DiyMobileAudio.com Car Stereo Forum banner

1 - 11 of 11 Posts

·
Registered
Joined
·
104 Posts
Discussion Starter #1
I'm a bit stumped at the moment and could use some help. I just installed new door speakers and added a sub into my 18' F250. The stock 4.2" radio was retained with the use of splicing harness FOR-11CK. I also reprogrammed the audio control module to give me line out signals to my amp without any eq. There will be a Dayton 408 added soon but i wanted this in before a road trip.

My problem came up when setting the gains with my dmm. I stream test tones from a function generator app but can't read any voltage on the speaker outputs. The meters i have were verified against the garage outlets. I tried running 60/100/500/1k Hz tones with no luck. This craftsman dmm before for setting gains.

What am I overlooking here? I've tried with/ without speakers hooked up to verify the tones are playing.
 

·
Premium Member
Joined
·
4,992 Posts
what happens with the speakers hooked up?
 

·
Registered
Joined
·
45 Posts
Just curious, what is the lowest A/C voltage setting on your DMM? It sounds like your voltage signal may be below your DMM sensitivity range. This is all based on the assumption that when your speakers are hooked up you hear sound from your test tones but see no voltage reading on the DMM
 

·
Registered
Joined
·
8,645 Posts
You're measuring wrong. If you have sound from the speakers, you certainly have voltage on the wires. Make sure the meter is set to AC voltage. Or, put the meter away, I don't think it's the best way to set gains.
 

·
Registered
Joined
·
104 Posts
Discussion Starter #6
200 vac is the lowest setting on the meter. I've read less than 10vac on this meter recently when changing house outlets. I even checked my cheap harbor freight meter with same results.

I don't see how it could be any simpler. I left the speaker + leads. Turn on the tone with the hu at about 50% and place the meter across a speaker terminal.
 

·
Registered
Joined
·
3,187 Posts
Take a picture of the meter please. Chances are you have the wrong tool for the job.

Ge0
 

·
Premium Member
Joined
·
4,992 Posts
And the voltage is astonishingly low... in a home system with 8 ohms, getting to a few volts is a chore.
Subs are different.
 

·
Registered
Joined
·
3,187 Posts
Yeah, that ain't gonna do it. You don't have enough AC resolution to accurately read small signals. If you wanted to do something on the cheap then:


However, I am also in the camp with those advising against setting gains with a DMM.

Have you considered having a shop do it? If not, maybe look into one of those Steve Meade meters to help you out. At least they can detect a distorted signal.

Ge0
 

·
Registered
Joined
·
104 Posts
Discussion Starter #11
Well I feel like an idiot. When I originally setup the system I was using high level outputs from the HU. That's where i came up with the target numbers for max volume and voltages. Since then, I reprogrammed my radio to give me low level. After making the corrections it reads as it should.

So like it was mentioned above, I was measuring wrong.

I appreciate the help!
 
1 - 11 of 11 Posts
Top