Originally Posted by FOH
Nice, thanks for the details. I know nothing about this stuff, so I'm all ears/eyes. Have fun.
I have had a single Crowson actuator underneath my seats for years. I originally had it just on the floor, (carpet over concrete), without the riser. I could shake the seats, but I always noticed that the floor didn't shake, and that I got no sensation through my feet; and therefore I've always found the effect to be compromised. About 6 months ago, I built the riser to try to transmit some tactile sensation to my feet to make the experience more believable. It worked quite well, so I'm now extending it to the new riser and the new seats.
I have 2 friends who's HT's are on the 2nd floors of their homes. They are on "suspended" floors. They both get incredible tactile response from acoustic-mechanical coupling of the bass to their floors. The floors shake and transmit tactile response to your feet, but they also shake the seats and transmit tactile response to your body. It's an all-inclusive experience.
This is the effect I'm trying to emulate in my room. My HT is in the basement, on a concrete floor. Without the tactile actuator, I get ZERO tactile response, even with 3 Submersive HP's. It's simply impossible to shake concrete with acoustic-mechanical coupling. The only way I could get anything close to what my friends have is to use a tactile actuator. I looked at all of them, (Buttkicker, Aura, I-beam, etc.), and decided on the Crowson. (The Earthquake wasn't available at that point.)
After installing the actuator and riser, I found there is actually an unexpected benefit to this arrangement over shaking the whole floor. A suspended floor shakes at a "resonant frequency", which means it only shakes when actuated with that frequency, (or the range around that frequency.) So, sometimes you get *massive* shaking when you have LFE at that frequency range... and other times you don't get much shaking at all, when the LFE is outside that range. With a tactile actuator, you get shaking at all frequencies, and you can actually feel the difference between different frequencies.
I have set up the "source signal" for the actuators a little bit unconventionally. I use Audyssey XT32 for room correction. This means that both subwoofer outputs on my pre/pro are exposed to the EQ for that room correction. The tactile actuators don't need or benefit from room correction, so the challenge was to find a source signal without room correction. I could not get one from my pre/pro. Then it dawned on me... since the vast majority of my "quality" viewing/listening is sourced from my Oppo BDP-83, and since it has MC analog outputs, including a subwoofer output, and those outputs are active even when the HDMI connection is in use, I simply connected the Oppo's subwoofer output to the amp for the Crowson directly. I then set the Bass Management in the Oppo to re-route all the main channel bass to the subwoofer output,an viola
... a "pure" subwoofer source signal without room correction.
The one downside is that the signal is not exposed to the Master Volume Control, so I need to control the "volume" of the actuator manually. I have settled on 2 different settings, one for movies and one for music, with the music setting being about 25% lower than the movie setting. It's a simple matter to set it before listening to one or the other, but there have been occasions where I forget and I get the mvie setting for music...
I am using the Buttkicker mono amp to drive the Crowsons. It delivers 1,000 watts into 4 ohms. It has an LPF and an HPF. I set the LPF at 40 Hz and disable the HPF. I don't like the actuator to shake at higher frequencies. 40 Hz is the highest frequency I find "believable" for shaking. Above that, and it becomes gimmicky and fake. I do enjoy the shaking for the infrasonic stuff. The Crowsons have response down to 3 Hz, as does the Buttkicker amp, so you get really good shaking with the ULF's.
The one downside to using an actuator with a riser is that the riser can become a "speaker." It can make some noise with the shaking. However, it's a low enough level sound that it is completely masked by the sounds from the speakers and subs. I never hear it or notice during normal use. In fact I only hear it when I have the speakers and subs turned off, and I'm just driving the actuator. However, it is potential issue.
Otherwise, I would not give up my tactile response system for anything. It adds a level of immersion and enjoyment that is otherwise not possible in my basement HT.
Pic's to follow...