"PURE" Digital Factory Infotainment Integration Honda Civic Bose / Acura Integra ELS

[Ash @ S2i Audio]

Volume control interface has been fully packaged

I also received my custom 3" midrange door and center channel adapters from the machinist. These are manufactured in Delrin:

 

[matttheazn]

Just curious if you have found any issues with the microphone and phone calls with AA? I have been trying to read through your post getting a better grasp of what is going on. I think if you could save yourself using the 5v PSU and use a step down voltage from the 12v remote line used to turn everything(amps, and dsp) off and on. Just tie the ground from Arduino board back the power distribution block for the amp to avoid ground loops. Tying all the grounds to a single place will save you a lot of headaches in hunting down ground loops.

Is there a factory 12v remote out of the HU?

I am wondering if you only convert RS485 output signal to coax, and go direct into a Helix DSP, you still get transport controls(play, pause, next track from all the oem buttons)? Is OEM volume control integration the only thing lost without using an Arduino board? Is there any active noise cancelation in your type s?

Could you please post pictures or go into a little more detail on actually conversion coming out of the OEM radio. Is is just one cable from the HU to the amp? Pardon my stupidity but I am just not comprehending the signal flow, for both with and without using the Arduino board to send the correct volume change signal to a 3rd party dsp.

 

[Ash @ S2i Audio]

Just curious if you have found any issues with the microphone and phone calls with AA? I have been trying to read through your post getting a better grasp of what is going on. I think if you could save yourself using the 5v PSU and use a step down voltage from the 12v remote line used to turn everything(amps, and dsp) off and on. Just tie the ground from Arduino board back the power distribution block for the amp to avoid ground loops. Tying all the grounds to a single place will save you a lot of headaches in hunting down ground loops.

Good questions/ideas. That said, I have no concerns with ground loops because I intentionally chose isolated hardware for this very reason. The Mean Well is isolated, and the UART device is too. There's no chance for ground loop interference. Also, you don't want to use the remote turn on lead for power supply - it's not meant to carry much if any current. It's just a voltage trigger. And yes, the Arduino can step down 12V to 5V internally using its own voltage regulator, but that shortens the lifespan of the device due to thermals, and the level of isolation is much higher with the Mean Well step down.

I will be grounding all components in a star pattern regardless, too.

oh, and the microphone side of things runs on its own circuits, independent of the amp. So it works perfectly.

Is there a factory 12v remote out of the HU?

yes, but as I said above, it shouldn't be used for anything other than as a signal for turn on. The Arc Audio DSP will be receiving that signal, and then that amp has its own RTO output which I will chain into the subwoofer amp.

I am wondering if you only convert RS485 output signal to coax, and go direct into a Helix DSP, you still get transport controls(play, pause, next track from all the oem buttons)? Is OEM volume control integration the only thing lost without using an Arduino board? Is there any active noise cancelation in your type s?

The RS485 signal is indeed on that protocol, but the actual codes that it sends are proprietary and still need to be decoded. Simply converting to coax will not work - the software has to be modified/"interpreted" too. It is possible to decode more that just the volume signal, but it's much much more complicated topologically. This was the most complex portion of my buildout of this device, and took the longest time/testing to get right.

Control of the head unit thankfully happens within the head unit, not the amp. So you don't have to worry about play/pause/etc. What you "lose" is volume, tone controls, and other settings like 3D sound, centerpoint, etc.

Yes, the Type S has ANC, but thankfully that's its own signal pair so you just leave it out. From what I saw on the Civic wiring diagram, it's the same thing. in fact, simply unplugging the ANC module accomplishes the same thing.

Could you please post pictures or go into a little more detail on actually conversion coming out of the OEM radio. Is is just one cable from the HU to the amp? Pardon my stupidity but I am just not comprehending the signal flow, for both with and without using the Arduino board to send the correct volume change signal to a 3rd party dsp.

Of course! You're not stupid - this is complicated.

Here's the simplest "diagram" I can describe:

• two channel digital "music" signal: S/PDIF protocol over coax with proprietary CE2 connectors. Single coax (so technically still two leads) from the head unit to the factory amp.
  • Re-routing: head unit to aftermarket SPDIF input (factory amp disconnected from this chain)
• Volume and tone control digital signal: RS485 protocol over two wires (+/-). Wire pair goes from head unit to factory amplifier.
  • Re-routing: head unit into my volume control interface. Factory amplifier is disconnected from this chain.
  • Output of my volume control interface is 3 potentiometer wires: Rhigh, Rwiper, Rlow. These plug into the appropriate terminals of your DSP's remote control input (this is why selecting a DSP with a simple analog voltage-based volume control is critical).
  • My device also needs a 12V accessory input to power it, so there are two wires going from it to the car's closest accessory outlet.
• Speaker wires
  • You will disconnect the speaker wiring harness from the factory amp outputs and adapt it to the DSP amp's outputs instead. This can be done with the appropriate "T-harness" which can be easily sourced, or made, by a competent installer.

Feel free to ask followups if this isn't helpful.

 

[matttheazn]

The RS485 signal is indeed on that protocol, but the actual codes that it sends are proprietary and still need to be decoded. Simply converting to coax will not work - the software has to be modified/"interpreted" too. It is possible to decode more that just the volume signal, but it's much much more complicated topologically. This was the most complex portion of my buildout of this device, and took the longest time/testing to get right.

So you would probably need access to a Civic to modify the code? I am not the best at coding, in fact I hate looking at i. I am sure chatgpt can get my into trouble though .

Volume and tone control digital signal: RS485 protocol over two wires (+/-). Wire pair goes from head unit to factory amplifier.

I assume that you need these signal wires to be connected to something, otherwise the OEM radio will output 0 volume? Hench why you said a simple coax conversion will not work?

two channel digital "music" signal: S/PDIF protocol over coax with proprietary CE2 connectors. Single wire from the head unit to the factory amp.

• Re-routing: head unit to aftermarket SPDIF input (factory amp disconnected from this chain)

You just need to re-terminate the end for connection to the DSP?


lol probably the last question for now until I am further along in my install in the coming months.

Did you decode the speed compensation signals? Do you think this a volume boost or a compression happening on the OEM amp? From my unprofessional DIY ears, when speed compensation kicks in at over 80ish MPH, it sounds like an compressor kicking on with a volume boost rather than a simple gain in out I could be very wrong though.

Thank you again for everything mate. You are a true legend!

 

[matttheazn]

Also, you don't want to use the remote turn on lead for power supply - it's not meant to carry much if any current. It's just a voltage trigger.

This makes sense. I was putting my test bench setup in my mind's eye when visualizing the power schematic.

I am currently using a taramps smart battery charger in my home to power a helix DSP, a sub, and a couple of amps using a simple switch on the 12v remote line. All using a single power distribution block. This is how I discovered and fully understood ground loops after connecting an externally powered headphone amp to the dsp.

In my home application a step down voltage regulator would work great.

 

[Ash @ S2i Audio]

So you would probably need access to a Civic to modify the code? I am not the best at coding, in fact I hate looking at i. I am sure chatgpt can get my into trouble though .

So, based on the diagrams I have seen, as well as the similarities between the head unit hardware, I would be very surprised if Honda is using a different encoding strategy between the Civic and the Integra for the volume portion of the signal stream. But it is possible. And if that's the case, I could walk an installer through the process of determining what the Civic's encoding is for volume, using a windows laptop and an RS485-to-USB converter device to sniff the signal (pretty cheap part available on Amazon).

I assume that you need these signal wires to be connected to something, otherwise the OEM radio will output 0 volume? Hench why you said a simple coax conversion will not work?

No, that's not the reason. Yes, the factory sound system stops outputting sound if you unplug either/both of the SPDIF and/or RS485 signal wires. But the reason you can't just plug the RS485 into a DSP's coax input is because they are on completely different protocols. It's like speaking two different languages. Yes, the devices can "hear" something broadcasting but it's jibberish to the incompatible listening device.

You just need to re-terminate the end for connection to the DSP?

not sure I'm following this question - can you elaborate?

lol probably the last question for now until I am further along in my install in the coming months.

Did you decode the speed compensation signals? Do you think this a volume boost or a compression happening on the OEM amp? From my unprofessional DIY ears, when speed compensation kicks in at over 80ish MPH, it sounds like an compressor kicking on with a volume boost rather than a simple gain in out I could be very wrong though.

Thank you again for everything mate. You are a true legend!

Speed compensation is *probably* calculated by the head unit but I haven't tested this yet. If I am right, the head unit will do one of two things: either A) "add" steps to the current volume level at higher speeds, or B) another portion of the RS485 signal's code carries the speed compensation modifier. I think B is more likely based on how you describe the effect, and because it's just a better way to implement the feature. If B is the way its done, you would lose speed compensation if you make this modification.

 

[matttheazn]

two channel digital "music" signal: S/PDIF protocol over coax with proprietary CE2 connectors.

not sure I'm following this question - can you elaborate? - What is the connector type going into the amp? What ends are the CE2 Connectors on? I am trying to understand the what is need to be done for the factory HU SPDIF signal output wire to connect it to a dsp, with toslink or coax input.

No, that's not the reason. Yes, the factory sound system stops outputting sound if you unplug either/both of the SPDIF and/or RS485 signal wires. But the reason you can't just plug the RS485 into a DSP's coax input is because they are on completely different protocols. It's like speaking two different languages. Yes, the devices can "hear" something broadcasting but it's jibberish to the incompatible listening device.

I think we are saying the same thing. I understand that the RS485 +- wires are control signals and not audio that is carried by the coax cable.

So you can not go straight from HU to the DSP with just coax? You need the Arduino board to send the signal to HU to tell it there is > 0 volume output. Without it the factory HU outputs 0 volume with nothing connected the RS485 wires. Is this correct?

 

[Ash @ S2i Audio]

two channel digital "music" signal: S/PDIF protocol over coax with proprietary CE2 connectors.

not sure I'm following this question - can you elaborate? - What is the connector type going into the amp? What ends are the CE2 Connectors on? I am trying to understand the what is need to be done for the factory HU SPDIF signal output wire to connect it to a dsp, with toslink or coax input.



I think we are saying the same thing. I understand that the RS485 +- wires are control signals and not audio that is carried by the coax cable.

So you can not go straight from HU to the DSP with just coax? You need the Arduino board to send the signal to HU to tell it there is > 0 volume output. Without it the factory HU outputs 0 volume with nothing connected the RS485 wires. Is this correct?

Ah, now I understand your question. Sorry I misunderstood you.

You can actually run the factory SPDIF coax directly into your DSP (after you physically convert the CE2 terminal to RCA), but you will have to use the DSP's external remote control accessory. You will lose volume control from the head unit knob and steering wheel. With the addition of my part, you retain the factory volume controls. It is absolutely NOT necessary, just convenient.

The factory amplifier's SPDIF coax connector is the aforementioned CE2 connector. I built a form factor "harness" that converts from CE2 to RCA so that I don't have to do anything permanent to the factory wiring.

This is what CE2 looks like (top left is the style on our amps).

 

[Ash @ S2i Audio]

And here's a picture of a Bose amplifier from an 11th gen Civic. you can see the CE2 connector on the left.

The middle connector carries the RS485 input as well as chimes, phone calls, ANC, etc.
The right most connector is the power and ground for the amp, and all of the speaker level outputs.

 

[matttheazn]

you will have to use the DSP's external remote control accessory. You will lose volume control from the head unit knob and steering wheel. With the addition of my part, you retain the factory volume controls. It is absolutely NOT necessary, just convenient.

ok thank you for clearing that up. I plan to use a Helix control knob for volume and bass control, and have the DAP right next to it for transport control.

Do you have any experience on using usb audio? Do you need local files in flac or wav form or can you use a "streamer" to play files into the usb port rather than the HU playing the files off a USB stick? I plan to use a Fiio M21 and wondering if I plug that into the USB audio port, would it even play music from streaming apps like spotify, and would you get transport controls over usb?

 

[Ash @ S2i Audio]

I have used the car's USB audio. First off, it needs to be formatted in FAT32. most modern storage devices are exFAT so you will have to reformat with your preferred freeware utility.

The files themselves need to be at the root level, or in root level folders.

A streamer cannot play into the car's USB port. The car needs to retain control and select the files itself.

 

[matttheazn]

I built a form factor "harness" that converts from CE2 to RCA so that I don't have to do anything permanent to the factory wiring.

So you took a "CE2G111Z00" connector and made a RCA pigtail to go to the DSP? And the power terminal is the "shield" with the "terminal" being the signal rca center pin?

 

[Ash @ S2i Audio]

Yes, and you need to terminate the shield to the center conductor with a 75 ohm resistor, in order to keep signal integrity (the CE2 hardware is thankfully the same 75 ohm impedance as RG6 which is what is used for "RCA" type coaxial cables).

 

[matttheazn]

Yes, and you need to terminate the shield to the center conductor with a 75 ohm resistor, in order to keep signal integrity (the CE2 hardware is thankfully the same 75 ohm impedance as RG6 which is what is used for "RCA" type coaxial cables).

LOL I am dumb. Please take a picture if you can. If not no worries, hopefully my installer will understand this. I will stop bothering you now.

Thank you again for all your help. I think I fully understand the full scope of it all. You have been such an immense help in figuring out how to add an aftermarket system and to get the best sound quality. I am truly grateful that you also have a desire for a great sounding system, and are much smarter than I am. THANK YOU GOOD SIR!

 

[matttheazn]

Sorry a couple more.

Do all car alert sounds, voice nav, and phone call audio also run through that same digital audio output? Does your fake engine sounds also run through it?

Have you tested phone calls without the ANC hooked up? Do you know what the call quality is like on the other end?

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