I couldn't find a very detailed description of the product or the cutting involved before buying this - probably because, in the end, it's not that difficult. But - if anyone's interested in more detail, here you go:
The kit comes with 3 pieces of pre-cut foam. To use all 3, the Alt must be fully disassembled.
The thickest piece goes between the case and the top of the PCB. For the high profile, this required cutting it into 2 pieces along two scored lines put in by the manufacturer. This allows for clearance for a thin rib in the case - with that done, it fit perfect.
The 2nd piece goes under the PCB. To make this fit, all sides needed to be cut (maybe 1/16") so it would fit inside the plastic spacer / LED diffuser frame - otherwise the diffuser would not fit flush to the frame.
The 3rd piece goes on the on the bottom after the diffuser is installed and basically takes up the remaining space. The "wings" of this piece needed to be trimmed (again so it would not interfere with the diffuser frame).
None of the cuts were complicated - and no cuts were required for any details in the PCB or switches (thank goodness). With all the foam in place, the screws holding the Alt together had to be pretty tight so everything sandwiched flush - that might have been avoided by extra cutting, but I wasn't bothered.
I'm using the Alt with Epbt caps, replacement and modded stabs, and lubed Zelios 62g switches. I had no real complaints about the overall sound without foam. I decided to install it even thought the board was already built up when I received it. The result is a slightly deeper more thonky tone which I like - but it did not address any particular issue I was having. I only wish I didn't have to do a full disassembly to install; or, put another way, I wish I ordered it way earlier in the research and build up process.
The sorbo is plenty thiccc and fits the dimensions of the case quite nicely. I, like a few others, have the split top version of the Alt, so I had to manually cut the plate/pcb foam to account for this, otherwise, everything was a good fit.
I was using Halo Clears at the time and the pinging was still present but after lubing them and with the foam, my Alt is dead silent now.
Massdrop Alt Low Profile Foam Combo
Just needed a quick modification and it'll work great.
I got the high profile and the installation was really easy! Highly recommend these since the intentions were to definitely dampen the sound of the ping. And it worked! for the High Profile you'd just need to trim one of the foams. other than everything was great. If you're experiencing some pinging issue still, I'd suggest lubing your switches to see if that's the problem as well.
Cut perfectly for the drop alt