building new tops for my 3-way with Behringer DCX2496, has decided to choose Faital HF108 / LTH102 (the room is less than 12 feet wide) . the boxes is sealed 45L / 1.5cuft and the 12PR300 was long the first choice but it was out of stock and now i thinking about other drivers like : Faital 12FH520 or 18sound 12NMB420
-does anyone have a passive filter design for the HF108 CD ?
- how will these drivers look in my boxes compared to 12PR300 and how do they match with the HF108 / LTH102 ?
the subs is now in the corners but i thinking of move them out and and try to
stack the tops on them them, - then I would be able to move up the crossover point, - are there any advantages with smaller boxes if i crossover them at 200hz instead of 100hz ? i mean if i loose response or something else with
unnecessarily large volume ? .
here is my subwoofers : need commens on SPL dynamics ?
thanks in advance
-does anyone have a passive filter design for the HF108 CD ?
- how will these drivers look in my boxes compared to 12PR300 and how do they match with the HF108 / LTH102 ?
the subs is now in the corners but i thinking of move them out and and try to
stack the tops on them them, - then I would be able to move up the crossover point, - are there any advantages with smaller boxes if i crossover them at 200hz instead of 100hz ? i mean if i loose response or something else with
unnecessarily large volume ? .
here is my subwoofers : need commens on SPL dynamics ?
thanks in advance
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Qtc is the total Q of the speaker in an enclosure including all system resistances. A Qtc between 0.6 - 0.7 is considered desirable.
A Qtc of .707 generally produces the flattest frequency response with approximately a 12dB/octave rolloff which can smoothly combine with common 12dB/octave crossover circuits. A higher Qtc can sound more dynamic and generate higher bass SPL, but less cone control generates more overshoot / undershoot distortion. A lower Qtc can sound more accurate but generates less bass SPL with lower cone displacement for a dry sound.
In 1.5 cuft sealed volume: 12PR300 has Qtc=0.61; 12NMB420=0.54; 12FH520=0.46; Most designers would reduce the rear volume to create a Qtc ~ 0.6.
The 12PR300 can drop in with a 200Hz baffle step crossover.
The 12NMB420 would favor a slightly smaller volume, with a 200Hz baffle step crossover after some attenuation.
The 12FH520 would need a smaller volume, with more a complex crossover circuit(shape) for a 200Hz baffle step goal.
Example 1300Hz crossover for HF108 with LTH102 attached. (24" wide cabinet used in sim)
A Qtc of .707 generally produces the flattest frequency response with approximately a 12dB/octave rolloff which can smoothly combine with common 12dB/octave crossover circuits. A higher Qtc can sound more dynamic and generate higher bass SPL, but less cone control generates more overshoot / undershoot distortion. A lower Qtc can sound more accurate but generates less bass SPL with lower cone displacement for a dry sound.
In 1.5 cuft sealed volume: 12PR300 has Qtc=0.61; 12NMB420=0.54; 12FH520=0.46; Most designers would reduce the rear volume to create a Qtc ~ 0.6.
The 12PR300 can drop in with a 200Hz baffle step crossover.
The 12NMB420 would favor a slightly smaller volume, with a 200Hz baffle step crossover after some attenuation.
The 12FH520 would need a smaller volume, with more a complex crossover circuit(shape) for a 200Hz baffle step goal.
Example 1300Hz crossover for HF108 with LTH102 attached. (24" wide cabinet used in sim)
Attachments
A few simple simulations of the baffle shape and room placement will give a feel for the "under 200Hz" effects. It is common to design the baffle and crossovers together to provide some control options for baffle step compensation and in-room vs. near-wall placement.
Baffle Edge Diffraction Simulator
By Jeff Bagby Version 1.20
Baffle Edge Diffraction Simulator
By Jeff Bagby Version 1.20
Attachments
the cabinets are 16.5" w x 21" h with 33 mm radius on the sides ,
Previously I have used both passive and active crossover for the CD and active for the mids and the subs , - what is preferable ?
anyway, a good passive filter design would be great to comparing and listening, its part of the pleasure
Previously I have used both passive and active crossover for the CD and active for the mids and the subs , - what is preferable ?
anyway, a good passive filter design would be great to comparing and listening, its part of the pleasure
Attachments
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