I am looking to make a transmission line 1/4 wavelength folded subwoofer that would use three drivers. Standard theory that i have been using has been the port mouth area that defines the design is the same as a the drivers cone area (SD). So for a two or three driver design do I uses the SD of one driver to define the area of the mouth/port or do i use total SD of all drivers in the array?
I googled this a lot and i could not find a definitive answer. Thanks in advance.
I googled this a lot and i could not find a definitive answer. Thanks in advance.
Sd and the line size (area) arent related until you place Vas and Qes in front. They are what matters. But its also Qts at Fs which will steer the design around or below Fs as Fb
Those (Vas and Qts, Fs and (details in Le, MMS, BL^2/re, etc) as shown by a sim) make Vb, Fb, for the driver TS parameters and coresponding CSA and L to used as best.
Those (Vas and Qts, Fs and (details in Le, MMS, BL^2/re, etc) as shown by a sim) make Vb, Fb, for the driver TS parameters and coresponding CSA and L to used as best.
As BW noted, the design theory often posted on the net is designed to make a reasonably small [IIRC by circa 1965 standards] version of an infinite baffle [IB] often in the 100s of ft^3, so while a valid design, it's better overall these days to just stuff a relatively small sealed box loaded with a modern low [Vas], low [Qts'] driver.
Driver brand/model?
Right, total [Sd] plus [Vas]*3, [Qts'] stays the same and [Re], [Le] will change based on how it's wired.
[Qts']: [Qts] + any added series resistance [Rs]: Calculate new Qts with Series Resistor
[Rs] = 0.5 ohm minimum for wiring, so may be higher if a super small gauge is used as a series resistor plus any added resistance from an XO/whatever.
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