Audio upgrade problem with OEM heal unit, subwoofer distortion

**cecaa** · 05-11-2008 01:56 AM

I recently got an ALPINE PDX-5 amp, 4ch+1sub ch (300w sub, 600w total rms). Mounted a 10' Alpine Type R in a sealed box. Those are connected to the factory head unit. the oem sub has been taked off.

The problem is , when subwoofer is hitting , I can hear very significant distortion from the subwoofer or something in the box ( at least feels like this ). The installer told me with factory head unit, the signal is not good, even tho I bought and installed the output signal converter from them.

They did very bad job on mounting and wiring which I will get back to them later, but with the $1000+ system, the sound shouldn't really be like this.

BTW, I didn't even turn it loud!

AFter the installation, I also felt the 4 door speakers now sounds quieter and there is no low frequency sound coming out from them at all.

Now I feel like

**Kschroers1** · 05-11-2008 09:09 AM

Their is something they did wrong there. They should've never touched the OEM head unit. All that is required from the front of the vehicle to the rear is the Power cable to supply voltage to the amp. Everything else can be done by wire tapping into the OEM subwoofer thats connected to the OEM amplifier on the right quater panel area of the vehicle. Of course unplug the OEM sub. Then just test for a lead that supplies constant voltage to tap in your remote(blue) wire. I paid $250 for my 10" Alpine and a simple box and it hits hell'a hard with absolutly no distortion or anything screwy with my OEM speakers.

**gyroscope** · 05-11-2008 10:21 AM

If the sub is distorting and your factory components are missing their low end, there is either a voltage drop somewhere causing the amp to run at half power, or you may need to bridge the amp to use it's full potential. The first thing I would do is is to check the gain and the crossover frequency knobs while the system is running/playing. Tweak those two parameters first and see if you get any sort of change. chances are the installers screwed something up, possibly by not reinstalling the paasive reisistors or crossover components.

**Ski DraGoN** · 05-11-2008 06:21 PM

Sounds like they ripped you off and now they want to rip you off some more. Go somewhere else.

**LimiTed** · 05-11-2008 08:02 PM

Originally Posted by Kschroers1

Their is something they did wrong there. They should've never touched the OEM head unit. All that is required from the front of the vehicle to the rear is the Power cable to supply voltage to the amp. Everything else can be done by wire tapping into the OEM subwoofer thats connected to the OEM amplifier on the right quater panel area of the vehicle. Of course unplug the OEM sub. Then just test for a lead that supplies constant voltage to tap in your remote(blue) wire. I paid $250 for my 10" Alpine and a simple box and it hits hell'a hard with absolutly no distortion or anything screwy with my OEM speakers.

yup. the only thing that ran from the front is the power. my signal and remote hooked up to the harness that plugs into the stock amplifier. that way you're disconnecting the stock amp and sub as well. i have a 12" type-r that hits hard and clean. your head unit should have never been touched. if you search there's a thread that has the pinouts to the stock harness that you can tap into.

**Phrost** · 05-11-2008 08:14 PM

If you bought products from them and they installed it, and it sounds like crap... go straight back there and tell them to fix it. You paid for the install which should be 100% correct, and something isn't right. Just say, "hey you guys installed a sub I bought from you, but it doesn't sound right at all. Could you look at it and see what's wrong?"

Don't pay anything extra. You already paid for the install that should be right.

**BLACKa4QUAT** · 05-11-2008 09:17 PM

i never had any distortion using a hi-low converter with my factory headunit in my old b6, as it was said before, they should have tapped the lines in the amp in the trunk, if i'm not mistaken there are also line level inputs going into the factory amp. its been a long while, and i had the bently manual to check it. now i just have an aftermarket headunit

**Ski DraGoN** · 05-11-2008 10:43 PM

Originally Posted by Phrost

If you bought products from them and they installed it, and it sounds like crap... go straight back there and tell them to fix it. You paid for the install which should be 100% correct, and something isn't right. Just say, "hey you guys installed a sub I bought from you, but it doesn't sound right at all. Could you look at it and see what's wrong?"

Don't pay anything extra. You already paid for the install that should be right.

bump

**redlabel81** · 06-23-2008 11:27 AM

Originally Posted by LimiTed

yup. the only thing that ran from the front is the power. my signal and remote hooked up to the harness that plugs into the stock amplifier. that way you're disconnecting the stock amp and sub as well. i have a 12" type-r that hits hard and clean. your head unit should have never been touched. if you search there's a thread that has the pinouts to the stock harness that you can tap into.

So you take the signal before it enters the amp? Than you don't need a LOC or anything, right.......

Can you please tell me what pins you have to tap? Non-bose.

Regards
E