[Mike P.]

85 liters tuned to 23.5 with 2 - 100 mm ports 914mm long is what I came up with. 380 watts takes the subs to maximum excursion at 32 and 21hz. You will need a subsonic filter at 21hz to protect the drivers. If it were me I'd go with 120 liters tuned to 20hz. You would be giving up a few dbs in the low end and gaining more low end extension, which is what you want with a HT sub. Just my 2 cents.