Wayne's 12Pi sub

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anyone build one? i've seen all the information on it and he sent me the plans yesterday. i am considering, but the box is huge. seems moving them wouldn't be too bad with the grab handle and wheels. the band i play will be doing some outdoor shows this summer, but i think i could use these inside also. anyone hear this cabinet in person? however not much bigger then the dual 18 manifold i was trying to design. i am an engineer at a wood working company so building them wouldn't be an issue. i have access to cnc machining.
 
yeah it is similar. i have plans for the labsub also, but actually it is a little more intense to build due to some compound miter cuts. thought i would look at other forums on opinions. seems on the prosound forums everyone is biased towards the labhorn as with Bill Fitzmaurice's designs on his forum. i have been wanting to build some push-pull dual 18 cabinets, but i forgot about Wayne's 12Pi and how they used the push-pull concept also. the box is big, but would only be deeper compared to a dual 18 cabinet.
 
Setting aside the non-linearity cancellation of push pull in the 12 Pi , it'd be nice (from a prosound perspective, high voltage / low frequency) to have a version with both lab12 magnets in the throat
chamber for even voice coil cooling. Though it might detract from the already small 21 L? sealed
boxes in these enclosures. What do you think?
 
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yeah it is similar. i have plans for the labsub also, but actually it is a little more intense to build due to some compound miter cuts. thought i would look at other forums on opinions. seems on the prosound forums everyone is biased towards the labhorn as with Bill Fitzmaurice's designs on his forum. i have been wanting to build some push-pull dual 18 cabinets, but i forgot about Wayne's 12Pi and how they used the push-pull concept also. the box is big, but would only be deeper compared to a dual 18 cabinet.
The 12 Pi is almost double the volume of a typical dual 18" box. That 45" depth may not be a problem outside, but indoors may be. I have not used 45” deep cabinets since the late 1980’s, they just didn’t fit in too many venues.

If you compare the graphs of the 12 Pi to a JBL SRX 728 ( 98 dB one watt one meter at around 80 Hz) you see the 728 actually puts out more level at 50 Hz.

You could put almost two of the 728 in the same truck space as the 12 Pi, and two 728 would give another 6 dB over one.

My single 18" Keystone cabinet, 45” x 26.5” x 22.5”, about exactly half the volume of the 12 Pi, is very close to the same sensitivity and frequency response of the JBL SRX 728, the 728 has a bit more output below 37 Hz, the Keystone a bit more above 80 Hz.

http://www.diyaudio.com/forums/subwoofers/185588-keystone-sub-using-18-15-12-inch-speakers.html

Two Lab 12 in the Keystone enclosure are even more sensitive than the BC18SW115-4, but can't take as much power without thermal compression and running out of excursion, the BC18SW115-4 will put out more SPL given more power.

Two dual Lab 12 in ported cabinets half the size of the Keystone sub comes out to the about the same size and level as the single 18” Keystone, but uses twice the amplification.
Two dual Lab 12 have more LF output than the JBL SRX 728 and take up less space.
You could fit four of them in the space of one 12 Pi, and not get a hernia doing it.

As far as the reduction in distortion due to push pull, a brief look at the 12 Pi distortion compared to the Lab 12s in ported or TH cabinets shows that the 12 Pi has perhaps a bit more distortion than the normally mounted ported 12”, and a bit less than the normally mounted 12” in the TH.

As long as the Lab 12 is run below Xmax, distortion is not much of an issue no matter the configuration. The BC18SW115-4 will get a lot louder with less distortion than a pair of Lab 12s though.

Art Welter
 

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The LabHorn was designed to the requirements of the ProSoundLab members. In a stack of 6, it's great. In singles or duals it is useless. During it's first
year, Wayne spent his time bitching about how it didn't meet HIS requirements.

Don't build this design, neither the LabHorn or the 12Pi, in singles ... you won't be happy!!!
 
i heard a pair of EV MTL-4s the other night being used for a live band and loved them. More sound then my 4 peavey 118-HCs (double number drives acourse). how would the keystone sound running a Peavey lowrider 18? or maybe the 1801-8 in the 118-HCs.
Doubling drivers and power results in a six dB level increase, no mystery why eight 18s would sound louder than four.
EV MTL-4s get loud and punchy, but roll off steeply below 45 Hz, about 10 Hz higher than the Keystone.
If that low corner works for you, and you can afford all the cones, the MTL-4 design would be hard to beat, output vs. truck space.
However, LF extension always comes with either an increase in size or a loss in level.

I have not tried the Low rider 18 in the Keystone TH. From Hornresp simulations it looks OK, but is not close to the power handling and excursion capability of the BC18SW115. I'd expect it may "mush out" if driven hard in a TH.

Art
 
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which are? i've read this on here but i really don't know what they are.

i was looking for a driver around $200 a piece for this design. any suggests on the box other then that.
Truck boxes in the USA used to be limited to eight foot wide outside, resulting in a usual width of at least a full 90 inches wide inside. There are still many trucks with those dimensions in rental fleets, though semi trailers now are allowed 104" (IIRC) width.

Truck box integers for straight trucks in the USA therefore are 67.5, 45, 30, 22.5, 11.25 inches. Your cabinet design can easily be changed so at least two of the dimensions are truck box integers, making truck packing quick and neat.

As far as drivers go, you tend to get what you pay for. Since I have a small 5x8 trailer, I'd rather pay more for a high power, high excursion driver (the BC18SW115) than use two or more inexpensive drivers and twice the space to do the same job.

The Peavey Lowrider is a good value in the USA, as are many Eminence drivers.

Art
 
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the neo B & C drivers are going up in price as with all neo drivers. eminence does make a few good drivers so does Selenium. what other drivers would you suggest for your cabinet. i was also interested in the cubo 18 or maybe the cyclops cabinet. i also have a 5x8 trailer i use for now. i do plan to buy a new bigger one because i haul all the equipment including the guitar amps and drums.
 
anyone build one? i've seen all the information on it and he sent me the plans yesterday. i am considering, but the box is huge. seems moving them wouldn't be too bad with the grab handle and wheels. the band i play will be doing some outdoor shows this summer, but i think i could use these inside also. anyone hear this cabinet in person? however not much bigger then the dual 18 manifold i was trying to design. i am an engineer at a wood working company so building them wouldn't be an issue. i have access to cnc machining.

My TH-mini clone is one of the best sounding subs I've ever heard, and it's so small you can lift it with one hand. I'll admit that the lab sub has awesome power handling and output, but it sure is cumbersome and difficult to build. You can clone a mini for about $150 a cabinet, if you're willing to use Eminence or one of the inexpensive B&C neo drivers frm PE
 
My TH-mini clone is one of the best sounding subs I've ever heard, and it's so small you can lift it with one hand. I'll admit that the lab sub has awesome power handling and output, but it sure is cumbersome and difficult to build. You can clone a mini for about $150 a cabinet, if you're willing to use Eminence or one of the inexpensive B&C neo drivers frm PE

i'm interested. you have a link to your design. i have been reading a researching different cabinets for years now. i have the resources to build, but never found a design i wanted to produce. most designs used drivers that were hard to find in the US.
 
i really want to build something that will give me more output then the commercially sold subs here in the US.

Easy (relatively speaking) enough to do. You start with a bigger trailer. Eight lab horns will produce an incredible amout of bass - low bass - if you *can* afford the space. I don't think you could do better for the $5k (600 per cab, finished) you'd spend building them. You'd have to have an equivalent volume of 2x18's - with high end B&C drivers and 4x the power - to get the same output. When I thought about how much THAT would cost it was a no-brainer. They do roll around quite well -once you get them tipped up on their casters.

I agree with Welter and Don - in singles they have a horrible bonky nasal sound when used in singles. So don't even try it. That's par for the course with all front loaders if the total mouth area is too small. BFM horns included. It really does completely change things in a proper stack.
 
Art, are there detailed drawings of your keystone THs using Eminence drivers, in some thread that I have missed so far? Thanks.
Samuel,

No detailed drawings, but plenty of detailed information:
http://www.diyaudio.com/forums/subwoofers/185588-keystone-sub-using-18-15-12-inch-speakers.html

Detailed plans for the 2xLab 12" are here:
FREE SUB PLAN: Dual Lab12 (Front Loaded) by Welter Systems

A pair of the dual Lab 12 are the same size as the Keystone sub, they put out slightly more LF, the Keystone more above 50 Hz or so.

Art
 
There is a lot of information at the link below, acoustic measurements, thermal test results, Hornresp models, etc.

For home hifi use, or any other small venue, I'd probably go with a direct radiating sub like my three Pi sub, which is a 4ft3 bass-reflex box tuned to 20Hz. It's smaller and so can be more easily be used in a multisub configuration. It provides adequate output for small rooms, especially when used in multiples. However, the output of a hornsub is significantly higher than a direct radiator, so for larger venues or outdoors, the 12Pi hornsub is ideal. It is large, but the coasters make it easy to load in and out trucks with ramps.
 
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