Review on 🔊 Road Kill RKFR69 Foam Speaker Enhancer System Kit - Optimal for 6x9 Drivers by Daniel Bruce

I have just finished installing the product after watching a whole bunch of YouTube videos on how to do it right. Here's what I learned from that experience. :one. Sound engineering, speakers sound louder. (funnel effect) 2. Is the back ring very thin? Road Kill (RKFR69) please correct the rear ring thickness, it is not suitable for 6X9.3. The front ring fits perfectly, properly covering the entire adopter and directing the sound into the door grille. + for that!4. Now I had to cut a groove for the back "thick foam" so it could fit flat on the door.5. Now to the most important aspect! "Improving the sound quality". This reduces the resonance (void) of the door and absorbs some of the return wave) through the foam of the back panel. Not a big improvement as I've already soundproofed my doors. I would give it 5 stars but because the back ring is thin I give it 4. Note: ( I paid $20, I think it's too much money for the foam, it shouldn't be more than $10-13 be)