturbed471985 5,000+ posts]

Digital Multimeters, DMM, Multimeter

 

[Workin for DBs 10+ year member]

Ok I'm still a little confused...so the gain doesn't directly affects the watts? I didn't fully understand dipitydoo's post. The guy at the shop who gave me the info said an amp too powerful for a sub would burn out the voice coils. It sounds like i should disregard this?

 

[TheUnderFighter 10+ year member]

believe it or not, most stand the chance to blow a sub by not giving it enough power, since it takes a little more experience to pick up on when the amp is clipping.

No, you can not blow a sub by giving it "too little" power.

Yes, you can detect clipping, it's how we avoid frying the sub.

And while giving a sub more than its rated power won't always ruin the sub, It's not particularly recommended. Specifically in a situation as extreme as yours, where you are giving it twice as much power. We could be able to help you in wiring your subwoofers to a different impedance so you can draw a more ideal amount of power from the amp. In order to do that, we'll need your sub make and model, and amp make and model.

 

[LosIsATool 5,000+ posts]

I think I see your confusion.

Say you have 2v preouts like me. Your full power will be when the HU sends out 2v to the preouts normally at the decks 3/4 volume.

If you set your gain to match the 2v preouts(normally inbetween half and 3/4 gain, depends on amp. Some take 8v-.2v some take 4v-.4v) the amp will be at full power when the HU is at 3/4 volume.

If you set your gain below that full power mark it will not make its full power when the HU is at 3/4 volume

 

[akheathen Premium Member]

lol, i didn'r really mean by giving it too little clean power, but underpowering it can cause the user to clip the amp, which will cause heat, and i have personally witnessed this as the case 80-90% of the time with greens.... you can use ohms law and calculate at what ac voltage output that you reach your desired wattage output, i use a rule of thumb,because of impeedance rise, that adding 15% wattage, based on that voltage should get you at your desired output to the sub. set your digital multi-meter to ac and measure what it is feeding to the sub(s) with them hooked up to set the gains on a tone, with the head unit set at mid/flat/zero boost playing a tone. some like 40, some 50, some 60, amnd everywhere in between, i like to set it on the ow side of the hz, but that;s becausr that is what i like to play with, but if you are looking to set it to play music, i would suggest 45-50hz, and that is my opinion.