Snitch Lines

Citizens in Delaware Ohio and Columbus Ohio are encouraged to snitch on each other, even anonymously, for not covering their face or for large gatherings. Fact.

Delaware Ohio

To snitch in Delaware, go to this address:

https://delawarehealth.org/covid-19/

or call the hotline at 833-427-5364

Delaware is seeking mask snitching specifically:

Columbus Ohio

To snitch in Columbus, call 614-645-3111, or go to this address:

https://311.columbus.gov/311_main.aspx

and submit a service request.

Columbus is more concerned with gatherings, both indoors and outdoors, which are “violations”:

Gathering and mask snitching is currently the #10 service request in Columbus:

Celestial Movement: Know Less Understand More

The following are true and do not change perceptibly over an entire human lifetime.

  • The non-sun stars do not move relative to each other. Not now, not over thousands of years, not anytime we will ever know about. The stars remain a fixed spherical image we gaze out at from the inside.
  • The north star and southern cross remain in the same positions in the sky and do not move relative to an observer on Earth, even as Earth rotates. They mark the axis of rotation of Earth. Correct, they do not move at all. You could build a structure pointed at the north star one night and if the structure doesn’t move, it points at the north star day and night season after season year after year forever, whether you can see the north star or not, it’s there. (The structure would be called a gnomon, if you care).
  • All of the non-sun stars/constellations remain in the exact same latitude and therefore trace the exact same line through the sky each time Earth rotates, every day of our lives, no exceptions. The line a star traces through the sky at your location peaks at 90° – [your latitude] + [latitude of the star] always.
  • Earth’s rotational axis is not tilted. Earth’s orbital plane around the sun is tilted! When orienting celestial objects, we are forced to choose what we consider “upright.” Earth’s gravity cannot dictate “upright” for celestial objects. If you imagine Earth’s rotational axis as upright, the north star remains fixed as “north” or “up” and the orbital plane is then tilted 23° meaning Earth “moves north and south” as it orbits, or moves “up and down.”
  • The sun. slightly more complicated, but helpful because the sun is bright. What is a line of latitude? What does a line of latitude look like? The blindingly bright sun traces a line of latitude through the sky every day. On equinox days, the sun traces the 0° line of latitude (celestial equator) and on the solstices the sun traces the +/- 23.4° line of latitude. In between, the sun gradually traces lines of latitude from 0° to 23.4° to 0° to -23.4° and back to 0° again throughout the year. Each day the sun traces a slightly different line of latitude as Earth orbits.
  • Nobody is good at three-dimensional spherical-angle geometry! Nobody! Astronomers are not good at it. Nobody is! Then why does the current zodiac constellation represent the constellation behind the sun that we cannot see?? Because nobody is good at three dimensional geometry! Astronomers for millennia past and still today use the sun as a “pointer.” Nothing in the sky points like the sun. The sun is such a bright “pointer” that you cannot see what is behind it – but remember that the stars do not move relative to each other so if you have some idea of what the starry sky looks like, and you know the current zodiac constellation, you can reference the rest of the starry sky off of the sun itself. “Pisces is shining bright this month!” True statement – even though Pisces is only up during the day because looking forward the sun means looking toward the current zodiac constellation. We are currently in Pisces. “The sun pointer is moving toward the constellation Aries.” Another true statement. The line the sun traces through the starry background as we orbit is called the “ecliptic.”

Once you have some firm ground to stand on, you can start to remember some more basics and build. If you get confused, re-read the above and remind yourself that many things in the sky do not change!

  • Orion, the most widely-recognized constellation, is on the celestial equator. Therefore Orion rises directly east and sets directly west. Orion is “up” ~12 hours and “down” ~12 hours. Orion’s path peaks at 90° – [your latitude] above your horizon (directly overhead the equator). Also, Orion is visible from everywhere on Earth.
  • Orion is directly south of the border of Taurus and Gemini. The Taurus Gemini border marks the northern hemisphere summer solstice, so on the summer solstice the sun points near Orion. On the winter solstice, Orion is high in the sky at midnight.
  • Polaris, the north star, is located directly north at [your latitude]° above the horizon, always. Most people use the Big Dipper to find Polaris.
  • The two stars in the Big Dipper aligned with Polaris point to the ecliptic at Leo near its border with Virgo, so near the sun’s location at the autumnal equinox.
  • The Milky Way’s bright galactic center is among Sagittarius, specifically Sagittarius A. It is 29° south of the celestial equator so therefore peaks at 61° – [your latitude] in your sky (more visible in southern hemisphere). Being near the northern hemisphere winter solstice, it is most visible in northern hemisphere during summer.

Read Time v3 with an Accurate Mental Model

  • You are the observer in the center of the clock. Everything moves relative to the observer.
  • The sun position on the clock represents the actual longitudinal position of the sun.
  • Solar noon is noon on the clock. The two are one and the same. When the sun is directly overhead the observer, it is noon, and half of the day has passed.
  • Sunrise and sunset are depicted and labeled. Sunrise marks time 0:00 each day and sunset marks the day length. The day length changes gradually throughout the year with the seasons.
  • When the sun sets, the “official time” turns negative and begins to count down to sunrise. However, if you mark an event at +12:30 time v3 during an 11 hour day, +12:30 is visible on the clock even though the sun has set, the official time v3 is negative, and your event will be held in the dark. “+12:30” is still 12 hours and 30 minutes after sunrise and still a usable time.
  • The moon position on the clock represents the actual longitudinal position of the moon. Moon directly overhead on the clock, the moon is directly overhead the observer, “moon noon.” Moonrise and moonset are off to the side, just like the sun. I am adding small moonrise and moonset lines in the next version.
  • The moon phase is represented by the sun’s position relative to the moon and Earth, easily observable on the clock. Project the sun out to “infinity” and the sun points to the moon phase marked on the moon itself. Therefore the moon phase on the clock is determined just how it is in real life.
  • The locations marked on the clock’s Earth represent prominent geographical features approximately every 15° longitude. Therefore the sun passes one of the geographical features every hour. If you want to know the approximate time at a different location, just imagine the observer on the clock is at the location with everything else right where it is. Tilt your head if it helps or physically turn the clock on its side.
  • The sun pointing to the stars marks the seasons, just like in real life. The constellations on the clock are the constellations (official IAU) the sun points to throughout the year as Earth orbits. They are zodiac constellations on the ecliptic, for telling seasons, not the constellations on the celestial equator. The difference is minor (see below).
  • The stars pass overhead on the clock when those stars actually reach their peak to the observer. Star noon on the clock is star noon in real life.
  • Of note, the prominent constellation of Orion is on the celestial equator just south of the Taurus/Gemini border Orion borders both Taurus and Gemini. Therefore Orion is an excellent star reference to align the clock to real life.
  • The thin white line behind the equinox in Pisces shows 1,000 years of precession of the equinoxes. Yes, one thousand years, one millennium, 500 years in the past and 500 years into the future. The equinoxes do not move very much.

Understand Celestial Movement by Knowing Less

Notes

  • three buttons:
    1. 5040x with pause feature
    2. 21,600x with pause feature
    3. “sunrises / sunsets snapshots” time lapse
  • useful sounds?
  • add moonrise and moonset
  • The horizons showing day length are the only indications of latitude. I want to keep it this way. 2D, time is the 3rd dimension.
  • unify the new year globally making it the exact equinox. Focus locally, celebrate large events globally.
  • clock ticks in background on phones? battery life?
  • Digital doesn’t match graphic on some time lapses. Maybe only on past years?
  • digital font size correct for computers and phones
  • make “copy-able link” for the link generator
  • 90° and 270° ecliptic longitude are the solstices, correct?
  • astrolabe, Incan Inthuatana,
Fundamental Concept

Every movement of this clock is related to a naturally-occurring phenomenon. The sun, moon, and constellations are actually physically overhead the longitude physically shown on the clock. The only man-made concept is the unit of time: hours/minutes/seconds.

Within the constraints of being two-dimensional and using only concentric circle movement, the clock graphically displays celestial movement as accurately and with as much detail as possible in a way that promotes a practical mental model for the observer.

The horizons move to show the correct day and night length. They move in the correct direction to match the idea that the sun follows a longer path in the sky on longer days and shorter path on shorter days. In post-industrial time, noon is when the sun is directly overhead. This clock shows noon at the various world locations by being directly overhead the longitude. “Solar noon” is an industrial time concept.

The angle of the horizons does not directly correspond to the azimuth of the sunrise and sunset itself. For example, the sun being overhead a longitude location on Earth 100 degrees from your longitude when it rises does not mean the sun will rise 10 degrees north from east.

Two-dimensional is convenient for hanging on a wall, inexpensive to construct, can be displayed on a screen, and in reality people prefer 2D. 3D TVs never caught on. The outdoors is 3D enough.

Concentric circle movement is practical to construct and control. In addition, almost all the movement of the objects in the sky is due to the rotation of Earth.

Nature presents us with an infinity of detail that the clock could depict. Computers enable us to easily do this and most products show maximum detail. This clock selectively provides the user with just the basis required to comprehend celestial movement in order to inspire the user to abandon the technology for the outdoors and more fully appreciate natural reality.

The Observer

On this clock, all objects are referenced to the observer as though the observer is standing aligned to the rotational axis of Earth. “Aligned to the rotational axis of Earth” sounds like an unnecessary complication, but it means all the objects move (almost) continuously and you can tell time of day, day length, night length, moon phase, moon rise and set, seasons, constellation and star positions, and even approximate world times, all using an intuitive mental model.

The observer is at the center of the post-industrial clock.

Observer’s Imagination

Notice, the gnomon of a sundial is aligned to the rotational axis of Earth. The ancients knew how to think about this. If you want to be familiar with the movement of the Earth and the relative motion of the sky, you must align with the Earth. If you accept the one complication of aligning with Earth, all else naturally falls into place.

You might say gravity is the biggest obstacle to aligning yourself to Earth’s rotational axis. True. To eliminate the gravity problem, just imagine you are on the north pole. If you were sitting on the north pole during an equinox, you would see all the objects on the clock rotating around your horizon just like they do on the clock.

Rotation and Orbit

Notice “rotate” means an individual object rotates, and “orbit” means an object moves in a path around another object. Objects can rotate and orbit in different planes, but because of the way the solar system was formed, rotation is mostly closely aligned with orbit. One notable example of misalignment is the tilt of Earth’s rotation relative to its orbit around the sun.

The Sun, Horizons, and Time

The position of the sun determines all time-related items.

The rotational position of Earth is shown by the sun appearing to move relative to the observer. The position of the sun in relation to the eastern horizon and western horizon tells the time of day.

Day length is determined by the distance the sun must travel through the sky from the eastern horizon to the western horizon. Day length is shown by the position of the two horizons. Night length is the remainder of the 24-hour period as the sun returns to the eastern horizon. The horizons move because of the tilt of Earth and its orbit around the sun.

The sun points to the season on the backdrop of the stars. The 12 Zodiac constellations are used because they are aligned with Earth’s equator and are visible from most positions on Earth. The Zodiac seasonal periods are named based on when the constellation is aligned with the sun. Ironically, it is exactly during a particular Zodiac constellation’s season that the constellation is not visible in the night sky because it is directly behind the sun.

The stars move around the observer because of the rotation of Earth, like the sun. Because of the orbit of Earth around the sun, the stars actually appear to move slightly faster than the sun. In a way, the stars “chase” the sun across the sky. Because of this, the constellation that is low on the western horizon immediately after sunset indicates the next season. The constellation will “chase” the sun down, setting because of Earth’s rotation and then each successive night set four minutes earlier until it sets with the sun.

Moon phase is determined by the position of the moon relative to the sun. The position of the moon relative to the sun is immediately apparent on the clock giving the user an intuitive mental model of moon phase. The moon rises and sets independently of the sun, so there are separate horizons for the moon.

Relative to the Observer

The stars do not move relative to each other, so you can relate your favorite constellations to the Zodiac constellations to quickly know where they are if desired. The position of the Zodiac constellations on the clock are accurate relative to the observer. The observer need only adjust for latitude. If a constellation is directly overhead on the clock, it is directly south in the northern hemisphere or north in the southern hemisphere, or overhead on the equator.

Approximate world time is asking the question, “What time is it to other observers?” or “Where is the sun relative to other observers?” The user can look at the other cities on the clock and see where the sun is relative to them. If the sun is directly over another location on the clock, it is noon in that location. The sun is moving relative to other observers just like it is moving on the clock. If the sun appears directly to the side of another observer, it is near rising or near setting. If directly below, it is midnight to that observer.

Sun/Moon/Stars to Sundial to Pendulum to Quartz to Atomic Vibrations to Smartphones to Sundial to Sun/Moon/Stars

Progress is a cycle.

Pre-history: humans evolved with celestial objects ruling our lives and became familiar with them. The sun and moon are encoded into our genes in our circadian rhythm.

Thousands of years: humans quantified the movement of the sun with sundials, and used charts for the phases of the moon and seasons.

Industrial Revolution: humans used rudimentary machines to club our minds to submit to rigid schedules.

Post-Industrial Clocks: humans use advanced machines to conform technology to nature and re-connect with our natural selves.

Like this clock, the gnomon of a sundial is oriented parallel to the rotational axis of the Earth. If you called this clock an “indoor sundial” you are not too far off. However, “indoor solar, lunar, and celestial fully-automated schedule” would be more accurate. Therefore, is this new? No, but is anything new? Not according to the Bible,

Ecclesiastes 1

9  What has been is what will be, and what has been done is what will be done, and there is nothing new under the sun. 10  Is there a thing of which it is said, “See, this is new”? It has been already in the ages before us.

Life is a cycle and it is time to revisit some of our past. We now have the time and resources to do it.

Knowing what the sky looks like can certainly be done with charts, phone apps, websites, maps, but to develop a useful mental model, you need to periodically and quickly see something that is practically relatable to practical day-to-day events. This is our natural ability that was erased by industrial time. Industrial time is great for rigid old obsolete machines to cheaply give us rigid schedules, but computers enable machines to imitate nature and can enable us to re-connect with nature rather than brutally beating nature out of our minds with the incessant ticking of pendulums and gears. Computers can be better, let’s use them.

history, manufacturing, time, astronomy,

Living History

Draft, working on this post.

The following is a list of historical figures, selected primarily for having been interesting. Most either were extremely successful, crazy, won or lost key battles, or committed or were victims of atrocities. The goal is to learn history by knowing the context of their lives and their contemporaries.

Also, I want to quickly summarize their lives using geographical features and cities (rather than modern national borders).

551-459, Confucius

450-404, Alcibiades, Greece, Anatolia

381, King Dao of Chu, Early ruler in the warring states period.

375-316 “Olympias, Queen of Macedonia”, Alexander the Great’s mother

350,-285, Pytheas of Massalia, “Pytheas the Greek” Explored from Greece to Britain

367-283, Ptolomy 1, “Ancestor to Cleopatra, inherited Egypt from Alexander the Great”

312-63, Seleucid Empire figure?

247-181, Hannibal Barca, Carthage, Defeated by Hublius Cornelius Scitio Africanus

~-161, Maccabean Martyrs

215,-164, Antiochus IV Epiphanes, Historical monster

106,-48,Gnaeus Pompeius Magnus, Lost to Julius Caesar

5-67, Paul of Tarsus, wrote much of the New Testament, “Reading from the Letter of Paul to … ”

69-155, Polycarp

100-165, Justin Martyr

202 Irenaeus

244-311, Diocletian, Ended the 3rd Century “crisis of emperors.”

298-373, Athanasius

437, Gunther, Scandanavia, Hungary?, Killed by Attila the Hun, Norse legend.

480-575, Saint Brendan the Navigator, See also Patrick and Brigid of Kildare

500-548, Theodora, “Mabbug, Cyprus, or Paphlagonia, Wife of Justinian, convinced men to stay during Nika riot, insisted on wearing royal purple.

573-634, Abu Bakr, Muhammed’s father-in-law, Sunni leader.

686-741,Charles Martel, Stopped the Muslim advance at Battle of Tours

752-803, Empress Irene, Byzantine Empress. Killed her own son.

885-954,Erik Haroldsson, King of Norway and Northumbria, “Erik Bloodaxe”

-986, Bjarni Herjolfsson, Overshot Greenland and landed on Labrador Coast / Newfoundland

-1014,Samuel of Bulgaria, Lost to Basil II. 99 / 100 of his men were blinded after loss, brutal.

1022-1066, Harold Godwinson, Harold II, Last Anglo-Saxon King of England. Beaten at Hastings, William the Conqueror.

1215-1294, Kublai Khan, Successor to Ghengis

1304-1377, Ibn Battuta, Major traveler. Berber. Never the same path twice.

1336-1405,Tamerlane,Uzbekhyzstan,,Murderous.
1371-1433, Ma He / Zheng He, Explorer, huge fleet, did not conquer. He was a eunuch.

1450-1500, Bartolomeu Dias, Cabo de tempestade, Portuguese explorer

1485-1547, Hernán Cortés de Monroy y Pizarro Altamirano, 1st Marquess of the Valley of Oaxaca. Burned his ships and defeated the Aztecs.

1519-1589: Catherine de’ Medici – influenced by Il Principe (2nd book printed on press behind The Bible), married to King of France, instigated St. Bartholomew’s Day Massacre.

1583-1634: Albrecht Wenzel Eusebius von Wallenstein – Bohemian military commander influenced by Gustavus Adolphus of Sweden

1635-1695, Michael Toussaint. Became Michael of Ruffine. First Ruffing.

Respect Literacy: Blogs are the New Book

Like books, personal blogs seem to have an innate ability built-in to the medium to bring out the best in people.

Do not confuse blogs with social media.

I have been keeping this list of my friends’ websites for several years now. Many are small business sites (pillars of society), none are vanity-driven, and all of the information is thoughtful, meaningful work by people who care. All of it is good. It represents the cream of 100+ years of electronic communication. That’s a strong statement and it’s true.

If you became literate and started reading books 500 years ago after the Gutenberg Press, you got ahead. If you understand the power the internet brings to people by enabling blogs, you get ahead.

Magnus Carlsen Just Lost

Norwegian Magnus Carlsen is the Tiger Woods of chess. That’s why chess has become a mainstream sport! OK, that’s extreme, neither mainstream nor sport (debate!?), but Magnus Carlsen was the youngest player to top the world FIDE rankings when he reached the top in January 2010 and he has been on top since.

Magnus Carlsen’s Recent Loss

Four days ago, on 24 January, Magnus Carlsen lost to 18-year-old Russian Andrey Esipenko. It was a huge upset. The tournament schedule is here and the final round is played on 31 January.

Watch the game analysis of Carlsen’s loss here.

Two days later, On 26 January, Magnus Carlsen bounced back and won his next game. Watch the game analysis here.

On 27 January, Magnus Carlsen, World #1, played World #2, American-Italian Fabiano Caruana.

Watch the game analysis here between the world’s top two players.

How to Watch Chess

Chess games last several hours, and it’s chess at a level we cannot understand. However, agadmator’s Chess Channel makes the games watchable and even exciting. Here is agadmator’s website. Agadmator’s name is Antonio Radić and he is Croatian guy who is a really good amateur chess player and now comments on chess full-time.

The International Chess Federation, FIDE is the most widely-recognized governing body. (but their calendar stinks)

Magnus Carlsen’s own schedule might be the best place to follow. Other options are chess.com calendar, agadmator’s site, FIDE ratings, more … ?

Who’s Who of Chess

Chess has a long history. We’ve heard some of the names without being able to place them. Here are some:

Paul Morphy, 1837-1884: dominated in America, then crossed the ocean and dominated in Europe.

Bobby Fischer, 1943-2008: American who won the most widely publicized chess championship of all time, the 1972 World Chess Championship considered a Cold War US versus USSR chess showdown. I have not yet seen the movie, Searching for Bobby Fischer.

Garry Kasparov, 1963-living: longest reign at top of FIDE ratings.

Computers Playing Chess

The chess computer Deeper Blue beat the reigning world champion in 1997, and computers have not looked back. Modern computers beat all humans at chess.

Audio Terminology and Reference

Stereo Versus Mono

Stereo sound means left and right can be a different audio signal. Usually the two signals are nearly identical, but sometimes the difference is very noticeable. A stereo signal is two mono signals. Most people are familiar with this concept.

“Channel”

When buying mixers, pay attention to what “channel” means. Each stereo input is two channels. Therefore a “four-channel” mixer or recorder can often only properly handle two inputs. Indeed each channel is a separate audio signal, but if configured as stereo, there will only be one volume control for two channels together, for example, among other inconveniences. The mixer I bought is 12 channels, 4 microphone (mono by their nature) and 4 stereo inputs for a total of 8 separate volume controls. 8 has been plenty for me and I expect to never exceed it in my whole life.

Balanced Audio Signal Versus Unbalanced Audio Signal

Balanced audio uses two separate conductors carrying the same audio signal with opposite polarity. There is also a third conductor called ground or shield. The advantage is any noise picked up by the cable is picked up equally on each of the two conductors and therefore the noise cancels itself out leaving only the audio signal. The most common example is a microphone connected to an XLR input. See the XLR pin diagram below as the archetypal balanced audio example.

Unbalanced audio uses a single conductor to carry the audio signal, plus a ground. The most common example is headphones. There are three conductors because of stereo sound but each of the signals is a single unbalanced audio signal to the headphone speakers.

Microphones: Dynamic, Condenser, Electret Condenser, MEMS

Dynamic microphones use a magnet and coil to produce the audio signal. Advantages: do not require phantom power as the moving coil produces the electric signal, no self-noise, better at loud sounds, usually rugged and durable. Disadvantages: not as good at capturing detail. The most common example is the Shure SM58 performance mic.

Condenser microphones are delicate studio microphones that require phantom power to charge a “backplate.” While they produce some self-noise, they are better than dynamic mics at capturing sound detail, especially with with quality phantom power and using balanced audio signal. The most common examples are studio music recording mics and tech nerd podcasts. There are large diaphragm and small diaphragm condenser mics but if you care about that you are reading beyond this post.

Electret condenser microphones cheap and small. They don’t match professional mics in quality but they are very good and make up for the quality with small size and price. They are condenser microphones because they use a capacitor (charged plate) to produce the signal, but they do not require phantom power because the “backplate” is chemically charged in a way that does not decay for hundreds of years – pretty much permanent charge, like a permanent magnet. Note: I have had little success connecting these microphones to an audio mixer. While the description says they do not require power, I have also heard that they require 5V or 12V or 3-12V that is provided automatically by the computer or phone they are connected to. … ?

Cell phones use MEMS microphones (MEMS = microelectro-mechanical systems) because MEMS microphones are etched directly onto a silicon chip, often together with required circuitry, and they require very little power.

Phantom Power

Condenser microphones require phantom power to charge a backplate.

  • Music mixers provide phantom power on their XLR inputs.
  • Phantom power is almost always de-selectable with a switch on the mixer.
  • Although dynamic mics do not require phantom power, most will not be damaged by it. Many musicians use phantom power with dynamic mics all the time without knowing what it is and the only result is a barely-audible hum.
XLR Input and Pin Diagram

An XLR input is a dedicated balanced input typically designed for microphones.

Male Versus Female

I don’t need to explain “the birds and the bees” here, but pay attention with XLR because it’s not immediately obvious especially when buying cables. Pictured above is female XLR that would require a male cable to connect.

TRRS Diagram

TRRS stands for “tip ring ring sleeve.” The only use I know for TRRS is stereo sound plus microphone:

*Note: some TRRS diagrams show the microphone as a ring and the sleeve as ground, but I believe this was probably an old standard now obsolete that was abandoned because the audio signal could interfere with the weak microphone signal.

TRS and TS

TRS is “tip ring sleeve.” The standard example is stereo headphones:

Notice the two signals on standard TRS headphones are unbalanced, therefore unbalanced stereo. Unbalanced sounds “bad” but it is just slightly more susceptible to noise than balanced audio, an effect less important than many other factors in most cases.

TS is, you guessed it, “tip sleeve.” The most common TS example is a mono audio signal. The tip is the audio signal and the sleeve is ground.

“Phone Plug” Sizes (“Phone Plug” = TRRS, TRS, & TS)

I quote “phone plugs” because although it may be the official term, you will have better luck searching TRRS / TRS / TS. “Phone plugs” come in the following sizes:

  • 1/4″ = 6.3mm = “phone plug” = “the big ones”
  • 1/8″ = 3.5mm = “mini-phone” = “normal headphone”
  • 2.5mm = “sub-mini phone plug” = “the tiny little ones”
Balanced Audio on TRS

TRS can be used to carry a (mono) balanced signal (not common). For example, see the female 6.3mm TRS input on the XLR diagram above. The TRS input says “BAL OR UNBAL” beside it. A TRS balanced signal looks like this:

Signal Levels: Passive, Powered, Amplified

These are not “official terms,” but I would say there are three “signal levels.”

A passive signal is the signal a microphone produces for example. The signal is generated by the physical movement of the internal parts of a microphone. These signals must be amplified and are therefore sensitive to noise because any noise picked up will be amplified along with the audio signal. For this reason, passive signals often use balanced audio. Passive signals cannot even drive headphones.

A powered signal is the most common type. Once any electronics are involved, there are small amplifiers to drive the signal. Any powered signal can drive headphones, but usually not a speaker without external power.

An amplified signal can by itself drive a large speaker that does not have external power. Notice, with mono audio, some amplifiers will output an amplified signal via TS capable of driving a large speaker. You must use a robust TS mono cable to carry this signal to drive the speaker and not all TS mono cables are capable of this.

RCA Connectors

RCA connectors are common enough to warrant their own heading. They usually carry unbalanced mono signals and come in color-coded pairs for stereo.

Analog Versus Digital

All signals I refer to here are analog. USB is a good example of digital. Digital signals can be manipulated by software and digital can travel lossless over long distances. Digital has its advantages, but the conversion to digital and back to analog means delay even locally so once you are dealing with digital signals, you cannot listen to locally-produced sounds in real-time because you can perceive the small delay.

Bluetooth Transmitter

Once you have an audio signal on a standard headphone TRS, notice how versatile a Bluetooth transmitter can be with battery-powered Bluetooth speakers. Search for a Bluetooth transmitter and find many options, very affordable.

Bluetooth Receiver

If you want to mix in a pre-recorded track, a Bluetooth receiver is a great option to connect a music-playing smartphone or other digital device to your mixer. Many options, very affordable.

Surround Sound

I don’t know! I’m sure a home theater system salesman can talk for hours about it for free though!

Produce. Persevere. Own. Succeed. Fail. Care. Do. Learn. Win.