Taking Home Theater Sound one stage further
without spending any real money!

This page is for those individuals who are not afraid to tackle a few do it yourself projects namely in the Bass End of a home theater sound system.

After checking out a number of systems over the past few years I realized that a good bottom end gave the most dynamic effect when watching an action flick! After building two 15" sealed sub woofers that nearly split my house in half! I found myself still wanted more maybe something in the sub sonic range an earth quake effect possibly. Looking around on the Net on day I came across a thing called a "Tactile Transducer" these devices induce vibrations into anything they are bolted to but do not produce any audible sound. The DIY page I found on the subject showed a fellow who strapped lead to an old speaker via a flex plate which in turn was epoxied to the paper cone (voice coil) end of a speaker. I immediately new what he was trying to accomplish having built a EMT plate (reverberation plate) years ago for my brothers  recording studio it to used a speaker to transduce vibrations into a large metal plate where as after you would pickup the signal in two different places at the other end of the plate giving you a great stereo reverb sound for mixing down original tunes. Any way to get back on track a few companies down in the States are selling these transducer for Home Theater and car audio use and after a number of inquiries it looks like you would have to spend at least $300.00 to $500.00 US to get one that really performs. Before I yak any more follow the story line through a series of comments & pic's below!

Steps towards shaking your couch to every explosion, space ship, depth charge, etc.

Step 1

1. Find  an old thrashed speaker from a garage sale, swap meet or if you want to start with a new one Pyramid speakers are inexpensive and available just about anywhere. I had a couple of 15" speakers that blew out due to rotten foam around their surrounding edges so there was no worry or cost in  the transducer experiment. In case this whole site sounds to weird and your not sure what I am really up to check out the basic concept in the diagram below.


Photos of the work being done

The last image you see here is the unit bolted to a bar which in turn is bolted to the couch frame. Also I found wedging another piece of steel from the mounting bar into the rug against the floor underneath added a more solid and larger low frequency effect. The only engineering hurdle you will need to make in this project is the thickness of your flex plate, to thin speaker moves up and down to easily canceling the transfer of any vibrations, to thick and absolutely nothing happens, just right and it will transfers it's internal fight into the mounting bar giving you the lowest sensation of bass you will ever feel....  A good bench test before installing is to set the TT on a solid surface and pound the magnet end once with your fist, if it hums for about 2 sec. your in business. The actual up and down travel of the magnet and left over chassis will only amount to 1/32" and when everything is running right the transducer will appear blurry during operation.

Step 2

 Pick up an old amp from the 70's again check garage sales I am not kidding there are tones of these old amps kicking around peoples basements the one I found for $5.00 just needed a couple of fuses to get it going, it's an old Pioneer 35 watts per channel power amp. In the photo above the amp is my home built 70 Hz role off filter which I plan to talk about later in my pages, it is not a necessary part of the  TT project do to the fact the transducer only really operates from about 50 Hz and down, do to the mechanical principals involved it sets up it's own filtering. Only low frequencies can cause the flex plate to bend slightly allowing the transfer of vibration into the couch and surrounding floor.

There are a few places you can get the sub out signal to drive the amp (1). Use a Y connector right out of your Home theater receiver, that means one goes to your sub system while the other goes to your low budget TT amps aux. (2). Take a line out  from your existing sub speakers amp. right to the aux. input of the transducer amp.


A quick look at the speaker set up with the transducer

 

Conclusion

After spending a total of 25 hours  on the TT project I have come to the conclusion it has to be the best improvement anyone could add to their Home Theater for the lowest amount of money, $8.00 in total was spent . The movie U571 has left a few of my friends physically shaken! one started on the TT project the very next day. I have read on a couple of websites, once you experience this effect you will never be able to watch another action movie without your couch being "plugged in" and yes they were right I am totally spoiled. Just imagine a  frequency response down to 1 cycle, my system is now only limited by whatever the audio engineers can put out.

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