Whats wrong with turning the gain up all the way

[Rashaddd 5,000+ posts]

What most people dont realize is, an amplifier is ALWAYS working at 100%. Yep, its true. Know why it doesn't always output the same amount of power though? Because its input source varies how large of a signal it has to amplify. The larger the input signal is (in volts), the larger the output from the amplifier. The amp's output stage is always 'pushing' with the same 'force', it simply has more, or less, to start with. This is exactly why amplifiers are sometimes called "gain blocks" and how you control the amplifier's output from the driver's seat, with the headunit's volume controls. Wrap your brains around that one kids.
So, knowing this, explaining gains correctly becomes easier. The gain knob simply adjusts the input sensitivity of the amplifier. The output stage always pushes with the same force, but how much signal voltage it has to start with is determined not just by the source unit's output voltage (your head unit), but by how sensitive you adjust the input stage of the amplifier to be. Will your h/u max at 1 volt of output signal, or 8 volts? The gain knob tells the amplifier this.

What happens when you adjust the input stage of your ammp to be too sensitive given the input signal it can receive? Clipping. As shown in a pic above, its a squaring off the of the signal waveform. What was said about it was true, the problem does lie in the fact that more power exists under the shape of a squared wave. This is because amplitude does not increase, while area under the waveform does. More power, but no more cone excursion to help dissipate the excess heat that will be generated. So no, clipping will not help exceed your speaker's mechanical limits, but it certainly can help exceed its thermal limits.

To argue if 'clipping' or 'excess power killed a speaker is semantics. The excess heat was caused by the clipping. So long as its understood that 'clipping' in and of itself does not kill speakers, only when it helps drive the speaker past its thermal limits, then saying clipping killed the speaker is acceptable. But then, we love to revel in these arguments here, dont we.

This is the biggest conglomerate of bs I've ever seen. You must have added some of your own shit to the bull's to make a pile that big

 

[Mass Car Audio 10+ year member]

i did what you said and i got it sounding just how i want now.. and btw when i said i thought my sub was bottoming out it really wasnt.. it was just a really really weird bass ive never heard in a song before that kinda sounded like it

thats called extreme clipping...lol

 

[Rashaddd 5,000+ posts]

thats called extreme clipping...lol

aka dB'z

 

[Mass Car Audio 10+ year member]

aka dB'z

lol..

 

[Rashaddd 5,000+ posts]

you guys are boring as fawk

 

[Jakeeck 10+ year member]

thats called extreme clipping...lol

what?

 

[sexiewasd 10+ year member]

//content.invisioncic.com/y282845/emoticons/beatdeadhorse5.gif.5d70132dea1eb89b73bf2fdbb6027dd6.gif

I'm with Rashaddd on this one.

 

[Forrest Gump 10+ year member]

what?

When your sub makes unnatural noises it is a good indicator that your signal is clipped.

It is a signal that your sub is not built to reproduce and will damage and eventually fry your moofer.

 

[thch 10+ year member]

i have my 15" IA LI 4 ohm dvc wired for 2 ohms on my hifonics 1208d.. so it should put out 900w at full gain right? well the gain is like 3/4 of the way up so im getting 600-650.. whats wrong with turning the gain all the way up so im getting 900?

nope, its not like that. to work with any HU, the gain can be adjusted over an excessively wide range. lets say an amp's output is limited to 100V. one HU provides a 10V preout, while another provides a 1V preout. both at maximum volume settings on the HU. for the first case, the amp would need a gain of 10 to convert the 10V input into 100V output. the second case, it would need a gain of 100. so if the gain on the amp was set to 100, and the first HU is used, then the output should be 1000V, but the amp is limited to just 100V.*

so lets look at what really happens -- people do crank the gain, and without damage. (though not always). why? because these people instintively correct for the excessive gain by turning the volume on the HU way down. in the case above, the guy with the HU capable of 10V output at max volume would turn down the volume until the output was closer to 1V.

this is fine, not optimal, but not destructive. These people will typically see this as a sign of a quality system -- it gets very loud at low volume settings. the system may max out at 1/3rd the maximum volume setting on the HU, and be unlistenable at 2/3rd max volume setting.

Why is this not optimal? firstly, you've just removed 1/3rd of the volume settings on the HU. but that's probably ok, many people could probably be happy with just "very loud", "loud", and "talking" volumes. but now any other speakers might not be as loud (or too loud), or might not blend in. The fully cranked setting might limit your options to fix this. Also, the lower signal level might allow more noise to get into the signal, though for subwoofers this might not be as noticable.

This should explain why the amp's potential is not limited by the gain setting -- the amp is fully capable of outputting full power even at low gain settings, but that requires a higher input signal.

*the test method also smoothly moves from in to out. this means the amp's output voltage changes from 0 to +100V then back to 0V then to -100V then back, and does so smoothly. this leads to clipping when the gain is excessive. also, it leads to a case where the amp's actual output power is higher then its rated output power because the rated output was rated for the smoothly changing test signal.

 

[Jakeeck 10+ year member]

When your sub makes unnatural noises it is a good indicator that your signal is clipped.
It is a signal that your sub is not built to reproduce and will damage and eventually fry your moofer.

its not like that.. its just one part of a song that has a weird bass that sounded kinda weird.. ive tried every other bass filled song and its all good

 

[CRXBMPN 5,000+ posts]

thch, i'm waiting for rashaddd or whatever to tell you you are full of b.s. lol, good read though, thx for the info, and i like the fox news quote, them bastids //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

 

[Rashaddd 5,000+ posts]

nope, its not like that. to work with any HU, the gain can be adjusted over an excessively wide range. lets say an amp's output is limited to 100V. one HU provides a 10V preout, while another provides a 1V preout. both at maximum volume settings on the HU. for the first case, the amp would need a gain of 10 to convert the 10V input into 100V output. the second case, it would need a gain of 100. so if the gain on the amp was set to 100, and the first HU is used, then the output should be 1000V, but the amp is limited to just 100V.*
so lets look at what really happens -- people do crank the gain, and without damage. (though not always). why? because these people instintively correct for the excessive gain by turning the volume on the HU way down. in the case above, the guy with the HU capable of 10V output at max volume would turn down the volume until the output was closer to 1V.

this is fine, not optimal, but not destructive. These people will typically see this as a sign of a quality system -- it gets very loud at low volume settings. the system may max out at 1/3rd the maximum volume setting on the HU, and be unlistenable at 2/3rd max volume setting.

Why is this not optimal? firstly, you've just removed 1/3rd of the volume settings on the HU. but that's probably ok, many people could probably be happy with just "very loud", "loud", and "talking" volumes. but now any other speakers might not be as loud (or too loud), or might not blend in. The fully cranked setting might limit your options to fix this. Also, the lower signal level might allow more noise to get into the signal, though for subwoofers this might not be as noticable.

This should explain why the amp's potential is not limited by the gain setting -- the amp is fully capable of outputting full power even at low gain settings, but that requires a higher input signal.

*the test method also smoothly moves from in to out. this means the amp's output voltage changes from 0 to +100V then back to 0V then to -100V then back, and does so smoothly. this leads to clipping when the gain is excessive. also, it leads to a case where the amp's actual output power is higher then its rated output power because the rated output was rated for the smoothly changing test signal.

//content.invisioncic.com/y282845/emoticons/read.gif.ff512c499c00ed3faae9a20f4b088b29.gif

 

[Jeepjones85 10+ year member]

Straight froward

http://www.the12volt.com/installbay/forum_posts.asp~TID~85479~PN~1

I didnt bother to read the whole thing. But mabe this will help

 

[endofdays89 5,000+ posts]

you can turn your gains all the way up if you turn the volume on your head unit down more, especialy with a 2 volt preout. It is true. My amp has to be turned to 80% using the dmm just to achieve 40 volts. You never know where the levels are on the amplifier gain, some amps are more sensitive to turning the knob than others.

Flame on, but its true.

 

[endofdays89 5,000+ posts]

Nothing is wrong with it if you have such a low input voltage that it needs to be set that high.
Incorrectly or improperly turning the gain up all the way isn't a great idea, however.

this is correct, the head unit is the biggest factor. The lower the voltage on the preouts the better chance you have of turning the amp gain almost all the way up with out hurting anything. Just be careful with the volume knob on the HU