I built two 6.5 cf enclosures to house gen 1 Maelstrom-18s. One of the Maelstroms developed a issue, so I got a replacement. When I model the Maelstrom gen II in my 6.5 cf box the Qtc goes from ~.7 to ~.6.
I built the 18" enclosures. I vacuum pressed two layers of 3/4" MDF to make 1.5" MDF panels. Way over kill. This time I wimped out and had John at AEspeakers do the build using Baltic birch ply.
I like woodworking, but I wanted to get the speakers built in a timely manner and I'm over committed.
Now I'm pondering how to get a sub on the back wall. I don't have a lot of room, but then again, the only purpose would be to move a null. We'll see if I need anything. The 18's do a good job, and having on each side of the seats is really smooth, but they do get a bit stressed with the sub 20Hz high volume passages. I've had two 18's fail. I'm not sure if I'm over working them (I doubt it) or just a bad run. Both speakers had the same issue, the spider came undone from the VC.
I bet youre overstressing them. As I sit here with my four 18's I keep wondering specifically about you people with two 18" maelstrom-Xs...seriousely.. and Graham with his 2 18" Fi Q's. Ive already bottomed out my four 18's and I am ported, so Ive been wondering how mine compares to yours and planned on doing some WinISD plots later. I find it NUTS that you are separating spiders rather than smashing coils, but I guess since your suspension is so much tighter than mine I can understand it a little better. Of the 100's of times Ive bottomed 9 IB3's Ive only ripped two spiders off and that was while finishing them off intentionally on a TermLab SPL meter.
Im sure you thoroughly thought out your alignment and enclosure constraints, but If you went LLT with the pair and you weren't too far from satisfaction with two sealed, you just might be more than pleased just doing different enclosures. Porting them down below 20Hz will significantly reduce your excursion while significantly increasing your output. I'll never go sealed again, though I dont dispute it has its place.
Maelstrom-Xs cant be reconed can they? thats too bad. That was a factor in my decision not to get them, though I am sure Fi would send you recone kits that would work.
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