# Both Bass Speakers have open circuit according to VAG COM



## WillemBal (Nov 20, 2010)

I am getting an error with VAG COM, indicating that my bass speakers in the front doors are both having an open circuit. The error I'm getting is this:

Address 47: Sound System Labels: 7Lx-035-4xx-47.lbl
Part No: 3D0 035 466 
Component: 12K-AUDIOVERST 0115 
Shop #: WSC 00000 000 00000
VCID: DFC6212231670AE4

2 Faults Found 
00870 - Bass Speaker Front Left (R21) 
011 - Open Circuit
00871 - Bass Speaker Front Right (R23) 
011 - Open Circuit

When I the link in the error log, I enter the advanced diagnostic mode and that menu guides you through a series of tests, where each speaker can be audibly tested. I noted that both bass speakers do not produce sound, while all other speakers are producing (sequentially) a 1000 Hz beep tone. Although this beep tone might be suitable to test both mid-range speakers and tweeters, it can't possibly a reference signal for the bass speakers as this high frequency never would be able to pass through the low-pass filter of the bass speakers.
I am not sure whether the bass speakers are really having open circuit. I don't want to rip off the trim of my doors to replace these speakers until I'm sure that they are really broken. Does anyone has experience with this error? If both woofers are correctly reported as defective, then I think that these woofers are not so good. I have the 12 speaker system (2004 W12 with full options).


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## Prince Ludwig (Mar 24, 2007)

I have the same problem but with my mid-range bass speakers but since I can hear a tone when it tests the bass speakers I guess something makes it through. This thread might be of some interest.

Harry


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## WillemBal (Nov 20, 2010)

*Wiring amplifier*

Thanks Harry,
I'm audiophile and can hear that something is missing in the sound reproduction, but don't know what. And in fact, the low reproduction of the speaker system is not at all that bad. Therefore, I wanted to know whether it is a known issue of the VAG COM rather than a failure of the bass speakers. If the conclusion of VAG COM is correct, then the next step would be to check the suspect woofers. Rather than dismantling the door trim, I would disconnect the speaker connections at the amplifier end, then measure the resistance of each speaker. I have a tone generator to do more advanced checks.
The thread you gave me in your reply was pretty usefull, however I couldn't find a wiring diagram and how to get to those wires easily without dismantling the battery. Any suggestions?


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## PanEuropean (Nov 3, 2001)

Willem: 

It's a known issue of the speakers, not of the VAG-COM. The VAG-COM is most likely telling the truth. 

Look at the pictures on the thread that Harry referred you to. 

Michael


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## PanEuropean (Nov 3, 2001)

WillemBal said:


> I couldn't find a wiring diagram and how to get to those wires easily without dismantling the battery. Any suggestions?


 It is a bitch to try to work on the connectors to the audio amplifier behind the right battery. If it was me (and I have done this in the past), I would take the door panel off. 

There are posts in the Phaeton Forum 'Table of Contents' (FAQ by Category), with illustrations, that show how to get access to the audio amplifier, how to take door panels off, and there are also wiring diagrams posted in there. 

I have a killer toothache right now, were it not for that I would provide you with direct links. But, I feel awful, and am going to go back to bed, so you will have to go digging in the FAQ to find that stuff. It's not hard to find. 

Michael


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## WillemBal (Nov 20, 2010)

PanEuropean said:


> It's a known issue of the speakers, not of the VAG-COM.


 Toothaches can be like hell, Michael. So better take care of that first. 
Well, I looked through all the posts and pictures and conclude that most likely the two woofers are blown. I can handle that. But there seem to be a lot of issues with these speakers. Did the replacement of your own woofers permanently fix your problem? I am interested to know the story behind “known issue” and whether and how it has been solved permanently by VW, on this particular audio system. One fix that I can think of is replacing the speakers by better ones, like Dynaudio or other brands, or improving acoustic damping, thicker wiring etc. and a couple of other more advanced measures. Do you happen to have some more information about how to prevent the blown speakers in the future?


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## madreg98 (Jun 1, 2009)

*blown woofers*

i also have the same problem. both woofers are blown. if you choose an upgrade, please let me know since I will have to replace them. 

thanks, 
Dennis


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## PanEuropean (Nov 3, 2001)

WillemBal said:


> ...But there seem to be a lot of issues with these speakers.


 Hi Willem: 

Actually, the only issue that we know of here is that if you turn the volume up too loud on the cars with the 12 channel sound (the DSP), the darn speaker works so hard (moving back and forth) that the little wires eventually break from fatigue. 

Other than that, the speakers are pretty reliable and sound quite nice. 

The 'fix', I guess, is to not turn the volume up so high, especially if other features such as dynamic compression, loudness, and a higher than normal bass response have been selected. 

The first time I had this problem with my car, we (my VW dealer and I) replaced the speaker. The second time I had the problem (on the opposite side speaker), we just re-soldered the wire, because it seemed like a waste of warranty money to replace the whole speaker. I have since had no further problems (5 years have now passed). 

It is possible (this is pure speculation) that VW may have become aware that these little wires were breaking sometime around 2004, and subsequently asked the speaker manufacturer (Blaupunkt, from Tunisia) to make the soldered connections a bit more robust. 

Michael


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## PanEuropean (Nov 3, 2001)

madreg98 said:


> i also have the same problem...


 Dennis: 

Just take the door panel off, inspect the speakers, and re-solder the broken wire (assuming you find a broken wire). It is not a simple job to take the door panel off, but it is not beyond the scope of a dedicated DIY person, presuming you have the right tools. 

There is a post in the Phaeton Forum 'Table of Contents' (FAQ by Category) that explains in detail (with pictures) how to take an interior door panel off. I think it is the post entitled "Door Handles - How to troubleshoot and replace exterior handles (Keyless Access button not working)" 

Michael


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## WillemBal (Nov 20, 2010)

madreg98 said:


> i also have the same problem. both woofers are blown. if you choose an upgrade, please let me know since I will have to replace them.


 Dennis, how far are you willing to go with an upgrade? The speakers cost 70 Euro each and there are a few alternatives, like Dynaudio and Kicker, as I read on a related thread. Upgrading can go a lot further than that, like adding acoustic absorbers in the door, replacing the LS wiring with audiophile silver plated, large diameter OFC and ultimately replacing the entire speaker set with Dynaudio, if at all available and compatible with the amplifier and passive/active filter system.


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## WillemBal (Nov 20, 2010)

PanEuropean said:


> The 'fix', I guess, is to not turn the volume up so high, especially if other features such as dynamic compression, loudness, and a higher than normal bass response have been selected.


 Hi Michael, 
This sure is a good advice. I always listen w/o such adjustments, i.e. no loudness and with the tone adjustment set to zero, because I like the music to be reproduced as it is, i.e. was recorded. I guess one of my two sons, might have been headbanging in my car:banghead:. 



PanEuropean said:


> The second time I had the problem, we just re-soldered the wire,


 Then you did a good job! Soldered wires under varied stress normally fail at any point in time. I think I will focus on replacing the woofer with an after market speaker. 



PanEuropean said:


> the darn speaker works so hard (moving back and forth) that the little wires eventually break from fatigue.


 True, though another cause is just resonance. Given the fact that the speaker is installed in a non-ideal cavity, resonance frequencies may occur, causing the cone to make strokes which are a multitude of the original applied voltage. This effect makes many car audio systems go like boom boom boom. To large extent, also the body work of the door adds to this resonance. I wonder whether anyone ever came up with a solution in the form of applying stiffeners and acoustic absorbers to reduce excessive resonance. 
Another way to reduce that is to choose an amplifier and wiring with really low impedance and a speaker with a very low DC impedance as well. These are just some "tricks" which cause high end audio systems to cost very much. I don't want to go that far, so I think I will look for a good speaker replacement and possibly make some modifications to the door.


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## madreg98 (Jun 1, 2009)

Thanks for the input Michael. I am going to have to take the door interior off and we'll see if it's busted wires or blown speaker. I'm going to bet blown speaker only because if I play low volume both woofers play fine. I have had this issue on some guitar speakers and found out that the speaker cone had separated. I'll post when I get the door apart.


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## madreg98 (Jun 1, 2009)

HMMM. Probably not that far. I was looking more at speaker materials, magnetic cone weight and power handling for those occasional times when a great song need super volume! I just didn't want to go back to the factory original figuring that if they both blew out once they could do it again.


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## PowerDubs (Jul 22, 2001)

madreg98 said:


> Thanks for the input Michael. I am going to have Josh take the door interior off and we'll see if it's busted wires or blown speaker.


 



:laugh:


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## WillemBal (Nov 20, 2010)

I'm not going that far either, after seeing these nice pictures following this link: http://forums.vwvortex.com/showthread.php?4615036-Repair-Replacement-of-Window-Regulator-add-to-TOC 
It gives a good impression of what you can expect to see once the door panel has been removed. The woofer has part number 3D0035454. It's called a "Tieftoener", literally "deep toner". I've never seen such a small woofer before, it only measures LxBxH :165x155x60 and it is only 2 ohms. I have no idea why it is so low. So both dimenions and its impedance are going to make it hard to find an alternative. My preferred choice for woofers would be Scanspeak. They are the best, but their products are usually much bigger. With more magnet too. I am curious to know what you will find after you've taken the panels of. Some modifications may be necessary when you want to install an alternative.


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## PanEuropean (Nov 3, 2001)

Here is a picture of the two speakers in the bottom of the front door. I am going to assume that these are the low frequency speakers. 

When everything is working, they sound just fine. The little wire that sometimes breaks from vibration (discussed earlier in this thread) is visible on the speaker on the right side of the picture. 

*Speakers in bottom of front doors*


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## PanEuropean (Nov 3, 2001)

Below is a picture showing where a wire broke (presumably from vibration). This is quite easy to fix and does not require replacement of the speaker. 

Based on all the conversations and discussions I have participated in during the past 7 years about "no bass" sound problems, I am convinced that this (a broken wire) is by far the most common cause of the problem. So, start your troubleshooting here. 

There is a post in the Phaeton Forum 'Table of Contents' (FAQ by Category) that explains how to take the inside door panel off. Here is a direct link to that thread: Repair / Replacement of Window Regulator . The instructions and illustrations begin a few posts down from the top of the thread. 

*Broken Speaker Wire*


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