RCF art 412a ?

Purpose? For stage? Good! At home? Only when there are no neighbours!

Both can get very loud. I guess the higher price of the nx series is not because of the pressure they can supply.

Specsheets usually show meassures made on axis, the best position to get a good frequency response. When you leave the axis (and that's what you gonna do on stage for sure!) the response is steady changing. More with some, less with others. Some monitors have a wider beam, some a more focussed. Depends on your band what you need. Wider beam when it's important that you can walk around and when you band shall hear what you play, focused beam when the monitor is mainly for you only and you try not to disturb others too much. Another thing is, that a monitor blowin directly in your face is blowin on the strings too and might lead to feedbacks, so even when you plan to stay on one place, you could like to stand off axis.

The angles of the beam are usually somewhere in the specs, but every manufacturer has it's own way to meassure that, so these specs are not that serious. But you should be able to compare monitors of the production line of one manufacturer.

The nx has coaxial speakers and that takes away some problems. The coaxial design allows a better frequency response when you leave the axis or walk around. Also some phase shifting effect because of the distance between the two speakers can get reduced when the speakers are on one axis. That all leads to a better clarity and clarity can't be wrong to cut in full bandmix.

At the other side, the construction of coax speakers is much more complicated and I guess that's maily the cause why there are no budget coax monitors. Coaxial, loud and reliable, hard to build...

When the nx is already in your head, do you believe you can ever get happy without having tried it ?

Quote from Jefonyx

or if I should save money to buy a real big system like RCF NX 12 things...

Yes, you should.

The NX 12 SMA is unbelievable.