I've been watching this, and commend your work, having everything together and ready to go and install along with a detailed website and as you mentioned, customer support. When I first saw it I went right to AliExpress and checked prices on the exact components, with a speaker from eBay. I Diy, so I wouldn't need a kit, but again, it looks perfect for people who just want it ready to roll. You mentioned you have a "low pass filter" installed, but looking at all the pics of the setups I don't see one wired in anywhere?

Well, the apprehension here is people don't like to see people screwed over....Not knowing how to DIY, and being willing to pay a premium for something that is "ready to roll" is what some want, others look at it as a $6 amp, $3 low line input, $22 speaker, $2 Plexi, and "CNC speaker mount", (not really necessary) and $4ish of wiring.....the "low pass filter" question is valid, as it was stated by the seller (OP), not backed up, then ignored when questioned (because it's obvious it doesn't exist(see every picture)), but it's a simple $6 PCB add on (all prices via AliExpress, speaker eBay). Hey, if your happy with it, it sounds good, then who cares....but yes, do your research...