Up until recently, my all sealed sub system consisted of 2 eD A7S-450s and 2 vintage Cambridge Soundworks PSW1s. I placed my PSW1s nearfield, right behind the listening position. This made a big difference in tactile feeling.
With this system, I hit 111db at 10hz measured via REW in my 2100 cubic foot room.
I was itching to see what would happen if I upgraded my nearfield subs. I came across a great deal on a pair of LFM1-EXs, so I jumped on them and replaced my PSW1s. After much tweaking to try and get my sealed A7S-450s to play with my ported LFM1-Exs, I finally got the curve that I liked.
As you can see, both curves are pretty much +-1.5 db down to 10hz. HOWEVER, these curves sound or rather FEEL very different!!! I thought my sealed PSW1s were good, my ported LFM1-EXs add a completely new dimension to my listening experience!
I wonder why that is? My guess is fairly intuitive. My PSW1s rolled off at around 25hz, where as my Outlaws roll off at around 11hz. Obviously, a big difference in extension. However...from a 'sub system' frequency response standpoint, my FRs are pretty much the same!
As to which sounds/feel better, 1000% the outlaws! But it's counter intuitive that very similar FRs can sound/feel so different. Also, does a ported sub have more 'tactile' feel than sealed subs given the same FR. I would think not, but my subjective impressions is that yes they do. I've observed this in two different home theaters.
Also a MAJOR contributor to a sub system is its tactile feeling. The tactile 'dimension' for sub systems is such a HUGE (IMO, perhaps the most important) factor, that people subjectively discuss, but never really measure (in my perusing, anyway). You could potentially have a razor flat to 10hz system in a huge room w/o nearfield placement and compare it to a razor flat to 10hz system in a small room with nearfield placement, and there would be absolutely no question which people would prefer...the huge room would likely not have much if any tactile feeling or pressurization where as the smaller room would have it in spades. Everyone would prefer the pressurized, tactile feeling of the smaller room. So, to post a graph of a sub FR only tells a portion of the subwoofer story...you really need to add and eventually compare its tactile feeling to some sort of reference point so that we can all relate to your vantage point.
So, when we talk about subs, or rather subs systems; shouldn't we also have some sort of reference point that measures tactile feeling? After experiencing the shaking in my new setup, I would EASILY sacrifice extension, to nearfield placement for the tactile feeling all day, any day. In fact, I would recommend that to everyone.
So, I did some minor investigation on how this could be measured...and came across vibration meters....and wouldn't you know it, there's an app for that. I have no transducers...this is all sub listening at reference level, with my subs measuring at 112-115db on a concrete floor. See video below:
Here's the scale (MMS) for reference:
1.0 - Instrumental. Felt by animals
2.0 - Weak. Felt indoors by a few people
3.0 - Slight. Felt indoors by several
4.0 - Moderate. Hanging objects swing
5.0 - Rather Strong. Dishes broken
6.0 - Strong. Heavy furniture moved
7.0 - Very Strong. Difficult to stand
8.0 - Destructive. Fall of walls
9.0 - Violent. Noticeable ground cracks
10.0 - Intense. Almost destroyed
11.0 - Extreme. Rails bent greatly
12.0 - Cataclysmic. Total destruction
Here's the conversion to the Richter Scale:
I hit 7.0 (Very Strong. Difficult to stand) on the MMS Scale, and 5.0 on the Richter scale at my main LP!!! This was on the app; Vibration Meter for the Android. I was playing the Irene scene in Blackhawk Down. I hit 7.0 during the ULF portion (7hz or so) of that scene. I hit 7.4 with WOTW.
So, here's my questions to you all. All feedback is welcome:
1) Do you think some ported designs generate more tactile response than sealed, given the same FR?
2) To really determine the overall quality (all aspects) of a subwoofer system, should we start measuring the system's tactile response? What's the best way to measure tactile response?
3) While #2 remains unanswered, what's the best app across the Iphone, Android, etc. that we could start measuring the tactile response to get a general idea of our sub systems? Obviously, it would be beneficial to run the same app across OSs so that we could have a baseline...
4) If your so inclined to download the app, please share your results! Low and high numbers are welcome. We have no reference point, so it's all great info!
Lots of questions...would love any and all comments!
One of the reasons why I started this thread was I wanted to see if there was any tool or measurement that would allow me (and others) to really know how it 'feels' in each others room. Obviously, there are many factors that come into play and you'd never truly know how it 'feels', but my hope was that it would at least give you a general idea of what it feels like to watch a movie in your room.
Based on my experience and those who have contributed so far, I'd classify 'tactile feeling' in two ways:
- The shaking caused by physical objects (seating, floor, etc.) that are in contact with your body as a result of the pressure waves created by the sub or mechanical shaking of a transducer moving those physical objects. An example of this would be an 'earthquake'.
- The pressure waves traveling from the sub that come in contact with your body directly. I equate this sensation to the 'kick in the chest' sensation. An example of this would be a jet flying over, or another example would be blades of a helicopter. In this case, the pressure waves are directly affecting your body, and not indirectly through other objects. IOW, you could be standing in a concrete bunker and still feel this sensation.
Edited by dominguez1 - 12/29/12 at 6:29am