Whoo boy...
Yeah, a situation like what poor hizzaah is faced with here is why forums like this one can occasionally be frustrating and do as much harm as good
You've had a few bits of bad advice given to you, and it's even more difficult because you're coming to this forum specifically to ask questions and gain knowledge, but you're faced with conflicting recommendations. To top it off, if you don't already know the answers, you can't tell who's giving the good advice and who's, unfortunately, giving some misinformation.
There are a lot of knowledgeable folks on this forum. And I'm actually amazed at how much we tend to agree more than disagree. Honestly, that's extremely rare. And I'm very happy to say that, the vast majority of the time, we're pretty respectful around here and a lot more in agreement than disagreement. The social environment here is the main reason I visit this forum more than any other
But sometimes, we do disagree. And sometimes, folks who are very knowledgeable still write some bad advice on certain topics. I'm as guilty of that as anyone else! I'm certainly not right all the time. I simply try to pass along the experiences and recommendations that I would like to receive if I were starting all over again, and I was looking for advice myself
Anyways, to be a little more specific:
we know what subwoofer you have. It is the HSU VTF-3 MK3. So we know it's got a 12" driver that's actually mounted on the side, and it stands on four round "feet". It is also a ported subwoofer, with options to run it with two ports open, one port open, or with the optional "turbo" attachment, which, by increasing the lengths of the ports, gives you the lower tuning of the one port open option combined with the higher output of the two ports open option.
There is no built-in option for plugging both ports though. And in EXTREME cases, where you are pushing the loudness of the subwoofer to its absolute maximum for extended periods of time, you really should not block both ports. The VTF-3 MK3 was not designed to run with both ports blocked. It was designed to be ported. And the switch on the back for 1 port or 2 ports changes the setting on the low end filter, which is there to protect the driver from bottoming out or overheating.
Now, in the real world, you're highly unlikely to run into any sort of physical or safety problem. You will almost certainly never have that subwoofer playing at it even near its maximum loudness capabilities. You will be damaging your hearing and experiencing pain well before that happens in any sort of normal room size in a house or apartment. But strictly speaking, just follow HSU's instructions. Do not block both ports. And set the switch on the back correctly.
As for the whole damping platform issue, I've said my piece, I'm not looking to argue about it, and the easiest thing by a country mile is to simply try it for yourself, and see if it helps.
The folks who are, for some odd reason, against even the concept of damping are way out to lunch, but it's pretty obvious that nothing is going to change their minds at this point. The floor is not vibrating the sub. That's ridiculous. Waves propagate through a medium, the medium itself does not travel - so calculating mass has nothing to do with the propagation of a wave. But at this point, it seems as bad as arguing about religion or politics, so I'll leave it to the simplest and most effective advice, which is to simply try damping in between your subwoofer and the floor, and observe the results (or in your case, your neighbor's results
) for yourself.
As to things like dual opposed driver arrangements or other "force balanced" designs (like Paradigm's hexagonal subwoofers), it's absolutely the case that if those designs are effective at cancelling out vibrations (and they should be, unless they are unbalanced, or the drivers are out of phase), then there's no need for damping. But you have a VTF-3 MK3, with a lone driver on the side. It most definitely vibrates. And damping SHOULD help to reduce the structure-borne noise that is bothering your neighbor. Naturally, you'll simply have to try both the damped and non-damped configurations when your neighbor is home, and ask him to tell you if there was any improvement one way or the other. Again, advising you to not even try makes no sense to me. This is about solving a problem. I'm offering a potential solution. How does the advice to not even try help anything? Anywho...
I still don't understand the opposition to damping, or even how it can be so misunderstood. Get a long table, put a vibrating cell phone on it, and it's pretty darn obvious how loud that can be! Even if the cell phone is very lightweight and the table is extremely heavy. Not only is the sound of the vibrating cell phone way louder when it's on the table, but the cell phone could be on one end, you could put your hand on the opposite, far end on the table, and you'd feel the vibrations. It's not the mass. And it's not the cell phone vibrating the air and the air then vibrating the long, heavy table. I really don't understand how anyone is unfamiliar with this experience. Meanwhile, put the same vibrating cell phone on the same table, but with a pillow in between the cell phone and the table - is anyone seriously going to claim that it's just as loud or that you can still feel the vibrations with your hand on the far end of the table?
I dunno. I've no idea how anyone doesn't "get" how this works. But then again, there's a whole lot of stuff that other people believe that I think is really obviously not the case. Can't even battle that stuff with logic or facts. But this one - damping a subwoofer - you can easily try that for yourself, and your neighbor can easily tell you if it worked or not. Saying, "don't even try it because *I don't believe it will work" just doesn't seem like good advice to me. That's the same as saying, "don't put the pillow under the cell phone. I don't believe it will make it quieter when the phone vibrates". Well we know the pillow WILL make it quieter. But even if we didn't know that, why would we not even try it?
Weird.
