newbie, adjusting amp gain

ok well im pretty new to this  whole car audio thing ok , but this is what i got .

head unit.... avic-z3  eq is flat loud id off subs are set on 80hz and  bass level is zeroed out

amp... memphis mc1.500

subs... 2 12" memphis m3's dual voice coil, in a regular cab  silverado 03 model   with 2  sealed truck boxs maybe 1 cubic ft of air

well ive did some homework  on here  on how to adjust my amp and all even dl'd some  hz tones on my iphone to help adjust my gain , when i try to  do this i cant even turn the knob a hair and then  i get  distortion .   can someone plz help me out ??

no im using mobil spec  4 gage kit with foiled rca jacks so thats pretty much taken care of there .  posi and neg terminals on subs are  correct also

waht is the other settin on  the amp for also ?   and how should   2 m3's and  500 wattt sound ?

I've never used a test tone, ever.  I guess I'm not that sophisticated or high-end.  But the only way I have EVER known any manufacturers say to set your amp gains is a simple procedure.  The steps are normally written in the owner's manual of whatever amp you buy.  In fact I've never bought an amp yet that didn't list the same steps for adjusting gains...

1. Turn amp gain all the way down.

2. Turn deck on to whatever music you want.

3. Turn deck's volume all the way up.

4. Then turn gain control to the right, slowly, until amp starts to clip or distort, then back it off a hair.

If you follow these steps, you should have no problems adjusting your amp's gain, and should have virtually no distortion.  But of course, after a few years, most people such as myself tend to turn our gains up a bit more.  Mine I usually just set to half way.  Then I make sure to not turn the deck all the way up.  If I do, and get a bit of clipping, I just back the gain off a bit.

A huge part of clipping and distortion issues lies not with the gain but with the amp being lower powered than the speakers.  Many people have the minsconception that you need less amp power than your speaker's max input or they will blow up the speakers.  Quite the opposite is the truth: you actually need a higher amp rating than that of your speakers.  It's not really the speakers distorting, it's the amp clipping.  So let's say a back yard car stereo guy puts a pair of 200 watt per channel (max) 6x9's in his car's back window.  He then runs out and buys an amp rated at 100 wpc max, thinking that if it was 200 wpc or more he would cause distortion.  When in actuality, the amp will begin to distort long before the speakers reach their full potential.  So the thing to do is quite different than the average beginner would do.  You want your amp to have a greater wattage output than your speakers peak.  Like if you have 200 wpc speakers, you want to run 250 wpc or more in an amp.  That way, you avoid overworking the amp and causing distortion.  Also, this way, you simply turn the gains down to avoid distortion.  I've actually ran 300 wpc amps to 200 wpc speakers, and even higher.  This might explain why my present front and rear amps are both 1000 watts max when the front speakers only handle 240 watts max and the rears only handle 500 watts max.  It will all work out.

Good luck with the gains.  I think you'll figure it out.

Wow, nice write-up.  I couldn't have said it better myself (obviously). I knew there are fancy technical ways to set input sensitivity, but I kept in mind the OP's first statement "I'm pretty new to this car audio thing" and figured the "old-fashioned way" would at least get him rolling for now.  To a car audio newbie, this technical sine-wave stuff might scare him away from even having a deck.  I was simply trying to help out someone with very little knowledge of car audio, or who is new to it.  My suggestion would be more than adequate for a simple deck and amp configuration in my opinion.

BUT...

Your link and that fancy write-up are what I needed for myself! Thanks!  That's awesome! Againk, if I only had a deck and 1 amp and a couple speakers, the typical old-fashioned way would suffice.  But now that I have 3 amps and a crossover, I need to know this complicated way.  Now after I read that write-up, I think it would be best for me to go to a reputable shop and have them tweek my system.  Right?  Simply adjusting gains really doesn't need to be so complicated for 1 amp and nothing else.  But I truly believe once the other 2 amps are added, and a crossover, it's gonna be a nightmare!  This was what steered me away from the Audio Control EQ-X, S, or L.  Too many things to adjust and tweek.  So, once I started looking at the Clarion crossover, I started to panic.  I keep asking myself how the heck to figure out what settings to make on the xover as well as the few controls on the amps.  So after reading this awesome How-To, I think it would be best to find a local pro to make any adjustments. 

Would it help to let the pro know what type of music I'm going to listen to most, therefore what frequencies I would prefer to hear more or less of?  As for my amp gains, I'm still old-school "just set em to half and call it good" kind of guy.  But now, after investing so much money and time in my present system, it's time to have the gains and other adjustments done right.  I keep wondering if the shops just set frequencies for their own personal preferences rather than what the customer prefers, or are all the setting usually done according to technical frequency measuring. Guess I'll find out, but first I have to find a shop to trust.

Thanks again.