Setting gains with dmm

[Buck 5,000+ posts]

How to do this? I tried to search but didn't have any luck.

Just want to see what my amp is putting out so my sub doesn't go poof again.

Click to read more...

 

[nauc 10+ year member]

scroll down to #3 http://www.thesuicidaleggroll.com/gain.htm

 

[FoxPro5 5,000+ posts]

Usless unless you're level matching between channels.

 

[Bender. 10+ year member]

get a 50 hz tone, set all of your eq levels to 0, set your volume on you hu to 3/4 of the way up, disconnect your subs, put you dmm leads on your amp outputs, set it to ac voltage, put the cd in and turn your gain up untill you get your target voltage

edit: you find your target voltage with this V= sqrt( rms X ohms)

so if your amp puts out 1000 rms at 1 ohm it would look like this V= sqrt (1000 x 1) or 31.6 volts

 

[nauc 10+ year member]

get a 50 hz tone, set all of your eq levels to 0, set your volume on you hu to 3/4 of the way up, disconnect your subs, put you dmm leads on your amp outputs, set it to dc voltage, put the cd in and turn your gain up untill you get your target voltage
edit: you find your target voltage with this V= sqrt( rms X ohms)

so if your amp puts out 1000 rms at 1 ohm it would look like this V= sqrt (1000 x 1) or 31.6 volts

you set the dmm to AC, not DC

 

[Bender. 10+ year member]

you set the dmm to AC, not DC

oh yea my bad

 

[alvitae 10+ year member]

Print this out and take it to the car with you, Easier than doing math.

http://i381.photobucket.com/albums/oo255/alvitae/RMSchart.jpg[/img]"]

 

[Bender. 10+ year member]

Print this out and take it to the car with you, Easier than doing math.http://i381.photobucket.com/albums/oo255/alvitae/RMSchart.jpg[/img]"]

i looked for that for him but i couldn't find it...thanks

 

[cf2004 10+ year member]

also set the track to repeat so if your not done right away, it will play the tone still.

and alvitae, good find.

 

[timaishu 10+ year member]

I just set my gains my DMM using that chart. I have one question though.

Whats the point in setting my HU to 75% when I never have it at that volume level anyways?

I never go past 15-20% on mine. Its too loud for me anywhere past that. So it wouldnt it be more realistic to set it using a level of volume I would likely use?

Can someone chime in on this? //content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif

 

[FoxPro5 5,000+ posts]

Its too loud for me anywhere past that.

Let me get this straight, 20% max volume is too loud for you WITH or WITHOUT your gains set with the above method?

If it's too loud with your gain set too high, you're just going to drive more noise and distortion with your HU volume.

If it's too loud without your gain set, then why are you adding gain to the signal in the first place??

What a lot of guys don't seem to understand is that you don't NEED to set your gain. Let the source (your HU) drive the signal. Some HU don't clip, but for those that do, 75% max volume is about the end of the line before clipping. Run that all the way out...and if needed, gradually increase the gain until you're satisfied.

I really think this stupid DMM method would go away and never return.

 

[timaishu 10+ year member]

I had set my gain previously by ear. It sounded good and pounded hard at my preferred volume level. But I wasnt sure if I was running the risk of clipping or whatever when I really pushed my sub hard.

So I figured I could try setting it using my DMM.

And according to the chart. I should set the gain with my HU at 75% and then set the gain.

What I said above is the part that I didnt really understand.

If I usually listen to my music with my HU set at 20%. Wouldnt it be more realistic to set my gain with a DMM, using the method in the chart, with the the HU volume at 20%?

 

[FoxPro5 5,000+ posts]

I had set my gain previously by ear. It sounded good and pounded hard at my preferred volume level. But I wasnt sure if I was running the risk of clipping or whatever when I really pushed my sub hard.
So I figured I could try setting it using my DMM.

And according to the chart. I should set the gain with my HU at 75% and then set the gain.

What I said above is the part that I didnt really understand.

If I usually listen to my music with my HU set at 20%. Wouldnt it be more realistic to set my gain with a DMM, using the method in the chart, with the the HU volume at 20%?

Don't look at that chart and don't use it. It's wrong. Ok? How's that?

It makes NO SENSE to only use 20% HU volume and then drive the rest of the signal with gain. Don't do this.

Just put it back the way you had it if you liked it.

This topic is absolutely beaten to death and this **** DMM method just makes everything worse. //content.invisioncic.com/y282845/emoticons/rolleyes.gif.c1fef805e9d1464d377451cd5bc18bfb.gif

 

[endofdays89 5,000+ posts]

Let me get this straight, 20% max volume is too loud for you WITH or WITHOUT your gains set with the above method?
If it's too loud with your gain set too high, you're just going to drive more noise and distortion with your HU volume.

If it's too loud without your gain set, then why are you adding gain to the signal in the first place??

What a lot of guys don't seem to understand is that you don't NEED to set your gain. Let the source (your HU) drive the signal. Some HU don't clip, but for those that do, 75% max volume is about the end of the line before clipping. Run that all the way out...and if needed, gradually increase the gain until you're satisfied.

I really think this stupid DMM method would go away and never return.

the gain is very sensitive, that's why i use the dmm method, it works extremely well for your component speakers. I just set the subs amp by ear though.

 

[FoxPro5 5,000+ posts]

the gain is very sensitive,

Yea, so take your DMM and make sure the amp voltage is the same to both sides of the car.

it works extremely well for your component speakers.

When you level match, yea. Otherwise, you're not actually doing what you think you're doing. "The DMM method" assumes WAY too many factors that you don't know...including actual power output by the amp, impedance rise, power compression, more. Don't do it, it's wrong.

I just set the subs amp by ear though.

They're playing distortion whether you hear it or not. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif