About to build my enclosure...Does this 4th order bandpass box make sense?

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Before I start building this, I was wondering if anyone...

Could confirm if the below box will function properly? Are these volumes even close to correct?

Thanks for any guidance!

I used the following website: http://colomar.com/Shavano/4thorder_info.html

1) Speaker Parameters

Diameter: 10.00 (inches)
Qts: 0.57
Fs: 33.80 (Hz)
Vas: 1.31 (cubic feet)
= 37.10 (liters)
S: 0.50 (response curve - .4 thru .7)

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2) 4th Order Bandpass Cabinet Parameters

Lower 3db Rolloff: 35.00 Hz (F3 Provided by user)
High 3db Rolloff: 110.38 Hz (Calculated)

Sealed Box: 0.55 cubic feet
= 950.48 cubic inches
= 15.58 liters

Ported Box: 0.43 cubic feet
= 735.47 cubic inches
= 12.05 liters

Tuning Frequency: 62.16 Hz
 
If you have Excel, use Unibox,

If not, use WinISD pro

The shavano site does not tell you the gain or loss in spl given by teh particular alignment you choose and it does not graph the response. If you want your box to sound good, I would caution against using anything other than an S of 0.7 in those calculations The lower S gets, the more severe the dip in response at tuning gets.

Bandpass boxes should not have any damping material in the vented section, as it reduces output and exagerrates teh vent organpipe resonance which is not damped by damping material.
 
Ron, I took your advice and got winisd. I am doing a little fine tuning. Thanks for the suggestion.


Simon, any ideas on changes I could make in size and or port to get a little better out of it? Remember, I need to stay pretty close to this total volume.

Thanks for any other input!!!
 
As alluded to previously (though I don't know where the 40 Hz figure came from) you don't necessarily want flat response or a low passband. Figure out where room gain will kick in (longest room dimension is 1/2 wavelength). Make that the lower corner frequency and the room gain and rolloff will cancel each other out for flat response below the lower box frequency. Of course, this makes the sub only tuned to that room.
 
If you don't have any roof then it's a good idea to design it flat anechoic.

You could have deeper bass with the same enclosure size but you will lose some SPL (about 2 dB).

20 liters sealed with 10 liters ported tuned to 57 Hz is ±2 dB from 30 Hz to 115 Hz.
 
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