Also, the examples typically use a low-pass filter to attenuate DAC output images before they go into the IQ modulator. For band-pass filters, a pullup network on the modulator side is needed to replace the filter termination and provide the modulator with its required common-mode voltage. ...
You want a high-pass filter to cut out the DC offset. So cap inline and resistor to ground. This approach will be fine - you could probably base it at a lower freq down to about 1-5Hz. http://www.bugbrand.co.uk http://soundcloud.com/bugbrand/ ...
2nd order bandpass for midrange. Which is a low pass and high pass added together. For the tweeter use a 2nd order high pass. Also, add a resistor to play with its value. Most of the time the tweeter is way more efficient compared to the rest of the drivers, and this resistor lowers...