You can find it in aliexpress by keyword “ HARMAN 1 inch 4 ohm 4 W woofer speaker” “28mm 2W 4Ohm stereo speaker”

but, must 27mm or 28mm unit. not 30mm or 24mm unit.

there many variations.

speaker spec is 4Ohm 2w, 27mm diameter, 12.7mm Hight

Model number is F27N4A , L00010-0001001, 019G, L4G4

i conform to above link replace speaker is same as my broken one.

https://detail.1688.com/offer/5813304949...