How to verify amp output?

hello 12v, noob to the board here  ;)

anyway, I just installed an a/d/s P4100.2 and an a/d/s 12" DVC sub.    The sub should be putting out at least 350 x 2 the way I have it configured but output seems low.

Is there anyway I can use my DMM to verify this amp is fully functional?

Thanks in advance - I will have plenty of more questions in the future.....

ok, my bad, I did not include the required info!

1993 Camry - completely stock

a/d/s components

a/d/s 12" sub

1 a/d/s P4100.2

1 a/d/s P840

O gauge wiring, no capacitor, stock alternator, normal battery

Good old Ohm's law.  Power = volts squared divided by resistance.

Disconnect your speaker.  Connect your AC volt meter across the speaker terminals.  Turn on the system and play a test tone in the pass band of that amplifier.  Increase HU volume level to your "normal" listening level.  Read the voltage output from your amp.  Square it.  Divide that number by the nominal impedance of your speaker (4-ohms?)  This will give you a rough idea of the nominal power your amp is producing at that volume level.

Why is power level important to you?

Thanks for the reply John.  Will try your method tonight..

I wanted to find a way to verify the amp is working ok because it sure doesnt sound like 700watts.

700W RMS?  Mono 700W Peak more likely?  If so, 700W x 4§Ù = 2800.  Then sq. root of 2800 is 52.92Vp.  52.92V x 0.707=37.41Vrms.  37.41Vrms x 4§Ù= 149.64W RMS (actual power).  This CAN be actually be wrong for the amp you have, but you said you were a noob, just hopefully not to car audio.  Most people still choose to buy an amp with "PEAK" power ratings.  Thats fine and all, but I hope the retail packaging on the amplifier you purchased explained RMS power ratings in the format provided by CEA2006.  If not, I can pretty much explain the WHOLE specification of CEA2006 to anyone, as well as give you a reason to pay full attention to RMS.

Is PoopyDavid aware that most speakers only require 1 watt to hear 90-ish +dB at just 3 feet of distance, which is usually always claimed by all speaker manufacturers?

Mostly, by the way, I hope your amplifier is live and well.....Keep Rockin!!!!!!!!

Where did I get 700W????!!!!!!!!!!  Sorry, my mistake right off the bat.  Either way, you can apply that with what you get.  By the way, if you want to conform to CEA2006 a little closer, buy or download some copy of some sound tests.  As long as you get a 1KHz sine wave.  You need an RMS Digital Multimeter.  Get a 4-ohm load, or whatever load the amp is going to be driven with, or at least leave the speaker wired to the amplifier(it will be good enough to figure this out).  Play the CD/media that has the 1KHz sine wave.  During the play, increase volume to....whatever, and touch the amplifier outputs with the meter leads.  Remember THAT AC voltage, while noting the load on that channel.  If your running stereo, make sure both/all channels are loaded, and all RCA inputs are connected with an input signal source.  Take the equation I mumbled above and apply your actual numbers to get your output power...in RMS.

well, I'll try the formula tonight.    If I read your post correctly and run a 1khz sine wave to a subwoofer, somehow that seems too high a freq. Pls clarify.

I dont think I am a noob to car audio, but havent tried this in particular before.

Yes, poopydavid is quite familiar with sensitivity ratings and what they imply. 

I just read through the CEA2006 standards and I fully agree with the argument they are making.   

Here are the specs of my amp. 

I'd bet good money that a properly working a/d/s amps would definately deliver its stated output rating.    are you familiar with a/d/s? 

Thanks for  both of your input and prompt replies to my post. 

yes, the sub is 4ohm DVC.

BTW, I forgot to mention the sub is brand new.    Perhaps breaking in of the sub is more a culprit than the amp.

As for the 1kHz, yes, the sub will do it but it is high due to the nature of the sub.  I would use 100Hz actually, because your amp's slope/rolloff, it probably levels out at 35Hz (even though it drops to 20Hz) if we were using a scope or looking at a chart.  So, 100Hz and above is more reasonable.

If the engine was running (from the alternator) 14.4VDC yes, but I realize you know more about car audio than you let on.  So, Im sure you know how the internal regulated power supplies work in amplifiers that determine whether that will make a difference or not.

Ive only installed 13 a/d/s components over the decade.  So, Ill feel more comfortable saying "No" being that I have not had to troubleshoot/repair one.  But, an amplifier is an amplifier.

Got questions.  You have two 4-ohm DVC subs.  An amp with the specifications you show above.  How did you wire them?  Did you wire the subs in series (8-ohms), or in parallel (4-ohms)?  Which ever way you wired the subs voice coils, in what order did you wire them to the amplifier?  Im wondering if you wired them in parallel/4ohm each as to have 2 extra channels that are open, or did you have other speakers not mentioned?  Im wondering, you may have wired them in series/8ohm which would explain theoretically lower sound output, in which you were expecting more....just trying to uncover the specific that you have so far not stated.  Let us know if we could further help.

For your test, the simplest and quickest way is to borrow another amp (any brand) with approx the same power rating and hook it up in place of your amp.  You will normally be able to do this at the store where you got your present amp.  If you notice a huge difference, well...you know where to look for the problem.  The amp itself.  If the difference is not noticeable, then it's not the amp.  If it still seems like only 100 watts of total output and especially if you get another listener's concurring opinion, then there is a problem in the installation somewhere.

Im back in town from some cars shows finally.  Its been a while since I have read all the posts....so what did you find out about the amp?

I read back - I didnt recall anything where you were defensive...its cool eh?