If the tweeter source is the head unit, why when you upgrade the system do you need to run new tweeter wires to crossovers or a dsp?
​​​​​​I have 90% of my parts and I'm getting ready to install. That's the only issue I'm having a hard time seeing.
B&O amplified system. Using Zen to a 5 ch amp. to factory speaker harness. No separate dsp. Upgraded speakers and sub of course.

 

I wrote a long reply and then realized you have the B&O system. I have the sync 3 radio with no amplifier and for me I was told the tweeter is run off the front door speakers but no one could tell me specifically where that connection happens. I too dont feel like wiring in new wires for my crossover. I may end up just doing a simple inline crossover right where the tweeters are.

 

I talked to someone about this. My issue was I didn't think the tweeters needed the amplifier like the mids do. I'm either going to run the wiring for the tweeters from the front mids in the doors or from the wiring at my amp.

 

I was told by Crutchfield and also a local car audio shop when I upgraded speakers that if I used 3-way speakers in the door there was no need for tweeters in the A-pillar. I wasn't sure about this so I left them in there and added my new door speakers. Something just didn't sound right, it was too harsh or something so I disconnected the tweeters and it sounded great after that.

 

It makes sense that you had a problem. 3 way speakers have tweeters already. You doubled the number of tweeters and they were in different positions so the timing would also be off. If I'm not mistaken, DSP can change the timing and the gain so you could have made them sound good. You would have needed to install a DSP though.
My front speakers are component so a woofer and external tweeter. My rears are two way. Woofer with an integrated tweeter. My bass will now consist of two 10" subwoofers.
There's always the chance that I'm full of what makes the grass grow green too. I'm still learning....

 

I've been having a similar dilemma. I am in the process of upgrading my speakers and at a later date adding aftermarket amplification and DSP. I picked up a set of Infinity Kappa components for the front and would like to direct wire them to the existing speaker circuits not using the Kappa crossovers. I'm concerned though because I don't know what the frequency range is on the factory tweeter circuit and I don't want to risk damaging the new Kappa tweeters by sending too low of a frequency to them. User 34SF posted a great upgrade document but he indicated that the factory tweeter has some type of bass blocker capacitor on it so that has me concerned. I sent him a PM to see if he could give me additional clarification. If anyone has wired their components into the factory circuits I'd sure like to hear their experiences.

I could use the Kappa crossover and wire the speakers to the door circuit but I'd like to take advantage of the factory DSP until I go aftermarket amplification. I don't think that the factory tweeter and woofer placement is ideal without using some type of DSP to adjust everything. The factory system most likely already adjusts for existing speaker placement. My assumption is that installing aftermarket components in the factory location and using no DSP will not result in very good audio. It wasn't until I started researching JL Audio's speaker placement recommendation regarding woofer/tweeter placement which let to further questions. Everyone always says components are superior to co-axial/tri-axial and now I understand that is true but they require proper tuning related to speaker placement.