59
votes
Accepted
If we use potentiometers as volume controls, don't they waste electric power?
If you do this, then it will waste a lot of power:
simulate this circuit – Schematic created using CircuitLab
You'll also need a very large and heavy potentiometer because it will have to ...
- 69.1k
38
votes
Accepted
What is the difference between a buzzer and a speaker and are there any other basic electric/electronic things that output sound?
A buzzer usually has an oscillating transistor circuit inside - to make the buzzing noise when voltage is applied, so it makes a tone.
Applying voltage to a speaker will not make a tone, so you'd ...
- 728
31
votes
I've become an electrical conductor for my headphones... but how?
The "buzz" is almost certainly RF pickup. This can be the mains (low frequency, 50/60/100/120Hz, unlikely in this scenario given a phone is involved) or rectification of the carrier frequency of the ...
- 64.7k
17
votes
Voltage of sounds of MP3 files
Amplification
It does not depend on the music file, but at the amplifier sending the music to a speaker, or to a headphone/earplug connector.
Music file
A music file only contains 'values', and ...
- 13.9k
16
votes
Audio spectrum analysis: PC Software vs Hardware Spectrum Analyzer
The deciding factor between stand-alone analyzer or soundcard would be the frequencies you're interested in.
I will record the sound it makes with a microphone (it sounds differently if it is ...
- 71.9k
14
votes
I've become an electrical conductor for my headphones... but how?
The main fact, in my opinion, is that noise is heard only in right channel.
First thing comes to mind is issue with grounding. But then both channels would receive the noise.
Second - the source of ...
- 6,930
13
votes
Accepted
What is IP and NK transformation (seen on earphones)?
Ok. Here it is. IP stands for Iphone and NK stands for Nokia. Both companies connect different parts of earphone to different conductor points (read below.) Although other companies also follow one of ...
- 146
13
votes
How can I make a reliable tick tock sound electro-mechanically?
If you want something simple, just send a pulse to a speaker. My ancient DIY Geiger counter basically did this. You won't have much control over the sound, but it may be sufficient for your needs.
You ...
- 14.9k
13
votes
How can I make a reliable tick tock sound electro-mechanically?
The obvious way is to use a large relay, and pulse it at 1 Hz. That said, I read Electro-mechanical relay durability curve and it caused me to fear that a relay probably wouldn't last. Especially a ...
- 1,111
11
votes
Why do different value capacitors and resistors sound different in same amplifier circuit?
The impedance (think of it as resistance) of a capacitor changes with the frequency of the signal passing through. The lower the frequency (bass sounds) the higher the impedance.
The impedance of ...
- 69.1k
11
votes
I've become an electrical conductor for my headphones... but how?
My guess is that there is a break in the insulation of the right earbud and that electrical hum from your body is flowing into the noise cancellation amplifier.
Try wrapping the bud in cling film and ...
- 32.5k
11
votes
Accepted
Where does this decibel equation come from, why a factor of 20?
Sound power (\$P\$) is proportional to the sound intensity (\$I\$):
$$
P = A\ I
$$
where \$A\$ is the surface area.
And sound intensity (\$I\$) is proportional to the square of sound pressure:
$$
I = \...
- 30.2k
10
votes
Accepted
Types of decibels
Decibels are a nice way to measure things which come in a very wide dynamic range as it is a logarithmic measurement.
At a certain amount of zeros it just gets hard to understand what's going on and ...
- 17.5k
10
votes
What is the difference between a buzzer and a speaker and are there any other basic electric/electronic things that output sound?
When someone is "buzzed" into the house, its with a relay (electro-mechanical) sound-maker.
A relay, wired as normally closed, but able to break the circuit, is a buzzer.
simulate this circuit &...
- 33.8k
10
votes
What is the difference between a buzzer and a speaker and are there any other basic electric/electronic things that output sound?
Traditionally a buzzer was a device designed to make noise. Traditionally it would have been an electromechanical device. It would typically be supplied with DC and the oscillations would have been ...
- 21.7k
10
votes
Accepted
How to produce a middle C on intel 8080?
DCR C decrements the C register and sets flags; it does not affect the accumulator (aka A register). The only instruction in this sequence which affects the ...
- 1,048
10
votes
Accepted
High pitch audio frequency measuring
Most common audio equipment is set to match human hearing, 20Hz to 20kHz is their operating range.
So you want to measure ultrasound, If you want only to measure high frequencies, you can use a bat ...
- 1,088
10
votes
How can I make a reliable tick tock sound electro-mechanically?
WWV transmits a "ticking" sound as five cycles of a 1000 Hz sine wave.
WWVH transmits a similar "ticking" sound as six cycles of a 1200 Hz sine wave.
When reproduced linearly ...
- 24.3k
9
votes
Accepted
Phantom Power supply for Electret mic
You have roughly the right idea, but you should use a resistor divider instead of a single resistor to bring down the voltage. With your setup, the microphone is still subjected to high voltage, ...
- 312k
9
votes
Why does an electret not pick up sound?
The output amplitude is so low the MCU ADC can't measure anything except the DC bias voltage. Contrary to your assumption, there is no built-in op-amp in the mic capsule.
You will need a suitable ...
- 136k
8
votes
Accepted
How to Construct This Small, Simple Electronic Device?
Here you go..........
simulate this circuit – Schematic created using CircuitLab
- 46.5k
8
votes
High pitch audio frequency measuring
By definition of the audio range for humans, beyond 20kHz is beyond audio. There are audio equipment designers such as Rupert Neve who believe the range could be wider, but this is not necessarily ...
- 6,030
7
votes
Types of decibels
We don't. Deci-bels are deci-bels, which is a way to express a power ratio.
dBA is just dB with a known fixed value for 0 dB. Instead of expressing the ratio of two arbitrary power levels, dBA is ...
- 312k
7
votes
Accepted
Why place capacitors in front of the line to a (headphone) audio speaker?
The two large capacitors are acting as AC coupling capacitors. A capacitor in series with a signal acts as a high pass filter (if you're curious about that, look into the impedance model of capacitors)...
- 106
7
votes
Audio spectrum analysis: PC Software vs Hardware Spectrum Analyzer
I would personally recommend using a PC for several reasons.
From a monetary stand point, if there is sufficient information currently to identify issues using a trained ear, there is no need for an ...
- 1,836
7
votes
I've become an electrical conductor for my headphones... but how?
If you have a multimeter available, you can put it into AC voltage measurement mode and try to measure between the different metallic objects. Note that you should only touch the objects with the ...
- 7,404
7
votes
If we use potentiometers as volume controls, don't they waste electric power?
\$\color{red}{\boxed{\text{Will it waste electrical energy?}}}\$
Potentiometers are variable resistors and resistors waste power: -
$$P_{dissipation} = \dfrac{V_{applied}^2}{R}$$
Or
$$P_{dissipation} ...
- 443k
7
votes
What is a modern 2SD669 transistor replacement?
The transistor isn't critical.
A \$25\:\text{W}\$ output into \$8\:\Omega\$ means a peak \$Q_{415}\$ emitter current of \$\frac{20\:\text{V}}{8\:\Omega}=2.5\:\text{A}\$. (Resistive load assumption, ...
- 77.4k
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