@Wolverinebass has a point. Half of the sound is coming from the bass driver and half from the horn. So, how do you mic up?
I made some quick measurements on a Monaco cab with the mic pointed at the horn. The top one (black) is relatively close, maybe about 30cm. The measurement looks quite clean but there's a distinct dip between 600Hz and 2kHz, which will affect the sound - it's two octaves. This is because the mic is well off axis in relation to the bass driver.
The red measurement is from about one metre. You can see that the dip caused by the bass driver has more or less filled in. However, at that distance, room effects are going to be noticable. In this measurement, you can see the change between 200 and 600Hz caused by room reflections. So, measuring at 1 metre is more accurate but the sound is likely to be affected by room reflections or other noises (instruments).
The logical conclusion would be to position the mic in between both drivers, which should allow the mic to be positioned closer. I'm so used to measuring on the tweeter axis that I didn't consider it at the time, but I can take a measurement in between the drivers is anyone would like to see it.
I do agree with @matybigfro, however. The design goal of the Monaco (and other LFSys speakers) is to reproduce the sound from the amp as accurately as possible. It makes a lot more sense to DI.