2001 non-BOSE Symphony Aftermarket Audio

[Nebone]

I just wired in a Pioneer Avic-U310BT and have some concerns. The car is a 2001.5 with the Non-BOSE Symphony where the deck drives front speakers and separate amps drive the rear speakers. Everything works with the new setup, except the rear speakers sound like 3x quieter than the fronts and quieter than they did on the Symphony HU. The RCAs and remote wire are all connected and I get clear audio from both rears but they are so damn quiet and can't even hear them. The fronts work awesome since they are driven off the Pioneer amp. I used the Metra 70-1787 harness. Could the Ohm level of the Pioneer HU not want to cope with the stock speakers amps?

Also any tricks to be able to have the HU work with the ignition off?

[walky_talky20]

Gotcha. Your problem has to do with the voltage of the "pre-outs" of your head unit. So volts, not ohms - but you were on the right track. The Audi rear-amps expect a pretty "hot" signal as far as low-level pre-outs go. Something like 4-5v. Most aftermarket head units have closer to 2-3v pre-outs. There are 2 solutions:

1 - Solution 1 is what I like to call "Fade Rear". You simply use the fader function to direct more of the power to the rear. Adjust to taste, problem solved. This will have the unpopular side-effect of lowering the maximum SPL you can achieve in the front speakers (i.e. you can't get as much volume out of it).

2 - Solution 2 is what I like to call, "buy some equipment". You buy new speakers and good amp for the rears which will give you adjustable gain control and the ability to match the volume of the fronts quite nicely. The other [cheaper] option is to buy a "Line Driver" or a line-level amp. It is simply a small amp that sits between your deck's pre-outs and the factory rear amp input and increases the signal so it will match the volume of the fronts. Something like this:
http://www.amazon.com/PAC-TURBO1-Pre.../dp/B000CEDZBU

That is a low-cost (low-quality?) example. Feel free to research better examples (aka: I would probably not buy *that* one).

Tricks for the headunit to work with the ignition off:
- The symphony "radio with no keys" feature is simply a function of the deck and nothing else. It has its own internal timer to shut off after 1 hour if you forget. To achieve this on your aftermarket deck it would have to have this feature. If not, you can add it! You simply interrupt the "ACC" signal to the deck with a SPDT switch. With the switch flipped to *Normal* or *Auto* it will work as normal. In the *Override* position (or the *Awesome* position, as I like to call it) the switch gives constant 12v power to ACC input of the deck, making it think the key is on when we all know that it surely is not. Bingo - feature added.

Good Luck.

[Nebone]

Thanks for the tip although what I don't get is how the BOSE Symphony works then. It only uses the RCAs from the aftermarket HU and the stock amps do the rest and they play nice and loud. I tried the fader and it just isn't loud enough (I'd have to blast it at 50 volume to get it loud enough wheras the fronts only need like 30).

If I get picky enough, I'll get some decent speakers for the rear and just use the new HU to power them. All I'd have to do is run some new wires to the rear.

[walky_talky20]

Absolutely. As you fade rear, it is not *actually* sending any more power the rear. Rather, it is just "cutting" (decreasing) the signal to the fronts. So you fade to the rear until it equalizes, then crank it up. You will have to run the volume control in a higher range (bigger numbers) than before, that is completely expected. To reiterate, when you "fade" you are not turning the rears up, you are simply cutting the fronts. That is just how it works.

If you just cannot get enough volume out of the system after fading rear to equalize, you will need to use option 2. Or option 3.

Option 3 is what I like to call "rewire some crap". You bypass the amp for the rears and rewire so you can power the rear speakers directly off of the internal amp in your aftermarket deck. I believe the non-bose system has the rear amp built into one of the rear speakers so this may require some surgery at best, or speaker replacement at worst. I haven't tried this so I can't say.

[MOtown A4]

im thoroughly impressed walky_talky!

[Shhmaudi]

Yea walky is a great guy very knowledgeable

[fltstone]

Yep me too! LOL, Somehow Audi seems to have the two rears running off the amp and grounded together. This may be your trouble. My Pioneer 790BT required separate grounds. When you feel the back of your head unit it's probably alittle warm not good. Hope this helps.