No, I'm not selling my Oy speakers and building something else. It just feels like I have new speakers again.
I'll start the story from beginning, instead of starting in the middle, going towards the end and then finishing with the beginning as I did on diyaudio.com earlier today.
I have always had a feeling there's something wrong with the speakers. Very bass-shy and diffuse soundstage. And on the first days when I was turning the speakers against eachother with a ~2cm gap in between and connecting them out of phase I still had a decent output when playing 20Hz sine waves. Not loud, but it was enough to disturb people around the house. But I didn't care more about that. I was just thinking they were bass-shy because they needed more burn in time.
Back to present time. While cleaning my room last friday I found a bag with sealing gaskets. They were supposed to be around the driver and terminal cutouts. So today I had some spare time so I assembled a table to work on and I opened up speaker number one, the one with the damaged baffle. Everything was fine, all cables connected as they should be. But on speaker number two I found the problem. The upper woofer was wired out of phase. Apparently I was in such a hurry to get them up and running so I didn't have time to double check the polarity. So I added the sealing gaskets, mounted the drivers and double-checked the polarity and WOW what a difference!
In theory I should have twice as much bass now than before, and boy I do! I can feel it easily in my chest even at lower volumes. Before I had been playing them without any damping material in the ports, but now I put in all of it and I'm almost thinking of adding some more to further attenuate the bass.
Another thing is the soundstage which got improved a lot. Now it's possible to hear where the musicians are on the stage and it's just wider, deeper and larger in general.
And here's some pictures of the sealing gaskets