Physics Research - SupraBaffles

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I've been haunting around this forum for a while and have been loving what I've run into so far, and have gone far enough to make myself a pair of Half-Chang's

To make a long story short I have to do some sort of research for my undergrad physics.

So now I have come to the experts for some advise. I was interested in doing my research on the effect of Suprabaffle shape on the response and investigating the diffraction and all that fun stuff. My basic plan of attack was to build one (pair of) cabinet (s) with a removable and interchangeable suprabaffle system. This way I can keep most everything the same except the suprabaffle and observe the results.

So my question is, what cabinet do you guys feel would facilitate itself best to this purpose? I'm entirely open to suggestions, but i was hoping to find one that wasn't super complicated to build. My hopes were to work with one of the Fostex 4 inch or 4.5 inch drivers.

And help or advise you guys can offer me is greatly appreciated.

Thanks again
 
http://www.zillaspeak.com/bib-howtobuild.asp

Scroll down to see a BIB with supra baffle in the Planet 10 drawing.

Also Bob Brines has shown some designs of the suprabaffle on his
MLTL designs for larger 6.5 in Fostex.

The BIB mentioned above can be dimensioned for any speaker
from small to big and the calculator at the Zilla site has some
samples for the most popular Fostex and other full range speakers.

My take on it is that the suprabaffle, round or oval by increasing the
depth of the cutout changes the BLH action on the BIB which I didin't care for. No proof, just my preference.

But my suprabaffle test was done with a calculated oval, just something that was close.

Your test results will be most appreciated.
 
For an uncomplicated build, and for a 4 to 4.4'' Fostex driver as inquired ,I'd also vote for a BIB, but inverted so it fires to the floor etc.. After that the A126 would get my vote, and then some of the BVR`s, that`s just me.. Dave🙂
 
Hi,

This would be some VERY valuable research. For maximum results you want a skinny cabinet without any main cab above the driver. You'd also like to be able to pull the box out from the wall.

Rules out BIB, Saburo, or any of the double-mouth Spawn.

The Frugel-Horn would be a good vehicle, but doesn't fit the easy to build. Your best bet would be Suzy (FE107) or a half-Olivia or the Floorstander Fonken that Olivia was derived from.

The extra extension of the FE127 would be very useful for this research, and of the 2 cabs for it suggested, a half-Olivia would be best.

Now half-Oliva doesn't exist, but once Scott finds out about this i expect we could easily get that together just for your research project.

dave
 
Thanks for the help everyone

I was too thinking BIB at first, but the point about the cab not extending above the driver makes sense.

I was also considering building a Frugal-horn... and in theory I could make it happen, but I figured a simple cab would be better. If you guys would suggest above all else a frugal-horn i'll go ahead and do that.

Anything that you guys can throw together would be greatly appreciated and I will forever be in your debt.
 
For this type of experiment I would suggest a simple, slim cabinet as a closed box, or possibly a BR / MLTL.

Any kind of horn construction willl usually have many dips and peaks that will make repeatability of measurements under different conditions difficult to interpret.

SveinB
 
Why does it matter if any main cab is above the driver such as in the BIB? The driver still has to dump sound energy down the cab under the driver in most cabs anyway, and the rest goes over the top etc, so why not have the frontal energy somewhat equal? I can't really see how this matters much,?? and this research could still be very useful for taller cabs that have a significant amount of box above the driver etc.. Dave🙂
 
DaveCan said:
Why does it matter if any main cab is above the driver such as in the BIB? The driver still has to dump sound energy down the cab under the driver in most cabs anyway, and the rest goes over the top etc, so why not have the frontal energy somewhat equal? I can't really see how this matters much,?? and this research could still be very useful for taller cabs that have a significant amount of box above the driver etc.. Dave🙂

We are testing supraBaffles. Any obstruction to the air flow around the sB will confound the results. Even better is if the cabinet dissapeard straight baclwards so that the sB is completely unencumbered but that is not really practical.

dave
 
planet10 said:


We are testing supraBaffles. Any obstruction to the air flow around the sB will confound the results. Even better is if the cabinet dissapeard straight baclwards so that the sB is completely unencumbered but that is not really practical.

dave

So would it make sense to test a superbaffle as a kind of OB? That way there would be no other interference between a box and the effect of various shapes and profiles.

bananaslug86
 
http://www.zillaaudio.com/bib-calculator.htm

In case you decide on a BIB the calculator is linked above. I think the BIB is a very good candidate for this application. It's only designed to enhance low frequencies (when stuffed correctly). Because there is space above and below the driver it can be easily retrofitted with suprabaffles of choice.

I also think a Voigt pipe of sorts will work too. I am interested to learn about your results. Good luck with your project!

Godzilla
 

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