Surprisingly good little speakers. My application is probably somewhat unique, as I used them for outdoor patio speakers installed in some old, gutted Cambridge Soundworks Ensemble II satellites. I removed the old paper cone drivers, plugged up the tweeter opening with plywood cut to fit, sanded and painted them. These 4" RF Primes dropped right into the woofer mount, although I did have to re-drill a few screw holes as they did not line up perfectly. Salvaged some old speaker brackets and mounted these under the eaves outside, out of the direct weather. With the rubber surround and plastic cone I expect these should do well in this application.

The most important thing is the sound, ofcourse. They are not going to blow you out with high volume or extended bass response, but for what they are they sound really good. I was using a set of small, full-range speakers before this and the RF two-ways have a much punchier sound with nice, crisp highs. Very clear and they go plenty loud for entertaining - perfect little patio speakers. The only caveat is that they are 4 ohm drivers, which is exactly what I wanted for my application (my amp is fine with it), but you should probably make sure your home amplifier is capable of driving a low impedance load before trying a project like this.

This 4 inch speaker does fit in my 2019 BRZ's dash. The dash has a stock 4 inch and a stock tweeter. I took out the stock 4 inch speaker and added this Rockford Fosgate 4 inch speaker. It takes a bit of DIY but you can get it to work. I tapped into the factory speaker wires and connected that to the speaker terminals with the cables provided by Rockford Fosgate. Putting the speaker in place, there is enough clearance for these to fit, you just have to use a razer blade or something sharp to cut away a little bit of the plastic inside where the speaker sits on the dash, you can see where the rockford fosgate speaker hits the plastic, so just cut that little bit away and then it rests in there easily. I didn't bolt mine back in since the stock bolts are a bit too big for these holes but its in there solid enough, you could zip tie it in there too but its just fine sitting there with the cover over it.

These speakers are amazing! I upgraded the speakers in my 2022 Ford Bronco and couldn't have asked for a better product. The clarity was crystal clear and the install was super easy. I've already bought another set for my floor speakers.

Installed in Vetter 1000/1100 goldwing kit (these were mounted to Hondaline/Vetter fairings above the bars on bikes without factory sound system) speakers were bad, these fit the speaker pods, grill covers were nicer than the ones I had so I used the grill and the speaker. Sounded good. Highly visible install, front and center above the bars, speakers looked good too. I don't have the box nearby so I don't remember if these were USA or imported manufacturer.

Later I got rained on and the casette radio died. Had to cut away a square opening for the new style receiver the Vetter speaker pods used the volume-knob-mounted style receiver. Had USB music stick plugged in the new receiver and speakers kept on rockin louder than ever. and still had clear sound after soaked in the rain.

Edit:I added some foam tape to these to seal the back side and they sound much,much better. Still annoyed they didn't at least come with a purpose built foam gasket to go on either front or back to work with various mounting positions.
Here's what I bought: https://www.amazon.com/gp/product/B004MSMFNG/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

Old review:
"Not impressed so far, lots of rattling and less bass than my 1989 corolla stock speakers on the same pioneer head unit.
I have a feeling the fact that these don't have a seal on the back side is part of it. I have ordered a seal to fill the gap between the speaker and the box they mount to. If that helps fix the issue, great. I'll update the review. But right now, they're not performing."