Hartley woofer

[Steve Mac]

You're welcome!


Again, based on these specs from the other thread and known to historically only being used in OBs, closet size sealed boxes it takes a humongous box, though nowadays we can use DSP/room EQ to frequency shape it to whatever in room response we want within its box tuning/minimal Xmax limits.

Fs = 20.9Hz
Qts = 0.65
Qes = 0.74
Re = 3.7 ohms
VAS = 1250 litres
Sd calc to 0.22 sq metres


For instance a T/S max flat alignment driven with a modern day amp's extremely high DF (insignificant output impedance):

net volume (Vb) (L) = 20*1250*.65^3.3 = ~6033.29 L/213.37 ft^3


box tuning (Fb) (Hz) = 0.42*20.9*.65^-0.96 = ~13.3 Hz


If we use the pioneer's 'classic' BR alignment, which really only applies to drivers with < ~0.4 Qts, then still 1250/1.44 = ~868 L/30.65 ft^3 tuned to Fs, so is this an OK i.d. size/tuning or what max O.D. dims can you tolerate and 'it is what it is'?

Fascinating, as Spock would say. So thanks!

Now if I were to say what the desired dimensions would be they would look something like:
Depth: 1.75 ft
Height: 2.5 ft
Length: some latitude but desired ~3.5 ft
~15 ft3

The listening area is a little over 9 ft wide(30ft long) and the planars I need to give a couple of feet minimum.

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these are good for bucket subs

https://www.milehighonthecheap.com/f...ickle-buckets/

I do remember a secretary who would always refer to engineers as bucket heads. So you may be onto something.