Hard time choosing between Butterworth and Linkwitz?
The difference is that Butterworth crossovers have a 3dB bump at the crossover point, whereas Linkwitz-Riley crossovers are flat.
You might say, why would I use a Butterworth then?
Well if your driver choice is such that you chose a low crossover point for a given tweeter, that bump can help you out.

Credits:
Functionality is borrowed from https://www.diyaudioandvideo.com/Calculator/SpeakerCrossover/.
Visit the site for more information about formulas, theory and origin behind this calculator.

Dag J. V. Nedrelid