to PAC or not to PAC

with the factory JBL head unit, would a dsp with high level inputs obviate the need for a PAC AmpPRO AP4-TY13?

 

In my opinion, no.
Ideally, you would do both. The pac will give you perfectly clean and flat audio and even the best DSP’s can only do so much for you. If you’re building a system and can’t splurge on both pieces up front, I personally would start with the AmpPro then add on the DSP.

 

based on all the reading i've done here on TW i started with the assumption that i'd be building around the PAC, but as i've been mapping this out i find that having the control a dsp offers is integral to the whole project for me. i'm looking at the Minidsp 8x12 which seems to have a fairly robust interface for routing, filters and gain for each input channel and couldn't help but wonder if that would make the PAC redundant given it's all downstream of the factory amp if i take high level inputs. another priority is keeping full OEM function and physical profile, so i'm not going to sweat the $350 for the PAC, but i'm still not 100% on signal path and the + vs - of the PAC.

 

as i think about it, you're prolly right, Destin. dsp or no, it's going to be a lot easier to deal with the output if i'm starting with a flat, summed signal.

thanks.

 

ok, here's the Grand Plan:

PAC AmpPRO AP4-TY13 with optical output to -
miniDSP C-DSP 8x12 v2 with 6x RCA out to -
JL Audio XD800/8 v2 to -
dash - CDT Unity 8
front door - CDT... HD- or ES-690
rear doors - not sure if woofer or coaxial would be best for rear fill
stock sub box - CDT HD-800

i'll get some more specific input from CDT on speaker choices. i like the idea of the wide band in the dash since there's no easy place to fit a tweeter in addition to a midrange to go 3-way upfront. it kinda seems like this is what Toyota was trying to do with the JBL system, those stock speakers in the dash seem to cover a wide range. the 8" in the stock sub box may not work out, but i'm not a bass whore, i just want accuracy. if i find it lacking, i'll buy or build a box in the place of the plastic shell/cubby.

i'll run a 4 awg line for power from the battery. can i run this line under the cab and come up at the back wall? there doesn't seem to be a lot of extra room in the runs going through the door jambs. i'm not sure how best to power the dsp. i can't find a distribution block that has something like a 12 awg out. can i just put a ferrule on a 12 awg line and and stick it in a larger gauge distribution block output?

i'm unclear on the full data path and the various PAC harnesses, specifically as regards final output to the speakers. i get the T-harness sending a signal to the PAC without interrupting the necessary signal to the stock amp. but what is the PAC APH-TY01 for? i don't need to take any output from the stock amp, do i? shouldn't the path be HU --> T-harness --> AMP-PRO --> dsp --> JL amp --> speakers?

all this will follow maybe 50% coverage of a damping layer plus a thin but full coverage layer of foam, and mlv where i can fit it. doors, floor from front footwells and back up the rear wall. i removed the rear seats on day 1 as i have a 100lbs dog that usually uses that space. i think i can fit the dsp and amp under the plywood platform i have in place. the plastic under-seat storage bins have also already been removed.

what else? what size speaker wire should i use? so far, i've only purchased the JL amp, it was on sale at Crutchfield. hopefully i can complete the acquisition phase over the next couple months. winter isn't the best time to work on the truck, but it tends to be when i have less work and more time.

 

if you've removed the seats and only put your dog back there, i would advise against installing rear speakers. being directly behind the front seats, they don't work great for rear fill anyways. they're closer to 'butt shakers', and a terrible job doing it at that.

a number of other installs have fit 1/0 cable through the door jambs, so a 4ga really shouldn't be a problem. that said, it's just as easy to do as you're thinking and run it underneath the truck. just be sure it's well secured out of harms way, and well sealed where it enters the truck.

i can't find any immediate info on the minidsp, if the input power is fused or not. typically, i'd connect it either at the amp power connection, with a separate smaller fuse.

i don't know the exact answer for that harness, but being that you're replacing all the speakers, and using a pac amppro, i believe you'd be able to entirely remove the oem amp-- it won't be doing anything, and the amppro is what's interfacing with the head unit from then on.

i like to run 12 gauge, many installers like to run 16-18 gauge, i generally won't run smaller than 14 gauge for 75w rms/channel like that. so it's all a preference, but 16 gauge minimum.


and just be sure you're purchasing oxygen free copper wiring. NOT CCA(copper coated aluminum). cca is cheaper, but suffers from thermal and connector issues due to the aluminum content. i generally use and recommend knuconceptz for wiring, as they don't cheat wire diameter like scosche does.

 

my thinking was to put the main fuse at the battery, then run to a fused block in the cab. that way the dsp would be be protected from the main power line.

as i understand, the stock JBL system amp can't be removed. it does some necessary processing or something to maintain stock HU integration, but in a way just ends up almost like a dongle, hanging off the end of the system. i just have never been clear on references i've read here to output directly from the stock amp after the AMP-PRO installation. maybe that's only for those taking speaker-level output into their aftermarket amp, not sure. (edit: tho again, that doesn't make sense to me either since the signal should be running through the AMP-PRO...?)

i've read yours and others' comments on that previously. thanks for the help.

 

it's a nice way to think of it, but as you were finding, they don't make distribution blocks that accept that small of a gauge of wire, and not to mention, they don't make fuses (ANL, or Maxi) for fused distribution blocks that are small enough to correctly protect the wiring. minimum ANL/maxi fuse is 20A. i can't find the power draw specs for the minidsp 8x12 in the user manual, but typically a device like that would be fused at 2-5A.

it could be easily added onto the radio power circuit behind the radio, however in this case, every connection you're making to the oem system is plug-n-play. connecting the minidsp this way would require cutting up a wire loom, or worse, factory wiring.

minidsp really should be including a fused power wire with it. i know my dayton dsp408 includes it. but neither dsp mentions it in their manuals.

i don't like the idea of relying on a fuse-tap for an audio device like that, as low powered as it is. i just plain don't like fuse-taps though. my preference is to connect to a terminal that i have full control of so i know it's torqued down for a solid connection. in this way, the amp power terminal is one of the best options.

in my last truck build, i had a powered sub and an alpine amp. i installed an ANL distro block directly between the two, and ran the dayton dsp off the distro block for power, and shared a ground with the amp. unfortunately, the amp and sub were installed on the back wall, and the dsp had to go under the seat, so i had to extend all the dsp wiring to reach. i did have some ground loop noise issues, though it never bothered me enough to track down if it was the dsp location, or other grounding issue.

my impression is the opposite. from what i've read so far on the amp, the radio sends a digital signal to the amp containing the volume information, as well as each channels information. the amp, the amppro, or the maestro are 3 ways to read that digital signal.

i haven't seen any indication that the amp offers any sort of feedback to the radio, the radio just blindly outputs the signal.[/QUOTE]

 

@soundman98 not sure i'm following as far as powering the dsp. if "amp power terminal" refers to the power inputs integrated into the amp itself, in this case there's no aux power out on the JL amp. there's no external distribution block (as in the case of your prior truck), fused or unfused, that i can find that has an appropriately sized output terminal.

the AMP-PRO does have a remote turn on output rated at 2 amps. it hadn't occurred to me before that this might function as a constant power supply, but....

regarding the stock amp, i remain confused. it shouldn't be needed, but it is, even with the AMP-PRO.

 

ok, so i think i've figured out the stock amp question. yes, it needs to remain in place but there's no need to run any outputs through the APH-TY01 harness. having read the description again (https://www.crutchfield.com/p_541APHTY01/PAC-APH-TY01-AmpPRO-Harness.html) it looks like this harness is only intended to allow you to run your final speaker output through the factory speaker wiring harness. and i'm not doing that. i'll run new speaker wire from the JL amp. the primary AmpPRO T-harness and factory amp will preserve the full factory CAN bus functionality.

so i still just have to figure out how best to power the dsp, and possibly find a cable path under the cab, with some entry point at or near the rear wall.

 

nice

 

So, did you find a work around keeping the factory HU with JBL. I read that you used thePAC AMP PRO. I have a 2023 TRD off Road model and would like to retain the factory HU. Im swapping the amps with have a DSP.

 

i have not yet done an install. i've purchased an amp, speakers and Pac Amp Pro but last year i had to put quite a bit of money into equipment for work, so i have yet to purchase the DSP and acoustic insulation/damping material. but since i want to keep a stock appearance and functionality, the Pac is integral to that plan.

 

I wanted to see if the PaC AMP worked on your '22,

 

i have a 2021.

 

You need the AP4-TY13 for behind the HU and the APH-TY01 to plug into the factory amp. The TY01 will give you speaker wire ends you can hook up to from the aftermarket amp. I just recently did this and it’s pretty straight forward. If you want to add any kind of aftermarket amp, speakers, dsp etc. I would say it all starts with installing the amp pro first. There are other ways of skinning the cat but the amp pro is the most straight forward and easily reversible solution. All plug and play on the oem side.

 

if i'm not mistaken, you need the APH-TY01 if you intend to use the stock speaker wiring instead of running new speaker wires. for those that intend to do new speaker wire runs, the AP4-TY13 t-harness will still maintain communication to the factory amp to maintain the stock head unit functions (nav, phone, carplay, chimes, etc).

 

Yes, you are correct