# 111hz resonant structure

#### Audiopium

Hey Folks...

Im trying to design a room that people can walk into that resonates at 111hz specifically.

The wavelength of 111Hz is 3.092m and I'm ok with standing waves (if that equates to point of maximum resonance) as long as about 6 people can experience the standing wave points at once. The people could be laying on beds or standing at specific points in the room.

Do you think I should build a hemisphere or a cuboid? What radius/length should it be? and where would you place the speakers/instruments to create the maximum effect... in the walls, and if so where in the walls, or in the centre of the room?

#### markbakk

A room like an organ pipe would be best I guess. You would like to have their ears at a pressure node, so either very close to a wall or ceiling or exactly in the middle, assuming one wavelength fits between boundaries.

A (cubic) room with sides of 3,1m will resonate at 55Hz too though. And have quite strong diagonal and oblique modes too, hence the thought of a long, narrow room. Furthermore, if you aim for the max effect, room modes in any direction would have to be in phase.

Come to think of it, probably a square room 3,1x3,1m with several speakers spread over one wall that produce a coherent sine will do just fine. If you use an acoustic absorbing ceiling the floor-ceiling standing wave would be damped well enough so that that would be masked by the majar standing wave of 111Hz.

Mind the temperature in the room, as the speed of sound changes with it.

#### DonVK

Any speaker will play 111Hz in any room.

However, if you have a penchant for resonant rooms, L3.055m x W3.055m x H2.4 is tuned to 111Hz. The standing waves will of course have nulls as shown in the pics. I assumed the listening position is 0.5m-1m of the ground. I used 2 speakers on the floor against one wall, however another 2 speakers on the opposite wall could eliminate the nulls.

Happy meditating.

#### Attachments

• freq_resp.jpg
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• Field@111Hz-Z50cm.jpg
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• speaker placement.jpg
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#### TNT

Paid Member
The REW application (free) has a "Room sim" function where you can set the dimensions and the listener position and see what that listener will experience in terms on nodes an dips... You can move the listener and observe how the node situation change as you move....

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#### Audiopium

@TNT nice. Thank you

@DonVK what if I wanted 6-10 people to be able to experience maximum resonance at any give time?

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#### DonVK

Depends on how much area (spacing) each person needs, that's your call.