bass extension to 5Hz?

[just.sounds]

Here it is the definitive subwoofer !

From DC TO 20Hz

Eminent Technology: home

Also nice for hot days :-)

[Jim vanBergen]

Originally Posted by just.sounds

Here it is the definitive subwoofer !

From DC TO 20Hz

Eminent Technology: home

Also nice for hot days :-)

That's a cool approach, but WOW on sticker shock... do I really need to spend 25k to have subsonic subs? And then stick it in my attick for the infinite baffle?

I think I'll stick with my Bag Ends, Danleys and Sunfire subs, thank you...

[weiss2496]

Originally Posted by Casey

Daniel, isn't it well understood that the infrasonics in the ambiance of a hall are created by the transient impulses of percusion and strings?

If you think about it this way it explains many of the points made in this thread. In my experience, this is why a symphony hall is so exciting. As you hinted at, it is the reverberation extending the near DC pulses that adds so much.

I believe you know Daniel Dettwiler. He and I recently discussed his recent "Selma" recording. I felt that it was quite rich in LF transient detail. Sure enough, his aesthetic and methods matched what I heard.

So while reproducing the sound of a symphony hall is difficult, I do agree with you that this is an interesting area to think about and explore.

-Casey

Yes, right. I guess to capture impulse responses from concert halls we should go down to infrasonics to have it all. Provided a playback system was able to reproduce that, I wonder whether we would feel more like being there.

Yes, I know Daniel Dettwiler. Have to get that CD. For those interested see:
Amazon.com: Selma: Selma Meerbaum-Eisinger,David Klein,Ute Lemper,Xavier Naidoo,Sarah Connor,Joy Denalane: Music

Daniel

[mohthom]

A big theatre I did some time in down in London had a pair of sub-bass speakers built into the venue; 2x21in drivers each side, and I forget whether they were 21 or 28 feet long . . .

They took the nicknames of 'Throb 1' and 'Throb 2'. 'Nuff said.

You couldn't hear them, but if you wanted to make someone wobble when crossing the stage . . .

MohThoM

[studio1117]

My understanding is that you will actually crap your pants at freq's below like 8hz at the proper volume. Military did tests in the 50's on this. As a demoralizer.
EDIT: Found the article..well a article Other Magazine The article says you can't make it loud enough etc, but the military was practicing with bombs that create loud sub freq's... nasty.

[Roland]

Originally Posted by studio1117

My understanding is that you will actually crap your pants at freq's below like 8hz at the proper volume. Military did tests in the 50's on this. As a demoralizer.
EDIT: Found the article..well a article Other Magazine The article says you can't make it loud enough etc, but the military was practicing with bombs that create loud sub freq's... nasty.

Total, urban myth. This was exposed on Mythbusters a couple of seasons ago.

With the exception of LFE in a cinema set-up, this unit would be of little use as it is common in mastering to apply HPF's at higher frequencies than this. I would personally want to see it demonstrated as I can't believe that a rotating fan wouldn't produce audible artifacts at other frequencies. If you want to reproduce 5hz (though I really can't see the point myself) I would suspect that a servo driven driver might be a better solution.

Regards


Roland

[studio1117]

Originally Posted by Roland

Total, urban myth. This was exposed on Mythbusters a couple of seasons ago.

"It was on a TV show...so it must be true./... now if I could only find it posted on the web it would now be 100% totally true."

I don't think I would use mythbusters as my test for fact. Although I would agree for all intents and purposes the bowel thing is probably not likely.

[Roland]

Originally Posted by studio1117

"It was on a TV show...so it must be true./... now if I could only find it posted on the web it would now be 100% totally true."

I don't think I would use mythbusters as my test for fact. Although I would agree for all intents and purposes the bowel thing is probably not likely.

The Brown note? This myth is so old it's got grey hair, even South Park did a skit on it. Yes, I'm sure that mythbusters is pretty staged in that I'm sure they know exactly what is going to happen. I've heard this myth ever since I got in this business, never yet met anyone who crapped themselves when played the/any sound. You think there isn't some wag out there that would love to make a crowd of people $**t themselves for a prank? If it could be done, it would be well documented.

Regards


Roland

[Casey]

Perhaps it would be useful to distinguish between, on the one hand, prolonged exposure to static low frequency waves, which clearly have been shown to cause nausia (or other less than desirable reactions!).

And, on the other hand, the highly random pitter patter of low frequency fragments coming from the stage of a well designed symphony hall.

The two cases are entirely different. The former not being particularly useful for this conversation, and the latter being the very thing at the root of the original question.

Can a recording sound more lifelike when infrasonic detail is maintained?

And the identical question, why does a recording seem to collapse when I adjust my highpass from 2Hz to 15Hz?

I think this is an excellent area for discussion, as I do feel it relates to both capturing the sound of a great venue, as well as simulating one if required.

I would also downplay the requirement of "actually reproducing such frequencies in a home or studio". I have found that quality speakers with bass extension just slightly below 20Hz are perfectly adequate for experimenting while trying to answer these original questions.

-Casey

[studio1117]

Obviously you didn't read the article.

[peeder]

I'll say this: when I got my extension cables from redco and moved all fans and moving parts out of my control room (which also doesn't have HVAC air currents but stays pretty cool year-round provided there isn't a sweaty band crowded into it), I noticed that things certainly felt different. I have a sub that does 30Hz OK and if I had a subsonic transducer I certainly think that would have an effect.

I descirbed it at the time as "It's as if the sound comes up on the monitors like a sunrise."

In any case I do suggest trying a zero-air-current control room: absolutely still. This means like I said NO FANS period in the room or openings with appreciable current to HVAC or outside or whatever (don't suffocate yourself though).

Your relationship with sound might change quite a bit.

[peeder]

Originally Posted by Casey

Can a recording sound more lifelike when infrasonic detail is maintained?

And the identical question, why does a recording seem to collapse when I adjust my highpass from 2Hz to 15Hz?

One thing to keep in mind is that ultra and infrasonic information can exercise your circuits (amplifiers etc.), soaking up a lot of power but not resulting in much appreciable contributed sound. But soaking up all that power and generating all that interference (not to mention possible IMD, etc.) may significantly harm the sound you can hear.

Now a lot of people like what we would consider "harm" sometimes. You might like sag effects, modulation, and the like. But if those effects are specific to your individual playback system, they can't be "canned" and re-sold and should be avoided as you aren't evaluating what other people are going to hear.

Another thing to keep in mind is phase shift from your filter. From 2 to 15Hz is actually three octaves...the same difference as 2.5KHz to 20KHz.

[Sounds Great]

You want some powerful bass?

Saw a PBS show yesterday about volcanic eruptions. Looks like nothing can create sound waves more powerful than these events.

The Krakatoa volcano erupted in 1883 and it is said the the sound reverberated around the entire planet 7 times.

Krakatoa

People who heard the explosions on Rodriguez Island, over 4600 km away, described them as sounding like the distant roar of firing cannons.

[studio1117]

Originally Posted by Sounds Great

You want some powerful bass?

Saw a PBS show yesterday about volcanic eruptions. Looks like nothing can create sound waves more powerful than these events.

The Krakatoa volcano erupted in 1883 and it is said the the sound reverberated around the entire planet 7 times.

Krakatoa

....and then crapped their pants

[Roland]

Originally Posted by peeder

One thing to keep in mind is that ultra and infrasonic information can exercise your circuits (amplifiers etc.), soaking up a lot of power but not resulting in much appreciable contributed sound. But soaking up all that power and generating all that interference (not to mention possible IMD, etc.) may significantly harm the sound you can hear.

Now a lot of people like what we would consider "harm" sometimes. You might like sag effects, modulation, and the like. But if those effects are specific to your individual playback system, they can't be "canned" and re-sold and should be avoided as you aren't evaluating what other people are going to hear.

Another thing to keep in mind is phase shift from your filter. From 2 to 15Hz is actually three octaves...the same difference as 2.5KHz to 20KHz.

One of the reasons that during mastering HPF is often added is to remove these problems/issues (unless it is deemed that the energy isn't there).

I'll say this: when I got my extension cables from redco and moved all fans and moving parts out of my control room (which also doesn't have HVAC air currents but stays pretty cool year-round provided there isn't a sweaty band crowded into it), I noticed that things certainly felt different. I have a sub that does 30Hz OK and if I had a subsonic transducer I certainly think that would have an effect.

I descirbed it at the time as "It's as if the sound comes up on the monitors like a sunrise."

In any case I do suggest trying a zero-air-current control room: absolutely still. This means like I said NO FANS period in the room or openings with appreciable current to HVAC or outside or whatever (don't suffocate yourself though).

Your relationship with sound might change quite a bit.

Listening in a clean enviroment, without low level distractions (computer whirring/fans etc) would likely improve your listening experience, this however is not proving that LF noise is making your sound more lifelike.

As pointed out earlier, large amounts of prolonged LF can be quite nausiating. Complex reflections/reverberation give us the clues to the size shape of the performance area. Surround helps with this illusion, I have a freind conducting tests with periophony, which he claims are yet another step up the listening experience ladder, however highly impractical for most listeners/end users.

Regards


Roland