Wow, You have a lot more experience with Velodyne than I do. It sounds like I should have gotten the plus models. I didn't know they made subs as far back as the late 60's. I pretty much grew up in radio stations and recording studios as a kid. It is probably where I got this bug in the first place. I got my first Velodyne in the early nineties. Up until recently they were my favourite sub. I did burn through an amp with both one HGS as well as one of the DD's (I cannot remember which ones). At the time I lived in So Cal so sending them to San Jose wasn't a big deal. Now, I am not sure where they are working out of. I also have not been able to listen to any of their newer versions.
I really liked the JL's, but they didn't dig as deep as either the Velodynes, nor the SVS. Granted, I had the version 1's of the '112' ( I think that is what they were called).
At the moment, in the California house we have all SVS - pair of SB16 ultras, which are really a fun sub, although not as accurate as the Velodynes or the Dynaudio. also have an SB 14, and an Sb 12 pro. The 12 is my least favourite of those. Just not in the same league as the others. I also have a 3000 micro in my home office in London which is about to be replaced by the Dyn 18S I was testing.
All of this being said, the Dyn sub really surprised me. I had previously watched the above linked video from the garage guy, and then the video from Absolute Sound. I got the 18S and cannot un-ring the bell. It was like getting a better version of my Velodyne's. I haven't heard the Plus version of the DD but I am sure they sound amazing. Also, I tried the Dyn primarily due to the fact that SVS are double the price here in the UK as they are in the US. I am glad I did. it is the best sounding sub I have heard to this point. Very pleasantly surprised.
Thanks for writing your experience with subs. You have a lot more than I and it brought back some very nice memories.
Cheers!
Ken