2,5mm would be a big no go.
But if I look at this youtube video's the 2,5mm Xmax is probably wrong. But I'm not an expert at all. Can you guys have a look?https://www.youtube.com/watch?v=MqknzdRjyw8
Edit: removed 2 links, wrong driver. (the box Speaker 12-280/8-A
instead of W
Maybe the chinese mixed the inches up with centimers, then the Xmax would be 2,5 x 2.54 = 6.35mm
The 280W spec is also very conservative (wrong) as I found people writing they use it up to 500W
Can I just order 1 driver and measure the Xmax by pushing the driver in?
This driver might be a well hidden gem.
It's weight of about 22lbs is a downside, but I found so many positive comments about the build and sound quality that I think I just order one, measure it and build a box for it and test it.
//edit: I have often found many bargains and my experience is that price is not an indicator for quality anymore. I have an 11Oz (!) Lepai/Lepy LP-2020A amp for $25 (new) incl shipping and poweradapter
but it sounds way better then my 25lbs? $500+ ax-700a yamaha amp from the days they made quality stuff, which I used before in my living room. Together with a €50 pair second hand monitor speakers with beta 12a drivers and horns in them and a €40 second hand pioneer TS-wx206a car dual bandpass sub with an 8" driver connected to my DBX pa2 and my sound is a lot more detailed and louder then many of my friends (who are musicians) audio systems they have at home.
Knowing how to use stuff correctly is where the biggest gains can be made imho. I was looking for sub placement when I came on this forum the first time about 2 years ago, and knew Bill's advice is right. Which made me look into his designs and became enthusiastic about them.