As the topic says. I'm looking to use my two Dayton 15" IB in as small an configuration as possible.
I don't need them to go below 35Hz and I would like to have them roll off at around 100Hz or so.
I have a couple of populated and tested FreeDSP classic boards and the means to program them via Sigma Studio.
I also have an unmodified DCX2496 (version with memory card slot).
I can use EDA's, decent at simulation SW but know very little about loudspeaker design.
I don't need them to go below 35Hz and I would like to have them roll off at around 100Hz or so.
I have a couple of populated and tested FreeDSP classic boards and the means to program them via Sigma Studio.
I also have an unmodified DCX2496 (version with memory card slot).
I can use EDA's, decent at simulation SW but know very little about loudspeaker design.
Well, i bet you will need bass boost to get down there.
Not many infintite baffle / open baffle fans here.
I had a qts .4 12" with fs of 50hz in an open baffle with 2' deep wings.
A buddy here tested his of same dimensions and the math worked out.
Dip 280hz, peak at 140hz, then rolling off below that.
I know it is not what you are asking, but my rip buddy wanted to try those 2 drivers in a bandpass......
Not many infintite baffle / open baffle fans here.
I had a qts .4 12" with fs of 50hz in an open baffle with 2' deep wings.
A buddy here tested his of same dimensions and the math worked out.
Dip 280hz, peak at 140hz, then rolling off below that.
I know it is not what you are asking, but my rip buddy wanted to try those 2 drivers in a bandpass......
Infinite baffle subwoofer drivers are an excellent choice for a dipole subwoofer.
The dimensions of a W frame are not critical. Make sure the magnet vents are free to breathe and that the cone does not hit anything. Narrow slots (cross sectional area much smaller than Sd) effectively add cone mass which reduces fs and increases Qts. This can be beneficial if you want to use the subwoofer below its natural fs. I would avoid it as fs already is 21.5 Hz. The slots exhibit a parasitic 1/4 wavelength resonance which should be above the passband of the subwoofer, so slot depth should not be too large. On the other hand, a larger depth spaces the front and rear of the dipole further out, which increases efficiency which is good.
In practice, W frames usually are designed such that the woofers barely fit and the slots have a cross sectional area of about Sd. It is OK to stick the magnet through a panel, as is done in most 'ripole' subwoofers.
Example: SLS Ripole Subs - DIY Audio Projects - StereoNET
One of the woofers can be flipped to cancel out even order components of the harmonic distortion. This however does not affect odd order distortion components, which are more offending to the ear. Some people say that even order components sound pleasent and should be left in place.
Example: Dipole Woofer
You would need a microphone which is flat between 20 and 1000 Hz to measure the frequency response of the finished subwoofer, so you can determine what equalization is required.
The dimensions of a W frame are not critical. Make sure the magnet vents are free to breathe and that the cone does not hit anything. Narrow slots (cross sectional area much smaller than Sd) effectively add cone mass which reduces fs and increases Qts. This can be beneficial if you want to use the subwoofer below its natural fs. I would avoid it as fs already is 21.5 Hz. The slots exhibit a parasitic 1/4 wavelength resonance which should be above the passband of the subwoofer, so slot depth should not be too large. On the other hand, a larger depth spaces the front and rear of the dipole further out, which increases efficiency which is good.
In practice, W frames usually are designed such that the woofers barely fit and the slots have a cross sectional area of about Sd. It is OK to stick the magnet through a panel, as is done in most 'ripole' subwoofers.
Example: SLS Ripole Subs - DIY Audio Projects - StereoNET
One of the woofers can be flipped to cancel out even order components of the harmonic distortion. This however does not affect odd order distortion components, which are more offending to the ear. Some people say that even order components sound pleasent and should be left in place.
Example: Dipole Woofer
You would need a microphone which is flat between 20 and 1000 Hz to measure the frequency response of the finished subwoofer, so you can determine what equalization is required.
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I'll have to learn spkr-design SW.
I am decent at KiCad and LTSpice but have no real experience with spkr-design.
Thanks for the suggestion 🙂