new question! about RCA cables...

[jaygeorge1979 10+ year member]

I am talking about the red and white part of the RCA cable things (the audio parts)....what exactly is happening in these cables? i beleive it is stereo sound...one is left channel, one is right channel....is this correct? the reason i am asking is that i am trying to figure out how i am gonna hook up my DCX when i finally get it...it has enough outputs, but the stereo i am using has one pair of RCA audio inputs...if i can use one (say, the left channel) for midrange testing and the other (say, the right channel) for a tweeter testing, i can test em both at the same time to see which go together well...it wouldnt be stereo sound, but it would be two channels....am i even close to being right?

Click to read more...

 

[squeak9798 5,000+ posts]

I am talking about the red and white part of the RCA cable things (the audio parts)....what exactly is happening in these cables? i beleive it is stereo sound...one is left channel, one is right channel....is this correct?

Yes

the reason i am asking is that i am trying to figure out how i am gonna hook up my DCX when i finally get it...it has enough outputs, but the stereo i am using has one pair of RCA audio inputs...if i can use one (say, the left channel) for midrange testing and the other (say, the right channel) for a tweeter testing, i can test em both at the same time to see which go together well...it wouldnt be stereo sound, but it would be two channels....am i even close to being right?

What exactly are you trying to do?

 

[thylantyr 10+ year member]

the reason i am asking is that i am trying to figure out how i am gonna hook up my DCX when i finally get it

I told you how you will do it, remember? //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

You need to digest the data I send to you //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

DCX is female XLR input, male XLR output.

Pic;

http://www.rcrowley.com/ComClone/images/Bottom.JPG

The one with holes is female, the other one with prongs is male. //content.invisioncic.com/y282845/emoticons/tongue.gif.6130eb82179565f6db8d26d6001dcd24.gif

You need a RCA {male end} to XLR male cable for sending a signal from

your 'RCA' source to DCX input.

Pic of XLR male end.

http://www.tonycolter.com/photos/potd/potd-20030429.jpg

For DCX output, you need a female XLR to 'whatever' cable.

female XLR looks like this;

http://www.coutant.org/a3f2.jpg

So.. if you have a proamp, you need a XLR [female] to XLR [male] cable

when using the DCX output. If you use a home amp with RCA input,

you need XLR [female] to RCA [male] cable.

Since the DCX output is a 'strong' signal you may not get the best signal to

noise ratio as home amplfiers have 'more gain', so you can cheat and reduce

output gain by 6dB if you do a 'trick' to the XLR to RCA output cable.

You can DIY these cables if you are skilled in soldering or you can buy

these adapter cables.

I don't know if the make the -6dB XLR to RCA cable.

If you want to DIY cables;

http://www.caraudioforum.com/vbb3/showthread.php?t=220559&highlight=cables

Once you get past the interconnect issue, the rest should be easy. If you never used XLR before,

it will be confusing. Take your time to digest the data. XLR in proaudio is a balanced interconnect,

home audio is unbalanced.

Who, what, why on this subject found here;

http://www.rane.com/note151.html

 

[jaygeorge1979 10+ year member]

i understand what ur saying thy, but my question is about that output cable...i want to be able to run two drivers (mid and tweet) at the same time...BUT when i run output to a cable that converts XLR into 1/4", then i get an adaptor to go from 1/4" -- > RCA, there will be TWO RCA cables for that ONE channell...well i only have one pair of inputs...now, when i run a DIFFERENT output from the DCX to another pair of RCAs i will have 4 RCA males going into a single pair of RCA inputs...even if i buy splitters it will still send BOTH his/lows to both left and right, which means the crossover setup would be inefficient...what i am thinking is to use only ONE male RCA for each of the outputs from the DCX (that is, take one of the midrange level output and one from the higher freq output and put them intot he input)...wouldnt this put mids to one amp channel and highs to the other amp channel>?

 

[thylantyr 10+ year member]

i want to be able to run two drivers (mid and tweet) at the same time

The DCX as six outputs.

If you want to test one midrange and one tweeter, then you will use 2 DCX

outputs, one for midrange, one for tweeter, each output has it's own seperate

cable, one signal only per cable.

...BUT when i run output to a cable that converts XLR into 1/4", then i get an adaptor to go from 1/4" -- > RCA

Why do you want to -> XLR to 1/4" to RCA ?

Why not -> XLR to RCA ? This is one cable and no extra adapter.

One XLR to RCA cable per DCX output is what you need.

If you DIY the cable, you can make a switch to include the 6dB output signal

attenuation.

//content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[thylantyr 10+ year member]

The special XLR to RCA cable I made with the 6dB attenuation switch.

http://home.pacbell.net/lordpk/cables/Belden_8760_Cable/16.jpg

Normally, XLR pin 1 is also connected to pin 3 in a XLR to RCA cable.

If you want attenuation you disconnect pin 3 and leave it open.

DIY XLR Output to RCA with -6dB output gain

XLR Pin 1 = Shield ground => RCA ground

XLR Pin 2 = Positive balanced signal => RCA hot {signal}

XLR Pin 3 = Negative balanced signal = don't connect

I soldered a wire from pin 1 to the switch, from pin 3 to the switch. Now I

can toggle pin 3 open or shorted to pin 1.

/simple

 

[jaygeorge1979 10+ year member]

even if i go from XLR to RCA there are still 4 total male RCA pieces and only 2 female RCA inputs...i think since each RCA cable is either left or right, i will hook the RED wire from each output that i use (one for mids one for highs) into an input RCA hole...this will be mono sound for each the mid and the tweeter, seeing as the left with be for the mid and the right will be for the tweeter...this will allow the amp to power each channel seperately considering whatever filter i have created from the actice crossover...NOW if thats all right...all i need to figure out is this attenuation hoopla...i dont want to build my own cables...that just seems like a whole other ball game...if possible, i would like to buy some XLR --> RCA cables and maybe mod them myself? is that possible?

 

[jaygeorge1979 10+ year member]

also, that whole pro audio is balance, home audio is not balance...i have no earthly idea what you mean...

 

[thylantyr 10+ year member]

even if i go from XLR to RCA there are still 4 total male RCA pieces and only 2 female RCA inputs...i think since each RCA cable is either left or right, i will hook the RED wire from each output that i use (one for mids one for highs) into an input RCA hole...this will be mono sound for each the mid and the tweeter, seeing as the left with be for the mid and the right will be for the tweeter...this will allow the amp to power each channel seperately considering whatever filter i have created from the actice crossover...NOW if thats all right...all i need to figure out is this attenuation hoopla...i dont want to build my own cables...that just seems like a whole other ball game...if possible, i would like to buy some XLR --> RCA cables and maybe mod them myself? is that possible?

To test one midrange and one tweeter keeping synergy, you should do this;

Input

Source left channel {RCA} -> DCX input [RCA male to XLR male].

Output

DCX output #3 -> XLR female to RCA male -> amplifier channel right [tweeter]

DCX output #2 -> XLR female to RCA male -> amplifier channel left [midrange]

If you have a 3rd amp channel and want to test a woofer;

DCX output #1 -> XLR female to RCA male -> amplifier channel 3rd [woofer]

Default configuration on the DCX is;

Output 1 - woofer

Output 2 - midrange

Output 3 - tweeter

Output 4 - woofer

Output 5 - midrange

Output 6 - tweeter

You can change this.

XLR to RCA cables;

http://www.bhphotovideo.com/bnh/controller/home?O=NavBar&A=search&Q=&ci=4201

http://www.bhphotovideo.com/bnh/controller/home?O=NavBar&A=FetchChildren&Q=&ci=1667

I'm sure if you look hard you can find a better deal.

.if possible, i would like to buy some XLR --> RCA cables and maybe mod them myself?

You can use a regular cable for now and if you have too much gain, DIY a cable

later. Mod a cable? If they connect that pin 1 to 3 at the connector side you have

to get in there to disconnect it, will this be easy to do or just make a cable?

DIY cables is simple;

See pics;

http://home.pacbell.net/lordpk/cables/

View pics in number sequence for step by step instruction;

http://home.pacbell.net/lordpk/cables/Belden_8760_Cable/

Read the DIY cable guide I wrote on that CAF thread.

You can get some good Belden 8760 cable cheap.

 

[jaygeorge1979 10+ year member]

thy, you said i can use a regular cable and if i have too much gain, then i can try DIY...what do you mean by too much gain? how will i kno?

in the event that i do, is there any chance i can slide you a little cash to make em for me //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif ?

 

[jaygeorge1979 10+ year member]

i still cant figure out what is the diff between balanced and not balanced...

 

[thylantyr 10+ year member]

thy, you said i can use a regular cable and if i have too much gain, then i can try DIY...what do you mean by too much gain? how will i kno?
in the event that i do, is there any chance i can slide you a little cash to make em for me //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif ?

Home audio amps usually have fixed gain and compared to pro audio world, the gain

will be on the high side. Pro audio amplifier have adjustable gain knobs and you

can adjust gain as needed. An amplifier with higher gain will create more audible hiss. Ideally you want to adjust the gain structure of the whole system for best

low noise.

In my case, my DCX drives both, one home amp, one pro amp. My proamp is

set about 1/3 gain, but my home amplifier is higher in gain driving tweeters, therefore the gain structure isn't optimum to keep the hiss low because the DCX

is driving a higher voltage into that amp. I do the 'trick' to reduce the signal into

the home amp. There is another way to reduce gain using resistors.

If I have time, I may be able to make cables. Later, if you have problems.

 

[thylantyr 10+ year member]

i still cant figure out what is the diff between balanced and not balanced...

Start here;

http://www.allaboutcircuits.com/vol_3/chpt_8/2.html

Learn what 'single ended input' is vs. 'differential input'. Differential is akin to balanced. A balanced setup is differential but a differential input doesn't guarantee that it's balanced.

Consumer audio is single ended input using a RCA cable. The generic RCA cable

has one wire to carry the signal and a grounded braided shield as the return path. Single ended meaning 'one input'. Some higher end home audio uses balanced or differential. All pro audio is balanced.

Balanced or differential needs 3 wires, two for signal, one for ground.

The signal is non-inverting and inverting that feeds into the amplifier and this

signal comes from the source, plus ground.

In proaudio they use [differential] balanced inputs to reduce noise induced in

long cable runs as differential inputs only amplify the difference between

input 1 and input 2 so any common noise on input 1 and input 2 will be rejected,

the amount of rejection is referred to as CMRR.

Pro audio also uses higher voltage preamp signal to raise the noise floor too, plus

balanced inputs, it kills any noises picked up by cabling.

To get off topic, you also have high speed digital electronics that have LVDS

inputs/outputs to get higher speed operation of the chip. 'Low Voltage Differential' Signaling;

http://www.webopedia.com/TERM/L/LVDS.html

There is alot of differential stuff in the electronics world, you just don't see it.