Audio Definition and 265 Threads

  1. M

    Feynman Audio Lectures: Complete Set Available?

    I love Feynman's Lectures on Physics and want to go over them again, but I find there's so much of his character is lost when just reading them. I have found a few selected audio versions of his lectures, but I would like to find the COMPLETE set. I know they exist somewhere, as that's how they...
  2. J

    How Can I Combine Two Audio Outputs Without Cross-Talk?

    Essentially what I'm trying to do is combine two headphone level outputs to one set of headphones. The earbuds are generally 23 ohms, so got four 24 ohm resisters and wired it like so: Left output #1 -> 24 ohm -> left earbud Left output #2 -> 24 ohm -> left earbud Right output #1 -> 24...
  3. L

    Questions concerning mobile audio: Capacitor to filter tweeters

    https://www.parts-express.com/dayton-audio-nd25fn-4-1-neo-silk-dome-tweeter-element-4-ohm--275-053 https://www.parts-express.com/cat/capacitors/68 Tried replacing the OEM speakers in my vehicle with a set of aftermarkets ...without exchanging the OEM head unit. Terrible idea, and I...
  4. L

    Removing Hissing Sound from Film Audio - Equipment Dependent?

    When you film something using the microphone on the camera or an external microphone, is there always that hissing sound that you have to remove by running the video through a high pass or low pass filter? Or does it depend on the quality of the microphone? I have a pretty cheap microphone, and...
  5. L

    Few questions concerning mobile audio

    Apart from the 30 some ought bands of EQ, pretty lights, phase control, time alignment, etc, what makes a receiver superior to another in terms of sound quality only? Clarion. McIntosh. Nakamichi. All of these manufacturers carry dead heads; that is receivers with no internal amplification...
  6. C

    Recording and listening to audio through a real time filter

    Could it be possible with the current technology to record the surrounding environment, filter it through all sorts of wacky filters, and then listen to it real-time? In essence, headphones with microphone, and echo, delay, chorus filters.
  7. T

    Phase cancellation with opposing and unequal audio frequencies.

    Greetings to ALL. tonequester here. I am re-doing my first, and LONG post. Concerning an electric guitar. Strings resonate at say, 800Hz. Wooden neck and body have their own resonant frequency, so I am told. No two guitars resonate at the same frequency, as no two, complex, combinations of...
  8. B

    Need help analyzing and audio amplifier [final exam study guide]

    Homework Statement Homework Equations See Image The Attempt at a Solution I am confused where to start this problem. Obviously i need to get at the DC load line for Q1. But the problem is that I was taught in class that the DC load lines intercepts for a transistor are...
  9. R

    Vintage RCA audio preamp I'm trying to fix/learn from

    I own a vintage RCA audio premp (BA-72A). I bought this as a module some time ago and it quit working on me for some reason. So it did work ok for quite a long time but not now. I get nothing out of it. Here are the schematics I have: http://imgur.com/OOuqhNP http://imgur.com/GIsxqAT I'm...
  10. Tesladude

    Audio amplifier power supply question

    So I had an old home receiver which broke down so i took out the large transformer 6800uf caps and rectifier. This receiver put out 60 watts out of each chip so from my many hours of being on google in the past, the chips should require +-35v, and because of the increase in voltage after...
  11. Y

    Physics - EE - Audio Engineering

    Hello, I am a physics undergrad currently applying to grad schools in physics with primary interests in experimental AMO and condensed matter. However, I also have some interest in areas of EE. Specifically, those are the areas of close proximity to condensed matter physics and DSP(digital...
  12. Z

    When is there going to be audio (academic) papers?

    Like there have been audio (layman) books.
  13. B

    Audio amplifier physical noise+possible popped capacitor

    Hello, I have this audio amplifier from Vivax AM 100. But it has somewhat weird problem. When you turn it on it starts buzzing but, not like buzzing on speakers but rather circuit starts buzzing, rattling noise. There is also like wax residue on the board, which i don't think its...
  14. C

    EE courses for designing audio amplifiers and speakers?

    Hi everyone. I've got my BS in physics, but I don't know much about electrical engineering. I've had a passing interest in do-it-yourself audio equipment for quite some time (designing and building your own speakers and amplifiers), and I've finally decided to get serious about it. So, it...
  15. jtbell

    Ray Dolby: Audio Pioneer & Innovator (1933-2013)

    http://www.sfgate.com/bayarea/article/Ray-Dolby-pioneering-sound-engineer-dies-at-80-4810882.php Those of us who grew up with audio cassettes remember the Dolby noise-reduction system for reducing tape hiss. It made cassettes capable of "high fidelity" music reproduction, at least by the...
  16. Tesladude

    Enhance Range for Remote Audio and Video with ASK Transmitter Modules

    Hi I think this may be a dumb question but what the heck... So i have a very small remote camera with audio, the thing is the size of like 4 dice. But it doesn't have good range with the reciever, only like 30'. I do a lot of electronics and have made remote controll circuits useing...
  17. Tesladude

    Audio power supply using DC-DC converter

    So I have been using some small audio amplifier ics in the tda series because they are good and easy to use but I have never had to power one with more than 24v. I am wanting to look into using a chip that requires about 35-40v supply but I can't find a transformer that is past 24v and am not...
  18. Tesladude

    Using Center Tabbed Transformers for Audio to Grounding on a 9v Circuit

    So I've used a chip like this before with a center tabbed transformer useing the tab as the ground for the speaker and everything. I want to run this on a 9v, what do I use as ground? is ground the -v on the battery or will just connecting all ground points together do it or what? I know that...
  19. Tesladude

    Suggestions for 9V Audio Chip for Portable Radio/Boom Box

    Hey guys,I am sure I am going to get some of the same guys on my last thread so, hey! I love the 20watt audio circuit with the lm1875 and will eventually pcb it for sure! This is another audio questions, but not like last time. So I want to make a small portable radio/boom box. I mean to...
  20. D

    Useful Representations of Log Audio Frequency Spectrum

    Hi everyone, So I'm trying to basically generate a list of numbers between 20 and 20,000 (Hz) in log space that will give good resolution to parts of the audio spectrum that matter! After all that is the point of using log scale for frequency in the first place. The list generator I have...
  21. Tesladude

    Troubleshooting an Audio Amp on a Breadboard

    Hello, I am trying to make an audio amp on my breadboard, for fun I guess. But it's not working! I am running off of this circuit of the lm1875...
  22. H

    Audio Source Moving @ Supersonic Speed

    Let's say I have an indestructible speaker and I launch it out of a cannon at Mach 1.5 while it's playing music. (To make things simple, it also has an iPod and battery attached to it.) If the speaker passes a stationary observer, will they hear each cycle of the sound wave from the speaker in...
  23. Tesladude

    Can the right capacitors improve audio quality in passive crossovers?

    Hey I am training to be an electrical engineer and am working with some audio passive crossovers just to for instance cut out the low frequencies going to a mid-range speaker. I want some good "hi-fi" stuff! So I know how to calculate the henerys and farads for the caps and inductors but I...
  24. S

    Passive amplification of a specific audio frequency range(microphone)

    Hi, I want to passively amplify a specific audio frequency range of a microphone. When I say passively I mean by non-electronic means - no op-amps or transistors. Like a speaker can be designed for specific frequency range - a woofer/tweeter/etc... I presume this works in the other direction -...
  25. J

    Cat 5 Digital Audio: Transmit/Receive 12 Channels @ 48KHz

    Hey guys I'm hoping someone can point me in the right direction here. My goal is to receive 12 and transmit 4 channels of 24 bit audio @ 48KHz over 100ft to 300ft. I would guess that at this distance I need differential signals. The Cat 5 cable would then have the following twisted pairs...
  26. S

    What are the accepted ranges for low, mid, and high audio frequencies?

    I am working on a small design project for class. I am making a simple frequency analyzer that essentially will multiplex a corresponding number of LEDs and turn a servo. I realize that the audible range of the human ear is roughly 60 - 20k Hz. Within this spectrum, what ranges of frequencies...
  27. P

    Using ATMega324P to Generate Audio Tone

    Homework Statement I'm needing to use an ATMega324P with fastPWM to generate an audio tone which gets sent to a piezo speaker. I'm generating a signal with a set of predetermined tones with an attached value for the various registers involved in fastPWM. tone is the variable associated...
  28. R

    How to build a speaker using an SMD audio (ring) oscillator?

    Hi! I aim to use a piezoelectric wafer and get it to work as a loudspeaker by supplying it with a fluctuating voltage withing the audible region. I know this can be done using a simple DC to AC invertor/oscillator circuit, but the challenge is to build it as small as possible. I looked up...
  29. M

    Help designing analog filter designs for an audio activated 8x8x8 LED cube

    I am working on designing a music visualization system using LEDs. I would like to create an analog design that uses op amps to filter, amplify, and add DC bias to an audio signal so it can be read into the A/D of a 5V microprocessor. The input signal is a +/- 1.5V volt audio signal coming from...
  30. L

    Troubleshooting Audio Amplifiers: Dealing with a Faulty Capacitor (C2)

    Hello people I am doing an audio amplifier, but I am really stuck in the circuit because the 1uF capacitor (C2 )doesnt work properly next the the potentiometer , but if I took off the Capacitor C2 I can hear music through my speakers, but with really bad quality. I don't know what you can...
  31. H

    How Do You Design an Op-Amp Bandpass Audio Filter with LED Indicators?

    I am attempting to build an Op-Amp circuit in which a sinusoidal input is used. Below is the description: An active, op-amp bandpass filter circuit for audio frequency inputs. The implemented filter circuit must provide a maximum gain of 14 dB inside the pass-band and less than 9 dB of...
  32. A

    High-Quality Output Buffer for Battery-Powered Audio Circuit | Impedance: 50Ω

    Hi guys, I'm currently designing a battery powered audio circuit. I've already finished all the signal processing stuff, and now I'm looking for a suitable output buffer to drive the speaker, which is about 50Ω impedance. Some of the requirements for the op amp buffer: - Single supply...
  33. D

    Reception of audio signal, through AC plug; bypasses a volume switch that works.

    I post to this forum, because I want to analyze this phenomenon with the aid of those who may understand the various nuances of scientific theory, by which such a thing could occur. I do not feel that posting to a forum dedicated to audio/video would yield quality results. This matter...
  34. E

    Audio Amplifier Design Basics: Problem & Solution

    I am studying basics of analog circuit design from microelectronics circuit analysis by donald neamen And in that i encountered a problem in design of audio amplifier. The question and solution is given in the attachment. And i want to know that in the output emitter follower why there are no...
  35. P

    Capacitance across an audio signal

    Looking at this datasheet: http://www.ti.com/lit/ds/symlink/lm386.pdf Most circuits near the bottom have a 250uF cap in line with the output. Would changing this cap affect the audio signal or would it just further smooth out the waveform?
  36. dexterdev

    Solving Audio Sources Doubt - Devanand T

    Audio sources doubt... hi all, I don't know where to post this. sorry for that. My doubt is that if there are 2 audio sources like one mp3 music file playing from a cd player and another speech signal coming from a radio. If I can hear both signals, what is the resultant audio...
  37. H

    Can someone resolve an argument over audio amplifier and wiring theory?

    Hey, I'm sorry to bother you guys but I got a quick question I was hoping you guys could answer. I was just hoping someone had a definitive explination as to why a $500 audio amplifier that can put out 200 watts per channel will sound exactly the same as a $10,000 amplifier putting out 200 watts...
  38. Doc Al

    Converting Audio Cassettes to MP3

    I have many old audio lectures on cassette tape that I would like to transfer to MP3 format on my laptop. Any clever ways to do this?
  39. V

    Program that accelerates video play speed and keeps audio at normal pitch

    I've been interested in this function Youtube offers on videos ever since I first used it a few months ago. It's amazing. Some videos are just way too long. The speakers will have something very informative to say, but they'll just ramble and/or speak very slowly. For some reason, Youtube only...
  40. C

    Laser Audio Transmitter Project Question

    Hi everyone, I'm attempting the laser audio transmitter project. And example of it is found here: http://www.freeinfosociety.com/site.php?postnum=2310 I'm quite new to electrical engineering type work, and am a little confused by why the circuit works the way it does. The diagram is this...
  41. N

    Capacitors in common emitter audio amplifier

    Homework Statement Hello. When I looked at my lab manual, I saw the capacitor CB is connected in reversed direction. The AC source is connected to resistor RS, then connected to the negative polarity of CB. But I have no idea why it connects in reverse. Can please anyone tell me the reason...
  42. N

    Impedance of an emitted audio amplifier

    Homework Statement I drew the emitted audio amplifier in the picture below. When I looked at my lab manual, it says the impedance should be Zin and Zout, which Zin = R1*R2/(R1+R2) and Zout = Rc I have a few questions about impedance relate to this circuit: 1.) I saw the...
  43. C

    Zero/Span Circuit for Audio Signal

    Hey all: I have an audio signal from an old portable CD player that on max volume outputs about 1-1.2V as shown when attached an oscilloscope. I want to feed this signal into a PIC microcontroller, but I hear you need to amplify and shift the signal into the 0V to +5V region for it to work...
  44. B

    Audio amplifier using only 1 op-amp [single supply]

    As the thread suggests, I am trying to amplify the signal from a microphone. Now, I have a circuit which uses 2 op amps with dual supply. That circuit works pretty well. I have to make now, a amplifier using only one op amp, single supply. The sound itself isn't of much...
  45. S

    Combining two audio sources, digitally

    I was playing around with some computer code to process some audio. As part of it, I needed to combine the audio from two different sources. Everything is in raw, uncompressed, 16-bit signed samples, at 48kHz sample rate. So now I'm thinking, do I add voltage, or add power? The sample values...
  46. S

    Path to audio electronic design

    I am 23 and have not been to college. I am currently working as a technician and panel builder for a small company that engineers and builds automation control systems. This is a decent job, but I feel underpaid due to lack of training, and want to step towards a field I'm personally...
  47. X

    Mono Audio DAC for ~20Mhz Microcontroller Synthesizer

    I have just joined EE senior design class. We have decided on making a synthesizer box with bunches of controls available to us. Ultimately, we would like to be able to output sound analog straight to headphones or external speakers through a 3.5 mm jack (standard headphones plug). I was...
  48. F

    Digital audio from a sound card

    I would like to do some audio programming for a school project, but I'm not sure how a computer processes audio and reconstructs it in a sound card. I've had a signal processing course that covered standard DSP topics but I'm not sure when or how they are applied to acquire, store, and...
  49. M

    Using a magnet near audio cable

    I was wondering if there was a way of having a magnet near an audio cable without having any interferance maybe by using a sheild. My idea was to have a magnet to replace the 3.5mm audio jack in a headphone cable and port so that it would magnetically attach. Is this possible?
  50. P

    Designing an Audio Amplifier Circuit: Tips and Components | Satya

    hi all, i want to design the following circuit. The circuit should listen to the audio and amplify the audio. could somebody provide me the circuit or help to design the circuit like which components shall i take for the audio input, the speakers what i have to select and additional things...
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