A HiFi system is a set of components designed to make music sound as good as possible. HiFi aims for clear, noiseless audio, not just high volume and boosted bass.
Music on a HiFi system will sound radically better than music on the headphones that came with your phone, due to many different factors like less signal interference (and thus, less noise), higher frequency response and clarity on the headphones, and a much better listening experience with over-ear headphones.
People who enjoy high-end audio are called “audiophiles,” and the audiophile scene is complicated and can seem hard to get into. Here, we’ll break down what each part in a HiFi setup does, and how it contributes to the overall sound.
Digital Audio Converters (DAC)
The DAC is essentially a really high-end headphone jack. It’s the starting point for all the audio in your system. Because of electrical noise in your computer, audio from the built in headphone jack sounds very noisy. You might not notice this noise on most headphones (as most headphones are noisy anyway), but on HiFi headphones it becomes apparent.
The solution is to isolate that electrical interference with an external DAC. These are built with much higher quality components than the built in DAC in your computer. They’re often are capable of powering higher impedance headphones and supplying phantom power to mics that need it.
For most speakers, and some headphones, you’ll want an amp to power up your audio before listening to it, as it may be quiet coming straight off the DAC. If you have lower impedance headphones, a USB DAC should power them just fine, but anything requiring 250 Ohm and above means you’ll probably want an amp so that the noise from the the DAC doesn’t ruin things.
The reason amps are necessary is because most DACs are not made to amplify audio beyond a certain point. If you were to turn the DAC up to 10, it would sound incredibly noisy (the bad kind of noise). However, you could turn it to 5, and then set the amp to crank it up 200%, and the audio would still be clear
Headphones and Speakers
All the parts above get the digital sound from your device out over a wire. At the other end of that wire, you’ve got the option of headphones or speakers.
Good speakers are complicated to set up, usually needing a large stereo receiver into which you can plug everything. Good sound is dependant on proper placement of the speakers and room acoustics. This can be mitigated somewhat with appropriate positioning and noise canceling panels.
Headphones are simpler, usually just requiring a single cable to plug in. These headphones will have an impedance, measured in Ohms. This is the electrical resistance of the headphones, and higher impedance headphones will require more power to drive properly. Most headphones will be very low, usually below 32 Ohms, while some headphones can go up to 600 Ohms. Generally, higher impedance will have better sound, but only if the rest of your setup matches in quality. If your DAC and amp can’t handle driving the audio that high, then you may not see any benefits—things could even sound worse off than before.
The main thing to check when looking for headphones is the frequency response and overall clarity. Some headphones, like Beats, will crank up the bass on their headphones to give the illusion of better sound. To an untrained ear, this can sound really great, but a HiFi setup should ideally have a reasonably flat frequency response, with no modification to the incoming audio. Overall clarity is hard to measure, but affects sound quite a bit. This will come down to the build quality and usually the price of the headphones.
Depending on your use, you might not need a mic, but people who are looking to record audio can easily add them to their setup. Most high end mics will use XLR connectors, which most DACs support. Some mics—condenser mics in particular—require 48 volt phantom power, which means it needs an external power source to function. It gets power from the XLR cable itself though, so you don’t have to plug in anything extra, just flip a switch on your DAC. Make sure though that you’re not delivering phantom power to a mic that doesn’t support it, though, as you could damage the mic.
You’ll obviously need cables to plug all this together, but not just any cables will cut it. Since most of these components take power from the wall, you’ll need shielded cables. Normal aux cords that you may use to play music in your car are not shielded, and will pick up tons of static from nearby electrical signals. Shielded cables come at a premium, but are necessary, because if any component in this loop is low quality, it’ll ruin the audio. You don’t need fancy, high-end, gold-plated connectors or anything, but shielding is a must.
So how does this all fit together? Well, when you play a file in iTunes for example, your computer sends it over USB to the DAC. The DAC decodes it and then sends the actual analog audio out to the amp (usually over a 1/4″ cable but sometimes over a standard headphone cable). After it’s been amped up, the signal travels to your headphones or speakers where you can finally listen to it.
The end result is amazingly clear audio.
So What Do I Buy?
You don’t need to buy crazy expensive components to have a great experience. The reverse is also true, you can purchase overpriced components and end up with noisy, distorted audio. It’s all about quality, and comes down to each part itself.
The exact components of your setup will differ depending on your needs, your budget, and your personal preferences. The market is very diverse, and as such we can’t easily put together a comprehensive guide to buying every single part you may need. We encourage you to do your own research and read reviews from more qualified audio professionals before deciding what to buy.