Plug and play amplifier that works with the 2015 1794 stereo system

Plug and play amp that works with the 2015 1794 stereo system

 

I know this thread is a couple months old, and you may have already got your answer elsewhere or moved on, but check out Tech12Volts.
https://tech12volts.com/shop/ols/pr...l-dsp4086-plug-n-play-except-power-and-ground

 

Do you have this amp? I am trying to figure out how it's connected to the outputs from the OEM amp - it looks like the inputs to it are RCA format but I'm trying to confirm

 

The inputs are RCA, pic for reference:


The amp comes with speaker wire to RCA male adapters, the 6 black plugs in this pic:


Factory integration wiring harness input side connects to those 6 plugs for input to the amp, output wires from the amp connect to the output wires on the factory integration harness. Easy enough to do yourself with any amp but Tech12Volts does it for you which is nice/makes it a no brainer to install.

 

so I’d figured out that the inputs were RCA, but had not deduced that those black plugs were RCA adapters. That’s very helpful - thank you!

perhaps a silly question - this is an 8 channel amp, but only 6 RCA inputs? I was loosely expecting 8 +/- wire pairs as input, and 8 as output as well. Does anyone know which wire pairs from the OEM amp output you’re meant to connect to those 6?

 

No matter what amp you get, you will need to run a fused power from the battery.

 

Not a silly question at all! Each RCA input accepts two wires, e.g. one positive and one negative. The little silver dots on the black RCA plugs are set screws, insert your bare wire and tighten them down. When it comes to RCA adapters there's essentially two types that serve the same purpose. Plugs like this or "solderless" connectors where the wires insert somewhere and are tightened down. The other type you might see have an RCA plug with a few inches of wire attached, in which case you strip back a bit of wire and solder or crimp your inputs/output wires to them. Four of the RCA inputs are used for Front Left, Front Right, Rear Left, and Rear Right input, and depending on the system/how the head unit is outputting a subwoofer channel, it might use one or both of the remaining RCAs. Some head units, factory or aftermarket, will have a mono subwoofer output and only use one or a mono RCA cable. Others will output a stereo signal on the subwoofer channel and use two or a traditional "paired" RCA cable.

As far as how Tech12Volts integrates this amp, I'm not entirely sure. Someone who's got one might be able to provide better insight on the wiring. If I had to guess, or at least how I would do it, would be to grab input signal for the new amp prior to the factory amp, match up outputs of channels 1-7 on the new amp directly to the factory output wires to the speakers, and then use channel 8 on the new amp to send a "better" or tune-able signal to the factory amp, which then ramps up the power of that signal to send onto the subwoofer. The JBL 4086 DSP amp only does 40w and 60 w @ 2 and 4 ohms respectively, so it's not powerful enough to drive a subwoofer on it's own, but you can still utilize the DSP feature of the amp to fix any factory bass roll off/processing/attenuation etc. to make the factory sub sound better.

This is how the JBL system in a 2015 is wired up, kind of hard to see as the forum shrinks the resolution but full size can be found here: (1) All Years Complete Audio System Wiring Diagrams | Toyota Tundra Forum (tundras.com)



As you can see, there are 8 channels being driven by the factory amp, so if adding JBL 4086 I'd power everything but the sub directly off the JBL 4086, and then use the remaining/8th channel to send a DSP tuned signal to the factory amp and allow it to still provide the necessary juice to the factory sub.

To give an idea of what these plugs etc. look like, AutoHarnessHouse has them here: Toyota Entune Amp Upgrade for Tundra and Tacoma (autoharnesshouse.com)

You have to email them to get the JBL versions, but essentially you get item #4438 and #4439 if you're keeping the factory amp and adding another amp, plug everything in at the factory amp location, and then match up your inputs/outputs based on the pinouts they provide. Not terribly hard to do yourself but can be a little daunting if it's a person's first foray into car audio.

 

I have the JBL harnesses from AutoHarnessHouse on order and am mostly not scared of matching up the positive/negative pins for each speaker and making the connections.

A minor point of correction - I am 95% sure that the Tech12Volts amp/package uses the line level OUTPUTS from the OEM amp as its inputs. From what I've learned about the JBL setup reading on these forums, the Headunit and OEM Amp work together in a way that's hard to integrate anything in between them (much to the chagrin of many forum members here).

Thank you for the link to the wiring diagrams. I see the 8 channels coming out of the amp that makes sense, but still trying to figure out how those 8 outputs translate into 6 RCA inputs. Will be floating this question on a couple different threads where lots of satisfied customers have this amp...will try to cross post the solution here if I find it.

 

This amp and many higher channel multi-channel and especially dsp amps allow you to take the signal from an input and assign it to one or more outputs. You can also do what's called signal summing and combine the signals from multiple input channels to get a wider and potentially full range signal for output channels. Some higher channel non-dsp amps will have intrenal signal summing as well, or for example an

$129 Audiocontrol LC7i 6-Channel Line Output Converter with AccuBASS

Audiocontrol LC7i line output converter also has internal signal summing.

If a JBL truck is like non-JBL, some of the speakers will have capacitors or bass blockers wired to them. The factory amp might also be doing that leg work, but since the doors have the woofers and tweeters wired together, I'd guess those are getting a full range signal, or at least a more full range than the dash center and corners, but those too might be getting a full range signal and have capacitors wired onto the speakers. If you were to pop off one of the dash corner grills and remove one of the speakers you'd be able to see if there's a capacitor on it. In my '21 non-JBL the dash corners and center all have capacitors.