input voltages and gains?

installing pioneer deh-940mp on an alpine f240 amp. the head unit puts out up to 6 volts and the amp is rated up to 4 volts. Will these two work together? Will the head unit voltage damage the amp or vice versa?

The amp would be "sent" into clipping very "early" because it is a little bit too sensitive for the 6v inputs. If you listen to it at reasonable volumes, ie don't turn the volume knob above 50%, then you'll be fine. I say 50% because your amp is very sensitive and you are sending it a higher voltage signal. This will cause the amp to put out more power then if, say, you had an HU that put out 4volt preouts for the same relative position of the volume knob.

Don't hold your breath while you're waiting for that meter to read 6 volts or you'll end up with the same problem Terri Schiavo has.  Just set your amp gain according to the practices outlined on this forum so often and keep an ear on the sound quality at high volume.

yeah, I was thinking of saying something about RMS voltage, but I didn't feel like it.

Poormanq45 wrote: you are sending it a higher voltage signal. This will cause the amp to put out more power then if, say, you had an HU that put out 4volt preouts for the same relative position of the volume knob.

krf0 wrote: 1AT BEST a line driver _could_ help noise. AT BEST. It WILL NOT increase power. Repeat. IT WILL NOT INCREASE POWER. Where did you get that advice? Or did you just come up with that yourself?

stevdart wrote: Maybe you'll take this at least to the point where you explain why a line driver is called for here?

now after just reading how Poormanq45 said that the higher output voltage on a headunit will cause the amp to put put more power, im confused as to why no one jumped up his ass, as they did when i applied the same principal to another disscussion. infact i didni't say directly that the amps power will increase...but someone assumed thats what i meant. my mother always said that when you assume you make an ASS of U and ME.

soundmasta wrote: now after just reading how Poormanq45 said that the higher output voltage on a headunit will cause the amp to put put more power, im confused as to why no one jumped up his ass, as they did when i applied the same principal to another disscussion. infact i didni't say directly that the amps power will increase...but someone assumed thats what i meant. my mother always said that when you assume you make an ASS of U and ME.

Well, the gain "knob" is used to match the input voltage sensitivity of the amplifier to the output voltage of the head unit. I think I worded my statement oddly. The amp will put out the same amount of power not matter what, until it clips, but if you have the amp set for a 2v signal and you are feeding it a 8v signal, the amp will reach maximum output much earlier, relative to the volume knob, then it would if you were to feed it a 2v signal. Now, if you set the amp for a 8v signal, but your head unit puts out a 2v signal, the amp will not reach its maximum power out put because it is not sensitive enough. You will have to turn the volume knob up higher just to get a little bit of power from the amp relative to a headunit that puts out 8v. Now, if you put a 2v headunit on an amp that is set for an 8v input, you are likely, if you are dumb, to turn the head unit to 100%, which would cause a clipped signal to be sent to the amplifier. Which would cause the amplifier to reproduce that signal.