PURE Digital Factory Infotainment Integration for ELS Studio

[Ash @ S2i Audio]

Let me know if you decide to replace the center, or even the door speakers, while retaining the factory amp. I can help you pick out the right stuff that will sonically match each other

And I agree that the center could REALLY benefit from some sealing. I am going to use a third One Audio WB3.e wideband in that location, but there are many many excellent widebands you could use in that space. Probably the easiest "high quality" choice would be the AudioFrog GS25 which should be plug and play from a size and mounting bracket perspective. Just need to select the correct wiring harness adapter and drop it in (and dampen + seal it, like you're planning).

The factory center channel might actually be the weakest link in the whole system. It's really terrible the way it's been implemented and you're right to be thinking about changing it, if you change just one thing.

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[Ash @ S2i Audio]

Arduino and digipot programming successful! Hopefully will be able to test this weekend... if it's not blizzard conditions

 

[Ash @ S2i Audio]

Volume control device completed. The enclosure for it arrives tomorrow.

If the weather permits, I'll start running power and signal cables through the car this weekend!

 

[Victorofhavoc]

Any plans to image it onto a single pcb to shrink down and make more solid or is it going in an enclosure and hiding it?

 

[Ash @ S2i Audio]

Yep it's going into an enclosure that arrives tomorrow, then the inputs, outputs, and power source cables will be installed into a Deutsch connector so it's easily removable and serviceable.

The Mean Well DIN mount power supply is actually underneath the three boards - they are mounted to it using VHB velcro tape, and the Mean Well supply will mount to the enclosure in the same way. This allows for serviceability if needed, and provides vibration damping for component lifespan.

 

[UWU-mancer]

Volume control device completed. The enclosure for it arrives tomorrow.

If the weather permits, I'll start running power and signal cables through the car this weekend!

I bet your fbi agent is panicking

 

[Ash @ S2i Audio]

RED OR GREEN WHICH DO I CLIP

 

[Ash @ S2i Audio]

Update:

I did manage to do some testing this weekend on the volume control device, and the test failed. While a USB-based RS485 converter did read the Acura volume signal (therefore enabling me to decode the specific volume portion of the signal), the integrated device I purchased did not even see a stable signal. I spent a good deal of research trying to understand why, and it seems to be related to two possibilities: 1) the RS485-to-UART device needs an isolated ground in order to read the (likely) differential RS485 signal from the car, and/or 2) the UART device is flipping to transmit mode due to noise on the line (this particular device is duplexing, and auto sensing). Since I don't need this device to ever transmit a signal back to the car's head unit, I found a new one that allows me to electrically force it into receive-only mode, and it's also galvanically isolated. This should lead to a very stable output. I also altered the Arduino code to lock on the last signal value if there are any dropouts, just for additional insurance. The new part arrives Friday so hopefully I'll get another whack at it this weekend. Crossing fingers that it works this time!

Second big thing: I got the midrange pods that I was planning to install on the dash, but they were incorrectly manufactured and came out larger than I specified. They simply won't fit anywhere on the dash without being obnoxiously intrusive into the cabin. So I'm axing the dash mount for now (one day, I will pay up for custom A pillars for the mid and tweet, but it's not in my budget right now and I don't have the experience with fiberglass and upholstery to meet my expectations for visual quality). I'm reverting back to mounting the midranges in the factory mid-door position. The cool thing about this is, the OEM midrange speakers are dimensionally identical to the center channel, so I took out the center speaker with the intention of replicating the built-in mounting bracket to be able to mount the One Audio WB3.e into the stock location with zero modifications.... and it looks like it's going to work! I decided to patronize a company I have heard good things about but never used: SendCutSend. You upload a CAD file to their online portal and in real time they create a 3D model of it, then you select your desired material (I chose 0.125" Delrin), and they build it. And it's AFFORDABLE. Like way cheaper than any other "custom" manufacturer I've ever seen before.

If this works, it will give others the opportunity to factory-integrate higher quality midranges into the doors and center - I'll be happy to share the wealth! I'm including the 3D model of the bracket as well as the factory speaker, so you can visualize the solution.

The final piece of the speaker puzzle is the tweeter mounting. I haven't decided if I'm going to hack-in the new tweeters into the factory A pillar location, or mount them on the Helix angle mounts on top of the A pillars or sail panels. It all depends on how well the factory locations can accommodate the new tweeter, and how much of it is obscured, which is bad for dispersion and can cause diffraction effects. TBD.

 

[Ash @ S2i Audio]

HOLY EFFING HECK I EFFING DID IT!!! POSITIVE TEST RESULT ACHIEVED!

I successfully completed the module that takes the Acura proprietary volume control and converts it into a simple analog varistor which is what most DSP's use for external volume controls (if offered as a feature). This means we have unlocked the ability to install a true high fidelity, pure original digital signal without any factory EQ and effects to "undo" in the analog domain (ie via speaker level inputs). I cannot tell you how excited and psyched I am for accomplishing this! I've never done anything like this in my life...

 

[Spart]

Hard to overstate how much work goes into a project like this. The frustration is real.

I pioneered a lot of the "open sourcing" of info around Sync 3 swaps and DSP integration in S550 Mustangs (with help from numerous others) back when a certain other people had decided to try and profit off the methods while putting out disinfo and FUD.

Good on you for putting it all out there for anyone to use.

 

[Ash @ S2i Audio]

So true. A lot of the comments I've seen around "it can't be done because it's MOD/CANBUS" have made me wonder if there is disinformation being sprinkled around by would-be manufacturers since there is no MODBUS or CANBUS between the head unit and amplifier at all.

I appreciate the recognition of the level of effort to do this. It requires stubborn persistence.

 

[Ash @ S2i Audio]

My custom adapters just arrived! They fit the WB3.e widebands beautifully. I haven't had time to test fit them to the car yet, but I don't see why they won't.

 

[Ash @ S2i Audio]

Volume control interface fully packaged:

 

[Ash @ S2i Audio]

I've been quiet for a few days because I ran into a problem with the volume control device that required a redesign. TL;DR, All is well now.

The longer story: the strategy of replicating a manual volume knob aka analog potentiometer with a digital potentiometer was not the right strategy, at least not for my DSP. The Arc Audio ecosystem uses relatively low impedance volume controls (500 ohms in this case) which is an intentional design choice for reasons I won't get into here, suffice it to say they know what they are doing. The problem arises from the fact that there are no 500 ohm digipots (the closest is 1 kohm) because they will be susceptible to ripple and noise.

I was mistakenly under the impression that the ratio of the impedances would suffice, but electrically the power input for the digipot from the DSP just can't overcome the much higher impedance.

So, back to the drawing board. I ended up switching the strategy completely from applying a resistive load to the static voltage supplied by the DSP, to simply using a DAC as an analog variable voltage source, bypassing the DSP's potentiometer power source completely. This is a much better design and will be compatible with more aftermarket DSPs (so long as they use analog voltage as the remote control strategy). The only thing that would need to be figured out for each DSP is whether the amp is sending 5V or 3.3V into the remote control as the VCC power source (the two industry standards). I could feasibly make this a product with two models - one for 3.3V amp remotes and the other for 5V remotes.

The new device is the little red PCB on the lower right corner. I'm also planning to design a PCB to micro-size this whole device, and I found a board-mount isolated power supply that I can use for even further shrinkage.

 

[Spart]

The Arc Audio ecosystem uses relatively low impedance volume controls (500 ohms in this case) which is an intentional design choice for reasons I won't get into here, suffice it to say they know what they are doing. The problem arises from the fact that there are no 500 ohm digipots (the closest is 1 kohm) because they will be susceptible to ripple and noise.

...two channel digipot and wire it in parallel?

It's always something with these projects.

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