Polo GTI 9N Stealth Audio Upgrade Guide / Stealth Amp

**flat6** · 30-10-2012, 09:45 PM

Finally got around to uploading my experience with this in the Polo, its one tight car to get a completely invisible sound system into.

The objective was to improve the overall experience of the system and actually have something that sounds like my setup at home and do it for under $1400

After months of research I decided to get 2 sets of Hertz HSK 165's and amp them with an alpine pdx-v9 amp, mount and install the whole thing keeping the factory look

Picked up the Hertz off ebay for $139, real deal, went to autobarn and had a look at their $499 pair, no difference what so ever in packaging, speaker build quality and materials used.

As for sound deadening and hours of research I decided to go for car builders sound deadener, they are a local Melbourne supplier for an imitation dynamat substance that i cant imagine to be any different, ordered it online and received it exactly as i was removing the door panels, pretty decent, light weight and easy to apply.
Sound Deadener - Car Builders - Sound Deadener Heat Insulation Car heat Shields

Covered most of whole outer section of the door panels

This part was fun, running the wire through the door required drilling a 16awg gap through the door terminals and running it through the rubber.. little time consuming but works quite well.
pre-drilling, i used the upper plug for my choice of hole

Removing the rear quarter panel you find amazing speaker boxes, at first i thought about building a sealed section in this compartment and putting 2x 6 or 8" subs, would be great but its a fair bit of effort

Driving without the rear panels on i realized that nearly all the road noise in the car comes from the rear wheel well,

removed the black panels and applied a heavy duty rubber seal to them, pick it up at bunnings for $12, plenty thick to prevent any rattles from the extra vibration.

Mounted with the rubber seal provided, had to do a little modifying to make it fit but it does the job perfectly

Applied a little econo seal to the bottom of the crossovers and screwed them to the black plate, always test the sharpness of the tweeters before applying the panel to save the headache of removing it a second time to adjust the

The single hardest part about this install was the front tweeters, god dam what a nightmare!

Firstly to get the bastard of an A-piller off you need to work around the Airbag strap to the panel, if you get this bastard out twice without breaking one I salute you, remember to remove the screw by removing the airbag logo clip off the A pillar and removing the screw before unclipping the panel..

Single most important piece of advice i can offer, test your tweets before mounting them, I had the unfortunate luck of dealing with tweeters that were absolutely ear piercing at high volume in the stock mounting position, I needed to actually raise them on one side to point them downwards to the dash, after doing this the difference was amazing, its actually really comfortable to listen to now

Simply sat them in the stock mount and listened to it with a few sharp songs like titanium, this will destroy your ears btw

Now as to mount the Amp in a totally stealth spot, I had thought about putting it in the boot but decided to go with the hardest option possible and mount this under the glove box

This decision has many benefits including very short RCA's and speaker wire, a lot less interferance

To devise a bracket that would be strong and small enough to mount in such a tight spot took a few weeks of thought, came up with using a 1m long aluminum off cut and forming it into the mounting shape then drilling it into the chassis using a couple self tapper screw, to my surprise it actually worked quite well and it barely even moves when driving, amp weighs about 2.5kg.

Amp is also completely invisible from outside, the carpet is the most you see from the passenger seat.

Picked up the PDX-9 for about $450, retail for about a $800 and currently just running a cheapie clarion 12"

Hope this helps anyone else who suddeny has the itch to torture themselves for 2 weeks straight installing an absolutely amazing system

To be honest i was disappointed at first but after a week or two of burn-in, the speakers have settled in nicely and sound simply awesome, HSK's rock

Stay tuned for my new subwoofer install, im designing a down firing low profile sub that will be stealth mounted in the boot, be light weight and removable, still trying to decide on alpine or hertz for the brand but im thinking the type r will do nicely.

Pat

**Masker** · 30-10-2012, 11:07 PM

Hertz HSK 165's

More info on the official website
hertzaudiovideo.com/default_en.htm

Hope that is a helpful extra to move the thread on to attract more interest and posts.

**kaanage** · 31-10-2012, 05:53 AM

When I pick up my Ultra Racing braces, I'd love to compare the sound from our 2 different approaches to ICE for the Polo.

**flat6** · 31-10-2012, 06:34 AM

Looking forward to getting that brace, believe they arrive this Friday, feels like its been forever!

Wished more people did these sort of audio upgrades now days, should be good to compare

**nightphotographer** · 31-10-2012, 07:48 AM

WOW! I really want to spend a heap of money on my stock sound system now! Ahhhh need more monies

**kaanage** · 31-10-2012, 08:11 AM

I've actually spent relatively little and I'm very happy with the result (even vs my full on component system with floorstanders at home) which is why I want to hear how flat6's sounds with the driver upgrades. Allegiance did all this in his 6R and, IMNSHO, it didn't sound as good as my system.

**Allegiance** · 31-10-2012, 08:40 AM

Got a link for the eBay HSKs? I've had a set of those before and liked them.

**flat6** · 31-10-2012, 10:55 AM

These are the speakers, you can make an offer of $139 and still get them

eBay Australia: Buy new & used fashion, electronics & home d

Kaanage, yep the stock system is pretty awesome and very comfortable to listen to, but once you compare it with this you see where it lacks in clarity, warmth and sound stage

Unfortunately its rather difficult to tame a loud audio system in such a small car thus you get the idea that it doesn't sound as good at first, it took about 2 weeks of tuning the amp to nail it perfectly with crossovers and gain, quite trivial unfortunately.