Previous in Forum: Irrigation Pump - Accessible to Mobility Impaired   Next in Forum: Copper Coated Steel Wire in Motor
Close

Comments Format:






Change Mode
Close

Subscribe to Discussion:

CR4 allows you to "subscribe" to a discussion
so that you can be notified of new comments to
the discussion via email.

Close

Rating Vote:







Add Vote
6 comments
Rate Comments: Nested
HiTekRedNek
Guru

Join Date: Oct 2006
Location: 44.56024"N 15.307971E
Posts: 8277
Good Answers: 270

Modulated Low Frequency Sound

06/20/2025 6:02 AM

What would the effect be if you modulated a low(inaudible) frequency sound wave with a higher frequency (audible) sound, using the low frequency sound as a carrier wave?

Could it travel farther and would a solid surface strip the low frequency carrier and leave the high frequency?

I don't have the equipment now to test this, so am hoping someone can give me some advice on this.

Thanks in advance for all help on this.

__________________
 "A man never stands so tall as when he stoops to help a child." "Never argue with a stupid person.They will drag you down to their level and beat you with experience" "To create an apple pie from scratch, first you must create a universe"
Register to Reply
Pathfinder Tags: Modulated low frequency sound
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

"Almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, vote them!
SolarEagle
Guru

Join Date: Mar 2007
Location: by the beach in Florida
Posts: 33392
Good Answers: 1817
#1

Re: Modulated Low Frequency Sound

06/20/2025 2:43 PM

https://physics.stackexchange.com/questions/791125/can-sound-waves-be-modulated

https://www.sciencedirect.com/topics/engineering/low-modulation-frequency

__________________
 All living things seek to control their own destiny....this is the purpose of life
Register to Reply
steve45
Power-User

Join Date: Apr 2007
Posts: 273
Good Answers: 12
#2

Re: Modulated Low Frequency Sound

06/21/2025 8:04 AM

Isn't this how we communicate with submarines?
Register to Reply
vsar
Guru

Join Date: May 2010
Location: Metro.Manila, Philippines.
Posts: 1269
Good Answers: 27
#3

Re: Modulated Low Frequency Sound

06/21/2025 8:25 AM

Try to remember how VLF communications remain functional... Utilizing very low frequency as the carrier of the varying high frequency tones, akin to the so called Morse code..

__________________
 vsar
Register to Reply
Rixter
Guru

Join Date: Apr 2010
Location: About 4000 miles from the center of the earth (+/-100 mi)
Posts: 9910
Good Answers: 1141
#4

Re: Modulated Low Frequency Sound

06/22/2025 7:01 PM

When you modulate two signals together, you are actually multiplying them, and the result is two frequencies, the sum and difference. For example, if you modulate 1000 hz with 100 hz, you end up with 900 hz and 1100 hz.

Multiplication works the same both ways, a x b = b x a. The carrier is always going to be the higher frequency.

https://en.wikipedia.org/wiki/Signal_modulation
Register to Reply Score 1 for Good Answer
No more "Almost" Good Answers.
vsar
Guru

Join Date: May 2010
Location: Metro.Manila, Philippines.
Posts: 1269
Good Answers: 27
#5
In reply to #4

Re: Modulated Low Frequency Sound

06/22/2025 7:18 PM

If I remember correctly, I think your explanation is the process of what "heterodyning" is about...

__________________
 vsar
Register to Reply
Haymaker
Power-User

Join Date: Feb 2020
Posts: 482
Good Answers: 7
#6

Re: Modulated Low Frequency Sound

06/23/2025 9:41 AM

Using frequency as a carrier, you can not modulate a low frequency with a higher frequency. But you can sample with it. Slice it.

The modulating F must distort the carrier. The mod rate, must be slower than the carrier rate.

But using rotation as a carrier, one can modulate a lower rotation with a higher rotation. Allowing a slow rotation to be modulated with a much higher rotation.

A rotating closed helix contains many rotations within the one.

A helical circumference. Multiple turns(rotations) within one turn(rotation). A slow rate distorted with a high rate.

A wobble.

Hayseed physics. A wheel within a wheel.

__________________
 Light is only half of what you think it is.
Register to Reply Off Topic (Score 5)
Register to Reply
Have a Different Question?
6 comments

"Almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, vote them!
Copy to Clipboard

Users who posted comments:

Haymaker (1); Rixter (1); SolarEagle (1); steve45 (1); vsar (2)

Previous in Forum: Irrigation Pump - Accessible to Mobility Impaired   Next in Forum: Copper Coated Steel Wire in Motor

Advertisement

Got Something to Say?
Ask a Question
Start a Discussion

Search this Forum
General Discussion:
Go

CR4 Sections
Aerospace
BioMech & BioMed
Chemical & Material Science
Civil Engineering
Communications & Electronics
Education and Engineering Careers
Electrical Engineering
General Discussion
Instrumentation
Manufacturing
Mechanical Engineering
New Technologies & Research
Software & Programming
Sustainable Engineering
Transportation

Site Directories
Forum Directory
Blog Directory
User Group Directory
RSS Feeds

CR4 Rules of Conduct
CR4 FAQ
Site Glossary

Who's Online (185 right now)
Show Members
Advertisement