I've made 3 types of traps. Rigid FG and cotton panel traps. Helped a friend with tube traps up to 20" inches diameter from pipe insulation. Some half filled with rock wool. I've also made membrane traps, using 1/8 and 1/4 hardboard as membranes.
The latter was the most effective with bass and didn't affect higher frequencies as much but were difficult to build and the least understood. To work their best, they should be solidly mounted with some air space behind them. They are often mounted diagonally across corners to maximize the air space behind them, without extending into the room and that air space will extend the maximum depth as well as the total effectiveness of the design. The total size and the material of the membranes is a big part of the equation and, in reality, it seemed that increasing air space beyond a minimum had reducing benefit. A membrane effective at 50Hz would be 4 times the area of the same material for 100Hz. Darn square root function.
I seriously doubt that tubes traps internally reverberate any frequecies inside 1" thick FG. It's just that they include an air space, making that 1" more effective. Maybe, some additional benefit when that air space is 1/4 the wave length but that's based more on total thickness of the material. A 4" FG panel placed diagonally across a corner would have the same benefit but with the added thickness. However, my results were even better with two panels, and twice the area parallel to the corner walls. Almost 1.414 times better.
http://www.soundonsound.com/sos/aug98/articles/practicalacoustic.html
What I call "membranes", they call "panels" and what we have called "panels", they call "mid and high absorbers". Realistic numbers, for a change.
It isn't a question of one type being better than another. It's just suitability.
The latter was the most effective with bass and didn't affect higher frequencies as much but were difficult to build and the least understood. To work their best, they should be solidly mounted with some air space behind them. They are often mounted diagonally across corners to maximize the air space behind them, without extending into the room and that air space will extend the maximum depth as well as the total effectiveness of the design. The total size and the material of the membranes is a big part of the equation and, in reality, it seemed that increasing air space beyond a minimum had reducing benefit. A membrane effective at 50Hz would be 4 times the area of the same material for 100Hz. Darn square root function.
I seriously doubt that tubes traps internally reverberate any frequecies inside 1" thick FG. It's just that they include an air space, making that 1" more effective. Maybe, some additional benefit when that air space is 1/4 the wave length but that's based more on total thickness of the material. A 4" FG panel placed diagonally across a corner would have the same benefit but with the added thickness. However, my results were even better with two panels, and twice the area parallel to the corner walls. Almost 1.414 times better.
http://www.soundonsound.com/sos/aug98/articles/practicalacoustic.html
What I call "membranes", they call "panels" and what we have called "panels", they call "mid and high absorbers". Realistic numbers, for a change.
It isn't a question of one type being better than another. It's just suitability.