New 15/1,4 Top

How did you form the 90 degree (or thereabouts) bend on the side of your grills???

Thank you both 

It's actually pretty easy. We always use cheap 1,5mm thick galvanised steel grills with square holes since all the fancy stuff is too expensive. 
First we cut the big sheets down to the right size with an anglegrinder. Then we use some steel flatbar (5mm thick) an clamp it with 4-6 big screwclamps from both sides on the part that will be bend. This contraption is then fastened in a benchvise with the bulk of the grill sticking out on top. We then just bend it by hand (two people is advised for bigger stuff like in this post) and finish it by using a small hammer to get the bend "sharp" enough. This works really well and it's no problem if there are some imperfections, since the foam hides them pretty well.
(this can also be done with grills that need all 4 sides bend, you just need the right lentgh of flatbar and some ingenuity for the clamping)

For these grills we then soldered some washers over the square holes where the screws go later after stripping the zink-coating with some sandpaper on that places. This ensured that the tops of the screws are flat with the foam without denting it. 
We came up with this method just for this build and it worked surprisingly well :)

Hope this answered your question :)

Thanks :) I actually mean soldered. We feared that we may have to weld them, but thought why not test soldering first. After roughing up the surface with the sandpaper and getting to bare steel (On the grill and the washers), we just used one soldering iron to heat the grill and another to do the soldering. With the fluxcore lead-solder it worked really well and wetted all the surfaces as good as it can be.
Obviously I can't tell you how long this holds, but since the joint is loaded just in compression from the screw, I don't think it will fail anytime soon :)

Thanks :) 
Yes it's a really nice combo. The HT Driver is just a pleasure to work with, albeit it's a bit pricey. We cross it over to the MT at 1kHz since we found this gives the best "pattern-matching" with the 15" MT. 

In general the combo is nice on the ears because the HT is not at all the bottleneck in terms of achievable SPL.