# Lost in the past



## ckcooper (Feb 20, 2011)

I hope this is the right place for this, if not, mods please move, and sorry for the miss. 
I haven't been up to speed on car audio equipment for a long while now but started researching for an upcoming project. I was looking at a JL audio amp, Slash 300/4v3 I think, and noticed it only has 4 RCA inputs, one for each channel. My past amps always had a pair per channel = 4 channel would have 8 inputs. Would anyone be so kind as to explain why this is and how I would connect to my head unit with pairs of outputs per channel. I hope I am clear on what I am asking, if not please let me know.

Thanks,
CK


----------



## Victor_inox (Apr 27, 2012)

:stupid: no idea what you tried to say.
pair of outputs usually means 2ch. I never seen an amp with 2 inputs for left and 2 inputs for right ch. there is absolutely no need for double inputs.


----------



## lurch (Jan 20, 2014)

each rca input is actually two separate wires.
the outer conductor is negative, the inner conductor is positive.


----------



## Victor_inox (Apr 27, 2012)

lurch said:


> each rca input is actually two separate wires.
> the outer conductor is negative, the inner conductor is positive.


RCA shield connected to the ground in 99.9% of all car electronics.


----------



## WestCo (Aug 19, 2012)

ckcooper said:


> I hope this is the right place for this, if not, mods please move, and sorry for the miss.
> I haven't been up to speed on car audio equipment for a long while now but started researching for an upcoming project. I was looking at a JL audio amp, Slash 300/4v3 I think, and noticed it only has 4 RCA inputs, one for each channel. My past amps always had a pair per channel = 4 channel would have 8 inputs. Would anyone be so kind as to explain why this is and how I would connect to my head unit with pairs of outputs per channel. I hope I am clear on what I am asking, if not please let me know.
> 
> Thanks,
> CK


Amps usually have 1 input per channel. I think you are mistaken...

Only a sub amp would have L/R inputs for 1 channel.


----------



## lurch (Jan 20, 2014)

ckcooper is recalling the era before rca was used, at least on most of the mainstream brands. 
we used amplified power outs from the source, each channel had a positive and a
negative, unless it was craig or a similar brand where a common ground was used
for L&r channels

i believe alpine was the first to use " floating ground "


----------



## Victor_inox (Apr 27, 2012)

lurch said:


> ckcooper is recalling the era before rca was used, at least on most of the mainstream brands.
> we used amplified power outs from the source, each channel had a positive and a
> negative, unless it was craig or a similar brand where a common ground was used
> for L&r channels



If that what he was saying then it makes sense.


----------



## Weigel21 (Sep 8, 2014)

Looking to use high level speaker outputs as the source signal? If so, then buy an LOC to convert the high level speaker wire output into low level RCAs to plug into the JL.


----------



## ckcooper (Feb 20, 2011)

I'm not explaining my confusion very well. I always thought each input should have a pair, thus 8 RCA inputs for a 4 channel amp. Look at the pictures on Crutchfield (they are good, clear photos) for the JL Audio Slash 300/4v3.

Thanks to all for the replies...

CK


----------



## Victor_inox (Apr 27, 2012)

ckcooper said:


> I'm not explaining my confusion very well. I always thought each input should have a pair, thus 8 RCA inputs for a 4 channel amp. Look at the pictures on Crutchfield (they are good, clear photos) for the JL Audio Slash 300/4v3.
> 
> Thanks to all for the replies...
> 
> CK


I suggest you look again 4ch 4 inputs


----------



## ckcooper (Feb 20, 2011)

Victor_inox said:


> I suggest you look again 4ch 4 inputs
> 
> You don't need to suggest I look at anything, I referenced the picture, so I know what it looks like. If you look, there is a single RCA input per channel. That is what I don't get.


----------



## dvcrogers (May 31, 2007)

I can't recall ever seeing anything having two RCA inputs per channel. Being that one RCA plug is a single complete channel (positive and negative all in one plug) I'm not sure how you go about using two RCA plugs per channel. Or why you would need to do so.

Now, speaker level input is a different story. Positive and negative each have a place for input..... So you would have 8 spots for wires to connect.


----------



## lurch (Jan 20, 2014)

read this 

https://en.m.wikipedia.org/wiki/Coaxial_cable


----------



## Victor_inox (Apr 27, 2012)

ckcooper said:


> Victor_inox said:
> 
> 
> > I suggest you look again 4ch 4 inputs
> ...


----------



## MACS (Oct 3, 2007)

The Coustic Amp-505DR, Amp-510DR, and Amp-514DR had two RCA inputs per channel, but they were balanced input amps. I can not think of any other car amps off the top of my head that used two RCA's per channel.

four channel Amp-514DR


----------



## quickaudi07 (May 19, 2010)

Well as everyone stated, you dont have to worry about running 8 rca cables for 4 ch amp... Simply run 4 CH rca kit and be done with it.... 

Sent from my A0001 using Tapatalk


----------

