60 Degree DIY Mid Hi - AKA PM60

Honestly I've never liked Hennessey's work, and this is no exception. Nice horn flare, but this imitation kind of misses the point of Peter's design. that's okay, though. I'm sure it's like 8 grand for a box that doesn't have a pole mount and doesn't play down to a reasonable crossover point. Seriously - their own subwoofers don't go up to 200Hz; what are they on?

Just another reason to never recommend them. It's a shame; I like their craftsmanship very much otherwise.
 
Marjan Milosevic said:
How is the Henessy design even remotely similar to the PM60? Beside the fact that is it a MTM horn loaded design, there are several significant diffrences.
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To be fair, you have a point. It is very different. It's not why I'm displeased, though. If you look back on their Facebook page at some of their posts while developing them, their target crossover, efficiency, and all of their components clearly started from Peter Morris's design. It's ended up being the same efficiency, having an arguably worse crossover frequency, heavier, without a pole mount, larger, and in my opinion uglier. It's just not in the spirit of what Peter created and posted, and they've clearly taken his component selection and pass band intuition without giving what I'd say is an appropriate nod. The only thing I like about them is that they are, in fact, trapezoidal, and that their larger horizontal horn mouth means that they will maintain their directivity about an octave lower than the traditional PM60 design.
 
Max Warasila said:
To be fair, you have a point. It is very different. It's not why I'm displeased, though. If you look back on their Facebook page at some of their posts while developing them, their target crossover, efficiency, and all of their components clearly started from Peter Morris's design. It's ended up being the same efficiency, having an arguably worse crossover frequency, heavier, without a pole mount, larger, and in my opinion uglier. It's just not in the spirit of what Peter created and posted, and they've clearly taken his component selection and pass band intuition without giving what I'd say is an appropriate nod. The only thing I like about them is that they are, in fact, trapezoidal, and that their larger horizontal horn mouth means that they will maintain their directivity about an octave lower than the traditional PM60 design.
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Peters design is not the first box ever made with similar performance. OHM HDMH box is like 15 years old at least. Our M28LA line array box was released in February 2014. Check this topic starting date.
If you use that analogy, every reflex box ever made is a copy? And they should all be pretty much same? But they are not. :)
 
To me it looks like there are some ideas that MAY have come from the PM90/60, IF they did I'm happy to take it as a compliment :)

The thing that is unique with my design is the amount of SPL and quality you can get out of a speaker on a pole. If it didn’t need to be pole mounted a lot of the design compromises would change, you wouldn’t need a bend the horn, it could be longer and wider at the mouth etc. and you would probably end up with something more like the OHM design that Marjan mentioned.

Using Lake processing the PM90/60 can achieve –
  • A very flat frequency response from 100Hz up to 18KHz (Note: its difficult to maintain efficiency and get the response to go that low in a small box, operating above 160Hz and achiving efficency in a box of this size is much much easier)
  • An almost perfect flat phase response over the entire vocal region
  • Excellent pattern control for what is a relatively small box
  • Stunning impulse response and waterfall plots with every driver operating in its piston range.
  • And it will even reproduce a 500Hz square wave on and off both axis - very few speakers can do that.
 
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Marjan Milosevic said:
Peters design is not the first box ever made with similar performance. OHM HDMH box is like 15 years old at least. Our M28LA line array box was released in February 2014. Check this topic starting date.
If you use that analogy, every reflex box ever made is a copy? And they should all be pretty much same? But they are not. :)
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There's a clear difference between using the same overall design and using the exact same drivers, horn, and target crossover frequency. If I go and build something using the same drivers as the SB28, in the same overall alignment as the SB28, with the same initial SPL and passband targets as the SB28, but then end up with a different port shape and a deeper cabinet, but otherwise largely the same cabinet, the design is clearly an iteration on the existing design. I don't necessarily mind this. I just mind that when asked about it, they claim it is a different design and only admit that it uses the same RCF horn, when it is clearly an iteration on the design choices Peter made and they've made multiple posts that show that they took inspiration from the PM60, and they put the same drivers on the spec sheet. It's just disingenuous.
 
Funny enough I believe Sean Hennessy was apart of the initial post and discussions. That box was made after Peter's initial DIY90 post.
Still a great design thanks Peter for being willing to share to the masses...
 
Thanks!

When I was building subs and kicks I'm glad that I didn't make "handle compromise", but in this case I think it's fine. In most cases I stack system with a friend :)
 
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