PA Horn Sub Design

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Here is a PA horn sub I designed and built, measured 142db at 1 meter with a 500 watt Driver. Good response from 32hz-300hz. Will work with about any driver with a mid to low Vas. though specifically designed for the MCM-1875 18" driver. It is a huge semi complex design, but 4 of these will cave your chest in. Feel free to use if you like. I also am looking for the EAW LA-400 design for reference or any PA application horn/manifold loaded subs not found on the net. I have the CV SL-36 design for trade.

Pulse Sub Horn 1

Good to have another "hornie" around here.

Thanks for posting your design. It looks interesting, especially with such an affordable driver as the MCM. I wonder how it would go with some of the Eminence designs which are available in Australia.....I need some smaller basshorns and I had been thinking along similar lines to yours, but taller, with the throat starting near the centre and following a snail path via the front and top. So far its only a thought excercise.

Have you measured the response, or do you have simulations from AJHorn or Hornresp you could post?

What would you consider as a trade for the SL-36? I used to have it but it was not backed up when a virus crashed my HD.

The Sigma 18 by eminence should work well, though I would halve to calculate out the response and parameters. I have tried the design with several drivers (nwx-18100, EVX-18) all yeilding similar results. I think the MCM sounds better than the EV at a Fraction of the cost. I hand calculate everything using my db meter and osciliscope. If you have some good modeling software for horns please educate me. Trial and error gets expensive. I will e-mail you the SL-36 design if you send me your e-mail. I just don't want to publicly post it, copywrited and all. I have a 15" design as well that uses the EV BX15. it is a small horn for a 15 overall dimensions is 18"wide X 24" Deep X 30" tall or round abouts. I will have to search for it and post it. I designed them for a buddy who DJ's outdoor school functions and dances. he uses 4 of them @ 1600 watts and they pound.

Also I have foung that you by using a more smooth transition through the horn (snail like) you essentially are tuning out the the higher 150-300 HZ range. By creating sharper turns you are reflecting the higher wavelengths through the horn instead of losing them on the smooth transition.
Horn software

First place to look is
where there is a lot of general horn info, especially for the DIY types, including hyperbolic/exponential and tractrix calculator applets. There is also a hobbyist forum with a few horn guys, and lots into single fullrange drivers.

A free and excellent horn simulator can be found at

AJHorn is a program I have heard good things about, but have yet to use. I might spring the $100 for it soon, as it will do all sorts of boxes and xovers too.

Another simulator that can do horns is SPEAK, but I know nothing about it.

Jeff Robinson's site has lots of designs, many of which were optimised using Hornresp. These are mainly sound reinforcement designs. Plenty to think about there anyway.

Sound Practices magazine has an Altec area that contains lots of info on thier theatre and PA designs as well as a heap of cabinet plans.

AudioAsylum has a specialist High Efficiency speaker forum with a lot of people there who are very experienced and knowledgable about horn systems, such as and djk who also posts here. Mainly directed towards 'philes but much of the info can be applied to PA, as a lot of the gear people there use is pro gear.

Another forum there is the Pi speaker forum. Wayne Parnham has developed a lot of easy to build designs, from bookshelves to huge PA gear. I beleive the plans are available for the emailling and requesting of them.

That should keep you busy for a while. I have tons more horn info if you need it.

I Measured 142db with the MCM-1875 driver using a crown K2 amplifier. I was running a tr-909 kickdrum pattern peaking it at 142db at waist level. I built 4 of the cabinets and running 2500 watts at 5 meters I read 136db peak on the spl meter. I think it is pretty respectable considering these cabinents can be built for under $200 a piece. Where as a retail cabinet of similar quality would run upwards of $1200. My goal is to provide low cost solutions to a way overpriced industry. I am currently working on a direct radiating dual 18" speaker with a peak spl of 141db @ 40hz. This cabinet will also use low cost drivers, I am testing with the NWX-18100's right now. Using WinISD it shows that it is possible but, I have not been able to measure it in real life I am playing with box shape now and I think it can be done.
Have any of you seen the horn subwoofer design project being hosted by prosoundweb? There are some serious heavyweights from the pro sound speaker building business involved.

This project is for mid to large venue concert work so you may not want to build the exact cab they are designing (plan is to get best results from having a stack of 6 cabs per side), but they are getting into the nityy gritty of what makes horn subs work. Cool stuff.


Thanks for the link. I have looked at the TS parameters of the MCM 18" (55-1875) driver. Everything look good. But X-max is 4.4mm/0.17" as opposed to nearly 1" for the EVX180. I wonder if the MCM would be able to operate at near full load for extended periods of time without mechanical damage or at the least non-linear operation. What was your experience with this driver, particularly because you have stated that the MCM sounded better than the EVX180?


Thanks for the link. I have checked out the TS parameters of the MCM18" driver (55-1875) and it looks good. However, x-max is only 4.4mm/0.17" as opposed to nearly an inch for the EVX180. Would full load operation cause mechanical damage or at the least non-linear operation? What is your experience with this driver particularly since you have stated that the MCM sounded better than the EVX?


Yes, I have beat on them rather hard, I run 4 cabs at 2500 watts which is well above the rated power. I have not had any failures yet. I imagine I will have to replace drivers eventually. My statement may have been a little misleading. I thought the MCM sounded just as good as the EVX, but B/C of the EVX's cost the MCM was better for my application. No doubt the EVX,RCF, JBL, ect drivers will have a much longer life. The cost of those drivers are just outrageous though. I am now looking at the NWX line of drivers they are manufactured by Nippon. They seem to have good characteristics for a high SPL direct radiating application, but I haven't tried them in a horn yet. I believe that has the specs on the nwx-18100's. If you buy them in lots of 100 direct from Nippon they are only $56.00 each.

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