Impedance Bass Reflex - check up Beyma 12B100R

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Below is a simulation and measurement of Beyma 12B100R in 2 cu. ft. bass reflex box tuned to 32Hz.

  • Can you comment differences?
  • How do you validate proper BR functioning?
 

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jzagaja,going back to your original questions;I would comment that if you compromise the enclosure size to a 60L internal volume,then you will need to use a higher Fb ''tuning'' to compensate for a non-classic alignment.The other anomaly that is shown in your last graph is an incorrectly calculated impedance correction network.
 
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I would need far more details of what you are wanting from your application to try to attempt a full reply.Your last entry adds information on two vents which is not mentioned previously.If I had a bass speaker that measured after full ageing,the T&S parameters given;I would look at a classic fourth order Butterworth alignment with expected losses,giving alpha =1.06.This results in an enclosure with an effective volume of 145.3L ,with an Fb of 28Hz.the resulting Fl should equal 14.24 Hz and Fh should be 55 Hz.If you are trying to use an electronic transform to achieve better results in order to use a small enclosure, or other corrections to satisfy your design target;you will need to give more details of your approach so far..
 
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Under sized enclosures are the compromise that the marketing people push in an effort to promote sales.If you are restricted by cabinet volume,then you will have to accept a higher tuning freq. for the bass reflex with the result of coloured sound irrespective of computer simulations to the contrary.The Beyma engineers have on the indications manufactured an excellent product and if you abide by what the T&S parameters tell you ,a first class bass performance is achievable.Furthermore,although the available literature on the 12B100R does not discuss larger enclosures(which is what you have based your construction on) any competent designer should be able to proceed to better implementations.
 
I checked my simulation. 62.5 litres and two ports of 65 x 110 mm give a tuning frequency of 43 Hz and a -3 dB frequency around 50 Hz. I would need to know your current crossover to tell more. If crossed low, the filter usually influences the low end and yields unexpected results! VaNarn is certainly right, you can get more kickbass using a volume of 100 litres or more.
 
I would love to see the results of this. The 12B100R is a great driver and can give great bass output if used correctly. This driver is not used enough and generally is much over looked. Give it a good bash:)

I have also been very curious about this driver.

Low fs, but what about the xmax? Is it usable to 30hz at loud volumes?
 
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