Palsa,
For a pole mounted setup like you were talking about maybe the sub could be refolded to be more cube-like for stability but it would require some creativity .. .😉
I would never be disappointed with having a Lab12 driver lying around. You could always go T45... Of course that's worlds larger but it would be guaranteed performance.
Hello Saba!!
Yes , So true !, after all the Lab12 was specifically optimized to kick copious tail in a Front Loaded Horn , and BFM is a master of FLHs ! 🙂
PALSA !!
GOOD NEWS! 😀
I just figured out the perfect fold to make this into more of a cube shaped box 😀
Path lengths and cm sq areas work out well too without being too cramped !
I will post it when finished, but so far it looks like it might be approximately 20"H x 13.5" W x 18" D
🙂
I was thinking about a refold, got creative with SW!
And Saba, that's true. As I was originally planning on the T45 when I bought the driver but changed my mind when I found the LAB15 special box haha here's the proof!
Is there such a thing as a front loaded horn that does gain 10dB over it's passband? Saba knows much better than I do how much low frequency efficiency is important and how being half as loud as the beginning of midbass frequencies isn't that cool =( I understand that the improve lots in stacks but I don't have the pack space for a herd of T45's =(
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Hi X,
Post #879: "...If I have time I will sim it as drawn..."
It sims better if the driver is moved a bit more up the horn path towards S3; e.g.: L12=78.10cm L23=47.20cm. The general idea is fine, but it needs a few more iterations, simulate-draw-simulate-draw.... 🙂 That takes a lot of time.
Regards,
Post #879: "...If I have time I will sim it as drawn..."
It sims better if the driver is moved a bit more up the horn path towards S3; e.g.: L12=78.10cm L23=47.20cm. The general idea is fine, but it needs a few more iterations, simulate-draw-simulate-draw.... 🙂 That takes a lot of time.
Regards,
Hey guys ,
A few new exciting observations:
The Alpine SWS-12D (2 and 4) works really well in this offset ML Transflex box! It is flatter down to 35 and louder on average! Takes 52 volts and is more affordable than the Lab12.. The Alpine also has a higher FS and tighter suspension so it should be more controlled below FB ... It also has an exceptionally strong motor for a 12 ..
This new fold with the more cubelike shape looks like it should work out really well , i might even be able to make the box slightly wider and a little less tall , but i am still checking on that to be sure .... Revised sketch coming soon!😀
A few new exciting observations:
The Alpine SWS-12D (2 and 4) works really well in this offset ML Transflex box! It is flatter down to 35 and louder on average! Takes 52 volts and is more affordable than the Lab12.. The Alpine also has a higher FS and tighter suspension so it should be more controlled below FB ... It also has an exceptionally strong motor for a 12 ..
This new fold with the more cubelike shape looks like it should work out really well , i might even be able to make the box slightly wider and a little less tall , but i am still checking on that to be sure .... Revised sketch coming soon!😀
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You guys are all doing awesome work thank you on behalf of the other aspiring low scale mobile DJ's who might be reading this! Haha Tb46 that drawing is super nice and MMJ, I like where this box design is going! Can we all see a comparative sim between the SWS and LAB12 in the new box when you get around to it?? Thanks!
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Concept fold , getting closer to a final product =)
I just wanted to show everyone what i had in mind .... I wanted to make this more cube-like but had to settle for a square footprint and a little less height which is a step in the right direction ... The 20" height didn't quite produce enough path length with this fold style , so had to fall back to 26" ...
Still working out the final details .... This sketch shows a stepped version, and also a version with one tapered panel for those purists out there 😛
Offset point ends up being between 60 and 70 centimeters depending on how it is calculated and the compression ratio on the driver falls into the right range...
Still working out more details ...
Palsa ,
I will post a comparison between the Lab and Alpine driver in a few minutes ...
I just wanted to show everyone what i had in mind .... I wanted to make this more cube-like but had to settle for a square footprint and a little less height which is a step in the right direction ... The 20" height didn't quite produce enough path length with this fold style , so had to fall back to 26" ...
Still working out the final details .... This sketch shows a stepped version, and also a version with one tapered panel for those purists out there 😛
Offset point ends up being between 60 and 70 centimeters depending on how it is calculated and the compression ratio on the driver falls into the right range...
Still working out more details ...
Palsa ,
I will post a comparison between the Lab and Alpine driver in a few minutes ...
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Posts #869 and 878
Hi again,
Here is an updated drawing that got a little bit smaller, and the mouth/driver access got a little bit bigger. I kept the duct after S3 the same height similar to previous versions, and shortened it a bit. Is should be easier to build.
Regards,
Hi again,
Here is an updated drawing that got a little bit smaller, and the mouth/driver access got a little bit bigger. I kept the duct after S3 the same height similar to previous versions, and shortened it a bit. Is should be easier to build.
Regards,
Palsa ,
Here is the comparison between the Lab12 and Alpine SWS-12
I wasn't able to overlap the two drivers on the same graph (using "filling") but you can get a pretty good idea of what is going on by looking at the screenshots since we aren't really splitting hairs with this comparison ..
Other benefits of the Alpine that i haven't already listed are the reduced mounting depth, and it's Santoprene surround (resilient even in a harsh environment, long lasting )...
The only concern i would have with that driver is mechanical noise at high excursions .... SabaSpeed mentioned that he had one of the SWS12s with some very noticeable mechanical noise, i think he said he sent it back for a replacement, maybe he can tell us how that all worked out ...
Here is the comparison between the Lab12 and Alpine SWS-12
I wasn't able to overlap the two drivers on the same graph (using "filling") but you can get a pretty good idea of what is going on by looking at the screenshots since we aren't really splitting hairs with this comparison ..
Other benefits of the Alpine that i haven't already listed are the reduced mounting depth, and it's Santoprene surround (resilient even in a harsh environment, long lasting )...
The only concern i would have with that driver is mechanical noise at high excursions .... SabaSpeed mentioned that he had one of the SWS12s with some very noticeable mechanical noise, i think he said he sent it back for a replacement, maybe he can tell us how that all worked out ...
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Wow! It looks like I may have to go for the SWS and keep the LAB12 around for a FLH if Saba can confirm the mechanical noise has gone away
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Fantastic work TB46 !
That looks really good 🙂 Path length
, Compression Ratio , offset all looks great 🙂 I think you may have nailed the single fold design for this cab, even compensated for the airspace taken up by internal panels .... Very nice indeed🙂
I fiddled around with the single fold idea the other night but gave up on it
because i couldn't get everything to fit and line up correctly, so i went with an additional fold and things are less cramped now which is good .... It is super cool for people to have a choices between tower style or shorter & stout build options for this alignment 😀
Thank you for going through the trouble of making these fantastic sketches ..
So much teamwork happening here , i love it!
As they say, It takes a villianage 😉
Post #869, 878 and 891
Here is the short (squashed?) version of the drawing from Post #891. Basically, it folded right over (well, kind of). 🙂 The simulation does not change.
Regards,
Here is the short (squashed?) version of the drawing from Post #891. Basically, it folded right over (well, kind of). 🙂 The simulation does not change.
Regards,
That looks amazing! Did you have the HR file for that?? Thank you! Fairly certain I'll be building that!
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LOOKING GOOD !!
Tb46 ,
You are great at this, and fast!!
I like how you managed to get the height to just below 24" 🙂 Excellent ....
I have a question for you .... Do you suppose it would be possible to maintain basically that same design but to remix the final few inches of the smallest portion of the path (before it enters the larger mouth chamber) so that it exits into the back of the mouth chamber instead of toward the front?
I have been trying to make it happen over here but i keep ending up with a 26" tall box instead of your 24" , and i like your 24" height much more 🙂
Post #869, 878, 891, 895 and 897
Hi MMJ,
Here is the remixed version bringing the duct exit to the driver mounting flange. I had to reduce the duct height to 2.47" (this corresponds to 200cm^2 for the cross-section) starting from S3 on out. Seems to work, but whoever builds this will have to trim the last board to make it possible to insert the driver; trimming this will not affect the response. I'll attach the Hornresp simulation too (w/ the understanding that the area around the driver is just an educated guess).
Regards,
P.S.: Post #896: "...Did you have the HR file for that?"
For the one in Post #895 the Hornresp simulation did basically not change.
Hi MMJ,
Here is the remixed version bringing the duct exit to the driver mounting flange. I had to reduce the duct height to 2.47" (this corresponds to 200cm^2 for the cross-section) starting from S3 on out. Seems to work, but whoever builds this will have to trim the last board to make it possible to insert the driver; trimming this will not affect the response. I'll attach the Hornresp simulation too (w/ the understanding that the area around the driver is just an educated guess).
Regards,
P.S.: Post #896: "...Did you have the HR file for that?"
For the one in Post #895 the Hornresp simulation did basically not change.
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Mr Steele! ,
Hi ! 🙂
It seems to be equal to a larger bass reflex ... I think Palsa said his Lab12 reflex is 100 liter? (not sure if net or gross) , and this OD-ML-TRANSFLEX box is 60L net .... I would be pretty happy with this design if it actually does compete against that much larger box in real-world performance, we shall see i suppose..
This box is also likely to have better midbass output until the bandpass cutoff and then surely drops off like a rock above that ... Bandpass cutoff looks to be around 230hz
🙂
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