I'm still new to all of this so take what I'm saying with a grain of salt. As with these speakers evolution I expect my tastes will continue to evolve.

In May 2025 I completed a Zkit1 (if you want to see the build check the Zit1  forum.) Then tried it with the speakers I had Klipsch RP-600M MKII and 70's Vintage Kenwood LS403As. As predicted I still preferred the Vintage speakers (Re-foamed and Solen Capped), perhaps I have poor taste in speakers.

After hearing some full range drivers (my best guess is Foster) in a coffee shop in Tokyo i decided that full range drivers should be on my audiophile credentials punch card. What I proceeded to build IMO is not a good representation of what the type of speaker is capable of, but its a part of my journey none the less. I plan to try other drivers in this arrangement but consider (for my listening preferences) the initial attempt a failure.

I put my partner in this project, ChatGPT, on finding possible options that would be efficient enough to work with my amp. After many hours I settled on building a set of Frugelhorn XL cabinets that would utilize Fostex drivers (FE206NV2). Because of tariffs these drivers became a financial liability so I cancelled my order with Solen Canada (I hope to do business with them in the future) and switched to Dayton PS180-8 6.5" drivers from Parts Express. I chose to change the front baffle design to a swappable design (foreshadowing I'm glad I did.)
This is just part one of my journey. The potential in the single full-range driver is still in the air as far as I'm concerned. And spoiler i was very happy with these for some genres of music (and get why some people like them) they just didn't do justice to all of the genres I like to listen to (I like a wide variety of music.) Anyways here's some pics from the process of building FrugelHorn XL version 1.

Thank you for the encouragement! I intend to do just that... reiterate and refine. I'm intrigued by this grout sponge idea. I'll be keeping that one in my back pocket as I continue what is now a full blown addiction.