Gain Setting on amp

[BlkonBlkFG 10+ year member]

I understand the way to figure out the voltage reading for setting the gain on an amp. I understand the concept, but do i use the 12v ratings or the 14.4 rating on the amp?? Cause I know my amp for the internals is rated at 12v....should i use the 14.4v rating for everything? However I've read different posts that say to use a 0db (here) test tone and a 1khz test tone (jl website). My question is which tone do i use? My other question is....does this have anything to do with the crossover setting? Or do you just adjust the crossover setting after you get done setting the gain???

TIA

Josh

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[AJ²06 5,000+ posts]

Bumnp for someone who knows all their ****... and what do u mean the amp is 12v? If its a car it will run at [hopefully] 14.4v

 

[helotaxi 5,000+ posts]

A test tone needs both a frequency (1kHz) and a recording level (0dB). Without knowing both specs you don't know what you are setting your amp to.

Personally I would use the lower power rating and a -3db tone somewhere in the middle of the frequency range being played by the amp I'm setting.

 

[BlkonBlkFG 10+ year member]

By using the lower power rating, that will just make it safer on the amp right? Also, how do I know what freq is playing in the music I listen to? What tone are all of you guys using to test your component amp? Also, like I asked above...I know this is where I will find my max (safe) setting....but then at what point will i set my crossover at? ....

 

[GrnEydDvl 10+ year member]

Yes, using the lower rating will prevent your amp from generating more watts than that rating, unless you somehow play some source materal that is recorded at a higher level than your test tone - not likely unless you are using a -6dB or louder tone and even then it doesnt seem to happen often and only for short periods of time in the recording.

This is assuming you don't boost any frequencies with an EQ after setting the gain.

1Khz is the accepted frequency for setting the gains on your component amp. Nothing special about it, it just happens to be near the middle of the range.

You can set the crossover after you establish a gain setting.

 

[BlkonBlkFG 10+ year member]

So it would be best to use a 0db tone with a 1khz frequency? Just put that on random with my speakers unhooked and then set the amp to the voltage i calculated? On the alpine HU I dont believe there is a way to turn off the "bass center frequency" and "treble center frequency"...so i guess i just leave those on when i set the voltage?

Some people say to turn everything off and flat on the HU when setting the adjustment....others say to set it to how your going to listen to it, and set it then. Which is the correct answer?

 

[BlkonBlkFG 10+ year member]

bump to the top

 

[BlkonBlkFG 10+ year member]

OK, ive got all the voltages down...I burned my test CD (-3db tones).....my final questions I need answered before I got and set everything are...

On the alpine HU I dont believe there is a way to turn off the "bass center frequency" and "treble center frequency" (basically boosts certain frequencies)...so i guess i just leave those on when i set the voltage?

Some people say to turn everything off and flat on the HU when setting the adjustment....others say to set it to how your going to listen to it, and set it then. Which is the correct answer? JL Audio says to turn everything off (flat)

 

[thch 10+ year member]

there are a few ways to do things. the DMM method's major failing is the inability to handle filtering. In the end, i guess it depends on desired use.

if you turn off all filtering, then add effects, the hope is that you are aware of the consequences. eg, you know that a +18dB boost will cause clipping. as such, less agressive filtering could be done, like lowering some bands.

if you do have a +18dB boost, and set gains @ that boost freuqency, you will end up with no clipping, but at the same time quiet sound.

in the end, its really your choice. if you're applying a lot of filtering, you'd probably want to set with that in mind. if you plan to keep filtering to lower levels, you'll probably want to set gains without the fitlers on.

as always. DMM is a tool. the ear is the only thing that matters. If you find you can get better sound by lowering gain, then do so. IMO the DMM method is more for people who realise, to some degree, what an amp does, but have forgotted that the amp is only a means to an end. somehow its now become fashionable to reccomend it on forums.

 

[GrnEydDvl 10+ year member]

On the alpine HU I dont believe there is a way to turn off the "bass center frequency" and "treble center frequency" (basically boosts certain frequencies)...so i guess i just leave those on when i set the voltage?

Some people say to turn everything off and flat on the HU when setting the adjustment....others say to set it to how your going to listen to it, and set it then. Which is the correct answer? JL Audio says to turn everything off (flat)

You may not be able to turn off the setting for what frequency to boost. But you should be able to set it to not boost that frequency any. EG 50hz at 0dB of boost.

I would set everything to flat and then try to keep boosting any frequency to a minimum (3dB per frequency) after setting gains. Since you are using a -3 dB tone versus a -6dB or lower one, you should have some room left for boosting and still not clip on most music.

 

[BlkonBlkFG 10+ year member]

I dont believe theres really anyway to turn it off...I do intend on using a BBE setting on my HU...so should I just leave that on when i'm doing my gain setting? Otherwise I'm not using any other boost on the amp or HU. Just the Gain / crossover will be adjusted...thats it. I think I understand...just set the "boost frequency" to something other then the tone I am testing...right?

 

[GrnEydDvl 10+ year member]

Yes, if you intend on using BBE then leave it on when setting gains.

 

[BlkonBlkFG 10+ year member]

But otherwise...leave everything else flat, right? Also, for setting the crossover after the gain is set you just use a -3db 80hz tone while the volume level is at the 80% mark...and then turn down the crossover until you can hear distortion with your ear right? (assumint you started with it at the higherst setting). This way the amp is at a safe power level and has a good clean and safe crossover setting?