using digital multimeter

[budahbuddy803 10+ year member]

I have never been able to correctly figure out how to use my multimeter for the purpose of setting my gain. With all the reading i have done recently this is what i have come up with, just trying to make sure this is correct.

Turn the knob to 20 DC Volts.

Plug the Red cord into Red

Plug the Black cord into the 10A DC spot.

Is this correct?

Then remove positive speaker wire from amp.

Turn gain all the way down.

Insert Red cord into positive and black cord into negative.

Slowly turn the gain up until desired voltage.

If i want to send my 15" IDQ 600rms @ 2ohm the gain setting tutorial says (600*2)=34.641volts what is the * what does that symbol mean to do?

One last question. My last amp didnt have a subsonic filter. That filters out the lower frequencies right? If thats the case why cant i let my speaker hit all the frequencies and just set the subsonic on as low as it will go? I dont really understand what the subsonic filter is really doing.

Click to read more...

 

[lilmaniac2 5,000+ posts]

pretty sure you need to set to AC

 

[mokedaddy 5,000+ posts]

The meter needs to set to AC volts.

Also a subsonic filter is mainly used in ported enclosures to keep the sub from bottoming out below the tuning frequency. If your sub doesnt bottom out than set it as low as it will go.

 

[budahbuddy803 10+ year member]

so if i use AC volts i turn the knob to 500 or 200?

and would i still plug the black cord into the 10A DC slot or would i plug it into the input jacks?

 

[goodstuff 10+ year member]

Set your meter to ac as this is what comes out of the amp terminals...subsonic filter blocks lows lower than a certain freq. pic of meter?

 

[budahbuddy803 10+ year member]

Set your meter to ac as this is what comes out of the amp terminals...subsonic filter blocks lows lower than a certain freq. pic of meter?

how do i set it? I dont know what i turn the **** knob to the instruction manual sucks and doesnt help me out so i am asking you guys if you can tell me what to turn the knob to and where to plug the black cord

 

[budahbuddy803 10+ year member]

 

[budahbuddy803 10+ year member]

red cord goes into the bottom

black cord goes into the one directly above the red one

set the meter to the top right category AC volts.

on 500 or 200?

 

[05gliguy 10+ year member]

black cord goes where it says COM, the bottom hole...

The red cord goes in right above it... NOT the 10amp one!

AC 200

And the symbol means to multiply

 

[Rich B 5,000+ posts]

red cord goes into the bottomblack cord goes into the one directly above the red one

set the meter to the top right category AC volts.

on 500 or 200?

Black = "Common", which means ground.

Red goes into AC V, and set it to the lowest setting that above the voltage you want to test for.

That meter is autoranging, so it will do the rest and give you the voltage reading.

 

[budahbuddy803 10+ year member]

well i think i got it i will just go mess with it a little bit tomorrow thanks.

 

[05gliguy 10+ year member]

You know to take the (watts*ohm load) and then the square root of that, right?

 

[goodstuff 10+ year member]

this might help:

http://mobile.jlaudio.com/pdfs/gainSetting.pdf

and this:

http://www.caraudio.com/forum/showthread.php?t=63933