rca input power

[Patthehat033 10+ year member]

So on a mono block amp that requires 2 rca inputs I currently only have 1 rca hooked up from a lineout converter coming from one of my stock speakers. If I hooked up 2 speakers to the line out converter and run 2 rca's to the amp, will I be getting more power?

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[akheathen Premium Member]

only if the single signal is not strong enough to drive the amp to full power, but i doubt that is the case. you could always get the same effect by connecting both speaker leads on the loc to the same wires

 

[Patthehat033 10+ year member]

That is what I was thinking, that maybe the amp would only be receiving a signal with half the amperage that it can handle. Which would in turn only allow the amp to run at 1/2 to 3/4th's of its potential. Or do I have the concept wrong.

 

[keep_hope_alive Premium Member]

You lose half of the signal strength with one input when the amp sums the two signals. More importantly, you lose any music that is mixed on the other channel.

Always give the amp both left and right inputs and let it sum them properly.

 

[Patthehat033 10+ year member]

Crap. So I can run probably around twice the power I am running now by running the second speaker on the LOC so I can run both RCA's?

 

[maylar 10+ year member]

Crap. So I can run probably around twice the power I am running now by running the second speaker on the LOC so I can run both RCA's?

No. You can usually adjust the sensitivity on the amp to give full power with only one input. Adding the second channel doesn't neccessarilly mean you get more power, it depends on how you have the gain set.

 

[Patthehat033 10+ year member]

Hey not that your wrong or anything since I am sure you know a lot more than I do about this stuff, but if you added a second input then the amp can now draw in even more current, because its not just getting one signal but two. And since when you turn up the gain you boost the signal voltage, you would now be boosting both signals not both. Or is that wrong?

 

[akheathen Premium Member]

You lose half of the signal strength with one input when the amp sums the two signals. More importantly, you lose any music that is mixed on the other channel.
Always give the amp both left and right inputs and let it sum them properly.

i have to strongly disagree. the rcas don't really pass any current at all. it's just a voltage signal. all a loc does is knock the voltage down to an appropriate level, and that is usually adjustable. i do agree that it will not provide any signal that is played in the other channel only, but that is not real common. last song i heard do that was beastie boys in the 90's. the only difference is that the preamp circuits in the amp should see a little less strain, and it may be possible that the amp may not reach full power if the loc is not putting out enough voltage. think of the rca signal and amp as a car. the rca signal is the gas pedal, and the amp is the engine. pushing the pedal harder will never net you any more peak hp from the engine. only a more powerful engine setup will do that. adjusting the gain is like moving the seat forward and back, and the rca signal is how much pressure your foot gives. and just as such, when you hit the floor board, that is all you get. so, if you move the seat far enough forward to push the throttle all the way, you have reached the max range. if your foot is strong enough to push it all the way, you are good. moving the set up and pushing harder gets you nothing but a sore/tired leg(clipping) and most likely a cramp(blowed up system)

 

[maylar 10+ year member]

Hey not that your wrong or anything since I am sure you know a lot more than I do about this stuff, but if you added a second input then the amp can now draw in even more current, because its not just getting one signal but two. And since when you turn up the gain you boost the signal voltage, you would now be boosting both signals not both. Or is that wrong?

No. It's a mono amp, so the 2 signals would be combined into one internally anyway. If you set the gain on the amp correctly with just 1 input you won't get any more power with both inputs. In fact you'd probably have to turn the gain down to keep the amp from clipping.

 

[keep_hope_alive Premium Member]

i have to strongly disagree. the rcas don't really pass any current at all. it's just a voltage signal. all a loc does is knock the voltage down to an appropriate level, and that is usually adjustable. i do agree that it will not provide any signal that is played in the other channel only, but that is not real common. last song i heard do that was beastie boys in the 90's. the only difference is that the preamp circuits in the amp should see a little less strain, and it may be possible that the amp may not reach full power if the loc is not putting out enough voltage. think of the rca signal and amp as a car. the rca signal is the gas pedal, and the amp is the engine. pushing the pedal harder will never net you any more peak hp from the engine. only a more powerful engine setup will do that. adjusting the gain is like moving the seat forward and back, and the rca signal is how much pressure your foot gives. and just as such, when you hit the floor board, that is all you get. so, if you move the seat far enough forward to push the throttle all the way, you have reached the max range. if your foot is strong enough to push it all the way, you are good. moving the set up and pushing harder gets you nothing but a sore/tired leg(clipping) and most likely a cramp(blowed up system)

don't take this as an attack. i'm not mad, i just need to clarify a few things. you are misunderstanding me, or how this works. i didn't say anything about current. we're talking about voltage, specifically line level voltage being fed into car audio amplifiers using standard source components. when the amp inputs sum the left and right channel - you get a 3dB gain (i.e. 2x the voltage) on the input signal - for signals that are equal left and right. if a signal is in one channel only, then obviously there is no gain. a voltage gain on the input = increased voltage on the output = increased output power (assuming all else is constant). i do agree that gains would be adjusted if you change from 1 input to 2 inputs.

there is no "strain" on input components - op amps and transistors don't experience "strain" from an input signal whatsoever. they'll just clip if the output is greater than the supply voltage - but the circuit is designed such that no amount of clipping will hurt the components - square waves are acceptable signals too.

EE's don't need analogies to understand electronics.

the bass guitar, floor toms, piano, etc. can be shifted in the soundstage depending on the recording engineer - it is album dependent and none of us will ever know how every song ever made is mixed. so we design systems that are universal and provide both channels to the system components.

 

[Patthehat033 10+ year member]

So basically when you break it all down, if you added another rca you can technically input more voltage, but since the amp will start clipping after a certain voltage you would have to keep the gain low with 2 rca's and the gain high with 1 rca to get the same power.

Also I am a bit confused on the "no current" thing. Is it possible to have no current? I thought voltage was thought of as the pressure of the current. current = amps? Without current what would the definition of voltage be considered?

 

[akheathen Premium Member]

don't take this as an attack. i'm not mad, i just need to clarify a few things. you are misunderstanding me, or how this works. i didn't say anything about current. we're talking about voltage, specifically line level voltage being fed into car audio amplifiers using standard source components. when the amp inputs sum the left and right channel - you get a 3dB gain (i.e. 2x the voltage) on the input signal - for signals that are equal left and right. if a signal is in one channel only, then obviously there is no gain. a voltage gain on the input = increased voltage on the output = increased output power (assuming all else is constant). i do agree that gains would be adjusted if you change from 1 input to 2 inputs.there is no "strain" on input components - op amps and transistors don't experience "strain" from an input signal whatsoever. they'll just clip if the output is greater than the supply voltage - but the circuit is designed such that no amount of clipping will hurt the components - square waves are acceptable signals too.

EE's don't need analogies to understand electronics.

the bass guitar, floor toms, piano, etc. can be shifted in the soundstage depending on the recording engineer - it is album dependent and none of us will ever know how every song ever made is mixed. so we design systems that are universal and provide both channels to the system components.

sorry, i didn't mean to offend, i should have stated the analogy was intended to help the o.p. understand what is going on. buy strain, i'm referring to more wear on one side in the preamp input section, than the other. first thing the signal hits should be a resistor and capacitor, possibly switches/pot, before hitting one leg of an op-amp. many times i've seen the output common/neutral tied in with the input/output connections directly and indirectly. strain/wear is minimal, and you probably wouldn't notice in a mono anyways. the point was that you could achieve the same level of rca signal if you tap one speaker wire, or 2. o.p.- when it comes to rcas, there is a miniscule amount of current passed through the rcas, and so, for the point of argument, it is basically no current passed. where you pass current is through the power and sub connections. and yes, when you break it down, you can get the same max power with one rca turned up as with 2 rcas turned down

 

[keep_hope_alive Premium Member]

gotcha. agreed.