JBL's best systems like K2-S9800 (and Project May, of course) use constant directivity horns. I've seen many members use biradials successfully in their DIY projects in lieu of exponentials. However, it still narrows with increasing frequency, since no additional high-frequency energy is provided in the first place. I recall from the literature that the pattern is typically something like 140° X 60°, but don't hold me to that until we find the reference. The lenses on the front of exponential horns function to spread or disperse the conical beam they produce. Constant directivity horns and waveguides, on the other hand, put out a controlled-width sound field of essentially constant amplitude at all frequencies within the operating range. (JBL is also using PT's with cone drivers, but that's not the subject here.)Įxponentials do that compensation "automatically" by progressively narrowing the beamwidth at higher frequencies.
#Tractrix horn vs exponential horn drivers
They require equalization, usually built into the crossover, to compensate for the power response characteristics of compression drivers they're typically used with. PT waveguides are constant directivity like biradials, both decidedly different animals from exponentials. They're cheap, and if you don't like them, it's very likely another member will buy yours to try out. Thus, there's no consensus about anything relating to them, and I'd like folks not to take my word alone, rather, that they try them for themselves. I like the PT's personally, and as you have seen, have committed to using them in some of my "upgrades" here.īut, I'm about the only member who's actually used them extensively and reported on them here. That's the advice I'm giving everyone right now. You might want to spring for the $100 for one of those and a throat adapter (if you're not gonna use 2431H or 2435H as your driver) and try it. The PT-H95HF square version is available, tho. It's certainly the main one I want to compare with the PT-F1010's (100° X 100°) I've been using. I've got some on order, but they show no inventory, ever. To the best of my knowledge, JBL has only made protypes of the PT-F in the 90° X 50° pattern.
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