- Feb 12, 2006
- 60,963
- 5
- 220,650
- Disclosures
- Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
In your opinion... which goes against just about all of the science and engineering behind the subject.
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Help me finish my polystyrene cab build
- Thread starter neal sanger
- Start date
Fair, but I got the idea from a Tech ingredients video where he made large speakers by attaching surface mount drivers to sheets of the same foam board. The frequency response of the panels was limited only by the frequency range of the transducers.
- Feb 12, 2006
- 60,963
- 5
- 220,650
- Disclosures
- Development Engineer-Mesa Boogie, Development Engineer-Genzler (pedals), Product Support-Genz Benz
Don't believe everything you see or read.
The math and best practices engineering principles scream "bad idea". I don't need to go through the work and expense of proving something doesn't work well when all the data says it won't work well and all of my past work supports these thoughts too.
Being knowledgeable and experienced doesn't mean it's necessary to go down roads that have already been gone down with the results of failure.
If you don't have the knowledge and experience, then by all means prove us wrong but don't let confirmation bias get in the way of the data/results.
Found this in my attic from 5 years ago. Built for an 8" driver. Weighs under 3#.Two layers of fiberglass inside, three layers outside. Two layers of tape on the corners. Important--donut of 1/2" ply for speaker mounting. Durable, sounds great, weighs near nothing, and gets me incredibly sick working with the materials. A very valid concept--wayyy too many hours necessary---not much profit. But cool.
This..."then by all means prove us wrong but don't let confirmation bias get in the way of the data/results."
Neal, I respect your outside of the box initiative and your efforts but now is the time for objectivity. You were asking earlier how to test and the very best way to do that is by benchmarking against a known control. You need to do this with an open mind and be ready to accept that your experiment (in its current configuration) might not actually be an improvement or a viable alternative to the status quo. A negative does not invalidate the experiment.
Neal, I respect your outside of the box initiative and your efforts but now is the time for objectivity. You were asking earlier how to test and the very best way to do that is by benchmarking against a known control. You need to do this with an open mind and be ready to accept that your experiment (in its current configuration) might not actually be an improvement or a viable alternative to the status quo. A negative does not invalidate the experiment.
Well, Ampeg have sewn up the market on the "Fridge", so it's probably a wise move to come at them with the "Washing Machine".
The key difference between Mike's cab and mine is all the walls and corners are braced. Additionally, the interior of the front is fully laminated with ply and the baffle is gasketed on. Also no fiberglass as it would (I hypothesized) deaden the cabinet acoustically.
Graphs and stats to follow either on my spring break in 2 weeks or on a coming weekend. I also can't measure the walls without a vibrometer but can feel them with my hand (which I can't quantify or convey over the internet).
Why not put the Fender Bantam Bass Styrofoam speaker in the OP’s cab? I mean....
There's a fundamental difference between the speakers in the Tech Ingredients video and what you're doing. In the video, the foam panel is being used as the speaker "cone". They are not really "speakers" in the conventional sense, they are drivers hanging in the open air. Those flat panel open back speakers are great if you hate bass, because you'll never hear it from open-air drivers like that.
But you are not mounting a large flat foam board to a speaker coil, you are using foam board to build a speaker enclosure with a conventional bass driver. Foam board is not rigid enough for this, as your testing showed. When the speaker cone moves out, the cabinet will flex inward, so you'll have weird phase cancellations. The speaker driver and cabinet will actually work against each other.
But you are not mounting a large flat foam board to a speaker coil, you are using foam board to build a speaker enclosure with a conventional bass driver. Foam board is not rigid enough for this, as your testing showed. When the speaker cone moves out, the cabinet will flex inward, so you'll have weird phase cancellations. The speaker driver and cabinet will actually work against each other.
I'm well aware of the difference in what I'm doing and what tech ingredients is doing. The potential for flexing in the cabinet is why I braced the cabinet how I did. please go look further up the thread for pics. The sides are cross braced under slight tension and the back is T braced to two of the other sides. The bracing is reinforced across it's length and at the contact points with the box. I haven't done the testing yet. You may well be vindicated in your wet blanketry, and the consensus of the forum is definitely with you. If you looked up the transducers he used, you will notice the extraordinary poor bass extension they spec. Many other people in this thread have made the EXACT same point to me, however I am the only person in my bedroom with this cab. Why don't we all just hold our horses until it's tested.
I am not a physicist or an engineer. I am doing this for fun in my spare time.
And this is why I'm cheering you on.
Maybe this will add a new subjective description to "wooly" "woody" chimey" "boxy" Now "FOAMY"
Or even Choady. A little fat and woody but woolly also.
