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Questions tagged [microphone]

A sensor converting an acoustic signal into an electric one.

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1answer
75 views

What's the purpose of the inductor in this microphone biasing schematic?

I'm just wondering what's the purpose of the inductor in this microphone biasing schematic? Could it be that I have very low input signal from the microphone because of missing L1? Bias generator ...
10
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2answers
2k views

Using a microphone from the 1930s

I have an old Braun Cosmophon BMF2020 microphone at home, which I have long been wanting to use for good ol' fun. I have virtually no technical knowledge, so I am completely uncertain how to power ...
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1answer
86 views

Positive pin on microphone

Hello can anyone tell me what is the positive on this microphone ?
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2answers
64 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 ...
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2answers
79 views

A question on the meaning and model of microphone impedance

I’m a little perplexed by the circuit model and meaning of a high or low impedance microphone. Here is an example where someone at this page is trying to investigate the effects of low or high mic ...
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1answer
74 views

How can an electret microphone have a more or less flat response?

I've got two concerns. The first is that the voltage across the electret capacitor is proportional to \$\frac{1}{d^2}\$. For the voltage to be proportional to the pressure difference between both ...
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2answers
205 views

Device to loopback mic to headphones

I have an issue with my headset. I can’t stand not being able to hear myself speak. I’d like to build a passive device to loopback the mic to the headphones that would be plugged in-line between the ...
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1answer
166 views

Why is the electrolytic capacitor not polarity sensitive?

The issue I was making a project in which I had to use a 2.2uF electrolytic capacitor in series with a microphone and weirdly, the circuit works even if I toggle the polarity of the capacitor, that ...
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1answer
56 views

Can I use 48 V DC power supply to make my own phantom power?

I want to know if I can convert a 48V DC power adapter that I have at home to use it as phantom power for my condenser microphone. I only want to add some sockets that can support a microphone. ...
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0answers
78 views

Powering and regulating supply DC voltage for a digital MEMS microphone

I want to use Infineon IM69D120 microphones [1][2] in an array (about eight of them), and I am confused as to how exactly (with which components) should the MEMS microphones be supplied. I chose USB ...
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1answer
95 views

Inject 5V bias power (“fake” phantom power) for microphone (ModMic)

I've recently bought a ModMic4 for my PC, but the signal level is very low and have to amplify it quiet a lot digitally, which introduces ton of white noise and I have to use noise supression which ...
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3answers
164 views

High pass filter for electret mic to mobile phone

I’m currently working on making a lavalier microphone for use with my phone and gopro camera. I know these types of microphones are readily available and can be purchased fairly cheap, but where would ...
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3answers
123 views

Amplify an Electret Microphone using an input Jack 3.5mm

First time on the platform, I will try to be as clear as possible, and electronics is a hobby for me, so I'm open to any welcommed criticism. I'm trying to build a little project, recording the sound ...
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2answers
79 views

Why don't we use analog remote mics?

All remote microphones sends digital samples over the ether. Why no analog remote microphones? I know that digital signals are less sensitive to noises, but there are several advantages of analog ...
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0answers
50 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 ...
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0answers
61 views

Custom microphone amplifier poor high frequency response

I've designed and received a custom MEMS microphone amplifier PCB, but am having issues with poor high frequency response and very low sensitivity/gain. Basically the microphone stops picking up ...
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2answers
66 views

How can I test a microphone circuit with a test signal

I have a microphone circuit very similar to below but I don't have a mic which is on back order. I would like to test the circuit (and the processing that happens downstream) in the meantime. Is it ...
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1answer
69 views

Converting a non-electret condenser microphone circuit to electret?

I'm trying to convert an MXL 603s circuit, which has a non-electret capsule, to an electret version. I'm pretty certain that the only real difference between the two would be the fact that the non-...
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1answer
49 views

Stereo Microphone Output into Mono Input

I'm not at all familiar with microphones, so sorry if this is a very simple issue. I have a Sony XAV-AX1000 headunit in my car and the standard microphone included with the kit. It's very similar to ...
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1answer
47 views

Changing microphone's jack to headphone's jack

I was trying to change my microphone's jack into my headphones with mic jack by cutting my microphone's wire and connect it to my headphone jack's wires. But these 4 color coded wires makes me ...
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1answer
64 views

How to mute microphone in 2-way communication when the speaker is active?

I'm making my own two way intercom for my house. There will be a speaker and microphone above the front door of my house (as well as a camera). When someone rings my doorbell, I get a notification on ...
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1answer
138 views

Laser Microphone setup

I am currently constructing a laser microphone using 5mW red laser pointer source based on the idea below, not directly output to a speakers or headphones, but the signals must be fed into computer ...
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1answer
99 views

Connecting two electret microphones to computer to record stereo sound

I have two electret microphones. I would like to connect them to my computer to record stereo sound. I've checked a couple videos on YouTube and people there show they connect them "directly": signal ...
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1answer
74 views

Input offset voltage for microphone circuit

Does anyone know what's the input offset voltage (oscillated 2.5V) to the op-amp in the circuit for? From my understanding, the input offset voltage needs to be extremely small so that output DC ...
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3answers
91 views

Does somebody have a schematic for a stereo electret condenser microphone?

I’m trying to use a Cmoy headphone amp (built around an OPA2227P chip) as a hard-wired in-ear-monitor. I bought a stereo electret condenser microphone from Jaycar this afternoon, but I can’t get any ...
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1answer
325 views

Low noise electret mic circuit

i wanna make a FM microphone for my guitar but the problem is that the electret mic itself output a lot of background noise even before amplifying its signal. so obviously i need a preamp circuit ...
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0answers
64 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 ...
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3answers
89 views

What could be a near rail-to-rail opamp with very low voltage for this use?

What could be a near rail-to-rail opamp with very low voltage for this use? LM386 seems to be out of limits for my needs. How do I choose it from datasheets? What values are important (of course ...
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1answer
117 views

How to find these resistance values in microphone phantom power power supply?

In most phantom power supply schematics or documentation (see for example https://en.wikipedia.org/wiki/Phantom_power#Technical_information), I see: 6.81 kΩ when powered by 48V 1.2 kΩ when powered by ...
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0answers
133 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 – ...
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0answers
67 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 ...
2
votes
1answer
107 views

How to improve this microphone phantom power supply to have better SNR?

I built this power supply for my Schoeps CMT30F vintage microphones: It works, but it's not the best I can expect in terms of SNR. What would do you to ensure the SNR is the best possible? Use 0,1% ...
2
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1answer
82 views

Can I test a XLR microphone with a DMM?

I have a microphone with a XLR output and a XLR to PL cable. I don't get from it any signal on my PC. Can I test with a DMM the microphone and the cable in order to locate the problem?
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1answer
116 views

Help with design a mic preamp with opamps for PGA and ADC

I want to sample an audio source using an electret microphone and analyze the spectrum of it with a uC. I'm interested in the 100Hz-2.5kHz range, so I calculate with these values when I tried to ...
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2answers
85 views

Convert CMOS-level signal to microphone-level (0..3V --> -1..+1V)?

I'm building a microcontroller circuit that feeds its output into a microphone input of an audio recorder. The output is a square wave. (Think old-style 3.5mm Square credit card readers). What can I ...
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2answers
60 views

Why can mobile microphones handle high noise now?

I'm wondering why mobile microphones can now record just fine in very noisy environments? (like loud rock concerts) when just a few years ago the sound would be cracking so terribly that you could ...
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1answer
151 views

I need schematic of this simple microphone [closed]

wires inside the microphone were cut and I don't know the correct place of wires to solder them so I need schematic or your explanation to repair this microphone. This microphone contains only four ...
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1answer
342 views

Convert from line level to mic level, without worsening the sound quality

I have an audio signal coming out from an iPhone which I would like to record in iPad using its mic input. I have tried this with simple resistor divider (and TRS-TRRS connectors), but it seems to ...
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1answer
162 views

SPW2430 MEMS MIC Taking time in returning to base Voltage

BREAKOUT BOARD SCHEMATICCIRCUIT SCHEMATIC Green probe is for DSO and red probe is for DMM I am trying to create project using ESP 32 with arduino IDE which turns on when a snap is detected. I will ...
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1answer
45 views

PC microphone isn't outputting any signal into a scope

I have one of those average cheapo computer microphones that connects into the sound card via pink 3.5mm jack. I wanted to find out how much voltage can I expect from it, to get a ballpark value I ...
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0answers
22 views

Solution to coefficients for Spherical wave equations

Are there any methods for solving coefficients \$A\$ and \$B\$ for the Spherical wave equation below? \$p(r,\theta, \phi) = \sum\limits_{n=0}^{\infty} \sum\limits_{l=-n}^{n} \Big[A_{nl} h_{n}^{(1)}(...
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1answer
90 views

Why do I see 0v on electret microphones?

I've got a few electret microphones and I tried to make this circuit: It didn't amplify my sound, it continuously buzzed. Without mic it did same thing. So I probed mic and I saw 0.000v. Also 0mA (...
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1answer
182 views

Difference between increasing microphone sensitivity and amplifying output signal in software

I am a bit of a newbie to the audio world, so please bear with me. What would be the difference between getting a high sensitivity microphone and using a low/medium sensitivity microphone and using ...
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3answers
183 views

Linking Android phone to motorcycle helmet comm set

I have a little mystery for you... I want to connect my motorcycle helmet communication set to my Android phone, including the push-to-talk (PTT) functionality. This is a simple wired setup, not ...
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2answers
357 views

Why LME49710 does not perform at least as good as LM358 for audio mic op-amp?

I built a hobby mic op-amp circuit as described here: It gave me a pretty ok result: Now I replaced LM358 with LME49710. The circuit is the same, except from the wiring to the LME49710 pins (LM358 ...
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3answers
1k views

Does a pickup microphone work in space (vacuum)?

Of course in space there is no sound transmitted via air, so there is no air-borne sound, but there is structure borne sound. This sound can be recorded with a pickup microphone, but do pickup ...
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3answers
272 views

Best microphone picking up sound within a small room?

I've tried several Electret Condenser Microphones as input to a generic USB audio sound card: MO064202-4 MO064402-4 MO064402-5 All mics work great at close range (about 1 or 2 inches). However, none ...
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5answers
348 views

What microphone (sound sensor) that can work with Arduino to detect gunshot?

I am working on a project to detect a very loud sound/Pop(like gunshot).I am using a microcontroller like Arduino. Currently I am using this simple sound sensor. But the issue is, it is very ...
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1answer
118 views

How to calculate power used by my microphone?

I want to plug a microphone into my camcorder. The battery from the camcorder will provide the power to both the camcorder and microphone. The specifications for the battery are as follow: capacity = ...
22
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5answers
4k views

Normal capacitor vs. audio capacitor

I'm building a power supply for old Schoeps CMT30F microphones. Standard condenser mic are 48V-powered nowadays, but these are 60s/70s Schoeps mic from RadioFrance/ORTF, customized at that time to be -...