Hi,
has anybody ever tried the subwoofer enclosure from the 18sound website:
http://www.eighteensound.com/Portals/0/EnclosuresKits/18sound_12BANDPASSKIT.pdf
I have the 12LW1400 laying arround here and wonder, what to expect ?
How would it compare with the Klipschorn, as the cutoff from the horn is also arround 40hz ?
I have two K-horns with Le-Cleach 400Hz horns for mid/highs..
Any experience - worth building the bandpass enclosure ?
Any good alternative suggestion for the 12LW1400 ... ???
regards, Ulli
has anybody ever tried the subwoofer enclosure from the 18sound website:
http://www.eighteensound.com/Portals/0/EnclosuresKits/18sound_12BANDPASSKIT.pdf
I have the 12LW1400 laying arround here and wonder, what to expect ?
How would it compare with the Klipschorn, as the cutoff from the horn is also arround 40hz ?
I have two K-horns with Le-Cleach 400Hz horns for mid/highs..
Any experience - worth building the bandpass enclosure ?
Any good alternative suggestion for the 12LW1400 ... ???
regards, Ulli
The link doesn't work for me. I mostly have bad experience with BP enclosures. I'd attribute it to the "nature" of the box.
Corrected link: http://www.eighteensound.com/Portals/0/EnclosuresKits/18sound_12BANDPASSKIT.pdf
Looks pretty decent if the FR graphs are correct.
If a driver's specs are good for a 6th order BP, they're likely also good for a tapped horn (TH). A TH will suffer from a lot less compression effects at higher volumes, but won't have the distortion-filtering advantage of BP designs.
Looks pretty decent if the FR graphs are correct.
If a driver's specs are good for a 6th order BP, they're likely also good for a tapped horn (TH). A TH will suffer from a lot less compression effects at higher volumes, but won't have the distortion-filtering advantage of BP designs.
The eighteen sound cab desigbs look very well thought out, they do require dsp to work as intended and don't expect to dial the settings in to another brand dsp and get the exact same response, but as they publish the dsp graph it is no trouble to match your dsp to it.
Very much worth a go, looks like a very straight forward build. DSP is a must though.
Very much worth a go, looks like a very straight forward build. DSP is a must though.
Thanks for the answers,,,
I will give it a try and build the bandpass enclosure.
I used the 12LW1400 in a very large tapped-horn prototype enclosure. Although it worked great, that box doesn't fit any more in the living room, after renovation an replacements of furniture.
I may not reach 25Hz(-3db) anymore with the small bandpass, but the box will be by far more compact...
Ulli
I will give it a try and build the bandpass enclosure.
I used the 12LW1400 in a very large tapped-horn prototype enclosure. Although it worked great, that box doesn't fit any more in the living room, after renovation an replacements of furniture.
I may not reach 25Hz(-3db) anymore with the small bandpass, but the box will be by far more compact...
Ulli
Was thinking of building Marc O. MTH 30 12" Tapped Horn nice performance but I do not have access to PD drivers. I am thinking of building 2 x 18Sound 12" Bandpass cab with 18Sound 12" woofer (12LW1400). I need 2 as sometimes I need more spl as I am a mobile DJ. I have the tops BFM SLA Pro. I need small and loud I don't have the back anymore like I had in the 80'-90's big EAW cabs for mobile DJ.
I am curious if you had built the 18Sound 12" subs. Thanks😕
I am curious if you had built the 18Sound 12" subs. Thanks😕
not built anything like that but
BP build
Mikesound Letohrad - zvuka? Jaroslav Mikyska ? Mike 2003-2019 Ozvu?ov?n? kulturn?ch akc?.
THAM12 type discussed
THAM 12 - a compact 12" TH - Speakerplans.com Forums - Page 4
BP build
Mikesound Letohrad - zvuka? Jaroslav Mikyska ? Mike 2003-2019 Ozvu?ov?n? kulturn?ch akc?.
THAM12 type discussed
THAM 12 - a compact 12" TH - Speakerplans.com Forums - Page 4
The THAM 12 has an F3 above 50 Hz. That sort of stretches the definition of "subwoofer"...
I like those made by Mike Sound I've seen him in other sites. Thanks for those pictures now I am inspired I gotta build at least 4 cabs and i have not owned an 18Sound speaker. Now is the time. I like compactness and will fill the void of a small powerful subs, small footprint is important for me. Thanks😉
The Mikesound 12" 6"th order series-tuned BP looks like a pretty decent build. The only thing I might change is to put in a central brace to tie that removable panel to, and possibly opt for slot vents optimized to null out the primary out of band resonance modes, but that would really be engaging in a bit of lilly-guilding here, as it seems to be a pretty good design already.
Hi Brian Steele, that mod would take another 2-3 hours as you have to attach it to the back panel, then as you say that smaller extra access panel is also attached to the central brace. meaning the larger outer access panel is by itself to seal the cab. Plus the holes.😉
I'm looking to build an active version of this cabinet. I was curious about the cone excursion (and limiter settings).
Not sure my calculations are correct, but.... Based on the recommended limiter setting of 9 dbu, this would equate to 87v or a bit over 900W @ 8 ohm which seems right for the driver. But this ends up with a huge amount of cone excursion.
Even with the 30hz highpass filter, seems like it should be limited to more like 300w / 49v to keep the peek at 55hz within xmax. And maybe needs a more aggressive highpass filter.
(modelling using horn resp with 57L main chamber and 16L second chamber)
Not sure my calculations are correct, but.... Based on the recommended limiter setting of 9 dbu, this would equate to 87v or a bit over 900W @ 8 ohm which seems right for the driver. But this ends up with a huge amount of cone excursion.
Even with the 30hz highpass filter, seems like it should be limited to more like 300w / 49v to keep the peek at 55hz within xmax. And maybe needs a more aggressive highpass filter.
(modelling using horn resp with 57L main chamber and 16L second chamber)
Care to share your simulation?
I suspect that the bandpass nature of this box would filter out some of the distortion caused by Xmax being exceeded, but that depends on where the peak excursion occurs in relation to the upper cutoff frequency of the box.
I suspect that the bandpass nature of this box would filter out some of the distortion caused by Xmax being exceeded, but that depends on where the peak excursion occurs in relation to the upper cutoff frequency of the box.
This is the "mod" I was suggesting. All it requires is replacing the existing brace with a larger one that extends to just below the access panel (close enough so that the access panel can be screwed into it.). Any increase in box-building time should be minor, and tying the access panel to the brace should reduce its tendency to flex by quite a bit, which should in turn improve response a bit at upper bass frequencies.
.
Here is the displacement in horn resp with 300W input and the recommended filters.
At 900W / 85v input, displacement is 15mm at 55hz and 22mm at 28 hz.
At 900W / 85v input, displacement is 15mm at 55hz and 22mm at 28 hz.
I'm not sure on my initial calcs on the limiter setting. Using dBu alwasys confuses me.
I assumed 32 dBu gain from the amp +9 dbu = 41.
Solved for dBu = 20 Log(v/0.775)
V=0.775 * 10^(41/20) = 87v
I assumed 32 dBu gain from the amp +9 dbu = 41.
Solved for dBu = 20 Log(v/0.775)
V=0.775 * 10^(41/20) = 87v
Published Xmax for the 12LW1400 is 8.5 mm, so 155 @ 55 Hz seems a bit much. Going by my usual V(Xmax)+3dB guestimate at power handling, I'd rate this box as a 600W box, but that's just me 🙂.
Xmech unfortunately isn't quoted for that driver. 3*55 Hz = 165 Hz, which is outside the usable passband of this subwoofer, so the odd order distortion is going to be attenuated. However, the 2nd order distortion (which will appear at 110 Hz) will not be filtered much, if at all. However 2nd order HD is usually not that objectionable.
Excursion at lower frequencies can probably be reduced by using a higher order filter,and adjusting the filter's Fc until the excursion peak matches the in-band excursion peak.
Xmech unfortunately isn't quoted for that driver. 3*55 Hz = 165 Hz, which is outside the usable passband of this subwoofer, so the odd order distortion is going to be attenuated. However, the 2nd order distortion (which will appear at 110 Hz) will not be filtered much, if at all. However 2nd order HD is usually not that objectionable.
Excursion at lower frequencies can probably be reduced by using a higher order filter,and adjusting the filter's Fc until the excursion peak matches the in-band excursion peak.
It's a loooooong time ago, when I started this thread about 3.5years ago.
I am surprised that there seem to be still some interest in this design and speaker chassis.... but I have to thank you for the great links which were posted.
I agree, the builds of Mikesound in CZ are looking great and are well build.
Unfortunately there are no measurements taken, to find out, if his practical build matches the measurements of 18s manufacturer...
But anyway, I think one can trust this famous italian manufacturer....
In the last 3 years, I could not make any time to work on the speakers.... not even much music listening either...
However I again start to think about building something....
I have made some simulations with Brian Steele's Excel sheet using the MLTL Boxsim with hornresp.
The speaker is purely for home use , not PA
So I reduced the port for the MLTL 2.8 speadsheet to less than half of the Sd of the speaker, as I would never use it at max SPL...
With arround 200cm2 port size and exactly same size than the 18s design, the port output will max at arround 35Hz, which is lower than in the BP6 housing.
It suggests, that such a MLTL will be a better match for me any my home use appl.
Brian, if you still follow this thread: What would you prefer ? BP or MLTL
I have Beyma 10G200 for the mids and a 400Hz LeCleach horn with BMS 4550 from about 1kHz...
Full active setup with FIR filters..
MLTL will be much easier to build so I would prefer this.
What port size I should choose for this speaker - how about 180...200cm2 for home use ?
(For PA I would better stay with 260 or more...)
I am surprised that there seem to be still some interest in this design and speaker chassis.... but I have to thank you for the great links which were posted.
I agree, the builds of Mikesound in CZ are looking great and are well build.
Unfortunately there are no measurements taken, to find out, if his practical build matches the measurements of 18s manufacturer...
But anyway, I think one can trust this famous italian manufacturer....
In the last 3 years, I could not make any time to work on the speakers.... not even much music listening either...
However I again start to think about building something....
I have made some simulations with Brian Steele's Excel sheet using the MLTL Boxsim with hornresp.
The speaker is purely for home use , not PA
So I reduced the port for the MLTL 2.8 speadsheet to less than half of the Sd of the speaker, as I would never use it at max SPL...
With arround 200cm2 port size and exactly same size than the 18s design, the port output will max at arround 35Hz, which is lower than in the BP6 housing.
It suggests, that such a MLTL will be a better match for me any my home use appl.
Brian, if you still follow this thread: What would you prefer ? BP or MLTL
I have Beyma 10G200 for the mids and a 400Hz LeCleach horn with BMS 4550 from about 1kHz...
Full active setup with FIR filters..
MLTL will be much easier to build so I would prefer this.
What port size I should choose for this speaker - how about 180...200cm2 for home use ?
(For PA I would better stay with 260 or more...)
I’ve built four of those 18 sound band pass boxes. They do not play below 32 Hz. For that is OK as the trade-off is they are small and have very high output. You do need DSP. I would strongly recommend flaring out the ports on both ends. Otherwise I had problems with chuffing noise.
next time I would however prefer flared slot ports instead of the vents because the slots can be made to increase the structural strength of the enclosure. Will the conversion to slots be as simple as making an equivalent volume with slots as the ports?
next time I would however prefer flared slot ports instead of the vents because the slots can be made to increase the structural strength of the enclosure. Will the conversion to slots be as simple as making an equivalent volume with slots as the ports?