2019 (B9 Sportback) RS5 Subwoofer - IS OUT OF PHASE from the factory

[Smac770]

Chip, I'm not sure the image conveys what djmika did at the voice coil terminals or Lensch did at the connector plug. The picture implies to me that you swapped to which side of the subwoofer the two wire pairs were connected. The write-ups imply to me that they swapped the two wires at each voice coil terminal. The green/black and yellow/orange stayed at their original sides of the subwoofer.

Since I couldn't get the answers here, I went and dug up pics of the wiring arrangement. The upside of that means I also found the same for the sedan/coupe rear deck sub, and now realize the wiring change is because the wires are on the connector plug in a different order on the rear deck version. Nothing to do with polarity. Which makes sense given all that is controlled via parameterization in the amp. I wonder if Audi simply parameterized the sportback amps incorrectly. You can't think they intentionally decided "hey, let's make the bass in our uplift sound system suck". I do wonder also if the standard sound system suffers this same issue, or if it's specific to the B&O config.

[Smac770]

chrisdazzo, are your pictures of the voice coil wiring before the modification or after the modification?

[AccordingToAlex]

Hey all, I guess the Audizine app for Android broke notifications so I'm just seeing this now. I'm one of the original preachers about this issue and I'm so glad it's finally gaining traction. As I've said before, this error IMO should be recall status. It blows my mind that this error was signed off before production. So happy the word is spreading about this bullshit and we can finally enjoy our B&Os the way it was meant to be!

There's a harness you can buy that takes all the guess work out of this, IAmPraneel is the man you should reach out to...

[Smac770]

It's a simple topic. I would like to know if the only actual pics of the wires on the 8W9 sub thus presented are pre or post operation.

Without waiting for that confirmation, I made this which basically breaks down the B9 B&O sub wiring, to the best I can determine from the available information, considering I don't have one in hand.


(the crappy image handling engine on this site; using external site instead; click on the image to get a proper visual)

The gist of the thread being to swap the + and - for each channel, A and B, be it at the amp, at the harness side of the plug, at the sub side of the plug, or at the sub itself. It's the same end result regardless of which.

If the pics are pre-op, then they agree with the expected wiring. If the pics are post-op, then they match the expected wiring after "correction". Which might explain why the wiring needed correction. Still very odd that Audi didn't catch this; it's easily corrected in the J525 DSP. Maybe the parameterization in the J525 is wrong because it's for the wrong vehicle, maybe the OEM just wired the sub wrong from what Audi expected. Who knows. It would be curious to know if the wagons, which use the same subwoofer part, are seeing similar results.

And if Audi does come along with a J525 update, it'll break the situation and you'll need to undo the edit.

[djmika]

This thing has caught fire! And I guess that is a good thing. I'm not 100% ready to blame Audi and call negligence. It's pointless anyway. We can gripe all we want - there will likely be no recall. Fortunately, the experiment easy.

For sure, reversing polarity nets more amplitude, especially at certain frequencies. Subjectively, I think most would prefer it the opposite of how Audi wired it. But also, phase relationship between sub woofer and speakers, especially when they overlap in frequency isn't always as simple as 0 or 180 degrees. I'm not going to to go into the science here, it's exhausting. Simply put, it is possible that with the sub wired as Audi had it, the lack of amplitude at certain frequencies coupled with the way bass below the tuning frequency of the sub works could have made some engineer think the pros outweighed the cons. I respectfully disagree and it seems most here do as well.

Bottom line, no matter how one goes about it, reversing polarity is simple. It's a straight swap, green with black and yellow with orange and you've reversed polarity 180 degrees. It doesn't matter where you make the swap - amp, connector, sub. Whatever works for you. You'll hear more bass amplitude after and for most, this is a desirable result. That's the long and short of it.

Sometimes the simplest method is the best method. As I've mentioned, I do home tech for a living. Part of that is audio and part of that part is hi-fi. I'm a dealer for a sub woofer manufacturer called REL. The man who runs REL is well regarded in our industry and responsible for the most widely accepted setup methods there are. His subs have a switch on the back with two positions - 0 and 180 degrees. Simply put, he wants you to sit at the listening position and switch back and forth. The position that has more amplitude is where you leave it. Then, you adjust volume and crossover frequency until the sub blends appropriately with the speakers. The thing REL has in common with or situation here is that a REL almost always overlaps frequencies with the right and left speakers. When phase is correct, you get reinforcement, reverse the polarity and you get cancellation.

[Smac770]

Yeah, I like REL. But they stopped fixing the old amps, so having to power my Stadium III with an external amp now.

Still would like confirmation of which way the wires were originally. Does the diagram have the wiring at the voice coil terminals in the 8W9 version the way it came or the way you guys are rewiring it? I'm also assuming the sub is following the standard config of left hand positive right hand negative when the cone is facing up.

[iampraneel]

Hey guys. This is Praneel. I make these harness on the link below and mentioned by Alex. I’m in the process of editing a video I made to test the polarity of the OEM Sub from my RS 5 Sportback. I read through the post and I’m not sure if anyone did a test yet so I went ahead and did one. Video will be up soon.

https://www.audizine.com/forum/showt...ubwoofer-Cable

[iampraneel]

Here is the video I made. I think this is just going to stir up more questions unless I’m totally off base on my findings.

https://youtu.be/el3oDX__NVE

[B9S5Droptop]

Anyone know if the cabriolet is afflicted as well?


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[chip_]

Ok so then it would look like the following after the cable swap - top is your original bottom is after the swap. Another question would be if you swap the stock sub out for the KICKER CompRT 6.75"(165mm) Subwoofer does the same cable swap apply at the subwoofer side?

Subwoofer1.jpg

[Smac770]

Cabriolet has a completely different subwoofer placement than any of the other body types. You'd have to try it each way and see how it comes across to you. As djmika referenced, it could be that it's better or worse in the ways important to you, but were not important to the system designer. Plus, the answer could be different top up vs top down.

chip, the polarity alignment should be the same and relevant to whatever driver is set into place. Now, if that new sub is a different enclosure laying in the cargo hold rather than mounted in the original sub enclosure in the original location, then it's not the same driver orientation, etc. So the answer might not be the same. A/B it, see which you like.

[iampraneel]

After I put my OEM sub back in the car I decided to take one of my harness and mimic changing the polarity on my sub, even though it’s not wired incorrectly, to see for myself if it makes a sound difference. Down below is the harness I made up.

But Before I wired it up, I decided to play a song to test with. The plan was to play the same song around the same time stamps to see the difference.

While wired with no modifications,I set the focus to front and had the setting for bass in the middle along with the sub. It sounded ok just like it did from day one. Then what I did was turn the sub setting all the way up, the bass got worse. I heard that phased out kind of sound. Then I decided to turn the sub all the way down. The bass coming from the front doors dramatically improved.

So next, I decided to wire it up using my harness. So I played the same song around the same time stamp with the focus as front and setting for bass and sub in the middle. Just as expected it sounded much better than before. So I did the same test. Turn the subwoofer all the way up and unlike before the bass improved.

My conclusion still is the OEM subwoofer is wired correctly (which you guys saw on my video) but door woofer speakers(Front or Rear or Both) are not wired correctly. Obviously this is just an assumption on the door speaker as I have no way to test.

Seems as though to sort of resolving this is what you guys have been doing by changing the polarity. Me personally I would use the harness as it can be reversed very quickly in case Audi does make some kind of change to the B&O amp or if there are any warranty issues.

If you guys want to pick one up, DM me.

IMG_2121.JPGIMG_2118.jpg

[djmika]

Praneel,

This is interesting. If you think it's mid-bass drivers in the front, rear, or both that are out of phase, more experimentation will have to be done. And to be honest, if you're correct, it's worth figuring this out and here's why.

Phase issues with the mid-bass drivers would impact the sound quality - in the mid range especially - if the mid bass driver is out of phase with the mid range and/or tweeter. That's kind of a big "if."

Usually, reversing phase in a multi-way speaker doesn't have quite the same impact as having two overlapping woofers being out of phase. And again, phase may not be absolute. In a 2-way speaker with a 2nd order electrical passive crossover, many will have the tweeter wired 180 degrees out of phase to compensate for shift caused by the crossover. Not reversing the phase most likely causes, among other things, a pretty noticeably different frequency response near the crossover frequency. There are so many speakers in our cars that overlap in frequency that the waters are undoubtedly muddied. We do have a few members here that have fairly extensive experience and likely well trained ears. I like to think of myself as one of them. And a hand full have changed out the mid range drivers in their cars. At no point have I seen anyone bring phase up in terms of anything except the sub.

It'll be a little more intensive to try to pin down phase abnormalities caused by wiring throughout the car. I think that starting with turning the sub down all the way (as long as it's actually off when it's all the way down). Then turn surround and 3D all the way down/off as well. And lastly, push the fader all the way to the front and listen to see if we can define whether we think there are phase issues related to the remaining, working drivers. Then, bring the rear speakers back in. If while doing this, perceived bass output decreases, we probably have mid bass drivers that are out of phase with one another. I'll also check the phase relationship between the sub and rear speakers now that I've reversed the sub too.

If mid bass drivers are indeed out of phase, I think it's likely to be the ones in the front door, not all of them. Reason I say that is when I conducted the experiment that caused me to reverse the phase of the sub woofer, I left the sub on and shifted the fader from the front to the rear. I heard much more bass with it set to the rear. I chalked that up to the rear speakers just not overlapping frequencies with the sub but if the suspicion that mid bass drivers are out of phase is indeed true, then reversing the phase of the sub is only a band aid. Now it's in phase with the woofers in the front door and out of phase with the rear. I think that we are all hearing more bass with the phase of the sub reversed due to where we sit in the car and the fact that the front door speakers make more bass than the rear. But if we still have phase issues, ironing this out will even further improve bass output in the car, not to mention the potential of improving other areas in the audio spectrum. Also importantly, this impacts everyone, regardless of what mods to the stock system people have done.

I'll play with this when I have some time and report back.

Micah

[JohnEnglish]

I wonder if any of the vendors here have contacts at Audi that could make a few discreet inquiries to the people who handled the audio on the B9.

[chrisdazzo]

chrisdazzo, are your pictures of the voice coil wiring before the modification or after the modification?

Before.

[Smac770]

Ok, cool. So my diagram is correct for the factory wiring. Meaning the factory wiring is the expected wiring based on the Audi documentation. That the audio result is less than desired could be intentional based on a differing opinion of the system designer on what is good sounding, or a defect in the programming of the J525. Or someone got the documentation regarding the amp channel polarity wrong, etc.

On the polarity side, that we conclude which wires make the sub move outward vs. inward is just a minor verification in the overall validation. Someone would need to get serious with testing the amp output channels and validate the polarity is correctly identified for each amp channel. And then validate all four door woofer polarities; we already know now for the subwoofer, visual validation by Praneel. Then make sure all the amp + and - are wired correctly to the speaker + and -.

Also, wasn't there an update in the B9.0 B&O amp programming involving the front door speakers and distorted bass? So that adds another configuration that would have to be validated for consistency. So nothing simple or easy about producing a vetted conclusion. It's not a simple system. But at least there's a simple "hey, if it's not that good, try this vs. that and use the one you like" path for the I just want to be done with it types.

[Jcgonzal]

Deleted

[iampraneel]

Hey folks. Been getting a lot of questions regarding which harness will work to make the OEM subwoofer sound better. The one you want from my For Sale link below is the Pigtail without RCA. I’ve also attached the image below.

https://www.audizine.com/forum/showt...ubwoofer-Cable

IMG_0953.JPG

For those who order with the intention of using it on the OEM subwoofer, I will send it unassembled and you would just wire accordingly based on post 52.

[Mugatu]

Just a quick update here - I just received and installed the wiring harness that iampraneel offered above.

The difference is immediate, and the bass even sounds great without even touching the subwoofer. And now when increasing the subwoofer, the system reacts as you'd expect....throughout all speakers.

If you have any issues with the sound system, do yourself a favor and get that harness. It's plug and play and I was up and running in 30 seconds.

[smokeyjoe03]

FYI - The standard sub (not B&O) is a single coil, it only has 2 wires, green and black, but it is also wired with backwards polarity. Swapping them over made a huge difference.

When I first bought the car I didn't even realise there was a subwoofer in it until I found it in the boot, now there is slight movement in the rear view mirror around full volume. Its still not ground-breaking but if you're not inclined to go aftermarket I would recommend sorting it. Better still,the driver is connected with two simple spade end connectors rather than being soldered so it's a 5 minute job to sort 👍🏼

*Car is a sportback

[DrewN209]

Hey folks. Been getting a lot of questions regarding which harness will work to make the OEM subwoofer sound better. The one you want from my For Sale link below is the Pigtail without RCA. I’ve also attached the image below.

https://www.audizine.com/forum/showt...ubwoofer-Cable

IMG_0953.JPG

For those who order with the intention of using it on the OEM subwoofer, I will send it unassembled and you would just wire accordingly based on post 52.

Do you offer one pre-assembled/wired to address the subwoofer issue in the B9 RS5 Sportback?


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[iampraneel]

They come unassembled but it’s really easy to do. I sent you a DM.


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[DaytonaRS5]

This was my favorite mod to the car so far. It finally sounds like it should. The bass is sent to the sub now so the mains upfront and rear can handle the mid and trebles, I’ve never been able to play my music as loud as I just did, because it just got worse the louder you went, the front would struggle and bass would become boomy. Now it’s crisp, punchy bass and clear mids and highs. I turned all the 3D, surround etc off as well. Haven’t enjoyed music in a car like that for a long time. First time I’ve driven my car and had music play over my exhaust, usually I just enjoy that but locked in the cruise control and played some favorites.


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[Rs5blkonblk]

Please how do I order one?

[ywang98]

So I went out there and just re-pinned the connector on the sub, swapping the + and - of each pair of coil. It was pretty easy with the connector pinning tools that I've had for years (for almost all German cars).

I think the sound after the swap is cleaner, but not much improvements as far as the sub-bass is concerned, just not as muddy in the sub-bass, but it is also not as loud now from the sub woofer.

I've already done the upgrade, changing out the factory sub prior to doing this.

[VVG]

Does anyone know if this issue is present in other models? My wife's '21 S4 B&O sub seems pretty weak, and adjusting the sub volume has only a seemingly small effect.

Also, is there any way of telling if the sub is wired out of phase or not?

[SpaceCowboy35]

This string caught my attention since I think of myself as an audiophile. It seems this discussion is directed around the sportback setup, is the B9 RS5 coupe also wired the same way? I’m a little underwhelmed with my B&O too. Thanks to everyone who has posted so far!

[Bobby Kinstle]

Now this is interesting. I do have a spare tire sub here I've been doing mad science experiments on, but my car wasn't equipped with it from the factory so I don't have any way of testing it in car. It's wiring colors matches the photos posted above by chrisdazzo. Seems like a huge oversight if true, but I have actually seen situations where a reversed phase subwoofer can appear louder in certain frequencies than proper phasing once it interacts with the environment. That's why some home subwoofers have a phase adjustment dial.

Here's some terrible port chuffing video:
https://www.youtube.com/watch?v=pJnp...l=BobbyKinstle

[djmika]

Now this is interesting. I do have a spare tire sub here I've been doing mad science experiments on, but my car wasn't equipped with it from the factory so I don't have any way of testing it in car. It's wiring colors matches the photos posted above by chrisdazzo. Seems like a huge oversight if true, but I have actually seen situations where a reversed phase subwoofer can appear louder in certain frequencies than proper phasing once it interacts with the environment. That's why some home subwoofers have a phase adjustment dial.

Here's some terrible port chuffing video:
https://www.youtube.com/watch?v=pJnp...l=BobbyKinstle

Bobby, I think you're dead-on on this. The factory sub, wired the way the factory had it did seem to me to play the very-low-bass more loudly whereas, with the phase switched, overall amplitude, especially in the 60-100 Hz range, went way up but anything below 45-50 Hz is mostly gone.

The factory sub in the SB is ported. In a 4th order box, below the tuning frequency where the port just acts like a hole in the box, the rear waves start to cancel the front waves. All of this "activity" way down low can do strange things. Especially in a car where cabin gains can have significant effect and especially at very low frequencies. Add in front door speakers that are either in a sealed or morel likely infinite-baffle configuration...

A theory; an engineer looked at the response curves, noticed what is probably a louder but peaky response with a relatively high roll-off frequency with the sub "in-phase." They then reversed it and saw a response that may look smoother on paper. Maybe even with a dip between 40 and 100Hz, but one with audible bass down in to the 30's in conjunction with the door speakers. They chose their version of the lesser of all evils.

I think the factory audio system and possibly the acoustics of the car have some interesting challenges. I certainly don't have enough info or specs, nor the proper measurement equipment to pin the main issues down. But I do have an experienced, reasonably trained ear and have experimented enough to say with relative certainty, that the issues with these cars isn't as simple as just standard or reversed phase on the subwoofer.

I think we're choosing the lesser of all evils for us when we reverse the phase of the factory, or even an aftermarket woofer.

MB

[JohnEnglish]

But there’s also the issue that a few people have checked their subs and found that they were wired correctly. That would seem to indicate that it was either a change made during production or there was a batch of harnesses that were wired incorrectly.

[Bobby Kinstle]

The factory sub in the SB is ported. In a 4th order box, below the tuning frequency where the port just acts like a hole in the box, the rear waves start to cancel the front waves. All of this "activity" way down low can do strange things. Especially in a car where cabin gains can have significant effect and especially at very low frequencies. Add in front door speakers that are either in a sealed or morel likely infinite-baffle configuration...

Did they change the box from the spare tire sub in my video? The one I have here is normal bass reflex not 4th order.

I think the factory audio system and possibly the acoustics of the car have some interesting challenges. I certainly don't have enough info or specs, nor the proper measurement equipment to pin the main issues down. But I do have an experienced, reasonably trained ear and have experimented enough to say with relative certainty, that the issues with these cars isn't as simple as just standard or reversed phase on the subwoofer.

I have some tools we can try on tuesday

[ywang98]

This string caught my attention since I think of myself as an audiophile. It seems this discussion is directed around the sportback setup, is the B9 RS5 coupe also wired the same way? I’m a little underwhelmed with my B&O too. Thanks to everyone who has posted so far!

Mine is a '21 RS5 Sportback, wired like what was demonstrated in this thread. I simply swapped the pins on the connector.

[bruce_miranda]

I am going to say that Audi aren't wrong. They have just made a different design decision. Changing the phases of the subwoofer will just alter the frequency spectrum where it seems louder. What you want is the subwoofer to play the lowest frequencies the loudest. For those who feel the subwoofers are wired in/correctly are just perceiving the sound they hear differently. As they say in sound...whatever sounds best to you is right.

[CARNERD]

So can this be done two different ways with the factory sub?

1 - swap the green/black and yellow/Orange on the woofer itself ....see attached pic. From what I read etc green and yellow are wired as positive and black and orange are wired as negative.

OR

2 - repin the harness plug

So this is the right way doing this right? Because the swap can happen with each pair as well. Just making sure.

[bruce_miranda]

You have to swap both pairs, else your sub won't move.

[CARNERD]

You have to swap both pairs, else your sub won't move.

So the post I quoted have it right?

[bruce_miranda]

So the post I quoted have it right?

Yes.
There are atleast 4 places you can perform this. At the amp plug, at the car harness plug, at the speaker harness plug and at the speaker itself.
So choose where you want to swap and then swap both pairs at that place.

[evhudsons]

It seems to me then, if I use the piggy back harness allowing me to use both the stock subwoofer, and the ager market 10 inch subwoofer in the basser box, that I should repin the stock subwoofer side, so only that subwoofer is reversed, and the basserbox sub would be wired as audi intended. The stock sub would be slightly louder not hitting lows which it's small size kind of prevents anyway, and the 10 inch sub can go lower hz?

[bruce_miranda]

In an ideal world, you shouldn't use 2 subwoofers. And then you definitely shouldn't have them firing out of phase of each other, as they will cancel out each other.
But like with most things sound related, do whatever Sounds right to your ears. Not what people like me tell you to do.

[evhudsons]

That makes sense. I might try both just to see. Repinning is reversable.

- - - Updated - - -

I just need to see if the auto parts store has a depinning tool.