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Audio Made Easy – Sound Advice Vol 1.

apartment system

High fidelity audio equipment, at first glance, can seem overwhelmingly complicated. This is especially true for people under 30, because we didn’t have the benefit of growing up alongside analog hifi gear. For a member of the iPod generation (someone who grew up with portable CD players, cheap headphones and MP3s) the number of components and their complexity can seem downright ridiculous. This leaves many potential analog enthusiast out in the dark, which seems to us a great pity.

Analog Revolution is here to help make sense of it all.

 

We’re going to start with some low-level concepts, and the physics of sound. This is the most complicated topic we’re going to talk about, but we promise we’ll keep it light.

At the most basic, most physical level, sound is just vibrations in the air. When you speak, your vocal chords vibrate. They push waves through the air. These waves hit a bunch of tiny hairs in your ears, those hairs pass the vibrations on to your brain, which interprets them as sounds.

Faster vibrations equate to higher sounds. Slower vibrations mean lower sounds. Big vibrations mean LOUD sounds. Little vibrations mean quiet sounds. You can draw these out, and they will look like sine waves (everyone remember sine waves? That’ll be the last math, promise.)

[Technically, this is a bit of an oversimplification. Don’t sweat the details too much.]

All sound reproduction systems (CDs, Vinyl Records, MP3s, Cassette Tapes, Reel-to-Reel tapes, whatever) work by storing an approximation of these waves. The closer they get to the original, the closer the sound will be to the original sound. Think about that. This is why we care about hifi–high fidelity audio– the better the equipment, the closer it can get to the original. High-Fidelity audio seeks to reproduce the original sound as closely as possible.

CDs and records take two different paths to get to the end goal. The CD takes the original smooth wave and creates a digital approximation of it. The original curves of the sound wave are redrawn using tiny squares. The end result looks something like this:

Analog vs CD
Analog audio vs. CDs

To be fair, this is also a huge oversimplification. In practice a CD is sampled 44,100 times per second. Those are very tiny rectangles.

The playback apparatus, be at a CD player or a computer, or whatever, has a bit in it called a DAC or a Digital to Analog converter. It takes these samples and rebuilds their component curves. This results in a very close approximation of the original sound.

MP3s take the audio from a CD and remove the bits that are hardest to hear, shooting for an optimally small file size. A good MP3 encoder, used correctly, can create audio that is indistinguishable from it’s CD counterpart. The MP3 file format was created specifically to take up as little space as possible. This is a dangerous idea as the smaller the file size gets, the more audio has to be removed. Think about pixels in a digital picture. They result in a rough approximation of the original image. The smaller the file size, the more obvious the pixels. Take a look at this:

Pcm

That’s our original wave, compressed and then displayed. It is certainly recognizable, but it could definitely look better. It is intended to represent a small MP3. It is a handy visual metaphor, although it is a bit of an exaggeration.

Compare the compressed wave with this, our original wave (which, in this case, represents our original uncompressed CD, or a well made MP3):

Pcm

Vinyl records work a bit differently. They are analog through and through, eliminating the need for a DAC. Records create sound by vibrating a needle through the grooves. These grooves contain a close approximation of the original sound waves.  As the needle is dragged through the groove it vibrates, recreating a very close approximation of the original sound.  [This, of itself, isn’t inherently better or worse than CD audio. There are benefits and draw backs to each format which will be dealt with in more detail in later posts. ]

As far as audio reproduction is concerned, CDs (and high bit-rate MP3s) can play back almost the full range of human hearing. They really are a technological marvel and, in the hands of a careful audio engineer and with some good playback gear, they can sound unimaginably good.

Sadly, in the quest for ever louder CDs, many albums today are badly mastered. The audio is amplified to the point that there is often audible distortion.

Vinyl records, on the other hand, have managed through a serendipitous technical limitation to largely avoid this issue. Records cannot be amplified on the disc as much as CDs, and they often make use of different masters (or simply of less distorted versions of the original recording.) This often results in a sound that could be described as “Bigger” or “Fuller.”

Vinyl is not without it’s setbacks. The disks are huge, you have to be careful when handling them, and you might not own playback equipment, and poor playback equipment can introduce various kinds of distortion in to your speakers. But the benefits (bigger/fuller sound, bigger album artwork, superior sound quality, the tactile nature of records) coupled with the ever-lowering cost of playback equipment, and the fact that some of the cheapest analog playback gear you can get can rival almost any digital stereo system under $500 in terms of sound quality, make them an attractive choice for many.

It is also interesting to note that used vinyl records are often significantly cheaper per song than their digital counterparts. (Think about it, $1/song in itunes for a 10 song album vs. $6 for a clean used copy of the record.)

[We are strong proponents for Analog Audio, but we are not Analog purists. Good digital audio is just as important as good analog audio in our books.]

We’ve covered the physics (or at least a close approximation there of), let’s move on to the equipment.

I’m going to assume that you’re familiar with MP3s and CDs, and I’m going to jump straight in to the analog equipment. Every home stereo equipped for playing vinyl records is going to need 3 or 4 dedicated components:

A turntable

This is the thing that spins your record. It has a needle (or stylus) that sits in the groove of the record as it spins. This stylus vibrates in time with the original waves pressed in to the record, and produces sound. Nice styluses pick up more sound than cheap ones. The stylus will wear down over time and need to be replaced. Don’t touch the stylus if you can avoid it, and you can avoid it.

Many turntables have RCA cables on the end (like a DVD player) and (probably) a ground cable. The RCA cables go in to your amplifier. If there is a ground cable, it needs to be secured to an available screw on the chasis of your amplifier, or else your turntable will emit a nasty buzzing noise.

Two stages of amplification

Stage one is called the phonostage. It will probably be built in to your turntable or your amplifier. Dedicated phonostages exist as well. This stage of amplification gets the audio from phono level to line level, meaning it takes the tiny sound from the needle and makes it big enough to play on a speaker.

Stage two is your normal (line level) amplification. It takes the signal from the phono stage pushes it through a volume knob so that you can control the volume, and then pushes it to your speakers or headphones. Most amplifiers have a watt rating. This can be translated, with some fancy math which we won’t bother you with, to a maximum volume. It’s easier to just test out an amp than to try and figure out how loud it will be paired with a give set of speakers.

Speakers or headphones

For listening. Nicer speakers reproduce more accurate sound. Bigger speakers reproduce loud sound. (Big AND nice speakers are the dream most people shoot for. We have a few suggestions on that front.)

Your speakers are connected to your amp with speaker wire. This is just wire, nothing fancy about it. For short distances, it doesn’t even have to be nice wire. (For longer distances, you might want to go with thick wire. We’ve got a couple of options, and some more information.)

That’s it. That’s sound. Nice and simple. Let us know if you have any questions.