Jump to content
SAU Community

Recommended Posts

ok im running two amps, one for each sub how do i connect them both to the rca outlet on the backof the headunit... through the pass through outlets on one amp to the other... or with a y adapter to each one thanks in advance

Hey there,

You can do it both ways as you stated in your post.

If you have output RCA's from your amp then just use those, but its just as easy to get some splitters. The signal will be exactly the same.

Fixxxer :D

Link to comment
https://www.sau.com.au/forums/topic/116786-rca-question/#findComment-2147922
Share on other sites

I beleive it would halve it, yes, that's what I meant. It gives more chance of noise to be introduced, but since the split will be fairly near the end, it might not cause any issues. Cheaper and better to use the 1st amp's passthrough for the 2nd amp.

Link to comment
https://www.sau.com.au/forums/topic/116786-rca-question/#findComment-2155989
Share on other sites

Yeah if the passthrough is there use it. It's easily the best option.

In my car i had to use a splitter for the sub output because i accidently stuffed up one of the rca outputs by running 12v through it and for some reason i hear a thumping everytime i turn car on/off or change tracks or radio stations. Very annoying.

Well when i split it, the amp needed to be turned up alot more, but it could handle it. A cheap splitter is around $1 from jaycar so not very expensive.

Link to comment
https://www.sau.com.au/forums/topic/116786-rca-question/#findComment-2156868
Share on other sites

haha, splitters don't halve the signal :laughing-smiley-014:

Amplifiers draw something like microamps from the signal line, its nothing that could cause any signal loss. Your main worry should be noise when running the cable. Longer cables pick up more noise and you lose a little signal to resistance. Never run RCA's next to the power cable aswell, they produce alot of noise and grounding problems.

Turn on thump is most likely a grounding issue btw

Link to comment
https://www.sau.com.au/forums/topic/116786-rca-question/#findComment-2159765
Share on other sites

In my car i had to use a splitter for the sub output because i accidently stuffed up one of the rca outputs by running 12v through it and for some reason i hear a thumping everytime i turn car on/off or change tracks or radio stations. Very annoying.

my head unit has done that since new... ive had it in for repair and they reakoned there was nothing wrong with it... (pioneer DEHP736) all i did to stop it was put a rocker switch on the remote wire... i turned it on and off before i turned the car off and after i switched it on or change radio stations ect... its a good thing to have if some nice policeman hears you music you can flick a switch and turn just the subs off until he passes :rofl:

on the rca note thanks all for your help i will definately be using the passthrough

Link to comment
https://www.sau.com.au/forums/topic/116786-rca-question/#findComment-2161272
Share on other sites

Yeah it's not actually signal lose your right but it is half the power. So the waveform going in is actually half the size of the non split one.

Thats not right :

Think about it like two resistors in parallel. Each resistor represents the input impedance of an amplifier (typically >10k ohms). One side of the resistor is grounded, the other is the RCA connection. If we ignore the slight resistance of the cable between the two amplifiers (its less than 1 ohm anyway) the resistors receive the exact same voltage. Current is split between the two... but thats irrelevant as amplifiers amplify the voltage at the input and not the current.

Signal loss can only really occur because the impedance has dropped at the amplifer side of the cable. So we have a 10k ohm impedance for one amp and a 5k ohm impedance for two (parallel resistors again). More current has to flow but accross a cable of say 50 ohms (exagerated) you only lose 0.1 of a volt for a 10v signal as opposed to 0.05 voltage for one amplifier.

In short, if your losing signal to RCA cables its probably a faulty cable or connector thats somehow making the resistance of the cable higher. Things like loose connectors, kinks in the cable, rubbing against metal and internal break from stretching will all cause it.

Link to comment
https://www.sau.com.au/forums/topic/116786-rca-question/#findComment-2162592
Share on other sites

While this is a very technical discussion, and I do have to agree that using splitters is not ideal, I think we have all over looked one small factor.

IT WONT MATTER. Yep, that's right. It wont matter one little bit.

The quality of equipment needed and its associated price makes this argument pointless.

Let me put it this way, go to a retailer, buy $1500- $2000 of equipment, instal rca splitters in the system and the equipment will not be of good enough quality to produce a level of sound quality that would represent an audible difference to the end user.

In English - the gear would not be good enough to hear the difference

On the other hand, spend $25k - $30k and you are starting to get into equipment that would be good enough to provide an oppurtunity to hear the difference.

And as logic would have it, if you were to spend that amount of money you would be getting equipment that would not need splitters anyway.

I guess at this point I should also provide an alternative, if you must use rca splitters and think they will effect your "sound quality" ( you wont hear it anyway) go out and waste, er spend you money on some crystal line drivers. They will take all the noise away.

Link to comment
https://www.sau.com.au/forums/topic/116786-rca-question/#findComment-2163191
Share on other sites

Thats not right :

Think about it like two resistors in parallel. Each resistor represents the input impedance of an amplifier (typically >10k ohms). One side of the resistor is grounded, the other is the RCA connection. If we ignore the slight resistance of the cable between the two amplifiers (its less than 1 ohm anyway) the resistors receive the exact same voltage. Current is split between the two... but thats irrelevant as amplifiers amplify the voltage at the input and not the current.

Signal loss can only really occur because the impedance has dropped at the amplifer side of the cable. So we have a 10k ohm impedance for one amp and a 5k ohm impedance for two (parallel resistors again). More current has to flow but accross a cable of say 50 ohms (exagerated) you only lose 0.1 of a volt for a 10v signal as opposed to 0.05 voltage for one amplifier.

In short, if your losing signal to RCA cables its probably a faulty cable or connector thats somehow making the resistance of the cable higher. Things like loose connectors, kinks in the cable, rubbing against metal and internal break from stretching will all cause it.

I stand corrected. I was thinking about the current which doesn't really matter in this case.

Funny that because i did a whole yearly subject on op-amps and did soooo many equations with them and actually designed one at uni. Well thats what happens when you don't look over things for a year.

Thankyou for correcting me :)

Link to comment
https://www.sau.com.au/forums/topic/116786-rca-question/#findComment-2163715
Share on other sites

I stand corrected. I was thinking about the current which doesn't really matter in this case.

Funny that because i did a whole yearly subject on op-amps and did soooo many equations with them and actually designed one at uni. Well thats what happens when you don't look over things for a year.

Thankyou for correcting me :D

No problems :)

frx026, I see the point your trying to make but splitters are actually the better option compared to pass throughs and line drivers. The signal remains shielded the entire time and isn't run through any components with noise of there own (e.g opamps) in a splitter. If it goes into an amplifier unsheilded (onto the board) with a switch mode power supply nearby and goes through an opamp and out again its going to pick up alot more noise than with a simple splitter.

That said, even if you spent 25k on audio gear I dout you'd hear the difference between a passthrough and splitter anyway. Its a limitation of our ears if anything.

As long as you don't buy absolute shit cable, you'll never have a problem. Any car audio salesman that tries to sell you oxygen free, quadruple shielded, snake-oil-included RCA's is just plain full of crap.

Link to comment
https://www.sau.com.au/forums/topic/116786-rca-question/#findComment-2164666
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • For DBA, check out their guide table here. https://dba.com.au/wp-content/uploads/2023/01/Direct_Replacement-Guide-2021.2.pdf   Additionally they have some other guides and info on how to make sure you choose the right pad.
    • Sorry, just assumed that talk of coloured pads meant EBC red/green/yellow/shit stuff. I don't know the DBA pads, but it's a reasonable bet that they will be OK. DBA make good stuff generally. Those 4000 series rotors I linked to are very good. I may well replace the RDA rotors I have with those when required.
    • The average previous owner for these cars were basically S-chassis owners in the US. Teenagers or teenager-adjacent. I often tell people that neglect is easier to fix than something that was actively "repaired" by previous owners.
    • Update 3: Hi all It's been a while. Quite a lot of things happened in the meantime, among other things the car is (almost) back together and ready to be started again. Things that I fixed or changed: Full turbo removal, fitting back the OEM turbo oil hardlines. Had to do quite a bit of research and parts shopping to get every last piece that I need and make it work with the GT2860 turbos, but it does work and is not hard to do. Proves that the previous owner(s) just did not want to. While I was there I set the preload for the wastegates to 0,9bar to hopefully make it easier for the tuner to hit the 370hp I need for the legal inspections that will follow later on. Boost can always go up if necessary. Fitted a AN10 line from the catch can to the intake hose to make the catchcan and hopefully the cam covers a slight vacuum to have less restrictive oil returns from the head and not have mud build up as harshly in the lines and catch can. Removed the entire front interior just shy of the dashboard itself to clean up some of the absolutely horrendous wiring, (hopefully) fix the bumpy tacho and put in LED bulbs while I was there. Also put in bulbs where there was none before, like the airbag one. I also used that chance to remove the LED rpm gauge on the steering column, which was also wired in absolute horror show fashion. Moved the 4in1 Prosport gauge from sitting in front of the OEM oil pressure gauge to the center console vents, I used a 3D printed vent piece to hold that gauge there. The HKB steering wheel boss was likely on incorrectly as I sometimes noticed the indicator reset being uneven for left vs. right. In the meantime also installed an airbag delete resistor, as one should. Installed Cube Speed premium short shifter. Feels pretty nice, hope it'll work great too when I actually get to drive. Also put on a fancy Dragon Ball shift knob, cause why not. My buddy was kind enough to weld the rust hole in the back, it was basically rusted through in the lowermost corner of the passenger side trunk area where the wheel arch, trunk panel and rear quarter all meet. Obviously there is still a lot of crustiness in various areas but as long as it's not rusted out I'll just treat and isolate the corrosion and pretend it's not there. Also had to put down a new ground wire for the rear subframe as the original one was BARELY there. Probably a bit controversial depending on who you ask about this... but I ended up just covering the crack in the side of the engine block, the one above the oil feed, with JB Weld. I used a generous amount and roughed up the whole area with a Dremel before, so I hope this will hold the coolant where it should be for the foreseeable future. Did a cam cover gasket job as the half moons were a bit leaky, and there too one could see the people who worked on this car before me were absolute tools. The same half moons were probably used like 3 times without even cleaning the old RTV off. Dremeled out the inside of the flange where the turbine housing mates onto the exhaust manifolds so the diameter matches, as the OEM exhaust manifolds are even narrower than the turbine housings as we all know. Even if this doesn't do much, I had them out anyways, so can't harm. Ideally one would port-match both the turbo and the manifold to the gasket size but I really didn't feel up to disassembling the turbine housings. Wrapped turbo outlet dumps in heat wrap band. Will do the frontpipe again as well as now the oil leak which promted me to tear apart half the engine in the first place is hopefully fixed. Fitted an ATI super damper to get rid of the worn old harmonic balancer. Surely one of the easiest and most worth to do mods. But torquing that ARP bolt to spec was a bitch without being able to lock the flywheel. Did some minor adjustments in the ECU tables to change some things I didn't like, like the launch control that was ALWAYS active. Treated rusty spots and surface corrosion on places I could get to and on many spots under the car, not pretty or ideal but good enough for now. Removed the N1 rear spats and the carbon surrounding for the tailpipe to put them back on with new adhesive as the old one was lifting in many spots, not pretty. Took out the passenger rear lamp housing... what do you know. Amateur work screwed me again here as they were glued in hard and removing it took a lot of force, so I broke one of the housing bolts off. And when removing the adhesive from the chassis the paint came right off too. Thankfully all the damaged area won't be visible later, but whoever did the very limited bodywork on this car needs to have their limbs chopped off piece by piece.   Quite a list if I do say so myself, but a lot of time was spent just discovering new shit that is wrong with the car and finding a solution or parts to fix it. My last problem that I now have the headache of dealing with is that the exhaust studs on the turbo outlets are M10x1.25 threaded, but the previous owner already put on regular M10 nuts so the threads are... weird. I only found this out the hard way. So now I will just try if I can in any way fit the front pipe regardless, if not I'll have to redo the studs with the turbos installed. Lesson learned for the future: Redo ALL studs you put your hands on, especially if they are old and the previous owners were inept maniacs. Thanks for reading if you did, will update when the engine runs again. Hope nothing breaks or leaks and I can do a test drive.
×
×
  • Create New...