Your impressions of bass below 20hz

[kgveteran]

I'm going to do a little subjective listening tonight to feel the difference between bass down into single digits and bass with a 20hz hipass from my BASSIS. I speak of the need for bass below 20hz, but never tryed it the other way. I think the hipass is 24db/oct.I checked the manual but didn't get an answer.

Have you guys chased this ball before ? Besides WOTW, and Blackhawk down , what other movies dig down into single digits.

Subjective is just that, opinion.I'm not looking for a war just some thoughts on your impressions.

KG

[Chris D]

I use it with my tactile transducers. My SVS dual subs also go subsonic. Not many subs do, though, and their performance really drops off right around the 20Hz point anyway, so you have to have equipment capable of it.

I think it's useful, as the tactile sensation you get from TST's and subs complements what you see with your eyes and hear with your ears to give you a fuller experience.

Be careful, though. There's a point, I think it's 8 Hz, where studies have shown that frequencies below that actually become harmful to the human body. I think that's based on resonance.

[RobP]

War of the Worlds has a part that goes down to 3hz. Its subtle but you can feel it.

[Brandon B]

The chicks dig the subsonics in the couch mounted tactile transducer.

"Better than a harley" quoth one.

Other low stuff:

The Haunting

Titan A.E.

Fellowship of the Ring opening sequence bass sweep (Sauron exploding) - this one got the Harley remark.

Men in Black - when the cool MIB mobile shuts off, there is a whole thing that goes on for a few seconds with its big alien turbine winding down that you can not really hear without a good subsonic capable SW.

On music, it 's not such a big deal to me. There is definitely material in that range, especially in some genres, and it adds something when it's there, but I don't miss it as much when I listen to something on one of the other systems in the house.

BB

[Race Car Driver]

The chicks dig the subsonics in the couch mounted tactile transducer.

"Better than a harley" quoth one.

BB

:T :lol:

[Chris D]

True 'dat. Specifically, the MIB car shutdown thing really is a treat when you have good subwoofers. The first couple times I saw the movie, it was with a so-so sytem. Once I bought good equipment and watched it again, I discovered that aspect of it, that I never knew was there. AWESOME.

[bigburner]

IBe careful, though. There's a point, I think it's 8 Hz, where studies have shown that frequencies below that actually become harmful to the human body.

This was someone's weapons research programme way back when I was a kid. Details following shortly...

[Chris D]

Ooooh, somebody that knows details. I'm waiting with anticipation!

[Hakka69]

This was someone's weapons research programme way back when I was a kid. Details following shortly...

I remember reading something about that a while ago, it was used as a weapon - the bass note damaged the internal organs of the ememy, only problem was the poor bloke who hung around to switch it on copped it too.
An interesting read.

[Hakka69]

I googled 'low frequency weapon' here's a few of the results.

http://www.globalsecurity.org/military/systems/munitions/accoustic.htm

http://www.lowertheboom.org/trice/infrasound.htm

http://trauma.cofa.unsw.edu.au/archives.html

7hz is the killer, I wonder if my test tone generator can do 7hz???
Hmmm......not very happy with one of the neighbours at the moment :twisted:

[Chris D]

Well, a good home theater fan would build up a tolerance to low bass tones, and become the ultimate weapon operator.

[Hakka69]

We get a TV show called 'Mythbusters', I think it is a US show. A few months back they investigated the 'brown note subwoofer', they basically set up a circle of subs around a test subject and then blasted them with high SPL low frew sine waves. The aim of the test was to try and make the test subject crap their pants.

They were unsuccessful but I think they conceded a bigger badder subwoofer setup might have worked beter.

They were using what looked like PA speakers to me, setup in a large empty carpark. Maybe an IB in a HT environment would be the go??

[kgveteran]

Silly talk if you ask me..........

I did a little listening and discovered a couple of interesting effects of VDB (very deep bass). There is this thing that happens in WOTW where the room becomes pressurized.I didn't get that feel with the hipass activated.I felt like the vibration in the room included me rather than just rumbled the walls.I think your talk of the bass weapon has somw truth to is.

On the other hand the SPL's were greater with the 20hz hipass engaged.The frequencies that did pass were quite strong. The hipass, I feel didn't effect the sound in a bad way other than limiting.

I like the VDB included in my soundtracks.Would i miss it if someone switched my hipass ? Hmmm. I would have to really be on my game that day to pick up missing frequencies that low.

KG

Now go back to your subass gun talk........Bassheads

[chasw98]

We get a TV show called 'Mythbusters', I think it is a US show. A few months back they investigated the 'brown note subwoofer', they basically set up a circle of subs around a test subject and then blasted them with high SPL low frew sine waves. The aim of the test was to try and make the test subject crap their pants.

They were unsuccessful but I think they conceded a bigger badder subwoofer setup might have worked beter.

They were using what looked like PA speakers to me, setup in a large empty carpark. Maybe an IB in a HT environment would be the go??

I saw that show. They used approx. 32 Meyer Sound Bass cabinets with 4 18 inch drivers per cabinets (I used to run 4 of them). Their biggest problem was that they were open to the top and to the front (so the camera could see them) and they were outside. I think the results would have been much, much different had they set up the rig indoors with some baffles around the array.

[chasw98]

Silly talk if you ask me..........

I did a little listening and discovered a couple of interesting effects of VDB (very deep bass). There is this thing that happens in WOTW where the room becomes pressurized.I didn't get that feel with the hipass activated.I felt like the vibration in the room included me rather than just rumbled the walls.I think your talk of the bass weapon has somw truth to is.

On the other hand the SPL's were greater with the 20hz hipass engaged.The frequencies that did pass were quite strong. The hipass, I feel didn't effect the sound in a bad way other than limiting.

I like the VDB included in my soundtracks.Would i miss it if someone switched my hipass ? Hmmm. I would have to really be on my game that day to pick up missing frequencies that low.

KG

Now go back to your subass gun talk........Bassheads

Now back to your serious experimentation here KG! I have built a unit that allows me to have a hi pass filter that is selectable from 8 Hz to 20 Hz. It is a 4th order L-R so it kicks in at 24 db per octave. On passages that have sub 20 Hz frequencies I can notice that they are there with the filter in bypass. With the filter switched in at various settings though, I notice that the rest of the spectrum above 20 Hz is much fuller. I believe it is because sub 20 Hz information will just run your amp dry when you are trying to reproduce high levels of sub 20 hz information. That is why I have just gotten some more amplifiers to see if I can I have the best of both worlds sub 20 Hz info and above 20 Hz fullness. Thomas has told me that he has tried 8 and 10 Hz filters and they just haven't made a negligble (sp?) difference in his IB. I am trying to quadruple my power so that it will make a bigger difference than just 3 db. With your drivers and your amplifiers you should certainly notice it, either through hearing it or feeling it. Try downloading some test tones at very low frequencies and play them back to see where audibility drops off and 'feel' kicks in. I have a Wavetek sweep generator that is flat down to .4 Hz I have been using to reproduce the low frequencies.

Chuck

[bigburner]

The 7Hz frequency that Hakka69 mentioned refers to the resonant frequency of organs inside the human body. If enough energy is applied the organs will vibrate and rupture.

Most things have a resonant frequency. For example, soldiers never march when crossing a bridge because the repetitive vibration of marching can match the resonant frequency of the bridge causing it to collapse. Soldiers break ranks before they get to a bridge and then resume marching when they've crossed it.

Small rooms like showers are great places to sing because you can easily find the resonant frequency of the room.