So the 600 liter enclosure would be about 21.5 cubic feet if I did the math correctly. If ported it can get any low end without the need for huge amps. With some modifications to that box design I could fit it in the lower living room behind the couch. Now this is becoming a more feasible idea. Just one woofer in the cabinet to gain ultrasounding earthquake low end. A single mono amp of 100 watts would be about all since my receiver has a sub crossover built in.