Goldwood GT-800PB 1" Horn 1-3/8"-18 TPI

The threads are not cut correctly. A typical American made driver (Eminance, EV, ect.) will get tight half way in. I suppose an equally badly cut driver might fit nicely. I had a few cheapies around that did fit. Also the threads are significantly longer (deeper) than normal. Some drivers that seemed to thread in alright didn't seat the nose of the driver into the throat of the horn but rather bottomed on the outside, leaving a short gap of larger diameter inside the horn. This will cause a frequency response divot.

Description says it's 18 TPI, however does not work with eminence drivers that are 18 TPI. Choose a different comparable horn.

My opinion of this unit is the same as everybody else's, and it's a very good choice for hf long throw after 1600Hz, or a front fill. The edge of this thing DOES fall off like a stone after 40 degrees horizontal off axis, however. For a mains application in a small box you may want to purchase a wider bi- radial instead, and get out the dagger saw.
My application was to replace some hf units in a pair of karaokes, and this design got me 1.5 dB MORE out of the system before the performers got mic feedback, all else remaining constant.