Hi ,
I'd love some help with a Sub project I want to build.
I've got 4 Morel 222 drivers available doing nothing.
The specs are as follows :
Fs=31Hz
Re=5.2ohms
L=0.5mH
Xmax=3.5mm
Qms=3.74
Qes=0.95
Qts=0.75
Vas=70litres
Cone=219cm2
Power=120W
Z=8ohm
When I plug the figures into my software it suggests ridiculously
large enclosure sizes >1000litres ??
Can anyone suggest an enclosure design utilizing these drivers
sealed/bass reflex/bandpass.....I don't mind. Good low bass , but
not "boomy" for use with HT & Music.
Thanks
Andrew
I'd love some help with a Sub project I want to build.
I've got 4 Morel 222 drivers available doing nothing.
The specs are as follows :
Fs=31Hz
Re=5.2ohms
L=0.5mH
Xmax=3.5mm
Qms=3.74
Qes=0.95
Qts=0.75
Vas=70litres
Cone=219cm2
Power=120W
Z=8ohm
When I plug the figures into my software it suggests ridiculously
large enclosure sizes >1000litres ??
Can anyone suggest an enclosure design utilizing these drivers
sealed/bass reflex/bandpass.....I don't mind. Good low bass , but
not "boomy" for use with HT & Music.
Thanks
Andrew
With that kind of Q, go for a sealed box
When Qc = 1.25, box volume is 3.5 ft3.
If you do a compound woofer configuration, the box will have two woofers in it and be 1/2 original enclosure size, 1.75 ft3. Efficiency will be that of a single woofer (assuming a 4 ohm parallel connection).
-andy
btw, if you can make it any larger than 1.75, i would recomend that you do so
I've never done anything with woofers with that high of a Q value, if anyone has any other suggestions please share.
When Qc = 1.25, box volume is 3.5 ft3.
If you do a compound woofer configuration, the box will have two woofers in it and be 1/2 original enclosure size, 1.75 ft3. Efficiency will be that of a single woofer (assuming a 4 ohm parallel connection).
-andy
btw, if you can make it any larger than 1.75, i would recomend that you do so
I've never done anything with woofers with that high of a Q value, if anyone has any other suggestions please share.
Okay, here are some suggestions.
Four boxes of different configurations. Two are 2 cu ft,
two are 3 cu ft.
Red. 3 cu ft. Closed box. Least output of the four.
Orange. Bandpass. 3 cubic ft total. 1.5 cu ft front chamber, 1.5 cu ft rear chamber. Tuned to 48 Hz.
Lt. Blue. Bandpass. 2 cubic ft total. 1.2 cu ft front, .8 cu ft rear. Front tuned to 60 Hz.
Dark Blue. Bandpass. 2 cubic ft total. .7 cubic ft front. 1.3 cu ft rear. Front tuned to 48 Hz.
Note that the bandpass boxes exhibit higher sensitivity and/or bass extension than the sealed.
Except for the dark blue, the depressions in the middle are not so unmanageable-2 or 3 db. Bear in mind that when a bandpass is near a corner, the tuning frequency is emphasized most of all, and that will fill in the middle depression.
The front chamber can also be tuned with a 10" or bigger passive radiator.
If you want less than 2 cubic feet, let me know,
but you are not going to get anywhere near 30 Hz output if it is smaller than that.
I have never built a bandpass box, but with the extra output it seems to put out, I plan to soon. I have also never used a passive radiator, but I understand the principles. I have built plenty of sealed and ported enclosures.
The graphs are only there to give you an idea of some possibilities.
Good luck!! 🙂 🙂
Four boxes of different configurations. Two are 2 cu ft,
two are 3 cu ft.
Red. 3 cu ft. Closed box. Least output of the four.
Orange. Bandpass. 3 cubic ft total. 1.5 cu ft front chamber, 1.5 cu ft rear chamber. Tuned to 48 Hz.
Lt. Blue. Bandpass. 2 cubic ft total. 1.2 cu ft front, .8 cu ft rear. Front tuned to 60 Hz.
Dark Blue. Bandpass. 2 cubic ft total. .7 cubic ft front. 1.3 cu ft rear. Front tuned to 48 Hz.
Note that the bandpass boxes exhibit higher sensitivity and/or bass extension than the sealed.
Except for the dark blue, the depressions in the middle are not so unmanageable-2 or 3 db. Bear in mind that when a bandpass is near a corner, the tuning frequency is emphasized most of all, and that will fill in the middle depression.
The front chamber can also be tuned with a 10" or bigger passive radiator.
If you want less than 2 cubic feet, let me know,
but you are not going to get anywhere near 30 Hz output if it is smaller than that.
I have never built a bandpass box, but with the extra output it seems to put out, I plan to soon. I have also never used a passive radiator, but I understand the principles. I have built plenty of sealed and ported enclosures.
The graphs are only there to give you an idea of some possibilities.
Good luck!! 🙂 🙂
Attachments
Found some more information which may help someone to help me !
The drivers were used in a Morel model MLP307 , 2 wired in parallel in a box with total of volume ~ 45 litres.
Each driver had it's own compartment of ~ 22 litres and each
compartment was rear vented with a aperedic?? port (not sure how to spell it) - (not a bass reflex port !)
These speakers had good low down performance , that's why I
thought of using these drivers.....
My "Spouse Factor" concludes that my sub needs to be built under
the coffee table , so I've got about 92 litres to play with.
So I'm trying to make the best of the available drivers & room space.
Many Thanks🙂
The drivers were used in a Morel model MLP307 , 2 wired in parallel in a box with total of volume ~ 45 litres.
Each driver had it's own compartment of ~ 22 litres and each
compartment was rear vented with a aperedic?? port (not sure how to spell it) - (not a bass reflex port !)
These speakers had good low down performance , that's why I
thought of using these drivers.....
My "Spouse Factor" concludes that my sub needs to be built under
the coffee table , so I've got about 92 litres to play with.
So I'm trying to make the best of the available drivers & room space.
Many Thanks🙂
Well, I don't know that much about aperiodic vents, but here is a page that explains things:
http://www.snippets.org/ldsg/boxes.php3#APERIODIC
Frankly, I think I would use one speaker in a 3 cubic foot bandpass enclosure, but that's just me.
I have seen other aperiodic designs using 2 chambers but have no link. I will post the link if I come across it.
Good luck.
http://www.snippets.org/ldsg/boxes.php3#APERIODIC
Frankly, I think I would use one speaker in a 3 cubic foot bandpass enclosure, but that's just me.
I have seen other aperiodic designs using 2 chambers but have no link. I will post the link if I come across it.
Good luck.
aperiodic vents
damp resonance impedence the same way adding 100% fiberglass fill does, according to Vance Dickason. This increases the effective size of an enclosure.
Do you plan to use all 4 woofers?
the bandpass idea is feasible, only large. How would the compound woofer setup compare soundwise? Could one design a coumpound woofer bandpass sub? I will see if I can find out.
andy
damp resonance impedence the same way adding 100% fiberglass fill does, according to Vance Dickason. This increases the effective size of an enclosure.
Do you plan to use all 4 woofers?
the bandpass idea is feasible, only large. How would the compound woofer setup compare soundwise? Could one design a coumpound woofer bandpass sub? I will see if I can find out.
andy
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