What would happen if I built a tube woofer with speakers at each end?

Would the pressure damage the speakers or help them return to the neutral state? Would a port help? I'm building a new box for my car since the one I have is too big. It was dynamite in my van but alas, she won't be paving the road of adventure for much longer. I like to listen to a variety of metal with double kick drums and/or intricate bass work so I'm thinking four 8" or two 10" speakers. Right now I have a 12" JL that drowns out all of the music or just sounds bland when I tweak the amp to pick up the bass work.

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faustfire5 years ago
If you are considering putting a smaller speaker behind a larger speaker in an enclosed box (in line) take into consideration the total stroke of both speakers, even if rated the same wattage wise, you could still over stroke one with the other and destroy the voice coils.
OpieJoe (author) 8 years ago
I found some really cheap Wal-Mart woofers in my garage so I'm just going to go for it. They sound decent enough in the box that came with, so hopefully they won't sound too bad in the tube. (I do know the difference between good and bad woofers but for what I listen to, big booming systems are far from necessary.) If worse comes to worse, there are some really nice 'ibles on building speaker boxes for the slightly less cheap speakers I have. I greatly appreciate the help and input!
seandogue8 years ago
There are designs that use the approach. I can't remember the name of the design. The important thing to remember is that the speakers need to have the correct phase orientation, so that when one is pushing outwards, the opposite is pushing into the enclosure. It's easy to do. If the speakers are physically reversed > < Just hook the one speaker up normally, then reverse the connections on the other. If they're positioned so that they face in the same direction > > then hook them up as you would normally do. However, if the connections are from a stereo source rather than a monaural source, you will still have a certain amount of phase cancellation and possible distortion, due to slight variations in their spectral content. other wise, I'd be inclined to put a partition between the two chambers and port them.
OpieJoe (author)  seandogue8 years ago
I've been thinking more about the situation, and it doesn't seem that the placement of the speakers would be relevant as I originally thought.

The air pressure inside will be affected the same whether the speakers are in-line as opposed to side-by-side and because pre-fab non-partitioned boxes tend to have speakers adjacent to each other and don't require a 180* phase it seems that the in-line should not be adversely affected.

I'm not trying to put your ideas and thoughts down, this is just a realization I've made since posting the question, although I do like your idea of speakers facing the same direction. It should allow more power from the outward speaker, making a lower quality rig produce a fuller sound. Maybe that could be enhanced with an 8" boosting a 10" or 12" or possibly adding a crossover to control the caliber of the inward speaker... thank you for giving my brain more to munch on!
No offense taken...was just relaying things I've seen and cautions for "the experimenter". best of luck
kevinhannan8 years ago
Respect to everybodies answers: I'dkeep it simple. If you want a tube design then go for that. The best speaker design IMHO is separate chambers which are ported and the speakers wired correctly. The tube design does allow for some stereo but not as much as if they were correctly placed; properly left and right. For me, it's a big difference so I'd be thinking of separate enclosures that could be locked together with a clasp to form one unit if desired. I wouldn't be keen to allow the speakers to share the same enclosure space because if the cone does not have free movement and has to strain against the air pressure, damage occurs to the speakers magnet. A little over time but like a dripping tapits slow and sure. Italso creates extra unwanted heat. Keep it simple; and you'll have the best music around!
I agree with you Kevin, from a practical point of view... Often I can't figure out if an Indestructables question wants a practical answer or simply wants to know if something is possible.Nothing worse than being empirical and having the law laid out on why you're an idiot or "you'll shoot your eye out", or "you're endangering my huge consumption of the world by being a DIYer.. I rarely ask questions for that very reason. But I do agree overall with your conclusion.