Altec 3182's in a 4 meter transmission line

[raytclark]

Has anyone else run across this site?

http://jgbouska.tripod.com/audio/sub_index_graphs.htm

"Low frequency response is flat down to an amazingly low 8Hz"

Looks like a "real" project, but very functional for a moderately sized room.

Ray

[HiFiPlayer]

Bull **** ! Sorry, I'm not meaning you. As far as I know that some points make me unable to believe.

1.) Human unable to hear such low frequency, Even within 20Hz to 30Hz I just can feel the convulsion, or have nothing can feel and hear. So, does it worth or meanings to the HiFi at home.

2.) Who can provide evidences to proof that it is true.

3.) There is impossible that someone?s DIY project can flat down to an amazingly low 8Hz. Cause that DIY sound system as a lethal weapon or it near to be. That guy might be has hearing the heaven?s music.

4.) Around 7Hz low frequency can penetrate through everything, even walls and human?s body. Then this is the main point that why I cannot trust. Cause human?s bodies are also work around 7Hz. If that system is flat down to the 7Hz in about 100Hz. So that guy?s body would has resonance. And then that guy?s heart, brain and pulse might be stop. So that guy will die with no any scar or damage.

To believe it or not!

[HiFiPlayer]

correction in 4.) 7Hz in about 100db.

[djnagle]

That would feel pretty cool to have your guts turned into scrambled eggs.

[Fitts]

Imagine if this system were to find the resonant frequency of the human sphincter muscle, maybe a new natural laxitive???

What shall we discuss next...

[dhook17322]

Actually that clain may be optimistic but not fraudulent. Adire Sound's site has 3 ported enclosure plans for their Maelstrom 18" sub, the largest of which is -3db at 12 Hz. on their response plot.
Remember the lowest note on many pipe organs is 16Hz which is borderline infrasonic. But response in this region gives tremendous depth to a recording where the acoustics of the performance begin to be reproduced. This requires very low freq. reproduction to give clean reproduction of LFE.

[raytclark]

Hey guys,
I have no idea about the validity of his claim to 8 hz, but even though very tall and massive (if I put them in my living room I would have to "build" them there ... and "leave" them there when I move).
I was thinking they are a visually pleasing alternative to a large "box". The key was also the choice of driver.

Also, not at 100 db but an interesting bit of trivia;

"October, 2000 - THE WORLD'S LOWEST BASS SINGER, Tim Storms of Branson's 50's at the Hop show at Branson Mall, set the Guinness world record for the lowest note ever sung (6.875 Hz) -- two octaves below the lowest note on the piano, inaudible to the human ear and slightly more than an octave below the previous record of 16.5 Hz. In the past, the title of lowest bass singer was previously held by another Branson artist, Dan Britton of Pierce Arrow (Db -17.3 Hz), and also the late J.D.Sumner of the Stamps Quartet."

Thanks for all the intersting reponces!
Ray

[joyspring]

Ray:

Looks like a real project. This guy really did his homework!

The MLS and FFT measurements are outstanding and are better than many recording studio control rooms.

Yes, he can attain flat response down to 8 Hz; both enclosures benefit from eighth-space (dual quarter-space) loading from the FOUR corners, and yes, he does attain 9 dB gain from doing so.

There are two paragraphs that explain this; the 2-200Hz waterfall plots also bear this out.

HiFiPlayer:

1. It's questionable whether response below 16Hz is necessary for domestic reproduction though by extending the passband far below audibility, this personal also moves phase shift at and below f3 lower as well.

That in itself is an appreciable benefit.

2. I've had a very close look at his measurements and they *are* believable and extremely impressive.

Instruments rarely lie and this person knows how to use them. He obviously understands acoustics FAR BETTER than audiophiles (he is, after all, a geophysicist who does field acoustic measurements).

His integration of system with the room is really what makes his system outstanding.

3. I've created loudspeaker systems with mass-loaded drivers that are flat to 8 Hz. Not that the maximum sound pressure below 20Hz was impressive but that tuning to 8 Hz is trivial work -- simply requires an understanding of the Benson/Thiele/Small's work, a little math and a few measuring instruments.

4. I don't believe it. That person will not die from high SPL (100dB) at 7Hz - that's a ridiculous assertion.

If that were the case, many people would have died from proximity to jet engines, rocket launches, explosions, etc.

David:

4Hz - 5Hz is the frequency at which high SPL will cause the **** sphincter to collapse.

This person's system appears to be fully capable of doing so. Keep this person away from a function generator ;-)

BobR

[HiFiPlayer]

Firstly, I need to explain that my computer unable to open that home-page (I don?t know why?). So I didn?t seen any contents about that site. I just imagine with my poor acknowledge.

Although he can follow principles to built his amazing system. But is there really such simple can reproduce ultra low frequency? Don?t forget that 8Hz is true infrasound!
Other hand, I doubt that speaker really able to load and against such low frequency such easy. Then please let me know what amplifiers, CD player, DAC and also driver units etc that he has employing. Cause I also want to get one such High Fidelity audio products. If there is true, so his system can easy to reproduce any true pipe organs sound, jet engines, rocket launches and also explosions. My Telarc 1812 LP and CD will take to recycle.

As Far as I know that once accident was happened. But I forget the details. You can see that just a story. A village peoples and animals were all dead within about circum 3 kilometers in an afternoon. Caused by a laboratory made a mistake to turn on the infrasound wave generator.

Take a look at this site if you want to know how terror about ultra low frequency or infrasound wave weapon.

http://www.fsr.org.uk/spi/freqnth.htm

HiFiPlayer

[thinking]

Also note that well down the page he comments that the room construction is masonry/cement. Lightweight construction won't give you the same result at the low frequencies that heavy will.