Electro-Voice ST350A horn removal

[charlie2]

Can the horn/waveguide be removed on a electro voice st350a compression driver and a diy synergy style one used instead anyone have any experience

 

[AllenB]

There seem to be four bolts holding it on.

 

[ICG]

While technically you can, you won't have much fun building a fitting adapter. It looks like this. The EV horn is sought for restauration but they are medicore at best. It's much more promising to sell them and buy better, modern drivers.

 

[AllenB]

ICG, that's the inside of the compression driver.

 

[ICG]

ICG, that's the inside of the compression driver.

Yes, exactly. The horn is attached by screws, like you already said. On the picture you can see the output slots of the pressure chamber. I posted the picture so you can see it only got one ring exit (unlike even cheap newer drivers), having because of the runtime difference of the sound already interferences within the driver, one of the reasons why it's medicore. That makes it very difficult to get an even response and dispersion and it's combination with other horns are critical. On top of that, the phase correction element is continued in the horn, making an adaptation very difficult because you'd have to rebuild that too and if you do, you can't fit other drivers to it. Back then a lot of ppl tried/used the driver with a different horn and complained of the bad sound. That's one of the reasons why they used a square non-standard mount on the ST350B.

Aside from that, the driver has to be crossed over quite high and got a very low power rating (5W rms), making it not a good choice for such projects. Back then they had tons of defect diaphragms, so many they even had to add an extra paragraph about the power and handling to the data sheet of the newer models.

Pictures of the 350B and the phase plug in front of the protection mesh.

Do I really always have to write whole novels? ..