Questions tagged [audio]

Questions about designing electronics for measuring, processing, and amplifying audio signals.

Filter by
Sorted by
Tagged with
1
vote
0answers
59 views

2 Crossovers in parallel: how are frequencies distributed?

So, the other day I connected on parallel a dual-voice subwoofer-system (a Pyle XSUB1-150-4-12d crossover — like this one ... link might be unavailable after Aug 28, 2019 ... — and 2 individual ...
0
votes
0answers
146 views

Low-Pass Filter Selection and Placement in Active Noise Cancellation

This continues in the same vein as my previous question - I'm working on an Active Noise Cancellation circuit to get rid of highway noises in my bedroom. Based off an ANC circuit pictured below, I ...
0
votes
6answers
237 views

How do I set my speakers out of phase?

A little bit of context: I'm doing a project for my physics class where I could choose the topic, and I chose to do phases in sound and noise cancellation (wavelengths and frequencies). Essentially, ...
1
vote
1answer
294 views

Linkwitz-Riley “isolator” equaliser question

I don't understand one thing about 3 way EQ based on Linkwitz-Riley crossover. We split the signal to 3 bands - low, mid and high. Why is mid band phase inverted? It doesn't make sense to me, but ...
0
votes
1answer
135 views

Class A amplifier with preamp design

I am currently working on a class A audio amplifier designed to work with line in voltage (about -400mv to +400mv). I plan on using an IRFP240 for the mosfet but am undecided on the transistor stage. ...
0
votes
0answers
50 views

Difference between car audio system and portable speaker

I designed a circuit which would turn on LEDs with intensity of the music (music reactive LEDs). I tested this using a portable Chinese speaker and it worked amazing. This makes me think that the ...
0
votes
0answers
15 views

Connecting balanced output with unbalaned input using adaptor

I want to connect my audio interface (balanced TRS jack output) with guitar pedal (unbalanced TS jack input) and I wonder if this kind of adapter will work: https://www.amazon.com/dp/B001JYSMV0/ref=...
0
votes
1answer
637 views

Audio mixing : crosstalk calculation

Here is an interesting article about mixing stereo. Most important issues when mixing stereo are : interaction between channel crosstalk noise Interaction between channel is explained here in 1.0 ...
4
votes
1answer
131 views

Why an 8kHz notch on the headset mic input of a Qualcomm WCD9330?

I have here a smartphone which uses a Qualcomm WCD9330 audio codec IC. (Itʼs a Galaxy Note 4.) Iʼve discovered through testing that the headset microphone input exhibits a roughly 10dB notch in its ...
2
votes
0answers
261 views

Op-amp circuit saturates to negative rail and only passes positive side of input

I've been working on a spring reverb driver circuit, based mostly on figure 5 from this site: https://sound-au.com/articles/reverb.htm. While there's lots of information on the how of the circuit, ...
1
vote
2answers
456 views

Boosting a microphone for a noisy, low sensitivity input?

To avoid running into an XY problem, here is the problem I really have: I have a RODE NTG2 microphone, and a Zoom H4n Pro recorder. The NTG2 has an XLR output, balanced, and it operates from either a ...
2
votes
1answer
6k views

How to calculate Resonance Frequency of Audio Speaker?

Okay so I searched all over the Web for the resonance frequency of my car speaker so I can properly apply crossover filters, but didn't found any reference of the resonance frequency of this speaker ...
2
votes
1answer
5k views

Calculating impedance in a two-way speaker crossover

I'm trying to come up with a basic two-way crossover for a speaker I'm building out of scrap. (Working with what I've got - no new parts.) My amp handles 8-16 ohms. Here's what I've come up with for ...
0
votes
1answer
146 views

Motorola telephone-style handset audio to 3.5mm jack

I retrieved a Motorola Telephone-Style handset wich was in service with a Motorola radio GM380. It is the same as https://shop.motorolasolutions.com/rln4756-telephone-style-handset/product/RLN4756A ...
2
votes
5answers
1k views

Isolated audio without a transformer

I'm putting together a guitar pedal for splitting the signal to two different amps. One of the features I want to put in is a 'ground-lift'; isolating the signal to avoid ground loops between the two ...
0
votes
0answers
36 views

Filtering analog audio signal using TLV320AIC3111-EVM

I'm working on a project to filter analog microphone data using the audio codec from TI, the TLV320AIC3111. We are using the EVM However, I'm facing problems with implementing the filters on the ...
0
votes
2answers
106 views

Guitar to MIDI conversion

I am wanting to measure the pitch of a single guitar string and convert into MIDI within 10ms. FFT takes too much time, I was wondering what other options are worth looking at? The main issue is ...
1
vote
1answer
35 views

How to drive a speaker (earpiece) in an antique (vintage) phone (67 ohm)

I am using a small audio player board (DFPlayer Mini) that has a 3w audio amplifier built in. I have hooked it up "as is" and it appears to work but has some intermittent static. While it could be ...
0
votes
0answers
73 views

How can I view a song from my iPhone jack on an oscilloscope?

I was wondering how to view a song from my Iphone on an oscilloscope. I tried doing it today but got mixed results. I set the horizontal sweep to 1ms/div, the vertical to 1 volt/div and the coupling ...
3
votes
2answers
163 views

Imposing AC ripple on DC voltage

I am trying to impose an AC ripple of 0.9V peak to peak (1kHz) on 36 volts DC supply for one of the test using following circuit. Without any load connected, I get the proper AC imposed DC voltage ...
2
votes
2answers
79 views

Op-Amp output voltage exceeds the power rail voltage (in simulation)

I'm designing a RIAA pre-amplifier based on the 2 op-amps from an NE5532 package. It seems that something is wrong, because the output of the 2nd stage is giving a 400V output which is way above the ...
1
vote
1answer
135 views

Best way to connect balanced audio line to ADC (with volume pot)?

Sorry for this more longish question: I'm currently collecting some ideas for my next project where I want to connect an external balanced audio line level signal to an ADC with differential inputs (...
0
votes
2answers
64 views

Preventing audio feedback in an underwater multiway intercom

I'm trying to transmit data(bytes) from a speaker (out) to microphone (in) via an FM modulated link. Now I have the problem that both will be used simultaneously (full duplex) and next to each other (...
0
votes
2answers
254 views

Mixing analog audio signals with resistors

I am creating a type of mixer for 2 audio inputs into 1 output so i can use 1 pair of headphones with 2 computers without buying an expensive mixer with a amp Currently i have 1k 1/2W metal resistors ...
4
votes
2answers
843 views

Line-in level from OpAmp

This is a follow on question from here: Simple Audio Amp for FPGA audio to PC in which I'm trying to get audio from an FPGA -> delta-sigma DAC -> op-amp -> Line Level. Following the advice given in ...
1
vote
0answers
48 views

DIY high fidelity audio using delta sigma adc

This question may be too general, but I will include all the details that I can. My end goal is to achieve a super high-resolution spectrogram of any recording I choose to make. By doing some tests I ...
-2
votes
3answers
936 views

Using TDA2003 as a typical op-amp

I used TDA2003 to make a simple audio amplifier using a circuit I found online and it worked. Then I was wondering since the TDA2003 as far as I understand is an op-amp why can't I use it this way: ...
2
votes
3answers
387 views

Mixed analog-digital power supply

I'd like to build a project where I'm essentially controlling analog signal generation in the audio range from a microcontroller. In other words, an analog synth with digital control. I'm at the stage ...
0
votes
3answers
1k views

LM386 amplifier buzz when not connected to signal

I've set up a simple LM386 amplifier on a breadboard according to the above schematic. When connected, the amplifier works like a charm driving a spare 8Ω speaker with impressively low (audible) noise....
1
vote
3answers
354 views

How to split audio signal into 3 separate channels?

I have been working with the following circuit: to build a audio mixer where you can take multiple line inputs, cd players, computer, phone, synthesizers, etc... and mix them together to a single ...
0
votes
1answer
359 views

What's the difference between SAI and I2S?

I'm developing a USB audio device using an STM32F407G-DISC1 evaluation board. For the audio output I was intending to just use the I2S peripheral connected to a DAC. However the only sample code I ...
0
votes
2answers
64 views

Phase splitters/inverters using valves with directly-heated cathodes

I'm building an audio amplifier using Raytheon 6418 valves and I'm struggling with the phase splitter. The 6418 has a directly-heated cathode and I'm wondering what limitations this might introduce. ...
0
votes
2answers
57 views

Amplifier Audio Ground to Signal Ground

I am using a VS1053 (on a SparkFun Music Maker shield) to provide audio for my project. I am taking a line out signal and inputting it into an op amp for signal processing, ultimately being input to ...
0
votes
1answer
72 views

basic DIY function generator and scope

I'm currently traveling and only have access to basic parts (soldering iron, an arduino nano and a breadboard!) but I'm able to buy parts from local suppliers. for a project I need to be able to ...
2
votes
1answer
88 views

Simple frequency-tunable spark generator?

This may sound weird, but... I am attempting to design a steampunk / gothic horror-styled electric harpsichord, with sparkgaps as the sound source in the vein of musical Tesla coils. Unlike musical ...
6
votes
6answers
2k views

Why does this potentiometer in an op-amp feedback path cause noise when adjusted?

I have placed a dual-gang 100k potentiometer in the feedback path of two op-amps that work as a Sallen-Key filters. This controls gain but also the Q factor of the filter (somewhat demonstrated on ...
0
votes
2answers
123 views

Artec QDD2 reverse voltage problem

I have an Artec QDD2 overdrive circuit and I recently powered it up with reverse voltage by accident and it doesn't give any sound on the stages of distortion, however it is allowing the bypass on ...
0
votes
0answers
34 views

Configuring GPIO directions for I2S interface

I am working on integrating a WM8731 audio codec chip with an AM335X processor. This is my first time working with I2S and I want to make sure I understand it correctly for configuring GPIO directions....
0
votes
0answers
49 views

Microphone input buffer circuit not behaving as in simulation

I have designed a circuit to interface the SPW2430HR5H-B microphone into a dsPIC33 ADC pin. The circuit has an active LPF and uses the AC coupling capacitor as a HPF to get an output on the frequency ...
4
votes
5answers
6k views

Shielded vs Twisted cables

For some reason low voltage, high quality audio interconnects seem to be made of 3 wires braided together, when normal low voltage audio wires are two wires surrounded by a grounding sleeve. I'm a ...
0
votes
4answers
142 views

Why is the audio input from the microphone connected to the inverting input on the TPA6111A2?

As far as I know, when we connect a signal to the inverting terminal of an op amp, we get an amplified output which is 180 deg out of phase from the input. Going through the datasheet of TPA611A2, the ...
1
vote
1answer
36 views

Fatal Error Audio equalization simulation LTSpice

I'm doing a 3s audio.wav simulation on LTSpice with the following circuit (3 band pass filters and amplifiers): In this example it's boosting the bass and attenuating the highs. It loads the first ...
0
votes
1answer
40 views

How does a video entry system send audio and video, as well as ring/unlock over 4 wires?

I’ve been trying to understand how my door entry system works. Between the monitor/base station and the bell/camera/speaker there’s only 4 wires: 12V DC GND Voice (2 way) Video (1 way) I opened it ...
1
vote
1answer
215 views

Audio volume levelling / AGC for spectrum analyser

I'm busy building a preamp, and want to include an LED-matrix spectrum analyser on the front panel (for aesthetics, not accuracy!) I've set up a circuit that uses a couple of MSGEQ7 chips to analyse ...
0
votes
2answers
42 views

Audio amplifier mono operation and power consumption

I'm looking to use a PAM8406 in Class-D mode, with only the left channel active. The datasheet doesn't discuss how to handle unused pins for the right channel to "deactivate" that half of the amp. ...
0
votes
0answers
30 views

Bad headphone driver resistance

I have a pair of ATH-M50 headphones where the right side has stopped working. I took them apart and measured the resistance at the L/R terminals on each driver. The good one measures about 35 ohms ...
1
vote
1answer
46 views

XO selection for 44.1kHz audio

I'm implementing a WM8804 S/PDIF transmitter in a project I'm working on. The datasheet states that clocks from 10MHz - 27MHz are supported. What crystal oscillator frequency should I look for in ...
0
votes
0answers
24 views

Question about pins on TCA940

So for the sake of learning i got this 10 watt audio amplifier and i wanted to see if i could make things work but i'm not sure what some of the pins are used for. Pin 5 "Compensation": From what i ...
0
votes
0answers
42 views

Emulating guitar pickup loading effects with a floating gyrator?

I'm looking to construct a high impedance buffer which emulates the loading effects of an electric guitar connected to a nonlinear, low input impedance amplifier such as the Dallas Rangemaster (...
0
votes
3answers
60 views

Quad voltage controlled resistance

In order to have a quad volume control, I thought of having a single log pot between a DC negative source and 4 gates of 4 matched JFET's as shown above. We're talking audio here, I haven't calculate ...