Raoul is correct. In fact most of the posts originally in the ascendant audio forum are scattered through out the "general discussion" section. However the thread I linked to I have only been able to find through the link I posted here. Here are a few pics from the 2nd page of the thread.
Attachments
WinISD predicts an F3 of about 80Hz for a dual driver setup in a 1 ft.^3 box, so that should fit your 80Hz crossover just fine. Incidentally, you can reach about an octave deeper by increasing the box size to ~1.8 ft.^3 and adding a vent.
Sensitivity of the two boxes (closed and vented) should remain the same until the point at which they roll off. The sealed box will begin to roll off at a higher frequency, but at a shallower slope.
Sensitivity of the two boxes (closed and vented) should remain the same until the point at which they roll off. The sealed box will begin to roll off at a higher frequency, but at a shallower slope.
I’ve modelled this in Unibox, vs the Peerless XLS 12 (830500), often considered better/ best vale for sub sound quality. Can be used up to 300 Hz with a 4the order.
The XLS www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=297-608 is $160, nearly twice the diameter (3.3 times the Sd), similar Xmax about 3.6 times the volume displaced. Also 3.3 times the Force factor.
The Ascendant has 1/ 84 the Voice coil inductance!
Here are the dB in boxes of two sizes, all with a 0.5 dB peak:
65 Litres:
XLS Ascendant
30 Hz 86 86
50 Hz 86 86
75 Hz 88 88
25 Litres:
XLS Ascendant
30 Hz 86 79
50 Hz 86 88
75 Hz 88 88
If the Ascendant can equal a dedicated sub in extension, cost only 22% as much, and go more than twice as high in Hz . . what’s the catch??
How is distortion?
The XLS www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=297-608 is $160, nearly twice the diameter (3.3 times the Sd), similar Xmax about 3.6 times the volume displaced. Also 3.3 times the Force factor.
The Ascendant has 1/ 84 the Voice coil inductance!
Here are the dB in boxes of two sizes, all with a 0.5 dB peak:
65 Litres:
XLS Ascendant
30 Hz 86 86
50 Hz 86 86
75 Hz 88 88
25 Litres:
XLS Ascendant
30 Hz 86 79
50 Hz 86 88
75 Hz 88 88
If the Ascendant can equal a dedicated sub in extension, cost only 22% as much, and go more than twice as high in Hz . . what’s the catch??
How is distortion?
gp4Jesus said:
The driver impedance is irrelevant. 2 equal drivers in series will be as sensitive, 3dB more efficient (2x the radiating area) (and lower distortion, better power handling) vs. a single driver. 2 in parallel will be 6dB more sensitive, as you get double the radiating area (3dB) and double the current (3dB) but the actual efficiency is only 3dB better.
Doubling the number of drivers, whether series or parallel, will always increase efficiency 3dB. What you change is the tradeoff of impedance for voltage sensitivity. Assuming 8 ohm drivers, series keeps constant voltage sensitivity, but is a 16 ohm load requiring half as much current. Parallel quadruples the voltage sensitivity (6dB), but it takes twice as much current for a given voltage due to the 4 ohm load. In either case you're only 3dB more EFFICIENT as it will take half as much power in either case to achieve the same SPL.
It's amazing how frequently this is misunderstood, given that it's one of the more simple and important aspects of many speaker designs
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