Is a knocking noise clipping? type r and a 600w alpine amp
bob watson
Unregistered guest
Posted on
i have a 600 watt at 2 ohm alpine amp it got birthsheeted at 655 at 2 ohm at 14.4 and a 1242 type r 500 rms 1500 peak in a ported box i have the gain set at 1 v my hu is 4 v some one said these should be the same ? and the bass boost on 8 on a scale of 0-16 i think im putting to much power and its causeing it sound like its knocking why is it doing this i read the thing on bcae about clipping cause alot are telling me that on forums but they said this happens due to not enough power i dont even know if its clipping sound like its hitting something but if i turn the gain to 1.5 or bass boost down then it doent due it and it olny does it at high volumes
you have your gain set WAY too high for that head unit. you have the amp set to be overly sensitive to 4 volts so the amplifier is clipping badly and the sub is distorting. if you haven't already damaged the sub, turn that gain down to 4V or near minimum. that should fix the problem.
I didn't misread a thing. if the amplifier's gain is set at 1 volt, that's setting the gain to be the most sensitive, for a 1 volt input signal (weak input, sensitive input stage on teh amp) and he's using a 4V pre-out with the subw level cranked to +8, which means he's sending a 4+ volt line voltage from the head unit to an amplifier expecting a signal of about 1 volt. He's overdriving the input stage of the amplifier and the amp is clipping badly. he's hearing the sound of his speaker killing itself.
the reason he doesn't hear it at low volumes is that the amplifier just isn't generating enough voltage across the speaker to cause damage yet.. when he turns it up, it does.
most amplifiers have a range of about 2 to 4 volts for input. when I said set the gain to 4V or minimum, I meant minimum sensitivity, which is 4 volts most times.. if the amp accepts 8 volt line signals, he'll need to turn the gain back up a bit to match 4V.
note this is why I hate using the improper term "gain" for an amplifier.
Use the correct term of "input sensitivity adjustment" and it all makes much more sense.
bob watson
Unregistered guest
Posted on
ok thank u very much i turned all of it down when i heard this cause i figured it was bad. The input senistivity goes .1 .2 .3 .5 .7 1 1.5 2 4 8 and i plan on turning bass bosst off so i should have it at around 4v for the input senitivity
@bob Maybe the problem is that everybody gets confused with (maximum) preout and (minimum)input sensitivity. Max is mostly clockwise and everybody goes for max intentionally, but here -because of the max of the HU- it has to be matched with the min of the amp to find the balance.
Just imagen two clocks, one (the HU) has 15:15 or 3.15 pm and the other (amp) has to be adjusted to 08:45 or 8.45 am. So both pointers of the clocks meet in the middle.
Hope I didn't confuse (sorry for not beeing able to put it in proper English).