set gain with dmm

[smiley2186 10+ year member]

how do i check to if my gain is set right with a dmm. i want my amp to get 800rms into 2ohm.

do i raise the gain to see if its read 40v on the dmm to be correct?

and connectin the dmm pos and neg, do i connect it to the pos neg on the amp, the car would need to be running right?

i have two amp same kind but im not straping them just wiring them with the y adapter but i need to match the gains, so one sub isnt getting more power then the others

thanks

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[SPL Blazer 10+ year member]

Check out this video on gain setting with a dmm.

Gain setting

 

[smiley2186 10+ year member]

cool site thanks

 

[cswann821]

Hey Everyone this is my first post... I just finished my first ever car audio install and have my basic gains set..but am playing around with my front stage. I have a couple insecurities of how and why I use different test tones, and what I can expect between their different Hz...aswell as some other questions.

I am running an Alpine PDX 1.1000 amp to power 2X 12" Type-r's (500rms ea.) and an Alpine PDX 2.150(300RMS, 150x2 @ 2Ohm & 4 Ohm) to run a pair of CDT HD62Z component speakers (180rms@100Hz).

Ok, right now I have my LP and HP crossover set around 70-75Hz. I've been happy with my sub gain set at max voltage of about 44.volts @ 55Hz, but I keep playing with my front stage.

Right now I tuned my front stage with a 1K tone, bringing the gain up to 24volts (but am kinda still unsure what/why I am testing other Hz tones, when I ask this I mean...what am I hearing (or expect to hear) when I switch between setting my gain to max volt useing a 100Hz tone VS 1K tone..

To find my Max volts, Im useing, sq root of Watts x resistance(ohm load)= volts.

Can you verify.....my front stage PDX amp wich is 300rms (150x2 @ 2 or 4ohms) and the speakers which have a resistance of 4Ohms. Put into the formula above ..sqroot (300X4)= 34.4 volts. This can't be right...theres no way I can put the gains up that high just by listening to it so far. So I found the JL sight that says the voltage on their 300V2 amp should be set at 24.4volts. So I'm guessing im not accounting for parrallell wireing which would make the resestance that the speakers show that amp 2Ohm not 4Ohms. Is this happening because of the tweater/woofers being hooked into their crossovers....or at the amp terminals were both left and right speakers hook into the amp?

Also, so I've been useing the 24volts(300watts) the JL sight reconmmends to set my max gain on my front stage. Should I therefore divide this...since the amp takes the 300watts and sends 150watts to each speaker side..therefore when I stick my DMM into the left positive/neg speaker terminal am I looking for 24volts(300watts) or 12volts(150watts) with my DMM??

So far I have it set, using the 1k tone. Now why is it that according to the CDT HD62Z specs on woofer.com, it says that these speakers can handle 180RMS @ 100Hz, but when I actually use a 100hz tone...I get clipping, before I reach 24volts(150watts). I've been useing the DMM with the speakers hooked up for this reason, and because I've been told I need to have the impedeance that the speakers show to get accurate readings on the DMM. Is this right? Or could I just be interpretting vibrations in the door paneling as clipping. I mean sometimes I hear apparent disstortion or a high fast past/pitched buzz..

Ive been told to find the /use the Frequency between 160Hz-1KHz which gives me the lowest gain setting to eliminate noise while reaching my max voltage(which would be 24 volts). But while I do this, I also have to pick and choose which frequency within this range sounds the best to me...right? Otherwise what I'm saying is that a 1K tone may give me the lowest gain setting @ 24volts, but it's not going to be as loud, compared to setting the gain with a lower HZ right? Initially

And basically, as far as what I hear is this correct.....the lower the test tone Hz...the higher the gain can be set, but I sacrifise quality & noise for loudness. (Is this all I'm doing when chooseing between different HZ tones to set gains at for my HP front stage)

Lots of questions, Just trying to get rid of my insecurities about what something may be and turn them into...YES thats what it is suppose to be!

Thanks

 

[Etac 10+ year member]

since its your first post its ok, never write a post that long again, no one will read it.. cliff it up

 

[stilltippin863 10+ year member]

//content.invisioncic.com/y282845/emoticons/escape.gif.52b661afb17bde1db0e0c7da97e75b38.gif

since its your first post its ok, never write a post that long again, no one will read it.. cliff it up

lol i know i read like the first couple of sentences then looked down and was like //content.invisioncic.com/y282845/emoticons/escape.gif.52b661afb17bde1db0e0c7da97e75b38.gif

 

[reasonable 10+ year member]

Honestly, I would just set it by ear if I were you, Th DMM method isn't really necessary.

 

[cswann821]

to much to read huh.

ok, then can someone tell me what I should expext as far as what I will hear overall when you choose to adjust your gains, useing the different HP front stage tones, Ie 100hz vs 140-1K? or otherwise

what changes do you expect to see when your front stage is set useing a 100hz vs 1k tone extra?