The Only Subwoofer

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rasmaudio

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The only true subwoofer that goes from 25 hz down to below 1 hz. In my 50 years as a audiophile this subwoofer puts every other subwoofer to shame in very low bass, power, and most important, transient response. Pipe organs, very large drums hit hard to all the sound effects (thunder, explosions, the T-rex dinosaur in Jurassic Park and rockets taking off. Eminent Technology TRW-17 Rotary Subwoofer IMG_0795.jpg
 
Picture of opening for rotary subwoofer

The opening in the floor (4' x 4') into the room for the rotary subwoofer. The amount of air this subwoofer moves is enormous. Will make my doors moves back and forth a 1/2" at 5 hz!!!!!!!!!! IMG_0621.jpg
 
Thats the best sub I have ever seen

How does it work?

I have never saw any available on the used market

Did you have to put this together by yourself ?
 
I've read about setups similar to this but can't remember where. It's all about moving the air thats it. Just that the fan speed has to react very quickly to changes in frequency. Awesome idea!
 
Google 'Thigpen rotary sub' for the technology.

Tools mounted to sub cabinet seems like a no-no....

Tj
 
I reported on this sub several years ago here on the site from when I went to CEDIA. It was nothing short of jaw dropping. Truly a visceral experience.
 
The sub cabinet

Google 'Thigpen rotary sub' for the technology.

Tools mounted to sub cabinet seems like a no-no....

Tj

I can understand what you are saying about the tools on the outside of the cabinet. Nothing vibrates on the cabinet because this enclosure is just for reducing the fan noise and is very rigid and braced inside. The opening into the room is very large (4' x 4') and there is no restriction of air passing through the enclosure and therefore does not vibrate. The rotary subwoofer also needs a large volume of space to operate properly for the back wave to vent (my basement is over 2000 sq. ft.) and is as close to a infinite baffle as one can get with out venting the sub to the outside. Thanks, Bob (rasmaudio) IMG_0793.jpg
 
Fan Speed

I've read about setups similar to this but can't remember where. It's all about moving the air thats it. Just that the fan speed has to react very quickly to changes in frequency. Awesome idea!

The fan speed is held constant by a motor controller and does not change with the audio signal. The blades on the fan pitch back and forth in relationship to the the signal and a modulating amplifier is used to accomplish this. IMG_0800.jpg
 
Motor Controller

A motor controller is used to set the speed of the fan. The speed of the fan is used to adjust for the volume of the room as well as loudness. When the blades on the fan are being pitched by the audio signal the motor controller compensates for the load on the motor to maintain a constant speed. IMG_0797.jpg
 
At around $20K for a subwoofer, it is way out of my reality.
its a $400.00 Variable frequency drive, a bunch of transducers, maybe 3 grand max for the motor/fan assembly and probably not-rocket science electronics. DIY, $7500.00 tops installed. Gotta love this high end business.
 
Try and build one

its a $400.00 Variable frequency drive, a bunch of transducers, maybe 3 grand max for the motor/fan assembly and probably not-rocket science electronics. DIY, $7500.00 tops installed. Gotta love this high end business.

Yes, its expensive, but try and built one. There are quite a few talented people right now trying to build there own rotary woofer; but, as yet, no one has been successful. I built the enclosure and the cost was half the amount that the manufacturer charged. It took Eminent Technology five years of research, planning, and testing for the final product. Check out AVS Forum: DIY subwoofers; Rotary Woofer. In this Forum I wrote many things about this product. There has been a lot of interest for the rotary sub (many comments and questions). I have been answering many questions and posted quite a few close up views of the rotary woofer. The bottom line; this new technology for producing very low bass works and makes conventional woofers pale in comparison. To me, it was worth the time and cost for such a quality, realistic and exciting product. I have been passionate for this hobby for over 50 years, and this has been the best single product I have owned. Yes, some of the parts are not very expensive, but time and effort are the things that cost the most. Also check out the very extensive review of this rotary subwoofer in (IAR, International Audio Review. Thanks, (rasmaudio)
 
From a real world, practical user perspective, why should anyone care about this item?

How many recordings, from a percentage standpoint, produce that level of low end? And within that minuscule percentage, how much is music that is worthwhile listening to other than to demonstrate the "my sub is bigger than your sub" factor.

It's like the worlds biggest ---------------------fill in the blank.

GG
 
Many Blueray Movies

From a real world, practical user perspective, why should anyone care about this item?

How many recordings, from a percentage standpoint, produce that level of low end? And within that minuscule percentage, how much is music that is worthwhile listening to other than to demonstrate the "my sub is bigger than your sub" factor.

It's like the worlds biggest ---------------------fill in the blank.

GG
If you are into pipe organ music or well recorded large orchestras the rotary subwoofer, in my opinion, is a must for a realistic sound reproduction.
While it is true, from a percentage standpoint, there are relatively few recordings that can benefit from the rotary subwoofer, listening to the Mormon Tabernacle Choir with that huge pipe organ is a real experience. The real benefit is from a lot of Blueray videos that have many sound effects (thunder, explosions, gun shots, the T-rex dinosaur from Jurassic Park, the many sound effects in War of the Worlds, the sound produced by Niagara Falls, rockets taking off that is simply stunning.) Please read the extensive report by Peter Moncrieff (IAR, International Audio Review) of the rotary subwoofer, titled "The Only Subwoofer". In this article he explains all the benefits of the rotary subwoofer for music as well as sound effects in movies. Best Regards, Bob (rasmaudio)
 
hate organ music, tired of jurassic park, parents live near the real niagara falls, rockets scare me.

but a Tom Cruise movie - now THAT'S worth $20,000!
 
I'm not sure I understand some of these responses. Since when was high-end audio practical or inexpensive? Bob has followed his passion unreservedly and I say kudos to him. Is a rotary sub for everyone? Of course not, but neither are high-end electrostats, battery operated pre-amps, air-bearing TTs, or any of another dozen far-out things a typical marginally-sane audiophile perpetrates.

Bob chased (and has caught) that last hertz. Many of us should be so lucky. And as for there not being enough material? Who said it's all about 1Hz? What about the quality of the LF reproduction in the range where it does positively impact a large cross-section of music? Many of us have JLs, or MLs, or other relatively expensive high-end subs because we care about quality. If the rotary sub represents another step up in quality, well, thank goodness that option exists, even if for a limited number of enthusiasts.

As a side note, I've been refining a CAD design of my retirement home for many months... next step, look to see if integrating a rotary sub is feasible and in parallel, seeking out an installation I can hear/feel for myself.

Cheers
 
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