Sound Advice - What do I need for a HiFi System?
Do you want a bit more from your music? Read on.
Unlike multi-channel audio which is defined by many different standards that combine into a wider format, stereo audio is rather harder to pin down.
‘HiFi' - a shortening of High Fidelity - is not defined by any written standard and the term has been attached to many items, not all of which really justify the description. As a result of this, the variety of devices that can conceivably be called a 'HiFi System' is extremely wide and potentially extremely confusing. This article is intended to try and establish what you need at a basic level for a HiFi system and what equipment can be used to supply it. Having established the basics, further articles will expand on different areas of two-channel audio.
What is a HiFi System?
In essence, a HiFi system is a device for reproducing an audio signal with sufficient quality and fidelity that the listener experiences a compelling reproduction of the original performance. Right from the start, one very important caveat to this is that exactly reproducing a performer or instrument - let alone multiples of them - is extremely difficult to the point of impossible and, regardless of your budget, all you can hope to achieve is a convincing facsimile. In the same way that a good home cinema allows for the suspension of disbelief, so it is with a good HiFi.
To do this, all HiFi Systems break down into three functions regardless of price, size and complexity.
SourceThis is the material that the system will use for playback. This can be from a wide selection of material and many systems can handle more than one type of source. Commonly encountered sources include CD players, turntables, streaming services such as Spotify, Apple Music or Tidal or music replayed directly from your computer. We will cover source options in much greater detail in a forthcoming piece but the good news is that in 2016 something you already own could very likely turn out to be a suitable source for your system.
AmplificationThis is the process by which the source signal is processed (amplified) to be at a level that is relevant to the user. Amplifiers break down into two categories and a selection of different types.
Pre and Power amplifiers- are amplifiers that split the two requirements of an amplifier into separate boxes. A preamplifier collates the sources and controls the volume required as well as sometimes performing other functions like tone control and headphone amplification. A power amplifier is the actual section that takes the signal from the source and boosts the level to be relevant to a speaker. Some power amplifiers are further split into one channel each for improved performance- these amps are generally called monoblocks.
Integrated amplifiers are amps that contain both the sections of an amplifier in a single box. This technically requires more compromises but integrated amplifiers are more affordable and more convenient. They are also capable of exceptional performance.
Amplifiers very broadly use three methods to generate their signal. There are exceptions to this but they are relatively uncommon. These differences are fairly technical and it is important to stress that any of them are capable of sounding very good indeed. We will be covering these different types of amplifier in more detail in a future piece but here is a simplified breakdown of the three main types.
Class A- This is the simplest form of power amplifier that uses one or more switching transistors. The transistor is always biased “on” so that it conducts the entire output signal of the amplifier, This results in high performance but generally lower power outputs with very high electricity consumption.
Class AB- In class AB a pair of push-pull transistors shares the task of creating the output instead of a single unit working all the time in Class A, At one point in the signal, both transistors are conducting momentarily and this changeover creates distortion not present in Class A. On the plus side, more power can be generated from lower power consumption.
Class D- In a class-D amplifier the output stage functions as an electronic switch instead of constantly active devices; they are either on or off. The analogue signal is converted to a stream of pulses that represents the signal by a process called pulse width modulation. Class D amps are much more efficient and can generate huge power outputs from small devices with negligible heat build up. While there is still a stigma attached to them in some circles, some seriously capable amps are now Class D based.
ReproductionThis is the means by which the amplified signal is turned into an audible one. This is done by a speaker of some description - be it a giant PA system or a pair of earphones, all of which will be covered in separate articles but the main candidates are;
Earphones- A device that uses a small driver to be small enough to sit on or in the ear canal. Provided that they seal the ear canal from the outside world, they are capable of exceptional performance.
Headphones- This is a larger device that is still worn on the head and which places one or more drivers in an enclosure that sits on or over the whole ear. The best headphones are capable of a level of performance not easy to rival by any other means.
Loudspeakers- these are devices that are intended to be listened to at a less immediate distance and as a result, can be listened to by more than one person at once. Speakers vary in size from a few centimetres tall with a single driver- the device that moves to produce the sound you here- to several metres tall and with a great many drivers. The price also varies considerably.
Regardless of their size, cost and relative complexity all HiFi systems have these functions. They may break down differently but they are performed all the same.
One box or many?Given that there are no fixed guidelines for what makes a HiFi system, you are free to decide whether you want to choose an all-in-one type system or one built from multiple single devices. There are pros and cons to both approaches, so it is worth pointing out the main ones.
An all-in-one system is, as the name suggests, a self-contained unit that features source and amplification in a single chassis. Some of these can also contain speakers as well. It is a common misconception that these systems are always cheaper and less capable than ones made up of separate components. If you look at reviews we've done for devices like the Naim Mu-So and the Geneva AeroSphère, you will see that these are very capable systems in their own right. If you look at systems that require you to add speakers, some of these are capable of truly excellent results and are perfectly competitive with comparatively priced separate systems.
Compact - Rather than needing a box per a function, an all-in-one system is able to
combine its functions into a smaller space.
Simple to get going - With everything coming from the same place, you can be
confident that the system will work correctly and be easy to set up.
Cost effective - An all-in-one system can usually offer more functionality for a given
price than a separates-based system.
Lack of flexibility - Often you will find yourself buying a system with features you
don't need rather than simply buying exactly the features you want.
Limited upgrade potential - while it is generally possible to connect at least some
additional sources to an all-in-one system, it might not be possible to always connect
the ones you want and the absolute performance of the system as a whole will be
governed by the performance of the main unit you are connecting them to. This
particularly applies to all-in-one systems which include speakers.
A separates-based system generally uses a separate component for each role in the system - source, amplification and speakers. This means you will need to be able to select the components you need and choose between different models to secure the best option for you. Like all-in-one systems there are pros and cons.
Performance - with each component focusing on doing one thing, separates-based systems can deliver higher performance and frequently better specifications than their all-in-one alternatives.
Flexibility - Separates-based systems allow you to choose exactly what you need and not buy the things you don't. They are also relatively easy to update and upgrade.
Features - Since they are more specialised single units, you can find features that are less commonly fitted to all-in-one systems
Space - A separates-based system will usually require rather more space than an equivalent all-in-one system
Cost - A separates-based system will generally cost more money than an all-in-one system and if you decide to pull out all the stops and go for something very serious indeed, you can spend many tens of thousands of pounds.
Complexity - We will cover this subject in more detail in due course but while most separate units will work with each other, they don't have the plug and play functionality of an all-in-one system.
What else should I consider?
To make the best choices on suitable equipment, you should consider the following:
What sources do I listen to? Make sure you buy equipment that effectively does what you need it to do. If you listen to a lot of Classic FM, there's absolutely no point buying a record player and just because you like the idea of something doesn't mean
it'll actually work in practise.
How much do I want to spend? Simply put, you might like the idea of a separates-based system with giant speakers but if your budget is rather more in line with a capable all-in-one system, that's really where your money ought to be going.
How much space do I have? We will be covering setting a system up in due course but a golden rule is that if you don't have a huge space to fill, don't buy a massive system and that equally, a compact all in one will struggle to fill a really big room.
Once you have established what it is you are looking for, you can move onto choosing what equipment is right for you which will be the subject of the next piece.
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