Long run RCA's - pre-DSP or post-DSP?

[bluedevil1]

Good morning,
I have read all of the various threads about quality threaded/unthreaded RCA cords, etc. and want to know if you're NOT using $100+ RCA's, should the long run be from HU to DSP, (DSP in back by amps) or DSP to amps (DSP under dash). If it makes no difference, feel free to be succinct!

[DavidRam]

Good morning,
I have read all of the various threads about quality threaded/unthreaded RCA cords, etc. and want to know if you're NOT using $100+ RCA's, should the long run be from HU to DSP, (DSP in back by amps) or DSP to amps (DSP under dash). If it makes no difference, feel free to be succinct!

The most likely place between the two, to introduce noise, is the run from DSP to the amps... So, if I had a choice I would put the DSP close to the amps and let the long run be from H/U to the dsp.

[preston]

I feel like the DSP is most likely putting out a higher voltage than the H/U, so my vote is for the DSP closer the H/U.
For me personally though I make the long run to the DSP with one RCA, rather than running multiple RCA's from the DSP to the amps. Much cheaper and easier to package that way.

[Cutaway]

I might get flamed for this, but i just dont think it matters... I think if you use "decent" RCA's and pay a little attention to how you run them (probably not best to wrap around your power wire), then you should be good.
i really like what @preston said here

I make the long run to the DSP with one RCA, rather than running multiple RCA's from the DSP to the amps. Much cheaper and easier to package that way.

One thing i did recently learn is that different amps use different RCA inputs (differential vs single ended), this is very common knowledge that i didnt have. in my collection of amplifies sitting on the shelf, i found that 1/2 of them used single ended Inputs and would probably reject noise better when Single Ended RCA's are used.

[bluedevil1]

Thanks guys! I knew there would not be consensus; I I can see the logic each way. Personally, my justification for putting it next to the amps was if there was to be any signal degradation at all you would want it pre-DSP, the DSP could then potentially clean it up. But I literally thought that up this at 4:30 this morning before my coffee and before my post, so I could be WAY off base!

[Holmz]

Thanks guys! I knew there would not be consensus; I I can see the logic each way. Personally, my justification for putting it next to the amps was if there was to be any signal degradation at all you would want it pre-DSP, the DSP could then potentially clean it up. But I literally thought that up this at 4:30 this morning before my coffee and before my post, so I could be WAY off base!

Yes, have another cup.
Noise cannot be removed as one does not know what the noise is.

I doubt that the HU, nor the DSP has a better noise figure than the other... so one would not gain much.
However a digital path is immune to analogue noise.

I could see the DSP being close to the HU an so then having the DSP spew out the tweeter channel with a really hot signal, and the tweeter amp with the gain at its lowest. That would be the only main argument I can conjure up to putting the DSP close to the HU.
I cannot conjure an argument for having the DSP in the back, other than less cabling and ease of installation... but that is a good reason to put the DSP next to the amps.

If the tweeters etc are in the front, then everything in the front would be ideal, and just running the sub's RCAs to back also makes sense.

Or if one had a rear engine car, then the sub in the front... and everything else.

[Theslaking]

What about differential input? Assuming differential output they get rid of any additional signal picked up along the way or what we call noise.

[vettefiend]

I would guess it doesn't make much difference audibly considering how many competition vehicles have the DSP back by the amps. There is probably less chance to introduce noise in a single run from head unit back to the DSP in the trunk rather than multiple runs from a front mounted DSP to amps in the rear. But that is just my speculation, I ain't got no science and facts to prove one way or the other.

[ckirocz28]

Good morning,
I have read all of the various threads about quality threaded/unthreaded RCA cords, etc. and want to know if you're NOT using $100+ RCA's, should the long run be from HU to DSP, (DSP in back by amps) or DSP to amps (DSP under dash). If it makes no difference, feel free to be succinct!

I use Stinger 4000 series rca's (cheap), and my wiring is basically a rats nest, the long runs are from HU to DSP, short runs from DSP to amps, all lumped into one tangle, no noise at all.
I think the quality of power and ground connections matters more than rcas, as long as the rcas are decent quality and intact.

To be succinct, it doesn't matter at all.

[Holmz]

I use Stinger 4000 series rca's (cheap), and my wiring is basically a rats nest, the long runs are from HU to DSP, short runs from DSP to amps, all lumped into one tangle, no noise at all.
I think the quality of power and ground connections matters more than rcas, as long as the rcas are decent quality and intact.

To be succinct, it doesn't matter at all.

Yeah but... if there was noise and particularly ground loops, you would likely have fixed it rather than try to make it 1/2 of way too much.

That fact that others use both approaches for placing the DSP, and they also get stunning sound, means that they too also have taken care of the basics first.