'06 Vert, non-Bose
I replaced the original HU with a Pioneer P8000PT and replaced the 3½" door speakers with Polk DB551s and disconnected the center speaker.

The Pioneer HU has RCA outputs for Left & Right, front & rear speakers. Also L & R sub-woofers. However, the adapter that mates the radio to the car's electronics doesn't have sub-woofer inputs like it has for front & rear.

Question: Should I...

• bypass the adapter box and wire the HU sub-woofer outputs to the existing external amp (not sure if that's safe without going through the adapter box) or
• run the HUs sub-woofer outputs directly to the existing sub-woofers in the doors?

I'm not looking for window rattling bass, just trying to get the system up to reasonable quality level.

Thanks, your input will be greatly appreciated.

 

you shouldnt have to do any of that

 

Somene correct me if Im wrong, but doing either of the two won't help. All of the front speakers run off of two channels of the stock amplifier, so you don't have multiple amplification channels to work with. You have to use the L & R Front RCAs.

Better yet, add a small subwoofer amp (like the Arc or Rockford Fosgate mini amps) and a subwoofer on one of the rear cubbies, and connect the sub out of the head unit to that. It will make a huge difference.

 

Connect the four front/rear outputs to the four inputs on the adapter. The oem amp will do everything else for you. Just make sure they're all set on 'full range' (HP filter is off).

Make sure you also connect the new radio's 'remote amp trigger' wire to the wire on the interface adapter that lines up with B3 of the oem plug (or you won't hear anything).

If you want to buy an aftermarket sub for the trunk, that's what you'd use the sub outputs for.

 

Thanks for taking the time to guide a novice through this installation. I’m still trying to understand this.

I think I do need to connect both front & rear HU outputs so that the Balance & Fader controls work but I’m still confused (not unusual) about the sub-woofer wiring.

The aftermarket HU has sub-woofer controls; I can turn the SW output on or off. I can also set the cut off frequency for the SW and high pass frequency for the L & R speakers. I’d like to take advantage of this.

The wiring harnesses (into & out of the amp) have sub-woofer wires. If I connect my HU's SW output to those wires, would the amp boost the signal and pass it to only the large door speakers or is this wiring only used for Bose systems and not supported by the non-Bose amp?

The HU can drive speakers w/o an external amp so wiring the HU sub-woofer outputs directly to the large door speakers (original speaker wires disconnected) should work. No? I know that’s not the best scenario but wouldn’t that be better than not using the sub-woofer outputs/controls? I could add a SW amp and better speakers later if I decide to.

I understand that the center speaker (already disconnected) is the sum of L & R. I think I read somewhere that the rear speakers are also combined. Where does this combining take place – in a harness or internally in the external amp?

Thanks again for your help!

 

Fill in the blanks with model numbers for all of your equipment that will end up in the car. Anything that's remaining stock, just say stock

Radio: _____________________

Interface adapter: ______________________

Amp: ________________________

Front speakers: ___________________

Rear speakers: ______________________

Sub: __________________________

If all you're doing is changing the radio and swapping in new 3.5" speakers in the doors, all you need to connect from the radio to the interface is the four front/rear outputs and the trigger wire. Make sure the radio is putting out a full signal on those channels (HPF off) and the oem amp sends the proper signals to the proper speakers. The only way your new radio sub outputs are used or controlled is if you intall an aftermarket sub/amp combo that is independant of the oem setup.

 

Radio: __Poineer P8000BT_______

Interface adapter: _Axxess GMOS-04 (from Crutchfield)

Amp: ___Stock - non-Bose______________

Front speakers: _Polk DB551 3½" door speakers

Rear speakers: _stock________________

Sub: no sub amp. Large door speakers are stock

It's hooked up per advice -L&R F&R - no sub connections. Sounds pretty good but definitely not great. Can you suggest what would be the next logical (cost effective) upgrade I should attempt? If i add a SW amp do I need to replace the large door speakers too?
I am thinking that it could use tweeters but mounting them could be a problem.

I am not a audiophile purest so there's no point in taking this too far. It's a fair weather car, the top is usually down so I mostly hear wind noise anyway.

Thanks again!

 

Next step is to add a sub in the trunk, but I'd skip ahead to sub in trunk + components in the doors, all powered by a 4-channel amp.