Best location for a DSP?

[StangTime]

Working out the hook-up details for my audio upgrade.

The system is made up of the following:
Hertz Mille Pro MPK165P3 2-way component speakers. Woofer in the lower door, tweeter in the midrange location. Factory tweeters, center channel, and rears will be disconnected. 2-ways will run active.
Hertz H8 DSP with DRC HE remote control for sub level and preset selection.
Hertz HCP5D 5 channel amp, L+R hi and lo + Sub channel

I have basically 2 system layout options:

1. Install the DSP where the factory amp is now above the drivers kick panel. Make a break-out box for all the connections using the black, grey, and brown amplifier plugs. DSP will feed 4 twisted RCA signals going back to the trunk amplifier (L+R main and L+R sub) the DSP will control the trunk amplifier's sub channel output. 9 conductor speedwire will connect at the factory plugs to then run back to the amplifier output channels in the trunk along with a remote turn-on.

2. Or install the DSP and amp in the trunk. Run a custom made twisted pair signal harness from the factory amp connector (black plug, line-level out) and the same 9 conductor speedwire running to the OEM grey and brown plugs to make the speaker connections.

I am paranoid of system noise. The old-school car audio installer in me is saying running the factory line-level signals from the black plug all the way back to the trunk is going to pick-up noise. I assume this would also need to be a shielded twisted pair? The inputs to the DSP are balanced. So they will naturally reject noise. But I just don't know. Likewise the amplifier inputs are also balanced.

Option 1 has the advantage of having the DSP tucked away and the DSP remote control cable won't have to run too far. I will have to build a circuit board for the break-out though. I am not too crazy about contorting my body to lay on my back on the driver's side floor wrestling the DSP and break-out box into place.
Option 2 is going to be simpler than a break-out box but I am concerned about the long signal run back to the trunk mounted DSP. Plus side I don't need long RCA cables.

What have others done for their installs? Any concern running those low-level signals all the way to the trunk?

Car audio has become way too complicated.

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[UserName]

My DSP is in the trunk with the amps. There is no detectable noise. Run the power wire down the passenger side and the rcas down the driver’s side and you should be fine.

 

[StangTime]

My DSP is in the trunk with the amps. There is no detectable noise. Run the power wire down the passenger side and the rcas down the driver’s side and you should be fine.

Are your RCA's running line level or speaker level to your DSP?

 

[UserName]

Are your RCA's running line level or speaker level to your DSP?

Line level. Grabbed the Front left and right signal before the factory amp and ran one set to the processors in the back. From there it goes to four two channel amps.

 

[StangTime]

Line level. Grabbed the Front left and right signal before the factory amp and ran one set to the processors in the back. From there it goes to four two channel amps.

Alright. Thank you. Looks like it's possible to mount my DSP in the trunk without issues.
Now to decide what type of wire to run...

 

[UserName]

Alright. Thank you. Looks like it's possible to mount my DSP in the trunk without issues.
Now to decide what type of wire to run...

I used mid grade wires with higher end amps and have no negative things to report. You should be fine as long as you don’t buy the cheapest set.

 

[5.0_SD]

In the trunk, no noise at all.

 

[StangTime]

In the trunk, no noise at all.

Pefect! Did you grab power for your DSP off the fuse block on the right? What fuse block is that?

 

[5.0_SD]

Yes I did, the connection to smaller gauge is underneath the board. It is a JL Audio fuse block.
https://www.jlaudio.com/products/xd-fdbu-4-car-audio-distribution-blocks-90462

 

[thill444]

Alright. Thank you. Looks like it's possible to mount my DSP in the trunk without issues.
Now to decide what type of wire to run...

I used speedwire and some mid grade RCA cables down the drivers side and ran the power down the passenger side with no issue.

An example of speedwire:
https://www.amazon.com/Metra-MC918-...d=1&keywords=speed+wire&qid=1591283982&sr=8-1

 

[StangTime]

@5.0_SD That block is really nice but it will blow my budget for hook-up accessories. Found a simpler one for for $8 from Knuconceptz.

@thill444 I have seen that wire and I have some on order. I also ordered the Stac64 connectors from Digikey to interface to the factory wire harness. I think I have what I need now.

All I need to do is decide if I will mount the DSP and amp in the spare tire well (try and keep the inflator kit) or to put them on display in a custom subwoofer box behind the rear seat.
The spare tire well is an easier install and easy access to make changes and adjustments plus I can have a removable sub box if I need to fold the seats down.

Thank you for your help guys !

 

[5.0_SD]

BTW, I just linked what it was, I did not buy it from JL. Probably bought off of partsexpress or something...can't remember. I was going with the kn but IIRC when I was building, knu didn't have a block with enough connections (two I think, I needed three). My big power and ground wire came from knu as well as some connectors...nice stuff they have.

Also, see the hole at the top of my amp board? The tire inflater goes there, just not shown in the picture.

 

[StangTime]

BTW, I just linked what it was, I did not buy it from JL. Probably bought off of partsexpress or something...can't remember. I was going with the kn but IIRC when I was building, knu didn't have a block with enough connections (two I think, I needed three). My big power and ground wire came from knu as well as some connectors...nice stuff they have.

Also, see the hole at the top of my amp board? The tire inflater goes there, just not shown in the picture.

Ah, I wondered what the hole was for. I will likely lay out my system like yours. Move the inflator up and have the dsp on the left and the amp on right near the tail.

I'm excited to start my build. It's been 30 years since I installed a complete system. It's going to be a fun project.

 

[5.0_SD]

An older gent like me...54, hadn't done a system myself since my 20's, lol. I enjoy working on the car, but I will admit it takes a lot for me to go do anything to it in the Florida heat....and I always seem to feel it the next day after working on the car lol.

 

[StangTime]

An older gent like me...54, hadn't done a system myself since my 20's, lol. I enjoy working on the car, but I will admit it takes a lot for me to go do anything to it in the Florida heat....and I always seem to feel it the next day after working on the car lol.

Yup. But not quite as old as you. I will be 51 later this month. My last system was a pair of 10" OZ Audio subs with a PPI Art series 4 channel amp and external Soundstream crossover. The front stage was all top tier MB Quart (they were the go to for sound quality back then, they make garbage now). All this mounted in the floor of my 92 Acura Integra finished in black vinyl and plexi glass panels with green neon lighting. Completely stealth - roll back the carpet and it looked like I had a nuclear reactor in there. I have no pictures of the work I did unfortunately. This was the time before cell phones and digital cameras.

I hear you on the muscle pain. When wrenching on the car my muscles are usually complaining next day too.

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