ModeratorDecember 15, 2021 at 4:11 pm
There’s generally multiple factors in where you want to select the x-over frequency. Here are the basics:
First, you have to look at the ranges of the drivers to see if they overlap, and in this case they do.
Second, pull up their spec sheets (if available, and these are). Look at the Fs of the tweeter. usually you want the x-over to be 2x’s the Fs. 633.75×2=1267.5 – that’s around the minimum you want.
Third, look at the frequency graph of the woofer. It’s logarithmic so you’ll have to guesstimate where that 1267.5 is on the graph. It looks like somewhere in that area is where the responses start to diverge. This is approximately where the woofer starts to beam. Do a search on here for a discussion of what beaming is.
Taking all this into account, it looks like somewhere around 1200 to 1300 Hz @8 ohm is where you want to cross over.
A plus about the spec sheet for the woofer shows that they measured it in the 8 ohm configuration, so that makes it easier on you as the designer. This comes into play with the SPL ratings.
The tweeter averages about 88.8 dB while the woofer shows 83.8 dB. That’s a 5 dB difference and that will make it sound bright. To compensate for that, you’ll need an L-Pad. Here’s a Calculator, at this page. Enter your tweeter nominal impedance (8) and the amount you want to reduce (5), and it will tell you the resistors you’ll need. Click on the Additional Information link and it will show you how to wire it.
I’ll let others expound further.