I have seen a lot written about the Jordan Eikona in the VTL box. Many places show the frequency response as down to 30 Hz or 35 Hz but I have not found a single site or document that states what this exactly means! Is it -3 dB, -10dB, -????? dB? Does anybody have reliable data on this?
Roger
Roger
The VTL is tuned to 45 Hz, the original fs of the Jordan JX92S. It has a similar rolloff to a reflex, so 18 Hz/octave. In room, the -10 dB point is around the mid-30s.
If you're after ultimate extension, the longer MLTL designs are tuned lower.
If you're after ultimate extension, the longer MLTL designs are tuned lower.
I did try to model it tuned as low as possible in MLTL, but an F3 lower than 40 is not doable i think with this driver. F10 is 31Hz then. The cabinet is 20x20x120cm inside with the driver at 30cm from top and the slot port (20x2cm and 5cm deep) at the bottom (like an Pencil). It will need a lot of stuffing to work altough. Sizes are internal.
But a driver that is a bit bigger is easier to tune that low. I did a MLTL with the CHN110 driver tuned to 30Hz F3 that works very well. The Alpair 10.3 can also do that btw. Scott did make some designs that are well documented for those (mine is not yet).
But a driver that is a bit bigger is easier to tune that low. I did a MLTL with the CHN110 driver tuned to 30Hz F3 that works very well. The Alpair 10.3 can also do that btw. Scott did make some designs that are well documented for those (mine is not yet).
Sure it is. It just depends on conditions. Assuming a voltage source amplifier with 0.5ohms series R for typical wire-loop, connection resistance (and because I'm a dinosaur something approaching a 'real' MLTL), then
L = 54.75in
CSA = 54.8125in^2
Zd = 19.125in
Zv = 46.4375in
Av = 4.908in^2
Lv = 3.25in
Box lagged on non-opposing faces with OC-703 or equivalent & adjust as desired.
Fb = 41Hz
F3 = 38Hz
F10 = 31Hz
[nominal anechoic]
More or less a maximally flat alignment. F3 is a fairly meaningless metric though.
If you want to push it, assuming a high power SET using 211s or something like one of Nelson's more powerful single gain-stage offerings with a moderate output impedance lurking in the 2ohm region (inc. the wire-loop, connection R), then
Same as above, CSA increased to 37.5in^2, Lv increased to 4.875in
Fb = 35Hz
F3 = 32Hz
F10 = 25Hz
[nominal anechoic]
Power-handling is somewhat limited though with a relatively high cone displacement -these are not huge drivers after all. 😉
L = 54.75in
CSA = 54.8125in^2
Zd = 19.125in
Zv = 46.4375in
Av = 4.908in^2
Lv = 3.25in
Box lagged on non-opposing faces with OC-703 or equivalent & adjust as desired.
Fb = 41Hz
F3 = 38Hz
F10 = 31Hz
[nominal anechoic]
More or less a maximally flat alignment. F3 is a fairly meaningless metric though.
If you want to push it, assuming a high power SET using 211s or something like one of Nelson's more powerful single gain-stage offerings with a moderate output impedance lurking in the 2ohm region (inc. the wire-loop, connection R), then
Same as above, CSA increased to 37.5in^2, Lv increased to 4.875in
Fb = 35Hz
F3 = 32Hz
F10 = 25Hz
[nominal anechoic]
Power-handling is somewhat limited though with a relatively high cone displacement -these are not huge drivers after all. 😉
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