Helix Sound Upgrade

helix-msrp2I had been pleased with Volkswagen’s MIB II base stereo. It’s no powerhouse, but it has cool features and adequate sound output. To add deeper bass, I would have been satisfied with simply tapping into the rear speaker wires to feed an amplifier and a subwoofer. But Volkswagen decided to discontinue its Helix subwoofer accessory, VW P/N: 000-051-419, meaning they slashed its price by over 50% to quietly clear their inventory. What was once an “is it really worth $660?” item was suddenly a very affordable $300. I managed to get the kit shipped to my door for $235 after some discount shopping and a manufacturer’s rebate. The wiring harness and digital signal processor alone are worth more than that!  

helix_croppedHelix is a German high-fidelity audio system maker that based the Volkswagen accessory on their existing (but now discontinued) PP50DSP. The system can be programmed with sound contouring specific to each Volkswagen model with a trip to a Volkswagen dealer (details below). Calls to three Volkswagen dealerships for installation quotes, as well as internet discussions, compelled me to tackle the installation myself: One dealer quoted a very confident $312, another did a round of back and forth phone calls over a few days and then never really gave me a great feeling about their plan, and a third dealership wouldn’t touch the installation at all (but would gladly sell me the part for $660). “No, thanks!”

helixspecsThe installation took me a few hours, but that’s only because I did some cleaning and photography along the way. The directions were cumbersome, but someone at VWVortex said all they needed was this YouTube video (profanity warning). I took a leap of faith and just followed along with the video, pausing as needed for certain steps. Everything went smoothly, especially when making a few exceptions that I think the video producer would agree with:

1) Kill the power! He said it; he illustrated why it is prudent. The instructions say to disconnect the battery for a reason. Just do it. It took just a few seconds to disconnect my battery’s negative terminal. I did not lose any settings. Also, open the hatchback before you disconnect the battery; the hatchback requires power to open.

removal-key2) I used these keys to remove the stereo chassis. He said not to shove them in until they click because they sometimes get stuck and can break. I could not pull my radio out without the keys slipping out. So I shoved them in a little farther… they clicked. “DOH!” Clicked into place, they held the radio and enabled me to slide it straight out. But the keys were indeed locked-in and stuck. No worries! With the radio in-hand, all I had to do was press inward on the retaining tabs (depicted by the arrow in this photo) and the key immediately released without need to fight with or risk breaking anything. This may be exactly how they’re supposed to work!

helix-connectors3) I used this pin removal tool from IDParts. The tool pair is a little more expensive than other tools, but they’re robust and reach deeper into bulky connectors. The larger tool worked perfectly for this job! IDParts’ web page has a link to a video that shows how to use the tool. Here’s a photo of it in my hand. I had slid the stereo unit out of the glove box and gently hung it by the cables that were still connected. I had to swap out one of the wiring blocks and re-pin two of the wires. It was straightforward with the video assisting me, but definitely not “plug-n-play,” as suggested by some of the vendors who sell the Helix upgrade.

4) There’s a tiny potentiometer near the end of the amp (red arrow). Some swear they got better sound after adjusting it. I’m not 100% certain of this pot’s role, but I know that it does not behave linearly. In other words, turning one direction doesn’t turn sound “up” while the other direction turns sound “down.” Instead, there appears to be a sweet spot in the adjustment range. I suspect this is an impedance-matching adjustment that’s set at the factory for various subwoofers that Helix specifies for different systems. My advice is to leave it alone. The only reason I know anything about the pot’s behavior is because I met someone whose sub stopped working after he adjusted it. We adjusted the pot and found a sweet spot. Also, the “screw head” is tiny, made of plastic, and very fragile. Again, LEAVE IT ALONE!

helix-testfit5) I did the electrical connections at the front of the car and then did a test of the stereo before committing to routing the cable under the trim panels to the trunk. I could hear the difference right away… much brighter. Of course, it sounded even better once I routed the cable and closed the doors. The Helix five-channel amp removes lower bass from the doors and dedicates it to the subwoofer, allowing me to increase the bass setting without over-driving the door speakers. The subwoofer sounds surprisingly good, especially when considering that it has only 6-inch drivers. It sounds like a “larger” system.

6) It very tempting to make sure all parts in the package are used. This includes a small jumper that fits in only one place. “There, all done,” one might think. Not so fast! This jumper is for use on right-hand drive (RHD) cars to force the DSP into accounting for the driver being on the “wrong side” of the car. 😉  It is not used in cars where the driver sits on the left side. Feel free to misplace this part if the system will never serve in a RHD car. I have no idea where mine went.

7) Disconnecting the battery causes the computer to lose track of certain position sensors. As a result, faults associated with the TPMS, traction control, steering angle, and maybe even something else will probably appear. DON’T PANIC! Simply start the car and drive it a few hundred feet. The errors will disappear on their own once the computer detects steering inputs and wheel rotation. The one-touch window opening/closing also needs resetting. To do that, switch on the ignition, close all windows and doors, pull each window-up switch and hold it for at least two seconds, release, then pull up and hold again. Driving the windows into their stops retrains the module, which allows the auto up/down feature to work again.

Dongle-578) Don’t believe VW’s claim that the system is “pre-programmed” for the Golf/GTI. Either visit a VW dealer or rent the programming dongle! Renting the dongle is far less expensive and makes programming the system at home very easy (it takes ~30 seconds). In my case, flashing with the dongle seemed to make only a subtle difference. But others have reported dramatic changes. Later, I discovered that the distortion I had at higher volumes was gone after programming. In fact, the volume can go all the way to maximum without distorting. Of course, I never listen at high volumes, but it’s good to know the system can do it.

faderSince Helix attenuates the bass frequencies on the four door channels, that means those speakers are able to work more efficiently at producing the mid-to-high frequencies, resulting in an improved sound stage. At “only” 102-dBA, it’s not going to win any sound-offs, but the quality of sound is very good for the price-point. Of course, there’s still room to tailor the tone of the music to suit individual tastes. But the point of Helix is to present an improvement to the stock system, as well as an ideal starting point for upgrades. Overall, I’m very pleased and could even be pretty happy with the system as installed if not for the fact that I had already planned and purchased parts for a subwoofer upgrade. Read more about my upgrade HERE.    See more photos below.

NOTE: Some have squeezed their Helix subwoofer in with the donut spare tire by removing the subwoofer’s rubber “feet” and using a longer spare tire retention “bolt,” VW P/N: 1T0-803-899-B. More details HERE.

Loving the Beat!


About Scott

I grew up near Houston, TX and joined the U. S. Coast Guard in 1986. I am trained on electronics and taught myself the basics about automotive systems and to perform some of my own maintenance (cars and bicycles). I became involved with Amateur Radio and computers in 1995. The explosion of technology has made my job and several of my hobbies quite interesting. I retired from the Coast Guard in 2016 and continue to work in the the electronics systems engineering field. My hobbies include Volkswagens, bicycling, electronics, amateur radio, web management, and reptiles. Visit my websites to learn more.
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2 Responses to Helix Sound Upgrade

  1. Jeff says:

    Good write up!! Pretty much sums up this pretty well.
    Can definetelly agree this fits into a Jetta mk6 with the spare tire as well, and ties down nicely with the longer spare tire nut fastener part. An awesome upgrade if you dont have Fender or a Dynaudio system installed factory.


    • Scott says:

      Thanks for the note, Jeff! Time will tell if my next car gets a custom subwoofer or if the Helix will suffice. I’m getting to the point where intricate work on the car interests me less than simply driving. The Helix upgrade is almost good enough for me to forego the subwoofer upgrades… almost. We’ll see. 😉


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