Awsome results.....

I just finished tuning my sub with room eq wizard and bfd and would have to say it is the second most bang for the buck (besides my shakers) for my home theater. I am now getting a second bfd for my shakers so I can fine tune them as well. Thanks everyone for the hook up!

[geekwithfamily]

Welcome Toe.

REW measures sound pressure levels in your home theater and BFD tames any frequency amplitude problems. I don't understand how a BFD could help shakers. How could you measure the effectiveness of the BFD with the shakers? Don't they just shake the attached furniture in sync with the LFE and bass tones in a movie soundtrack? I just don't want you to waste $100 on an extra BFD.

(Note: I've never used shakers so maybe I'm missing something)

[Wayne A. Pflughaupt]

Welcome aboard!

I noticed you said you tuned your “sub.” The BFD has two channels, so you could use the other one for your shakers.

Regards,
Wayne

[Sonnie]

Hi Toe and welcome to the Shack!

Wayne has a great idea... just use the other channel to eq your shakers and save the bucks.

Kyle, he can get measure down to 10Hz with REW and he could eq the response from 10Hz to 20Hz with an extremely wide filter at 20Hz.

[brucek]

Kyle, he can get measure down to 10Hz with REW

I think Kyle is asking, what method of transducer would you use to measure the shaker output? They aren't audible and have no interaction with the room anyway. I don't get it either Kyle...

brucek

I am not a pro by any means but.....the shakers produce a resonance in the seats and if the spl meter is close to the frame it does produce spl levels. certain structures will produce different peaks in resonace and the bfd can and will smooth the responce of these.....I am working on it right now.

I didnt even think of that thanks.....

[Sonnie]

Well, I don't really understand the how the Buttkickers and Bass Shakers work and maybe you can't measure them, however, there are people using the BFD to equalize them for whatever reasons. As earlier stated, I don't think I'd buy an extra BFD to do this, but if you have an extra channel you might experiment with it.

Here is the typical response of a bass shaker:



It may be well enough to just turn up the volume of the Buttkicker amp. There has also been discussion about using the BFD to create a lower cutoff frequency.

just realized that......just a small peak around 40hz....not bad..and not worth an extra hundie.

[khellandros66]

Sonnie they use high power mangets to create "Mothion Actuation" This was developed early on for the military sims so that fighter pilots and helocopter pilots could get a feel for real world incedents and practice trouble shooting w/o risking a $30,000,000 aircraft. It is also my understanding that it was also developed for forms of cancer and kidney stones too...

The tech isn't new but no longer privatized to military uses either.

~Bob

[geekwithfamily]

I guess you could use the second channel on your current BFD to alter the shaker's response. Because you're not dealing with sound waves, just electric pulses and couch vibration you could boost the frequencies between 16 Hz and the peak at 40 Hz. The shaker is tuned for movie explosions, but you'd think the lower it got the more shaking your butt would receive (maybe the shakers are tuned that way because the magnets' throw cannot accommodate frequencies lower the 40 Hz, the Y scale in the chart Sonnie posted is not amplitude but pounds of force).

The only issues I'd worry about boosting the signal would be blowing out the shaker, falling out of phase with the action on screen and hopping your couch across the floor (it's hard enough to keep your head in the sweet spot as it is).