Gain maxxed out.

[Grinder1989 5,000+ posts]

Imagine you have noise induced into your RCA cable. This noise will be induced at a certain level, measureable in volts (speaking simply here, its abit more complicated). So you have a 'noise floor' at a certain level in your signal cable. Noe you have two h/u's one with a weaker signal voltage (say .25 volts max0 and one with a higher possible signal voltage (say 8volts max). You try one h/u, and then the other. Each setup has the same noise introduced into the cable at the same level, but one h/u is supplying a signal voltage that exceeds this noise level by a greater amount. In effect, the hotter signal voltage has created a wider gap between intended audible signal (from the source unit) and the unintended noise level. This means, at any volume level, the system with the higgher signal voltage will display the noise level at a less audible level.
If you set your signal chain as you suggest, you have basically rediced the signal cable run from the EQ to the amps at the lowest signal level possible, making any induced noise as loud as the system possibly can, when we would want just the opposite. You will decrease the gap between induced noise, and proper signal.

If that is the case then I should be running higher voltage constantly? So if I set the gain a tad above the highest voltage (I'll say 6 volts) Where would the crossover gain half to be? Up really high? On my US-x3 it says "level" and there are knobs from 0-20. I'm not sure if this is voltage or what, but I have it set at about 3/4 with the gain all the way down on the amp and no sub level on the h/u. The vari loud control for bass is on half and its very loud. I'm not sure the gain is set correctly so I was looking for the easiest way to do it.

 

[audioholic 5,000+ posts]

If that is the case then I should be running higher voltage constantly? So if I set the gain a tad above the highest voltage (I'll say 6 volts) Where would the crossover gain half to be? Up really high? On my US-x3 it says "level" and there are knobs from 0-20. I'm not sure if this is voltage or what, but I have it set at about 3/4 with the gain all the way down on the amp and no sub level on the h/u. The vari loud control for bass is on half and its very loud. I'm not sure the gain is set correctly so I was looking for the easiest way to do it.

Well, you want as high a signal voltage as possible at any given time. But at some point, if induced noise is already inaudible, more signal voltage will give no more benefit.
The owner's manual should give you a signal input voltage range, this will tell you what the max setting is on the knob. If its simply labeled 1-20, hopefully the book will give a better idea what this corresponds to.

And don't forget, "max gain" means minimum input voltage. You are adjusting an input sensitivity. So if your signal voltage is 'high', your gain should be set 'low' to compensate. The hotter the signal, the lower the input sensitivity should be to balancce it out. I only mention this so nobody misinterpretets the terminology we are using here.

 

[mokedaddy 5,000+ posts]

How would this happen? By far the most common way to 'fry' a h/u amp is by placing an improper impedance on it.
If your h/u fries its own amp simply by running the volume near max, you had one shitty head that needed discarded anyway, and you should consider yourself lucky God gave you a sign that its time to upgrade.

Never said it was good product just that I have seen it before. And no it wasnt me.

 

[Grinder1989 5,000+ posts]

Well, you want as high a signal voltage as possible at any given time. But at some point, if induced noise is already inaudible, more signal voltage will give no more benefit.
The owner's manual should give you a signal input voltage range, this will tell you what the max setting is on the knob. If its simply labeled 1-20, hopefully the book will give a better idea what this corresponds to.

And don't forget, "max gain" means minimum input voltage. You are adjusting an input sensitivity. So if your signal voltage is 'high', your gain should be set 'low' to compensate. The hotter the signal, the lower the input sensitivity should be to balancce it out. I only mention this so nobody misinterpretets the terminology we are using here.

I checked the manual. The crossover actually goes from 0-9 volts meaning it should be set around 3/4. That mean the gain on the amps should be low. I'll have to play with it I guess.

 

[Propimp 10+ year member]

OP= butthurt *** attention whore

 

[Grinder1989 5,000+ posts]

OP= butthurt *** attention whore

Such an intelligent post. Maybe you should write for the New York Times? I might bring out the best in you.

 

[donpisto 5,000+ posts]

I personally think that the dmm method for setting gains *****. I guess it's just a more precise/easier way for people to learn how to set them.

If it *****, please tell me what better way I can set the gains and match them with a QVC sub with an amp on each coil. Not trying to be an ass or anything, but I don't see any other way...o scope yes, but no access, so other than that, if there is another way with less headache, it would be nice to know.

 

[audioholic 5,000+ posts]

If it *****, please tell me what better way I can set the gains and match them with a QVC sub with an amp on each coil. Not trying to be an ass or anything, but I don't see any other way...o scope yes, but no access, so other than that, if there is another way with less headache, it would be nice to know.

In the case of a QVC with an amp on each coil, a DMM would be better than an oscope actually. Both would be best, but a DMM would give you a consistant amount of power to each coil, where as just using an oscope would mean you wouldn't sending a squared wave, but each amp may/will clip at a slightly different level. Hance you'd likely be sending slightly diff power to each coil. At least, that's how I see it.

 

[donpisto 5,000+ posts]

In the case of a QVC with an amp on each coil, a DMM would be better than an oscope actually. Both would be best, but a DMM would give you a consistant amount of power to each coil, where as just using an oscope would mean you wouldn't sending a squared wave, but each amp may/will clip at a slightly different level. Hance you'd likely be sending slightly diff power to each coil. At least, that's how I see it.

Thanks. I figured DMM would be the best way to go about it.

 

[terra 5,000+ posts]

its ashame you own that sub and wanna try this...next time im talking to jacob and getting them before you.

 

[Grinder1989 5,000+ posts]

its ashame you own that sub and wanna try this...next time im talking to jacob and getting them before you.

Good luck, I'm a dealer. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif I haven't done anything yet.

 

[Jeremy M 10+ year member]

audioholic is a book of knowledge?

alot of people may say this thread was a waste of space, but i learned alot.

 

[MikeyB 5,000+ posts]

Pretty much audioholic needs to make a post of all of his knowledge about car audio and make it a sticky, then we can just refer all the mis-informed on here to just look at his post. It would save him the key strokes in the long run since he comes into all these threads and sets everyone straight.........