I'm putting together a little Tempest project that will allow multiple tunning points. I plan on tuning with three 3in flared ports. With three open the tuning will be ~24.5hz , two open = 20hz, one open =16.4hz. Initially I though I would never use the 16hz tuning just due to lack of port (lots o' noise) with 350w. I plugged and chugged into LspCAD and was a little surprised. These generic results are with 350w and 214 L net. Tuning pt: 25hz with #3 3in ports open- 22 m/s @ 25hz 20hz with #2 3in ports open- 20 m/s @ 25hz 16hz with #1 3in port open- 22 m/s @ 25hz I'm using 25hz as a reference because this set-up will be 75% music and most DVDs don't extend much lower. How can the speeds of these be similar with decreasing port area? I know the port air output increase around tuning freq but I expected that a Tempest w 350w and only a single 3in flared port would really be puffing at 25hz. Will the 16.4hz tuning and a single port be usable with moderate levels? Any thoughts?