Originally Posted by MBentz
I think it's a perfect thread for this if you're really trying to one up the QSC horn instead of just ripping it off...
Have you even quantified what it is you don't like? It seems like such a foreign concept to the DIY world...
Is off topic. This is about getting a QSC waveguide source and the secondary discussion is about designs a better waveguide. None of that has to do with any projects I have going, I have a thread on that topic that had enough discussion already.
Lets try to keep a little bit on the topic of finding new DIY waveguides.
I've spent more than enough time and more than enough of other people's money researching this topic. But all that is completely irrelevant, let's discuss data.
Why not post a link to the specific data you're referring to on HOM propaganda? If you're just gonna refer to an entire thread, then yes, I disagree with Geddes and don't consider his overall approach to be at all scientific, nor do I find his conclusions grounded in logic. And my opinion is more than willing to change if the right data is presented, but it just doesn't exist.
Its cool to disagree with him but you have no more data then he does so again its just subjective opinion back and forth. I argued about the fact that HOMs are hard to measure a long time ago but I also on his side about most horns sounding like crap so there is something there and his work has pushed waveguides into the DIY home audio discussions.
It loses pattern control below 900Hz because it's not large enough and above ~3kHz, even after normalizing to the on-axis response, it just barely starts to beam...likely due to the shallower profile on the dust cap and the cone breakup just above 3kHz. There are certainly 15" drivers out there that beam, but it has nothing to do with the fact that it is a 15" driver. It has to do with the shape of the cone and dust cap. In this case, the dust cap can act like a phase plug and the diaphragm behaves like a straight-walled horn.
I never considered calling the 360 deg directivity a lost of control, very interesting that you would post "Loses pattern control below 900Hz" when I think its 100% constant directivity.
YOu and I also have a different definition of beaming because beaming starts before -10dB down, its closer to -6dB around 45 deg. at that means the 15PR400 is beaming above 1KHz. Do you have some links to that define beaming for you?
I do own the Faitalpro 12PR300 measured by Augerpro, found herehttp://sites.google.com/site/driverv...talpro-12pr300
I know it beams around 1500Hz, again its all about the size of the woofer and its impossible for a 15" not to beam before 2KHz.
I'll get to the tractrix horn polar stuff later this week at the soonest, but more likely sometime next week.
Thanks! That would be cool. I have always been interested in the Tractrix horns.