I am not sure weather to ask this question here or the software section. I was just curious which DVDs are encoded with frequencies that go below 20hz. I've read somewhere on the forum that TPM can go down to 10hz and was wondering which other DVDs are recorded to go this low or around this low. Maybe it's a dumb question but was going to build a vented sub and was going to tune it to around 20hz. But if movies can go lower, I may aim for a sub that is tuned to about 16-18 give or take. Thanks for any answers/comments.