Before I get started here, I just wanted to say hello to everyone!
This post cought my eye. .... Well, both of them actually, hehe.
Anyway, what all of you here are discussing about tubes or pipes, and air compressors, and ways to modulate the air is actually old news.
This is exactly what a pipe organ does to create sound. If anyone knows anything about pipe organs and has possibly taken a walk through one at some point, then you know what I'm talking about. In fact, the largest stop in a pipe organ is a 64' Diaphone/Dulzian. This is in the Atlantic City Convention Hall. http://www.acchos.org/index.html This pipe runs off of 35" of wind. I'm not sure what that comes to in p.s.i., but it's a lot. The organ runs off a total of 385 horse power of blowers and generators!! And the lowest note played on it produces I believe 12Hz.
So if you are wanting to build something that will play all the way down to 1Hz or so, plan on making something huge!
Remember, there's no replacement for displacement.
This post cought my eye. .... Well, both of them actually, hehe.
Anyway, what all of you here are discussing about tubes or pipes, and air compressors, and ways to modulate the air is actually old news.
This is exactly what a pipe organ does to create sound. If anyone knows anything about pipe organs and has possibly taken a walk through one at some point, then you know what I'm talking about. In fact, the largest stop in a pipe organ is a 64' Diaphone/Dulzian. This is in the Atlantic City Convention Hall. http://www.acchos.org/index.html This pipe runs off of 35" of wind. I'm not sure what that comes to in p.s.i., but it's a lot. The organ runs off a total of 385 horse power of blowers and generators!! And the lowest note played on it produces I believe 12Hz.
So if you are wanting to build something that will play all the way down to 1Hz or so, plan on making something huge!
Remember, there's no replacement for displacement.
There is a great article about this topic in the the last issue I read of AudioXpress (AudioXpress.com) (March or April) The article deals with debunking the myth that low bass can't be reproduced in small rooms. Anyway, in the article the author describes a mechanical device that is used to calibrate microphones. The device is basically a cylinder, with the microphone inserted in one end and a piston in the other end. The piston is driven by a motor.
Think of the setup like one cylinder of a car motor with no valves, and the microphone screwed into a spark plug port.
Because the motion of the piston changes the volume and therefore the pressure in the enclosed volume as it moves, it has a perfect response down to DC.
So to have a response down to DC, means you have control over the barimetric pressure in the room. So you need a sealed room, that you can change the volume of.
I think phase_accurate stated it accurately when he said,
a sealed speaker in a sealed room gives a response down to DC.
Basically any size sealed speaker has a response at DC, if it is placed in a sealed room. The SPL level achievable is going to be related to the volume swept by the cone relative to the volume of the room. On the other hand, ported speakers got nothing at DC. Makes ya wanna go plug those ports!
Think of the setup like one cylinder of a car motor with no valves, and the microphone screwed into a spark plug port.
Because the motion of the piston changes the volume and therefore the pressure in the enclosed volume as it moves, it has a perfect response down to DC.
So to have a response down to DC, means you have control over the barimetric pressure in the room. So you need a sealed room, that you can change the volume of.
I think phase_accurate stated it accurately when he said,
a sealed speaker in a sealed room gives a response down to DC.
Basically any size sealed speaker has a response at DC, if it is placed in a sealed room. The SPL level achievable is going to be related to the volume swept by the cone relative to the volume of the room. On the other hand, ported speakers got nothing at DC. Makes ya wanna go plug those ports!
what is a 'hertz' anyway. it's cycles per second, isn't it? if you have 0Hz, you're not producing anything, are you?
unless there's some wierd vortex of sound...maybe there's a negative Hz, that works like a sonic black hole...sucks up the sound around it. then 0Hz would be the mind-boggling threshold between positive and negative frequency.
Sorry to bump such an old post but while looking for some questions of my own to satisfy the curiosity I stumbled onto this sites thread. Oh I’m new member I got a little bored with another site too crowded I hope this one is a lot peaceful.
As for this comment after reading though the OP post and other posts of negative views, I wonder is there such a thing I was thinking the same thing a few hours ago negative or -1Hz then -2Hz and so on.
But 0Hz is the limit unless lets say if someone press their finger on your stomach or you do it yourself, you feel it and what frequency is that at? It has to be well below 20Hz if not 1Hz or maybe below 0Hz?
The ear can’t hear the tone under normal conditions..
What about a digital crossover if there is one that goes all the way down to 0Hz so it can be tailored to cross-off other tones and use an assembly/array of subs to play from 0Hz to 10Hz then cross-off for then next array of subs to operate from 10Hz to 20Hz.
This hobby can be quiet good at times and damn right, expensive well.
Of course 0Hz is a discontinuity or limit. You can approach a sound of 0Hz but never get there as it would cease to be sound (vibration).
I believe BTW that the lowest note from the 64' stop is about 8Hz.
The device that the OP is looking for has, I think, already been created. Search for Fan Subwoofer.
Cheers.
I believe BTW that the lowest note from the 64' stop is about 8Hz.
The device that the OP is looking for has, I think, already been created. Search for Fan Subwoofer.
Cheers.
Rotary Subwoofer
8 hz is correct for the largest pipe organ and can be heard with
a rotary subwoofer (TRW-17 Rotary Woofer made by Eminent
Technology). Response is from 25 hz to below 1 hz and is
simply amazing at recreating very low bass.
Of course 0Hz is a discontinuity or limit. You can approach a sound of 0Hz but never get there as it would cease to be sound (vibration).
I believe BTW that the lowest note from the 64' stop is about 8Hz.
The device that the OP is looking for has, I think, already been created. Search for Fan Subwoofer.
Cheers.
8 hz is correct for the largest pipe organ and can be heard with
a rotary subwoofer (TRW-17 Rotary Woofer made by Eminent
Technology). Response is from 25 hz to below 1 hz and is
simply amazing at recreating very low bass.
Attachments
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.