First Residential Install of Thigpen Rotary Woofer

[Dennis H]

I don't get over to the $20K+ forum at AVS much so I had missed this one until now.

Way too long thread:

http://www.avsforum.com/avs-vb/showthread.php?t=651499&page=1&pp=30

More interesting blog showing the install:

http://bassment.wordpress.com/

I love this from the Blog. Thigpen set up a temporary demo with one unit sitting outside and ducted into the theater. The guy liked it so much he ordered two units for a permanent install to fill in his 3 Wilson subs below 20 Hz. But get this:

Also, it’s worth noting that the official demo attendees were not the only to enjoy the virtues of VLF at high SPLs. Turns out we had some unintended attendees… namely my neighbors about 1000ft away. As was related by this neighbor (who I had not met before this demo nite), she and her cul-de-sac neighbors were walking around the neighborhood wondering what was shaking their walls and rattling their pictures. It was a slow shaking she said, much like an earthquake, except it kept going on and off for hours during the day. So she and her son started wandering the neighborhood looking for what was the source of this wierd vibration. Well, by trial and error she found our house, and I fessed up. Of course, I took her and her son down the the bassment for a demo, and she turned into an avid fan (no pun intended) and wondered how she might get one of these for their home theatre.

Shaking the houses 1000 feet away! Now that's good bass! :T

[kirknelson]

Wow! :E I wish I had that kind of coin to drop on a sub-sub-woofer

[mrogowski]

That's amazing! Correct me if I'm wrong, but he has a patent out on that thing doesn't he?

[Dennis H]

Yeah, I'm sure it's patented. I think Thomas heard a prototype at RMAF and was suitably impressed. This is the first one (two) to actually go into a home.

[cjd]

All I have to do is build one...

C

[ThomasW]

All I have to do is build one...C

I hope you're a first rate machinest.... :B

Yep listened last fall at the RMAF it was pretty astounding...here's the thread about that and more info

http://www.htguide.com/forum/showthread.php4?t=15873&highlight=rotary+subwoofer

[Scott Simonian]

YES!

I was just talking about the Thigpen with my buddy a couple nights ago. He wants one in his car. I told him its mainly for <30hz but...why the f**k not? :P

Omg, I really wasn't ready for anyone to have a build diary of one of these anytime soon. Let alone TWO of them.

Sub-subwoofer...I like that.

[cjd]

I hope you're a first rate machinest.... :B

Not sure, never touched a machine setup before. I know one or two though...

C

[Mark Seaton]

Actually, Bruce did show a version he had worked out for car audio when "Tzucc" had everyone over for the temporary demo of this back in the spring. Very cool device, not exactly trival. It works very well, but I do expect there will be much more use of these in theme parks and related applications vs. home theaters.

[Jack Gilvey]

Of course, I took her and her son down the the bassment for a demo, and she turned into an avid fan (no pun intended) and wondered how she might get one of these for their home theatre.

Sounds like she doesn't even need one of her own...she's got his.

[ThomasW]

Bruce's car rotary sub...

[---k---]

Mark,

Are you sharing any details about the Sub-Sub you are designing yet?

[mrogowski]

Well, I'll tell you with some certainty what it WON'T have:
- a fan
- a motor
- the ability to do 100db with one watt of power at 20Hz
- be able to shake a house 1000 feet away (unless you buy lots of them)

:B :B :B

Best,
Mark

[Dennis H]

Sounds like she doesn't even need one of her own...she's got his.

Chuckle, yup. He says that will never fly in his upscale neighborhood for obvious reasons. But the test was with the backwave vented outside so they did some fancy carpentry to try to keep the backwave inside the house. It remains to be seen how successful they were.

[Jim85IROC]

Just wait until my wife asks me where the hell the ceiling fan went and I tell her that I'm building a subwoofer.

[cdwitmer]

Am I the only one who feels depressed and inadequate reading about a guy who gets to enjoy distortion-free bass at frequencies and sound pressure levels that are literally able to tear his house apart if he doesn't keep close tabs on the volume control?

It also occurs to me that this could be a lethal weapon, depending on the sound track. I wonder if a person could damage his health (or, conversely, possibly improve his health -- I dunno) through recreational listening to subsonic bass in a home theater setting. Maybe software manufacturers will have to start putting disclaimers on their products: "Warning, the surgeon general has determined that . . . "

[tzucc]

hi guys, I'm the nut with the TRWs. The backwave has been reasonably contained in the garage above the media room. We've suffered some drop in output as a result of not venting to the great outdoors (maybe 3-6dB according to Bruce Thigpen), but now we're sonically green wrt neighbors. I can turn up the volume on the amp to compensate... and there are some tricks we're trying to get back to room destruction amplitudes. Though honestly I am, for the first time, afraid of a subwoofer technology. First time I ever turned down a subwoofer not because it was going to hurt the transducer but because I was very afraid my surround speakers were going to depart from the wall!

Still at this time, as you can see at http://bassment.wordpress.com, I get nice output across the entire 0-90Hz spectrum.

We have more adjustments and tuning yet to do... it seemed simple at first, but with five transducers at play in creating the whole subwoofer channel, there is a bit of complex tuning to do wrt crossovers, timing and eq to optimize the SPL across the entire low end.

AND - we have to do this in such a manner as to control the fan self noise, which is quiet enough that it is nearly (but not totally) inaudible from the seating position when the room is silent. We just don't get to turn up the volume without considering background fan noise. Of course, my room is heartbeat silent, so it's a tough criteria to meet. During 99% of any given movie, with any slight ambient noise at all, the fan self noise can not be detected.

Anyway, there's the latest.

[ThomasW]

Hi, welcome, and thanks for the update... :T

Having spent 45min talking with Bruce and listening to his creation at last years RMAF I'm seriously jealous of your installation. And know words can not/will not do it justice..... :wink:

The image of the Bruce's co-conspirators leaning against the room's 2hr rated fire doors trying to keep them from bouncing in their frames, is forever etched in my mind..... :B

[kramskoi]

hi guys, I'm the nut with the TRWs. The backwave has been reasonably contained in the garage above the media room. We've suffered some drop in output as a result of not venting to the great outdoors (maybe 3-6dB according to Bruce Thigpen), but now we're sonically green wrt neighbors. I can turn up the volume on the amp to compensate... and there are some tricks we're trying to get back to room destruction amplitudes. Though honestly I am, for the first time, afraid of a subwoofer technology. First time I ever turned down a subwoofer not because it was going to hurt the transducer but because I was very afraid my surround speakers were going to depart from the wall!

Still at this time, as you can see at http://bassment.wordpress.com, I get nice output across the entire 0-90Hz spectrum.

We have more adjustments and tuning yet to do... it seemed simple at first, but with five transducers at play in creating the whole subwoofer channel, there is a bit of complex tuning to do wrt crossovers, timing and eq to optimize the SPL across the entire low end.

AND - we have to do this in such a manner as to control the fan self noise, which is quiet enough that it is nearly (but not totally) inaudible from the seating position when the room is silent. We just don't get to turn up the volume without considering background fan noise. Of course, my room is heartbeat silent, so it's a tough criteria to meet. During 99% of any given movie, with any slight ambient noise at all, the fan self noise can not be detected.

Anyway, there's the latest.

a question about the Wilson XS...does it drop off that quickly on its own?...the spectral analysis is showing about -35 dB @ ~15 Hz...from the 30 Hz peak...granted this is'nt a true FR sweep, just a representation of encoded frequency levels...still, that's a pretty steep drop off below 18 Hz. :E

[tzucc]

well. Good question. The crossover is definitely sloping down the lower edge of the XS spectrum. That being said, we did test the XS w/o the crossover in the loop and it seems to naturally fall off below 18Hz ... of course the XS is putting out acoustic power even at 1Hz, if left to it's own devices, but then we get back to the SPL question.