Questions tagged [microphone]

A sensor converting an acoustic signal into an electric one.

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5
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1answer
467 views

Piezo transducer preamp and AGC/compressor

I've been suggested this circuit as a good low-noise high gain piezoelectric transducer preamp (used to pick up really faint sounds in water). It is nice because it includes a high pass filter (yet ...
4
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0answers
144 views

imx6q sabre board microphone

I have been trying to record audio using the circuit below. It is different from the normal microphone circuit in that the MIC_IN and MICBIAS are separate paths. I tried to connect an electret ...
2
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0answers
47 views

How to represent a microphone using a voltage dependent current source in LTspice?

I am using the following schematic and I'm trying to simulate it in LTspice but I am not sure how to represent the microphone. My instructor said I should use a voltage dependent current source but I ...
2
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0answers
199 views

Poor man's oscilloscope - more simple

In our lab we have NI cards and work with -10 to 10V. Oscilloscopes are rare and some mobile and quick-and-dirty solution would be fine for debugging. Therefore the 'poor man's oscilloscopes' that ...
2
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0answers
240 views

How to connect Electret Microphone module and OPAMP?

I am trying to build a circuit that gets electret microphone input and maps into 0-1V for utilizing in ADC. The microphone module suggests using such circuitry When I tried that circuit and talked ...
2
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0answers
243 views

Convert 3V unbalanced microphone to 48V phantom balanced

I have the following circuit in an existing product, which has a microphone, power switch, LED indicator, and is powered by 2 AA batteries: simulate this circuit – Schematic created using ...
2
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0answers
144 views

How to connect a MEMS Microphone Breakout - INMP401 to a RN-52 bluetooth module?

I intended to use a INMP401 (MEMS MIC) to capture audio and stream it via bluetooth using an RN-52 bluetooth module (RN-52). The RN-52 has inputs for differential +- signals. The INMP outputs ...
2
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0answers
279 views

Can I replace electret microphone with audio connector and expect similar results (sound levels)?

Last night I built a circuit that allows me to obtain sound via a SEED Grove Sound Sensor and input it into my MKR Zero for frequency analysis. It's as simple as this: simulate this circuit – ...
2
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0answers
311 views

Dual antiphase electret mic preamp topology

I am currently trying to make a preamp for an electret mic pair, which are placed physically in antiphase. The main idea is to subtract one mic's signal from another and therefore boost the signal ...
2
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0answers
82 views

Audio: Camera activated external microphone

I want to build a relay circuit that turns on an external microphone (powered by an internal 9V battery) when a connected camera is turned on (a camera offering only 1V plugin power through a 3.5 mm ...
2
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0answers
2k views

Noise-cancelling headphone concept

Inexpensive noise-cancelling headphones use a single microphone located in a little lump between the plug and the earphones. They seem to work fairly well for ambient noises, but not for handling ...
1
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0answers
43 views

Building a “if” statement circuit where i can control different light diodes

I want to design a circuit to react in different ways depending if a microphone picks up one frequency and in different way if it picks up the some other frequency. I want different lights to shine ...
1
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0answers
31 views

Automatic Headphone Control Issues

A friend wants an automatic headphone controller for his bike. According to the Android spec we should be able to add a bias resistor of 5kohm between mic and ground, short mic to ground for play/...
1
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1answer
26 views

How does a channel know to drive in I2S TDM mode?

I'm learning I2S right now and am curious how to work in an environment where 8 or so audio devices could be in the setup. I understand TDM mode would allow the Controller (Master in legacy terms) to ...
1
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1answer
39 views

dB SPL Calculation is not making sense- values are seemingly too high

I am using an electret with a sensitivity of -38.44 dBV to make sound measurements at a distance of 1m. I decided to add an amplification circuit with a gain of 125. So in the end to convert to SPL, I ...
1
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0answers
99 views

SIM800L microphone problem

I want to feed SIM800L a microphone signal. I found this page in the datasheet and it worked but I need more a sensitive microphone. I want to hear voices in room as much as possible, like a spy bug. ...
1
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0answers
40 views

ADMP401 output voltage difference

Good morning. During the experiment with the sound sensor, a question arises, so I ask. The output of the sensor itself varies from the same sound. When one sensor is +ΔV = 220mV, the other sensor ...
1
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0answers
54 views

NPN condensor mic pre-amp really noisy

I have designed a pre-amp and I am having a lot of noise when silent. It seems to be around 70 Hz on my scope, but jumps around. I've tried adding bypass filters on the NPN emitter legs, as well as ...
1
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0answers
63 views

Audio Loopback Dongle Sanity Check

The same circuit as in Explain “Audio Loopback Dongle"; I wanted to know how it worked. Anything I couldn't figure out I found out via CircuitLab's time analysis: simulate this circuit – ...
1
vote
1answer
293 views

Microphone with LM386

I am trying to build an audio amplifier circuit based on this design using an LM386 opamp. On the output side (pin5) an Arduino is connected constantly reading out the pin ...
1
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0answers
95 views

MEMS Microphone noise floor power level & audio noise spikes measurement

I have a circuit with a MEMS microphone and would like to be able to measure the audio noise spike contents and check the noise floor power level in the audio circuit. My intention is to connect the ...
1
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0answers
148 views

Using an active bandpass on a very small signal

I am trying to design a active bandpass filter for an electret microphone (the output will then be read through a microcontroller to control some LEDs) (Image source - Electronics Tutorials) I want ...
1
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0answers
177 views

Is it possible to build an in-line stereo amplifier for piezo contact mics (stereo pair) with 2.5v plug-in power?

From one idea to the next, here's the back story: I'm currently taking an interest in sound design, and read an article about making sound effects from recording via contact microphones. I already ...
1
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0answers
79 views

earphone microphone out put voltage range

I want to send a signal through the 3.5mm jack(microphone port) to an android mobile and process the signal using android mobile application I created. But I don't know the voltage range the ...
1
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0answers
496 views

Switch CB Radio mic with SPST button

I'm a beginner with this type of electronics, but want to try this. I have a CB radio with a 6-pin mic/controller. The pinout looks like this: There is a DPDT switch in the mic that switches ...
1
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0answers
506 views

Choosing resistor/capacitor for wiring microphones

I've been researching how to wire up a electret mic and found this to be very common. I can't seem to find any info on what values should be used. Most people use 1k or 2.2k resistors and 4.7uF caps. ...
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0answers
173 views

Best possible specs for a MEMS mic in 2014?

I want to use the best MEMS mic that's on the market today (June 2014) in terms of audio quality. Since I know that "shopping" questions are forbidden, I'll phrase it like this: What are considered ...
1
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0answers
1k views

Connecting a geophone to Arduino

Simple question: I want to connect my geophone to an Arduino input. The geophone I have is actually output to a microphone jack and I can plug it directly into my computer. I'm pretty sure I can treat ...
1
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0answers
2k views

Electret condenser microphone, LM386 amplification… does size matter?

I've built a motorcycle intercom, of which comprises of two amp units, one for the rider, one for the pillion. Both are powered by a 9v battery each, and the option (using a jumper) to enable boost. ...
0
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0answers
10 views

USB microphone power, device connect simulation

My mic is Samson Meteor. It has aux output on the back, but it is the USB mic. Data (voice) and power are transfered via USB, but data can be transfered via aux also. (it still needs to be connected ...
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0answers
27 views

Connect an unbalanced microphone that requires 18V

I got a weird microphone years ago that I'm looking to use. I'm bad at electronics and I need your help. Here are some microphone specifications: Connector: DIN 45322 (5 pins) 3 pins connected: mic-, ...
0
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1answer
59 views

Help with electret mic

I'm using this preamp circuit for my electret microphone and then feeding the output to A0 analog pin of an arduino uno board. For some reason my serial monitor in the arduino ide shows the output at ...
0
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0answers
77 views

Audio jack acts like an antenna?

I am using a simple pre-amplifier circuit for an electret microphone. Here's the schematic and the AC transfer function: The output is connected to a 3.5mm audio jack through a couple of half a meter ...
0
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0answers
47 views

Connecting MAX9814 to Speaker

I am trying to build a fetal heartbeat sound detection using Adafruit AGC Electret Microphone Amplifier - MAX9814. I attached the MAX9814 mic to the hole of wood fetal hearbeat stetescope (picture ...
0
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1answer
68 views

Choosing microphone for texture sensing

I'm looking for a microphone that will record the vibrations of different textures and then with some signal processing I will get frequency as output. However, I don't know which microphone which ...
0
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1answer
40 views

How to connect microphone mono to stereo power amp

I try to connect mono microphone to stereo power amp like this image. I connect line of microphone to left and right of power amp input and ground of microphone to ground of power amp but it have no ...
0
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1answer
82 views

The SPH0645LM4H-B microphone seems to output all negative values via I2S

Attached is an image from the analyzer. I am afraid that the I2S is shifted one bit, because as it stands, the MSB bit is always high, all samples come back 0x3nnnn (18-bits, so MSB bit is on the left)...
0
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0answers
39 views

Design of 5+ channel microphone array

I'm interested in designing a microphone array which will have 5+ inputs which need to be synced, possibly more. I want to sample each input at 20-30khz at 8-10 bit resolution. I would prefer not have ...
0
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0answers
60 views

STM32 MEMS microphone - weird output

I have an STM32f407vgt development board that has a MEMS microphone (MP45DT02) on it. I aim to take processable data from this microphone. STM32 provides PDMtoPCM conversion library and I2S ...
0
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1answer
118 views

Confused about op amps and wiring for parabolic mic

I consider myself a fairly smart guy (20+ yrs web programmer, Computer Science degree), but in the past couple years, I've started to delve in the realm of electronics design and I'm constantly ...
0
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1answer
98 views

How do I slowly short pins 2 and 3 of a phantom powered mic signal?

Shorting pins 2 and 3 of a microphone signal will mute it and is acceptable for when phantom power is present. I can do this with a regular switch, or a solid state relay. But is there a simple way to ...
0
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1answer
64 views

Troubles with mic preamp for headphones with integrated microphone

I am designing a preamp intended to interface with a microphone in common headphones (e.g. apple earpods, or sony headphones with a microphone) which will then connect to my ADC's inputs. I've ...
0
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0answers
42 views

Cutting the earbuds and keep the microphone: will it work?

I have old still functioning earphones with a microphone incorporated. I want to keep the microphone and remove the earbud so that I can then put the microphone inside a small pipe and record sounds. ...
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0answers
90 views

How to Feed SIM800L MIC IN

I want to connect 8 Ohms/0.5W Audio output line from an ISD 1820 Voice module to SIM800L MIC IN. I see on both SIM800L MIC IN & ISD1820 Speaker out are not common ground.They have marked SP+ SP-, ...
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0answers
32 views

Intercom System

I am trying to make a prototype to test a circuit. It is about am intercom circuit. I have an intercom device with 2 wires, and it supports multiple stations and everybody can talk and hear at the ...
0
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1answer
48 views

Is the 3.5mm jack somehow connected to the phone's transceiver?

I could not find a clear answer to that and it's driving me nuts, because I have a microphone, which when connected to my phone via 3.5mm jack picks up a sort of buzz, as if from wireless inteference. ...
0
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2answers
101 views

When wiring an electret microphone is using the wire shielding as ground ideal?

Currently with a "single-conductor" shielded wire I have connected the (+) pole of the mic capsule to the wire, and the (-) pole to the shielding strands. I am wondering why the ground wire doesn't ...
0
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1answer
39 views

polarised condensor microphone

Sir/Madam, Kindly explain how is the following equation derived for the polarised condenser microphone? The output voltage V0 fed from the microphone to the preamplifier will be how is it derived? ...
0
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0answers
94 views

extracting DC from audio signal for biasing

I've been wondering if there is a simple means of extracting a DC signal from an AC+DC signal for the purpose of providing a small DC supply to a CMOS device. Essentially the signal I'm considering ...
0
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2answers
103 views

Simplest option for generating audio tones?

I'm looking for the simplest way to generate audio tones. Something like a square or sine wave, but I want multiple tone options. For example, two quick beeps, one at 440Hz, one at 1Khz. The tones ...