But how significant are the differences between "Mk"s with Hsu.....should they simply have different model designations with changes in amp/driver/box?
From what I have read of the reviews (if I remember correctly, I have read a bunch of different reviews) the VTF3 MK5 out paces the VT 15H Mk1, quite easily. So the differences are not subtle, it can be read through in the preview that Audioholics did.
I have a lot of data for the VTF-15h mk2, but I never published it. Now that I think about it, I should add it to the bassaholics spreadsheet. We never ran a full review on the VTF-3 mk5 or the VTF-15h mk2. I wasn't a writer for Audioholics at that point in time.
One thing that isn't quite reflected in that sheet is just how smoothly the Monolith 15" handles deep bass. It handles deep bass more smoothly at its limits than the Hsu or SVS subs. You can hear that the Hsu and SVS subs are a bit more stressed when pushed hard at the low end, even for the same SPL.
I think the numbers from the Hsu subs are taken from Hsu's website. Hsu actually tends to be a tad conservative in their reportage of CEA-2010. I think I was able to get a bit more out of the VTF-15h mk2 that I tested, but not a whole lot more. I would have to go back to look at my data. It wouldn't change the overall story told by your numbers very much. The story is that the PB-3000 and VTF-15h mk2 are pretty much even at 30Hz and above. The VTF15h and Monolith 15" have a bit more extension and can dig down to 16Hz whereas the PB-3000 is not that happy at 16Hz. When pushed hard, the Monolith 15" has more finesse at 25Hz and below.
One thing to consider is how easy it is to handle these subs. The Monolith 15" is a major pain to try to move around, another world compared to the VTF-15h and PB-3000. You have to take the logistics of moving it seriously. It is pretty difficult to handle, even with two people lifting. If you are moving it up or down a flight of stairs, you need a dolly that can handle that- you are not going to be able to handle that without a dolly or shoulder strap, even with two people. The PB-3000 is a total piece of cake to move around for a sub of its performance. I can carry it up and down the stairs by myself, and I am hardly a powerlifter. The VTF-15h mk2 is kind of in between. You will need two people to lift it since it's big, but it's not a chore to do that when you do have two people, it's pretty easy. When you have it in room, it's easy to walk into place.
Yes I believe what I saw is, you guys extrapolated the numbers taken from the HSU @ 1m, I think reducing 9db to compensate for 2m readings.
I feel like, even if the VTF 3 MK5 has
some extension in the 12.5Hz range, I'll pull the trigger on that, the room gain and and a 2nd sub will take care of my room really well in most cases I think especially for costing close to ~$1950 for a pair. If I head to the next step ~$1200, I feel the Monolith is the ultimate champ for that price range. Ridiculously good performance. If it had gone on sale the last few days, I'd already pulled the trigger, If I can't settle for the VTF 3, then I'll very likely stick with the Monolith.
I do actually have my in laws dolly, we just moved into this house last month, and I can bring it to my basement from outside with a friends help. Once I do the crawl, I don't know when I'll move it, I guess it will be like a piece of furniture.
The PBS-3000 is such a good sub, but that roll off below 16hz, and the lack of a single closed port option, lets it down in pure performance.
I called HSU today and they don't have the numbers below 16hz for any subs. I have tried looking online with no success so far.