Not being very inventive I followed the pioneer's placing a divider large enough to cover the horn's HF response.
Yes, I have a couple of bi-radials with me (2370 & 2380) and that's the way they are. But, the 2370 needs only a simple hi-shelf filter to get flat, as it does some acoustic equalisation as well.
https://www.lansingheritage.org/html/jbl/specs/pro-comp/2370.htm
Yes, and one of those reasons would be the absence of a diffraction slot.
Or a coaxial compression driver with annular diaphragms like the BMSes.
Yes! Today I'd use one of the coax CDs, but I did mine in the early '70s, so not even a pipe dream.
That's very interesting! Can the diffraction slot torment be removed?
I'm very curious about them now, but I bet shipping would be insane.
The only thing is I kind of want that decent vertical dispersion for when I'm laying down in the couch or because my kids will sit and eat on the floor during a movie or whatever, way off axis. But they could be worth a try, maybe the 2370 lens like you mentioned.
This $69 phenolic driver was considered as good (really better) than a K55V at the
Klipsch Technical - mod forum.
https://prvaudio.com/products/d2200ph/
There's some plastic horns at e-bay which were considered to be ok with the PRV.
Look - here:
https://community.klipsch.com/index.php?/topic/205246-a55g-vs-a55g2-vs-prv-d2200ph/
Back at my house (I'm dealing with decades of immobility + health issues) are a of Tom's prototype Unity horn - one w/o xover. I've not been there to visit for a year and dunno what might be moved around or ditched.
A horn on top of a Karlson box can be better than 1-15 reflex with horn.
Peavey FH1 are basically the same as LS/Belle. but better braced and much cheaper. For what little iits worth I prefer Karlson to short path W bin.
John Inlow;s 135Hz 8pe21 horn might make a cool little system - maybe cover the sins of a direct radiator woofer below (?)
Klipsch Technical - mod forum.
https://prvaudio.com/products/d2200ph/
There's some plastic horns at e-bay which were considered to be ok with the PRV.
Look - here:
https://community.klipsch.com/index.php?/topic/205246-a55g-vs-a55g2-vs-prv-d2200ph/
Back at my house (I'm dealing with decades of immobility + health issues) are a of Tom's prototype Unity horn - one w/o xover. I've not been there to visit for a year and dunno what might be moved around or ditched.
A horn on top of a Karlson box can be better than 1-15 reflex with horn.
Peavey FH1 are basically the same as LS/Belle. but better braced and much cheaper. For what little iits worth I prefer Karlson to short path W bin.
John Inlow;s 135Hz 8pe21 horn might make a cool little system - maybe cover the sins of a direct radiator woofer below (?)
Hello Lee
Don't be prejudiced by diffraction slots. Not all horns that use them are the same. Some sound quite good and the issue with HOM's is proportional to level. So depending on which horn and how loud you listen it can simply end up not being an issue. If you can have a listen and make your own decision,
Rob 🙂
No, that's what makes the horn perform well across the horizontal plane. However, there's no need to get worried over diffraction slots, just like Robh3606 has said above.
But there're other 1 inch horns without slots like 2373, 2374 etc.
You could save some shipping costs if you locate a pair of original CD+horn from the same seller, at some driveable distance for direct pickup. I say this since you're in USA where original JBLs sell a lot. Alternatively, try to locate a pair of 4671.
Please note the following before getting the 2370 horn.
The horns small vertical mouth dimension was chosen to allow a gradual narrowing of the vertical coverage pattern with increasing frequency. This provides acoustic equalization of the frequency response of the horn in the horizontal plane and compensates for the falling power response of all compression drivers. Should constant vertical pattern control be required, two or more 2370As may be stacked to restore full Bi-Radial performance.
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Lol, I wrote that response on my phone... the word "torment" was not supposed to be there at all, that's hilarious. That's phone typing for you. There were a number of other typos in a few posts - if you see one, that's the reason!
Do you think protective screens, like those that cover many compression drivers, or like the ones in the throat of my horns, can offer improvements if removed? I imagine it may vary from case to case, but I did read some reviews of one CD where it was claimed that removing the screen was helpful. I could figure out some tool to shove in my throats to cut out the screens and maybe file away any of the edges that remain. IDK if they add any additional physical impedance helping load the driver lower or not, or if they are truly acoustically transparent, or if they cause some diffraction or internal reflections (beyond what's inherent in an abruptly ending exponential horn).
Hello Lee
That is funny!!!! Auto correct strikes again!!!! Removing screens???? Might have to give it a try??? I never have and with some drivers I wouldn't even attempt it because the screen is in a ring that is pressed into the throat like the JBL 2426 as an example.
That said the JBL 1.5 drivers have their screens under the rubber gasket you can easily peel up and replace. In that situation you could try.
Here are a couple of pictures on the 2435 1.5 inch CD screen on and off. It's a risk with no screens so???
Also with HOM concerns have to wonder just how much energy is reflected back into the phase plug from the screen??
Rob 🙂
That is funny!!!! Auto correct strikes again!!!! Removing screens???? Might have to give it a try??? I never have and with some drivers I wouldn't even attempt it because the screen is in a ring that is pressed into the throat like the JBL 2426 as an example.
That said the JBL 1.5 drivers have their screens under the rubber gasket you can easily peel up and replace. In that situation you could try.
Here are a couple of pictures on the 2435 1.5 inch CD screen on and off. It's a risk with no screens so???
Also with HOM concerns have to wonder just how much energy is reflected back into the phase plug from the screen??
Rob 🙂
