There is but one person to blame for the many distractions and angst in the last 10 pages or so. The thread was moving along swimmingly before this statement:
As soon as I read this, I knew we were doomed....
ULF Perception comes in layers. Each layer adds to a better perception of reality or "realistic recreation of the onscreen event" (realizing this is silly and why it is in quotes). I'll explain the ULF layers in an example:
I have 4.5 Star ULF at 10hz in my 1900cf room. I sit on concrete, with 2 FV15HPs a foot behind my couch, and dual FTW21s flanking the front screen. The room is sealed with 3 concrete surfaces. I recently watched the OHF Washington Monument scene multiple times to try and get a better understanding of the different aspects of ULF perception:
The point of it all, is that the combination of all of the above, adds to the overall "realism" and what I experienced "in total" sitting in my main listening position. Take one of the layers away, and you're missing the potential of the ULF effect.
Layer 1 for this scene can be recreated by high ULF that interacts to objects that are in contact with you (couch, suspended floor), and potentially be recreated by properly implemented tranducers.
Layers 2 and 3 for this scene can only be recreated by high ULF.
IMO, you need them all for the full ULF experience.
I quoted myself (and edited my quote for clarity) because I wanted to bring this topic back up about ULF perception.
I'm thinking about expanding the ULF score to two separate star ratings to get a view into how others' HT systems perceive ULF through transmission of other objects (suspended floor, seating, transducers, etc.). You would use the star rating that you currently have, and then create another Star rating to determine tactile transmission.
If we can say ULF does impact us in layers, Layer 1 would be the new score that we would be measured. It would be largely subjective, but those with suspended floors, or nearfield placement, or properly implemented transducers, would heighten the ULF perception for Layer 1.
Layers 2 & 3, IMO, can be largely attributed to the original ULF score/star rating as I believe it is a function of the pressurization your room.
I would want to keep them separate and not try a combined rating as I would let others subjectively decide on what's more important to them, Layer 1, or Layers 2 & 3. Let's just throw out some examples:
The best HT ULF experience would be one where you have a 4.5 star and above ULF rating at 5hz or 10hz, combined with a 5 Star Tactile Sensation rating. Where it becomes interesting is what if you have a 5 Star ULF rating at 20hz only, with a 5 Star TS rating? How would that compare? Or perhaps you have a 3.5 Star ULF rating with a 5 Star TS rating...or a 5 Star ULF rating with a 3 Star TS rating...how would they all compare against each other?
Get the picture? Again, Layers 2&3 can be contributed to the current ULF Star rating, and Layer 1 would be the new Star rating for Tactile Sensation (TS), and could even potentially bring tactile transducers into the mix?
As far as how to determine your TS rating, I could describe the experience of what each TS star encompasses, and then the member could simply select their category, or I could collect info about their flooring, sub placement, transducers, etc...probably more the former the more I think about it.
BTW, I think it's crazy that you started a thread back in 2005 about your discovery and proclamation that WOTW was king; nuts I tell you! To think you and the few others have been talking/experiencing this for a decade is just crazy. No wonder this talk of ULF feels like a broken record to you most of the time...
I also got a kick on how you described ULF as 'dark space' moving through the room. It's actually a pretty good figurative description...goes right along with the talk about the 'Subwoofer theory of everything" or "Unified Subwoofer theory" discussion 15 pages back or so when we were trying to solve for the ULF model in order to make it work with very small and very large rooms.
This is a good point...
To add more input to this: I think it's pretty important to have a relatively flat Tactile Sensation response as well. I've experimented this in my own setup, where I boost some 'couch shaking frequencies' more than others. What I've found is while it is very cool in a 'Loudness Button' type of way, I actually found that the lopsided shaking took away from some of the other ULF effects (Layers 2 and 3) and as a result, felt like they were missing. Having the TS more evenly distributed enhanced the overall ULF experience, and I preferred it overall.
While I do think it's probably the majority of folks that have HT's in their basement on concrete don't get much tactile sensation (Layer 1), there are some of us that definitely do. As part of this thread, I'd like to figure out why that is for some and not others. It is nearfield placement? Is it the resonant frequency of the HT seating? Is it the design of the sub? Is it because the HT seating is close to a boundary? Don't know...
But, I do know that in my room, there is no mistaking the tactile sensation. It's not slight at all, but in your face. I recently had another AVS member over, and he couldn't get over the tactile feel of my HT system. He thought for sure I had transducers connected! Well, I actually do have tranducers, but not on the main LP where he was sitting. My couch is three separate pieces, with the outer pieces connected with Clark transducers. The middle section is 'all natural'. He continued to believe that the adjacent sections must have been adding some shake to the seating, so I turned them off and played more demos. Needless to say, he's now a believer.
So regarding transducers, here is my story:
When I originally had 1 FV15HP, I placed it right behind the listening position. Very visceral...however, the outer sections of the couch paled in comparison. They were anemic...so, I installed a pair of Clark transducers. When I was trying to get them calibrated so that they would match the tactile sensation that my middle seat provided...I actually blew both transducers up in the process! The transducers at full power could not replicate the tactile sensation I was getting from the sub! Not even close. I have the tranducers directly mounted to the frame of each of the outer section, and they could still not keep up...remember, I sit on concrete.
After I purchased my second FV15HP, I flanked the pair so they were directly behind the outer sections (and nothing directly behind the center section). This solved the problem. The outer seats are very close from a TS standpoint as the middle, but still the main LP is better. I actually don't need the transducers anymore, but they do add a little bit to the overall experience...enough to not uninstall them anyway.
From strictly a ULF standpoint, I don't believe the transducers did much at all. Perception wise, it could fool you into thinking that it had ULF because there would also be above 20hz TS present, but it could not recreate the ULF shaking that the FV provided.
Was it realistic? If I didn't know what ULF shaking really felt like, I'd probably say that it would add to the experience. But when comparing the two, it did feel 'fake'. Of course, I did mount them directly to the seats and not to a riser...
I've heard that the Crowson's go very low, but are there others that do the same? I know that some claim to (I believe the Clark's do), but didn't know if in practice they actually are capable of below 20hz shaking in a meaningful way.
Lots of shaking...seating, clothes, body...
I tried to measure it with a Vibration Meter Android App. I maxed at 7.0: "Very Strong, Difficult to stand" during the clip Black Hawk Down: