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Re: 12pi bass horn plans [message #64138 is a reply to message #64137]

Wed, 29 September 2010 07:28

Wayne Parham
Messages: 18786
Registered: January 2001

Illuminati (33rd Degree)

We do not make our plans available in DXF format. However, we do make flat pack kits that have precision CNC cut baltic birch parts with dado joints. The PDF plans distributed are really intended for hobbyists that want to build a single unit or small number for their own personal use. They are for the person that would cut to fit, using hand tools, like I did the prototype:

12π prototype construction

When we worked towards making the basshorn "productionizable", we did a lot of streamlining of things like cut angles and part sizes. The goal was to make as many things as possible the same, so cuts could be done without needing to change tools or setup. This, of course, required reverification and testing, both of the physical fit and of acoustic performance. So the point is there were many iterations before arriving at the current model.

12π production model construction

Since that time, we have had some people ask for our DXF drawing files and even our CNC files. One a few occasions, we allowed this. In those cases, the builders were planning to build a large number and buy the drivers, plugs and plates from us. They just wanted to cut their own parts instead of buying flat packs from us.

These outside shops that attempted their own CNC builds proved to be problematic in almost every case. My CNC programmer warned me that even if we give them our files, they would have to still do their own tool pathing and things like that. He was concerned that the operators can't just plug and go, it is still largely a procedural thing. This proved to be true. In each case, the builders had problems and probably should have just gone with our flat pack kits. To make matters worse, they tried to do all of them at once (repeating their mistakes each time) instead of doing one first and working out the kinks. In the end, it would have been less trouble and lower cost because they wouldn't have to rework things.

So now we will not give out DXF files. Instead, I encourage builders to use our flat pack kits if building more than a couple hornsubs.

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Re: 12pi bass horn plans [message #64205 is a reply to message #63735]

Wed, 06 October 2010 14:05

realaudioent
Messages: 1
Registered: October 2010
Location: Texas

Esquire

This is an interesting design. Please send me plans.

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Re: 12pi bass horn plans [message #64207 is a reply to message #64205]

Wed, 06 October 2010 18:21

Wayne Parham
Messages: 18786
Registered: January 2001

Illuminati (33rd Degree)

I was recently awarded a patent on the cooling system used in this basshorn. I'm really proud of it - it brings three powerful technologies together to make what I think is the worlds best prosound subwoofer. 1. Horn loading reduces excursion and increases efficiency, so distortion is low and SPL is high. 2. Push-pull drive further reduces distortion, particularly at low frequencies where the horn begins to unload and can no longer damp the diaphragm(s). 3. Cooling plugs reduce motor temperatures, wicking away heat in the core.

Direct heating from induction and indirect heating from voice coil radiation and convection heat the motor core to temperatures high enough to cook on. Diaphragm motion is limited because of horn loading, which is a good thing, but it reduces the ability of the woofer to generate sufficient forced air convective cooling through the vent. The cooling plug approach helps remove heat from the motor core, augmenting the woofer' ability to cool itself. This is particularly important on horn loaded subwoofers, because the cooling vents are partially stalled due to horn loading.