# Mk5 GTI audio and subwoofer questions



## 1canuck2 (Jul 22, 2007)

Just got my new Mk5 GTI and I have some stereo install questions.
In my old car I had an aftermarket Alpine head unit sending line level out to an Alpine MRP-M350 subwoofer amp with an 8" JL W0 in a sealed box. I powered my main speakers from the Alpine's built in amp. I was happy with the sound quality and thump from the system.
Now I gots me a GTI, and I am disappointed with the audio quality compared to my previous rig. I like the HU itself feature-wise, (esp. the steering wheel controls, 6CD and Aux in features), but the bass response from the speakers is terrible (and generally the SQ is not as good as I would like). I have had to roll off the bass to about 10 o'clock to stop it from distorting with the deck only at half volume... I need to do something!
The cheapest quick fix is to tap off the rears into my Alpine amp and put my old sub in the trunk. The MRP-M350 happens to accept line level or speaker level inputs (I have only ever messed with line level outs from aftermarket deck, so don't know how good the speaker level ins will be). 
If I do tap off the rear speakers, I'll want to use the sub for most of the lower end bass, but how to cross it over? If I keep the "Bass" dial at 10 o clock, surely this means the low frequencies will not be sent to the amp (since they are not being sent to the speakers, and its the speaker signal I am tapping). However, if I set it back to 12 o clock, the mains will play distorted bass. Anyone experienced this with a LOC-based amp/sub with stock system? Essentially, my amp has a LOC built-in, so I imagine the problems will be the same. 
Are you satisfied with adding a LOC/amp/sub to the stock system?
I searched but can't find much info on the Mk5 audio system. Its labeled Premium Sound in my manual (Canadian model GTI). Is there an external amp somewhere? Or is it using an amp built-in to the HU? Didn't older VW "Premium Sound" system feature an external amp? I am a newbie dubber...
Generally speaking, what would you say is the weakest part of the Mk5 GTI Premium Sound system? HU? Speakers? Amp (or lack thereof since I can't find one in my car...). In other words, if I upgraded the speakers only, would I get better sound out of the stock HU? I am reluctant to dump the stock HU, but don't want to invest in aftermarket speakers if the HU is the reason things are not good enough.
Sorry for all the questions, I appreciate any help or opinions folks can share.


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## afinley (Dec 29, 2004)

*Re: Mk5 GTI audio and subwoofer questions (1canuck2)*

you can put bass blockers on your door speakers, and just tap into the rear speaker lines (pre bass blockers) for the sub. that way you can turn up the bass on the HU and not distort the door speakers.
i dont have a mk5, so dont take my word for it, but if you cannot turn up the volume past half without bad distortion, it sounds like the amp is your weak link.
kwalton was in some magazine doing an install on a mk5 gti, and he's always here, so maybe he can tell you if you can just replace the amp, or if its a hassle like a mk4


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## 1canuck2 (Jul 22, 2007)

*Re: Mk5 GTI audio and subwoofer questions (afinley)*

Thanks for the reply. So, forgive my ignorance, but bass blockers are essentially inline crossovers, right? I would tap off to the sub amp pre-bass blocker, then insert the bass blocker after the tap and into the stock speakers?
So, I'd need to do bass blockers on both the fronts and rears then. Then essentially, the main bass signal is sent to the sub, and none is sent to the speakers. Sounds feasible but perhaps as complicated as just pulling the stock HU, which I am trying to avoid!
Anyone have a Mk5 GTI and done some stereo work? Care to comment on what my options are to improve "performance" from the stock system?


_Modified by 1canuck2 at 1:00 PM 7-23-2007_


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## afinley (Dec 29, 2004)

*Re: Mk5 GTI audio and subwoofer questions (1canuck2)*

yeah, you connect the bass blockers across the terminals on the woofers. so yes, you would tap the lines for the sub signal before that, and yes, bass blockers are inline crossovers.


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## pwnt by pat (Oct 21, 2005)

*Re: Mk5 GTI audio and subwoofer questions (afinley)*

From what I recall, the mk5 premium sound is a three-way active setup for the front woofers and two way active for the rear speakers.


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## SMkVGTI (Jun 14, 2007)

*Re: Mk5 GTI audio and subwoofer questions (pwnt by pat)*


_Quote, originally posted by *pwnt by pat* »_From what I recall, the mk5 premium sound is a three-way active setup for the front woofers and two way active for the rear speakers.

That is correct.


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## 1canuck2 (Jul 22, 2007)

*Re: Mk5 GTI audio and subwoofer questions (SMkVGTI)*

Thanks for the reply Can you expand on the setup please. 
Are there crossovers in the doors? Could I simply tap off the woofer feed from the rear door woofers (or unhook them altogether?
Do you know if there is an external amp somewhere in the GTI or is it all in the head unit?
If I want to upgrade the system, where would you start if doing it piece by piece? As I said earlier, I'd like to leave the head unit if I can get decent SQ by upgrading the speakers and adding a sub


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## kwalton (Sep 3, 2001)

*Re: Mk5 GTI audio and subwoofer questions (1canuck2)*

read about this install i did for a photograper for eurotumer. http://www.eurotuner.com/techa...ades/


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## 1canuck2 (Jul 22, 2007)

*Re: Mk5 GTI audio and subwoofer questions (kwalton)*

Hey, sweet! Thanks for the linky dink, that's an awesome walk through.
Couple of questions: You ran the power and RCAs down the same side, in my previous research when I subbed my Protege5, that was a big no-no, I ran power down driver's side and RCA's down passenger's side. Did you have any issues with noise?
Which cables did you tap off for the LOC? My Alpine MRP-M350 sub amp accepts speaker level inputs as wel as line level, so essentially it has a built in LOC, what do you reckon about using this as opposed to a dedicated LOC?
The bigger question is did you do anything about rolling off the bass sent to the main speakers. I am finding in my GTI that with the HU volume at only half way, the bass distorts from the doors speakers so badly that I have to roll off the bass control to around 10 pm. While adding just a sub will give me some low end thump, the crappy mains will still be distorting and rolling off the bass dial will affect input to the sub given that I am tapping off the speaker outs.
Do you know the actual design of the GTI Mk5 system? Is the amp part of the head unit? Where is the crossover for the door speakers? Would I get an improvement in sound if I upgrade the door speakers but leave the stock HU? 
Dropping some knowledge on me will be truly appreciated!!


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## TimmahTao (Jul 20, 2007)

*Re: Mk5 GTI audio and subwoofer questions (1canuck2)*

I'm interested in adding an amplifier in between the OEM head unit of my 5 door Rabbit (so it's the same head unit as in the GTI, without the factory amp.) I found this product, http://enfigcarstereo.com/shop...html , but I'm not sure exactly how I would integrate it into my system. It looks like it plugs into the back of the HU and gives me two pairs of RCA outputs. What would be the best way of using those inputs? There are 10 speakers in my stock system. 2 bass, 2 midrange and 2 tweeters in the front doors as well as 2 midrange and 2 tweeters in the back. Are they all wired in parallel or series? What would be the best way to connect them to the amps? Where are the crossovers? In the HU or the door/inline? I'd like to up the power and minimize the distortion.


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## pwnt by pat (Oct 21, 2005)

*Re: Mk5 GTI audio and subwoofer questions (TimmahTao)*


_Quote, originally posted by *1canuck2* »_Hey, sweet! Thanks for the linky dink, that's an awesome walk through.
Couple of questions: You ran the power and RCAs down the same side, in my previous research when I subbed my Protege5, that was a big no-no, I ran power down driver's side and RCA's down passenger's side. Did you have any issues with noise?
*That's an old wives tale. No issues can physically occour.*
Which cables did you tap off for the LOC? My Alpine MRP-M350 sub amp accepts speaker level inputs as wel as line level, so essentially it has a built in LOC, what do you reckon about using this as opposed to a dedicated LOC?
The bigger question is did you do anything about rolling off the bass sent to the main speakers. I am finding in my GTI that with the HU volume at only half way, the bass distorts from the doors speakers so badly that I have to roll off the bass control to around 10 pm. While adding just a sub will give me some low end thump, the crappy mains will still be distorting and rolling off the bass dial will affect input to the sub given that I am tapping off the speaker outs.
*Radioshack has nifty little devices called bass blockers. They're a simple 6db high pass filter that you wire inline with your speakers. Just grab one for each main woofer and wire it in.*
Do you know the actual design of the GTI Mk5 system? Is the amp part of the head unit? Where is the crossover for the door speakers? Would I get an improvement in sound if I upgrade the door speakers but leave the stock HU? 
*The amp is a seperate unit. Where I'm not sure. There is no crossover, it's built into the amp. There are three pairs of wires running to each side in the front, one pair for each speaker. If you upgraded the door speakers, you'd want to do so with a component set and would need an aftermarket amp. Dynaudio makes a drop-in system for the mk5 but it's PRICEY. Dynaudio is some tip-top gear.*
Dropping some knowledge on me will be truly appreciated!!


_Quote, originally posted by *TimmahTao* »_I'm interested in adding an amplifier in between the OEM head unit of my 5 door Rabbit (so it's the same head unit as in the GTI, without the factory amp.) I found this product, http://enfigcarstereo.com/shop...html , but I'm not sure exactly how I would integrate it into my system. It looks like it plugs into the back of the HU and gives me two pairs of RCA outputs. What would be the best way of using those inputs? There are 10 speakers in my stock system. 2 bass, 2 midrange and 2 tweeters in the front doors as well as 2 midrange and 2 tweeters in the back. Are they all wired in parallel or series? What would be the best way to connect them to the amps? Where are the crossovers? In the HU or the door/inline? I'd like to up the power and minimize the distortion.

See directly above.


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## TimmahTao (Jul 20, 2007)

*Re: Mk5 GTI audio and subwoofer questions (pwnt by pat)*


_Quote, originally posted by *pwnt by pat* »_
See directly above.

I have a Rabbit, not a GTI. The layout is different as I do not believe that I have an external amp, like the one in the GTI.
-Tim


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## 1canuck2 (Jul 22, 2007)

*Re: Mk5 GTI audio and subwoofer questions (pwnt by pat)*

Thanks for the reply pwnt.
Doesn't the fact that kwalton used a LOC right off the head unit imply the amp is integrated into the HU? Otherwise, the output would be a line level signal, thus bypassing the need for a LOC.
Kwalton: can you confirm? Did you use bass blockers anywhere on that system? Cos I can't imagine getting the sub to sound good without the main speakers sounding like poo and ruining your low-end addition.


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## kwalton (Sep 3, 2001)

*Re: Mk5 GTI audio and subwoofer questions (1canuck2)*

the audio from the factory radio has a high enough signal output to effectively use a loc at the radio itself. i was able to get the car sounding better by reducing the bass level on the factory speakers with the radio knob and used the bass boost on the alpine amp to help out a little with the bottom end. the result is a lot of volume and no distortion in the factroy speakers.


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## TimmahTao (Jul 20, 2007)

*Re: Mk5 GTI audio and subwoofer questions (pwnt by pat)*


_Quote, originally posted by *pwnt by pat* »_
See directly above.

I have a Rabbit, not a GTI. The layout is different as I do not believe that I have an external amp, like the one in the GTI.
-Tim


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## pwnt by pat (Oct 21, 2005)

*Re: Mk5 GTI audio and subwoofer questions (TimmahTao)*

If you do not have an amp, then you have wiring going directly from the head unit to crossovers in the door.


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