Door speaker crossover

[spazmochad]

Another door speaker question... so I installed some OEM philips silver fronted door speakers at the weekend. I have the 6 speaker set-up with a business HU, I tapped the tweeter feed because running through the door seems like actual work.
I soldered the speakers like so, straight onto the legs to the sides of what I think are signal in and signal out plugs:

Now the speakers works fine, but it quite harsh to me, like it has a ringing to it, kinda like it needs a crossover. I have felt extra deaf these past couple of days, kinda like being subjected to a loud, high frequency sound.
By not using the actual pins to wire the speaker have I missed out an internal crossover or something that filters the signal? Anyone with the better sound system know how it's wired?

I also did the sound deadening, made a nice difference. Although Hulk Hogan had been at the passenger door's waterproofing so I gotta replace that

 

[spazmochad]

Just to update I stuck a coil inductor on each speaker. I can't remember the frequency range exactly but I calculated it (air coil inductor 0,06mH 0.71 mm) to match the 10 speaker set-up in the non-THX system. Sounds a lot better now for the sake of £3 plus postage: http://www.ebay.de/itm/Intertechnik-Luftspule-Drosselspule-0-06mH-0-71-mm-270011-/151262257747?ssPageName=ADME:L:OC:GB:3160

 

[GuidoK]

For a tweeter you have to put a capacitor in series. That is how you make a 1st order high pass filter (6dB/okt)
For a second order high pas its a capacitor in series and a coil parallel.
Just a coil parallel lowers the speakers impedance to dangerous levels that can blow your amp. A coil in series is a low pass filter (1st order).