MAH Assembly

[GM]

So I think that I remember that my A7 cabinets are something like 12.5 CF. I could easily add a 7.5 CF box extension onto the back upper half of my enclosures. I just need some numbers-cubic feet total volume, cubic inches port volume.

IIRC, the 825 is ~12.65 ft^3 net and the 828 with its closed off horn cavities are ~11.42 ft^3 net. Which do you have?

Regardless, to keep from getting multiple band-pass cavity resonances you would need to make the whole cab deeper, i.e. remove the entire back except for a mounting flange to bolt up the addition.

GM