more often then not, its just as much work to change that enclosure as it is to build a new one. If you want to use that one, DC recommends 1.5ft^3, so you could try and cut that one down to that size (+port). You wont be able to use your current port area though. that would be much too large in a 1.5 ft^3 enclosure and result in a required port length of 71" to get about a 35 Hz tuning. Without knowing more details as far as preference and power.... I would aim for around the 20in^2 area for port. That would give you a required port length of around 25.5"
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