A few years ago I built sealed enclosures for (2) 18" TC Sounds LMS 5400 Ultras. I was always very impressed with what these subs were capable of. Each had a QSC RMX 4050hd rated 4000 watts @ 4ohm powering them. I had them nearfield behind my couch and they were firing into my back from about 3" away. The tactile sensation from this was insane!
Right after I finished them I had builders remorse though......I was questioning if I should have gone with ported enclosures instead! At the time I had a hutch behind my couch so I couldn't build ported anyways, but after a furniture rearrange I had a ton of room. I made the decision to build some ported boxes and make them into a couch table, you know something to put junk on, and somewhere to install beers while watching movies.....
Not knowing much on how to design a ported enclosure, I sent
a PM. Told him what I had to work with and he thankfully helped my out with a box. It is loosely based off of another design of his....the Cyclops.
Here is a SPL chart for (1) I have (2) of these so add 6db. The chart shows the difference between sealed and ported. Also this chart is at 1m outdoors. They are 3" away of my back, and inside. Not sure how to calculate SPL gain for being so close, and room gain (is there room gain when they are so close?)........ but I can tell you they freakin pound
The original PM to John was just about a year ago, and everything was finalized then. Unfortunately between kids, work, and life in general I didn't have any time to build them. About a month ago I decided to make it happen, and the following is the process.
Its kinda funny that in the last month I've seen at least 2 other couch table sub builds. I used to hang out a lot in the DIY forum, but not much lately. I have also noticed ported is the new cool thing to do. A few years ago it was sealed......guess im jumping on the band wagon.