"Twelve Shiva's Dancing Project"

    Note: this project was constructed early in the year 2000. At that time no appropriate and affordable 15" drivers available for the project. Since then there has been an explosion of high quality, moderately priced 15" drivers. People interested in duplicating the high output of the 12 Shiva Project should consider using 4-15" driver array mounted on a cube roughly 18"-20" on a side. 

    Tom Nousaine's,  "The Subwoofer That Shook The World", was a project published in the June, 1999 issue of "Sound & Vision". The project consisted of a column 17"X36", it was as tall as the floor to the ceiling in his basement. Each of the 2-36" sides has 4 TC-Sounds 15"s in a vertical array. These are mounted firing into the center of the column. The exit of the column is through the floor above, this is Tom's listening room.

    Now 8 TC-Sounds 15"s, are a little out of my price range, so after talking with Tom N., and the good people at Adire Audio, it was decided that 12 of the Adire Shiva drivers would be a "good" substitute.

    This project consists of a "box"  17"X17"X 47" OD. Three Shiva's are mounted on each of the four sides, all  fire inward in phase. The "box" is suspended from the ceiling of my basement, and exits through the floor into the HT above. The "enclosure" is the entire 1500 sq ft, of the basement, in other words, a true infinite baffle.  

   The "box" is assembled. Main baffle board is 3/4" MDF, inside this is a 15/32" layer of OSB. All the corners and the area between each woofer is braced with oak 1"X2"s. The OSB is for added strength and to give the "T-nuts" something to bite into. 

    The technique for mounting the woofers is as follows. A 1/2" conduit clamp has the end ground down to a "V". The "V" is inserted in the woofer mounting hole (remember these drivers are mounted from the back), The clamp is held in place with a 10-24 machine screw, damped with a rubber backed concave metal washer. The screw is then inserted through the "T-nut". There are 4 of these clamps per Shiva. The clamping pressure generated by these homemade clamps is quite high. The system allows for fast removal of any woofer, and quick access to the inside of the box.

      The unit is currently operational. It's performance is simply astounding, far beyond my expectations. There are levels of bass detail revealed, that I've never before heard. Excepting a live performance, there is nothing I've heard in 40 years in audio that is it's equal. 

    My thanks to Tom Nousaine, David Hyre VP, Adire Audio, and the numerous people from the "bass-list" that assisted in the development, design, and realization of this project. 

   

        What you are unable to see from these pictures is that there are triple interlocking joints at  each corner/edge of the box. The OSB inner-liner is coated with clear siliconized acrylic. The OSB was pressure laminated to the MDF outer box.

    They are wired into 2-3 ohm loads with 10 gauge wire. 

     With the external 1"X2" Oak bracing, the box is so strong that with enough pressure from the floor jack(14,000lb capacity), it can become a load-bearing element with regard to the floor above

   

    The front of each driver sits in a 1/2" deep recess. The front gasket of each driver has air-tight neoprene seal. Also don't be fooled by the simplicity of the clamps, these generate considerable clamping pressure

 

       The exit/throat for the sub is centered between my mains. 6" behind their frontal boundry.

       Here are some preliminary measurements. These were taken to determine the frequency response, not to determine output levels.

   Freq Hz---db output
    4.921-------79 db
    6.200-------82 db
    7.374-------87 db
    8.227-------89 db
    9.290-------92 db
    10.42-------94.3 db
    11.70-------95.5 db
    12.40-------96 db
    13.91-------98.5 db
    14.75-------98.5 db
    15.62-------100.2 db
    16.55-------100.8 db
    17.54-------101.6 db
    18.58-------102.1 db
    19.68-------102.4 db
    20.85-------102.9 db
    22.01-------103.1 db
    23.40-------103.3 db
    24.80-------103.4 db
    26.28-------103.2 db
    27.83-------103.2 db
    29.49-------103 db
    31.24-------103 db
    33.10-------102.8 db
    35.07-------102.8 db
    37.15-------101.4 db
    39.36-------100.4 db
    41.70-------100.2 db
    44.18-------100 db
    46.81-------100 db
    49.59-------100 db

   Measurement is at the "throat" or outlet where the IB exits into the room. This places the mic approx 12" above the top woofer. So "room grain" isn't a factor.

    The measuring system consists of a calibrated B&K 4133 Laboratory Reference mic, with a H/P 8058A Sound Level Meter/Mic Premap, and the NCH Tone Generator.

Clio RTA and sine wave plots are available HERE Note the Clio system isn't able to measure below 20Hz.

    Although crude, these are the only "plans" used to build the IB. The actual layout for drivers, dimensions for the baffles, spacing for the bracing, etc. was done in a manner similar to the process used for the "MarquisPlus". To see photos of that process click HERE.

During the fall of 2004 the Shivas were replaced with 12 Adire DPL-12s

   LINK to the "Cult of the Infinitely Baffled" forum