Amp not getting enough power?

[ShadeTreeMechanic]

8 minutes ago, cheatcode said:

the dd-1 is nice and does a wonderful job of detecting distortion, i think it's overpriced for what it is but it's definitely really cool. i know injection molding, coding, labor, assembly, and the time involved warrants the cost. yes I'm aware what forum i'm on and that steve runs the site. i've read some really great posts and saw a lot of people getting help and helping others and thought I'd sign up.

I posted a very well put together thread with pictures of me using a fluke scopemeter and the admin on the site tells me my rca's are garbage and proceeds to give me a tutorial on how to use a multimeter. Then before him shadetreemechanic and his $200 pawn shop build chimed in talking about resistance/impedance too like that had anything to do with anything. then you "ron36" hopped on the peanut gallery train adding to the constructiveness of this thread by saying "sounds like a jl fanboy" or whatever you said and followed up with letting us know you like to smell dudes asses that own JL stuff. only a fanboy brags about the stuff they have, exhibit a: your signature, i imagine you probably have an andorid or apple sticker on your car window too.

i am the duck is the only one saying anything that makes any sense, and @i am the duck, not sure what you mean by resolution, but increasing the output voltage on my HU isn't helping that's why i think it may be my amp isn't getting enough power - and before anyone says anything the amp has been ruled out and is not defective.

I was just trying to figure out how you arrived at 40 volts. It means nothing unless you are using a resistor as a load. Your head unit puts out .9v and you are trying to make full power? And now I have a pawn shop build.

[cheatcode]

I'm not sure if it's like troll Tuesday on this site and I just don't know it because I just signed up or what....  You couldn't figure out how I came up with 40v? Yes, with 3/4 volume and the SWL on +5db I only get .9v, that's perfectly normal and the amp could make full power with far less. I mean it's not a competition or anything but if this site gave out awards for the worst/cheapest build you'd arguably win a gold in each category. 

[Jessica]

no one is trolling, some people are just more direct than others. If you have 5v outputs, you should be seeing more than 1v at the amp inputs with a 0db tone. Are you using a 0db tone?

[06RTCharger]

If everything you did was done correctly and set correctly to ur standards....whats the issue? 

[cheatcode]

duck, my HU will do 4.7v clean at full volume but when i turn my volume down to 3/4 the voltage is reduced.

06, the issue is i don't think my amp is getting enough power and I don't know how to test for that properly. i feel like it gets enough not to switch into safe mode but not enough to allow the amplifier to properly amplify the signal.

[Jessica]

if your deck does 4.7v clean and you are getting 1v at your amp inputs, what does that tell you?

[cheatcode]

i don't know how else to explain that. if i turn my HU all the way up it'll do "close to" the rated, but i don't set my gains like that. i turn the volume down to 26 "from 35" and when you lower the volume it lowers the output voltage.

[Jessica]

maybe i am missing some information here. But a 90% drop in voltage across your RCA's is not normal. I have absolutely 0 against JL, but there is  a chance there could be a bad connection, a short, or a flaw. 

[ShadeTreeMechanic]

Forty volts is not a magic number. If you are unwilling to run at a higher head unit output to see if you can make more power, then me and all my junk stand by my original answer.

Turning it up to max clean signal is all you can do.

[cheatcode]

F*** it, this thread is already off topic. If you scope your HU you will find the max or rated RMS on the pre-outs is only achieved with the volume on or close to 100% and sometimes you can only get it to do rated voltage by boosting the frequency you're testing for and in every case adjusting the subwoofer level. While that's great, nobody sets their gains on the amps with the volume at 100% unless they're doing a SPL competition and only playing one tone.

So if your HU does 4.7 volts with the eq flat playing a 40Hz 0db tone with the SWL on +5 and your volume on 35 then that's pretty good but you would never set your gains like that. Now, every time you turn the volume knob down it reduces the amount of voltage your HU puts out. So while your HU can put out 4.7 volts at full volume when you turn it down to 26 out of 35 the voltage is greatly reduced. That's why it's nicer to have a HU with stronger pre-outs, this allows your 3/4 volume voltage to be stronger as opposed to what it would be on a 4v HU that does 4v at full volume. 1 volt at the amp is pretty strong and is more than enough for the amp to do its job, if you have any noise issues you can always get a line driver.