Installed yelobird's Atomic Pile, Speaker Mod and a couple of modfather's Pin Cups. Also put in a Flipper Fidelity speaker upgrade. I did the Stern replacement batmobile/disc and left ramp diverter and ramp ball deflector.
As usual, yelobird and modfather's stuff look amazing. (Photo's below.)
For years, I've done my own speaker upgrades, and I'm a bit picky. I typically follow this process:
A couple comments on the 10" "Speaker Light Option" Flipper Fidelity kit. While the Flipper Fidelity set sounds excellent, a couple things bother me. First, the 5/8" standoffs are way too long, and the backbox speakers, which only rest on two screws, are precarious at best (particularly when you consider the additional speaker panel depth created with the speaker light mod). They use these standoffs because the coaxial part of the speakers project significantly beyond the surface, and thus need clearance to not press into the speaker grill. That being said, they don't need THAT much clearance. Also, the new height interferes with the cable that the speaker panel hangs from. If it gets caught somehow on the speaker, it will bend the speaker mount points when opened. Given the precariousness of the mount, I'll probably move to a two-way coaxial (such as produced by Kicker) that I've used in other machines where the coaxial depth doesn't proceed beyond the speaker surface.
Secondly, shame on me for getting the 10" cabinet speaker. I think I literally had a brain lapse when I ordered that. 10" is completely ridiculous. It's fine for LFE in a home theater, or perhaps shaking your car, but for your pinball machine (particularly one with a shaker motor) anything beyond 8" is silly. If you want a sub, I'd probably get an external sub (maybe with the Pinnovators mod) and go that route. I typically cut a larger hole on WPC machines to accommodate the 8" throw and create a new mounting plate. This machine already has an 8" hole. In this case, you get a mounting plate adapter so you can mount a 10" throw over the 8" hole. A woofer throws air, so if you obstruct the surface too much, you're kind of losing the point. Still, the mounting plate makes connecting this enormous speaker easy, but again, it's partly obscured. The instructions with the Flipper Fidelity kit talk about adjusting the backbox volume, which I assume is the "Speaker Volume," and bass volume, which I assume is also known as "Bass." It reads like there should be a potentiometer like I install with the WPC speaker upgrade work...but there isn't anything like that.
This all being said, once I installed the complementary rattle tape on the playfield glass and turned down the bass a bit (I also had to turn down the treble significantly and balance out the volume, though I suspect some of this will be resolved with more music/call out level normalization in future releases), it's like my machine is explosive. I'm not going to lie, it's hysterically fun, in deep bass moments it's almost like it's the shaker motor going off.
Just some thoughts on this process.