Audible vibrations transmitted through air or other medium

learn more… | top users | synonyms

0
votes
2answers
24 views

How to design an auto-adjusted equalizer?

Think that I have a speaker and a microphone. I want to adjust the equalizer automatically depending to the surrounding the system is in with just the speaker and a microphone. How can I do that? ...
2
votes
3answers
75 views

What's the best way to measure sound at very lower power?

I want to implement a sound meter on a very low power wireless system but I've not had to deal with electret microphones before. The system right now draws around 5uA when in sleep mode, and wakes up ...
0
votes
1answer
24 views

AUX to XLR cable vs direct box

I use an AUX male to XLR cable to play music out of a PA at gigs. This seems to work so far. At a recent gig, the sound person mentioned that the cable I was using should not exist, and that I should ...
0
votes
1answer
28 views

How to decide on sonar signal?

I was wondering which waveform suits the best for ultrasound sensing. For instance, if I am going to detect distances to the objects, does it matter if I send sawtooth, square wave or pure sine wave? ...
0
votes
1answer
32 views

How does speaker's power output affect sonar's detection limit and it's resolution?

I am planning to make a sonar application using smart-phone speaker and microphone, and it is given that speaker's power output is 3 watts and sound frequency is 20 kHz. I wanted to understand how ...
0
votes
1answer
88 views

Music reactive LEDs [closed]

I want to make a bigger project, but I have run in to a problem that I do not understand. I want to make an LED flash to music, for use in a bigger project. I have looked at about 20 different ...
0
votes
2answers
69 views

Does audio OP-AMP circuit needs output capacitors?

I saw schematics with and without output capacitors. So in the end - do you really need capacitors in the output? I am using OPA2134 operational amplifier. I plan to use it both as headphone and ...
0
votes
0answers
54 views

EMI/ESD for audio output pins from Allwinner A20

I'm trying to connect the A20 Allwinner pins for audio to an amp speaker. In the schematics they indicate that you must connect a Ferrite Bead (low pass filter) to safe ESD but I don't get the RC ...
3
votes
3answers
77 views

Measure delay of sound in wood with piezo sensor without an oscilloscope

First of all, excuse my layman terminology but electrical engineering is not my speciality. I am currently trying to measure the delay of a sound wave travelling through different pieces of wood. I ...
0
votes
1answer
41 views

What are the causes and solutions to battery-powered LCD backlight buzz/hum?

Many battery powered devices with LCD displays (eg: clocks or thermostats) will illuminate with a turquoise backlight when a button is pressed. Some of them will emit a buzzing/humming sound while the ...
1
vote
3answers
153 views

Receive inaudible sound at ~20khz

I'm looking into receiving data to toggle a led. The data would have to come from a microphone that picks up sound at inaudible frequencies transmitted by standard speakers (TV, PC). I've looked at ...
4
votes
1answer
71 views

How do you know if a vacuum tube is going to suffer from AC hum or not?

I know that technically there is little difference between AC or DC heating of the tube - if it gives proper voltage everything is fine... Except the hum: I have read in various sources that some ...
1
vote
0answers
58 views

conversion dB into dB SPL

I'm using a sound calibrator (1kHz, 114dB SPL, GRAS Type 42AB). When I got my data from my scope, the signal has 5mV. In spectrum mode, it is -50dB at the peak of 1kHz. I'm using this preamp: GRAS ...
1
vote
1answer
39 views

3 mic sound direction locator solution?

I am building a robot toy. When a sudden surge of sound occurs, I wish to calculate the approx position of the sound source. I am going to place 3 analog mics on the edge of my round shape PCB, each ...
0
votes
3answers
148 views

How To Detect a Gunshot

Hey everyone I am working on a project that is a lot harder than what I thought. It is a project for school. How can I detect a gunshot indoors without using an array of microphones? I had something ...
1
vote
1answer
110 views

STM32 : reset the I2S DMA address pointer

For my application I have a DAC communicating with an STM32F4 through I2S. On the microcontroller's side, informations are send to the DAC through a DMA stream, with a circular buffer. On an external ...
0
votes
0answers
37 views

Switch off idle AC/DC converter?

I am using a 5V/1A power supply in my circuit. Unfortunately, the load is not uniform, so the power supply idles a lot during operation. And the power supply makes a unpleasant buzzing noise when ...
0
votes
2answers
49 views

How to increase speaker max input power

I have a tiny 8 ohm speaker rated to accept a maximum of 0.5W. The docs explicitly say adding 1.5W or more will "blow it out". However, I'd like to use this speaker with a 1.5W amplifier (PAM8302A). ...
0
votes
1answer
61 views

Flattening microphone's frequency response

It is typical for a microphone to have a non-flat frequency response like so: Is it typical to flatten the response curve by weighting the signal in frequency domain to get the most accurate ...
0
votes
2answers
136 views

Single Stage Transistor Amplifier

so I have a question to build a single stage transisitor amplifier. I know Rc/Re = gain. And the value of capacitor which is parallel to Re can be found by the formula F = 1/2piRC but I have ...
0
votes
0answers
77 views

How to make a sound-controlled variable resistance?

So I have those old analog video equipements (Panasonic WJ-AVE5, Videonics Video Equalizer) and I'd like to have some of the parameters (video crossfade, superimpose function, brightness level, etc.) ...
0
votes
2answers
53 views

how to measure power of a sound wave produced by a whistle?

i have a galtons whistle producing frequency of 10khz. I have no idea how to measure the power aassociated with it. Also if i say (10khz,10w) what does it mean? is it even possible to link mechanical ...
1
vote
1answer
267 views

How to generate sound in VHDL

I'm new to FPGA and VHDL. I'm working on lab practical and for the practical we were already given file that has an I2C codec and the basics for the codec registers were already done but I found the ...
0
votes
0answers
55 views

Ultrasound Sound Transducer for underwater purpose [closed]

Presently I am working on Underwater Acoustic Wireless Transmission. I desire to measure water parameters at the bottom of the surface of the water and then pass it to the water surface using ...
3
votes
1answer
80 views

What parts on a printed circuit board can make unintended sound? [duplicate]

To rephrase it: Since vibrations are responsible for soundwaves, what parts are most prone to such vibrations? Root causes are probably electrical oscillations between capacitors and inductors in the ...
0
votes
1answer
138 views

Low Pass Filter Impedances

I want to design a passive 4-pole low-pass RLC filter for my subwoofer amplifier. So far I found this page: http://sim.okawa-denshi.jp/en/RLClowkeisan.htm But it seems that changing the value of R ...
3
votes
1answer
141 views

Alarm sound signal arduino

My vehicle alarm consists of a control box containing some vibration sensor and relays, and a buzzer that creates an ear piercing sound upon triggering. I've recorded this alarm sound. After pulling ...
0
votes
3answers
156 views

12-15V short beep sound simple circuit?

I need to implement the short beep sound at PSU being switched On/(Off - if easy). Are there any simple circuits for this problem? The piezo buzzers are preferable of their size and PCB mountable ...
0
votes
1answer
31 views

Input for an electric guitar

I am new to dsp and I want to try making my own effects for electric guitar. I ordered a Line6 Tonecore developper kit but I won't have it before summer. Since I also want to try other embedded ...
0
votes
1answer
95 views

How to measure a dc or ac signal using PC as oscilloscope?

I want to measure for ex a battery 0.7V dc using a program like Visual Analyser/Soundtrack Oscilloscope/jDTF/Scope/xoscope. I connect the negative pole of the battery to sleeve and the pozitive to ...
-2
votes
1answer
46 views

How do plasma arc speakers work? Also, Bass? [closed]

Please see the following videos for examples of what I am asking about : https://www.youtube.com/watch?v=NeIAkKmUfn4 https://www.youtube.com/watch?v=rasp88nbsRw https://www.youtube.com/watch?v=...
1
vote
2answers
38 views

Chaining output of amplifier (to speaker) to another amplifier

I purchased this holiday card sound recording module: Link. It's hooked up to a 0.5W 8Ohm speaker, and the IC is shielded from the outside world, so I really only have access to the outputs to ...
0
votes
2answers
220 views

Buzzer vs piezo sound for generating sound

Correct me if i'm wrong. Buzzers can only produce 1 tone but are quite loud. While piezos can generate a wide variety but are most suited to ics. Is there anything i missed?
1
vote
1answer
108 views

How to using a 3.5 mm stereo plug mic with a EM11G LM 386N-1 amplifier

I have built a simple amplifier circuit using a EM11G LM 386N-1 amplifier chip which follows the following design (cap and resister values are slightly different): I connected this mic to the ...
3
votes
2answers
2k views

What is IP and NK transformation (seen on earphones)?

By the side of my earphones, there's a switch that flips between two initials, IP and NK. This Quora question suggests that this is the IP / NK transformation, which somehow makes the earphone ...
1
vote
1answer
245 views

Calculating SPL from voltage output of a microphone with MAX4466 amplifier

I'm using Electret Microphone Amplifier - MAX4466 with Adjustable Gain and I'm getting the output voltage ranging from 1.5V to 3V (which, to my knowledge, is already amplified by MAX4466). I know that ...
1
vote
2answers
117 views

can I understand which way sound comes from?

Is it possible to understand which way sound source is located with using microphones? I was thinking using multiple mikes pointed out different ways and getting db differences to predict direction. ...
0
votes
2answers
99 views

Analog Peak Filter

I'm currently working on a project building headphone and to had to build filters to cancel certain unwanted frequency. While researching and working on it, i came across a reference design which ...
0
votes
1answer
38 views

Lower sound from 1st input when second input has sound

I'm looking for an IC/device/... that can switch between sound inputs. Lets say that I play music through audio jack 1, and a GPS is connected to audio jack 2. I'd like the IC/device to lower/kill ...
0
votes
1answer
58 views

Guitar Pedal not functioning at all, no sound created

Ok, so I'll do my best to explain my situation. (FYI, I am a beginner) I'm building an overdrive pedal for a school project which I plan on modding with the help from a teacher. However, I thought I ...
3
votes
1answer
50 views

How can I mitigate SNR or THD for audio codecs?

During my studies at university, we didn't go too in depth about Signal to Noise ratios (SNR) and Total Harmonic Distortions (THD). I've been trying to work with audio codecs for some time and I only ...
1
vote
1answer
52 views

Sound combination using op-amp

I work on a project where i need to combine sound that comes from audio jack input (let say from tablet) with a sound we create from an MCU with DAC. So it basically means I need to sum the sound of : ...
2
votes
2answers
176 views

Does a sound card low pass filter input?

I ask this question just because I'm curious to find out. As far as I understand, the Nyquist theorem says that the sampling frequency must be at least twice the bandwidth of the signal to be sampled....
-2
votes
2answers
214 views

How might one connect a laptop's aux out to an oscilloscope?

I am using an online pure tone generator (which generates sinusoidal sound waves) on my laptop to output sound. The AUX-out jack on laptops outputs sound in analog rather than digital signals. Unless ...
2
votes
2answers
105 views

Is it possible a microphone sounds different when user hold it(or not)?

I am a computer-science student working on a signal processing project on smartphones based on recorded microphone signals. For my project, I need a really "reliable" recorded signal. The system works ...
-1
votes
1answer
125 views

Question regarding simple preamp+audio amplifier

simulate this circuit – Schematic created using CircuitLab simulate this circuit Hello,as you can see,I constructed a circuit which consists of an amplifier(first scheme) and a ...
3
votes
3answers
780 views

Types of decibels

Why we use dBA or any other type of decibel unit instead of basic decibels unit (dB)? Why we have so many types of this unit?
1
vote
1answer
95 views

Protect soundsystem from GSM/GPRS pulsing noise sounds [closed]

What is the best way to isolate soundsystem from an modem/cellphone to not hear pulsing noise sounds when GSM/GPRS communication is active.
1
vote
1answer
167 views

Negative voltage ADC and op-amp

I have this circuit and I am running code on the raspberry pi which checks the input pin continuously and converts the 10-bit digital signal to a readable voltage. So I can accurately see the voltage ...
0
votes
1answer
165 views

Arduino Recognizing pre-recorded sound clips from an audio stream

My project is to control a Nintendo 3DS hand held video game system from my Arduino Mega. I have all the basic controls wired up and working well. I need to be able to recognize the state of a video ...