How Do You Evaluate Stereo Speakers?

How Do You Evaluate Stereo Speakers?

For many people, listening to music is a fairly casual pastime. They might use a CD player, a turntable setup or a wireless speaker like the Amazon Echo. Plenty of them will stream to any convenient device or plug their phones or obsolete iPods into an aux socket or a dock. By definition these are not audiophiles. If they can listen to their music with reasonable balance and clarity, they’re perfectly satisfied.

This might be the way you’ve always approached it yourself. But if you’re starting to get intrigued by the potential of a modern sound system, which involves much more than just a music player and a pair of speakers, or a home theater system which has its own demands, you need a few tips on what to look for.

Seasoned hi-fi enthusiasts probably already have their brand allegiances and may not be interested in investigating alternatives. For any that do, and for those who might be new to the world of high-end audio, we thought it would be helpful to share our experience in assessing the relative merits of the many different types of speakers.

There are really just two sets of criteria to consider when you’re trying to find the best speaker system for your requirements. First, there are all the specifications and the manufacturer’s claims, the practical and technical matters. These will tell you a lot about the theoretical capabilities of any particular pair of speakers. Among other things they’ll give you a good idea of their versatility and any compatibility issues to watch out for. When you’re researching the best types of speakers on the market you’ll come across a lot of information about frequency range, frequency response, sound waves, sound quality, features such as surround sound and the amount of power each pair of speakers is fed from their drivers. All of this detail will tell you what, on paper, makes a good speaker, and that is all important stuff.

Second, the other consideration, and in many ways the more important one, is how you experience them. You’re buying a speaker system to suit your listening habits and preferences. Don’t be persuaded into thinking you have to tick all the boxes on the audiophile’s checklist. What matters is how your set of speakers sounds to you. So after you’ve gone through all the specs and the data, give them a thorough listen. Use tracks that mean a lot to you, ones you know well so you can hear the difference. Mix it up too, with some really full-on production numbers as well as some material that only features acoustic instruments and voices. Check out some wall-of-sound rock music as well as something spacious like Dub Reggae. All the facts and figures in the instruction book won’t make any difference to what you hear, so that’s where your decision should ultimately rest.

So, let’s start by briefly considering all the different specifications you’re likely to come across. If you’re prepared to pay top dollar for the best, then you should be looking for a combination of drivers that includes a dome tweeter, a midrange driver and ideally, two cone bass drivers. The frequency range should be in the region of 34Hz-28kHz +/- 3dB with a sensitivity of 90dB. The bigger the power handling range the better: 50-300w is great, although 50-120w is fine.

If you’re thinking about wireless options, then it’s very important to know exactly what codecs any speaker system will support. The way you stream will also depend on whether you’re using an iOS or Android device. AAC is the codec recommended for Apple while aptX HD audio is better for Android users. What you really want is to have as many options as possible as well as a really good Bluetooth 5.0 capability. A lot of modern speakers have dispensed with cable inputs so giving yourself the widest choice of streaming choices is essential.

If it’s a wired sound system you’re interested in, whether it’s wall speakers, bookshelf speakers or floor-standing models, then you need to make sure the speaker terminals offer not just the best but also the simplest connection. It’s actually easy to overlook the importance of speaker terminals, because they are one of the crucial physical connections in any sound system.

Size will obviously be a consideration too. If you’re lucky enough to have the space for a dedicated listening room, then you can go for some really big beasts, but if you have to fit your sound system or home theater system around your existing living room furniture, then wall speakers or bookshelf speakers may be the way to go. You don’t have to compromise on quality, just size.

Once you’ve been over all the technical information, you’ll have a better idea of which speakers to try out. Don’t feel rushed about this. Any serious hi-fi dealer understands it’s an important decision and a significant purchase. It’s in their interest as well as yours that you make the right choice. Be prepared to spend as long as it takes in their listening room to satisfy yourself that you’re getting the right solution. Ideally, have the choices lined up side by side so you can judge them on a level playing field.

The Heart of the Matter

What you need to do now is listen. That sounds simple but there are ways of doing it and specific things to look out for that can help you judge whether a particular speaker is going to serve you well in the long term or simply dazzle you with a few pyrotechnics in the listening room.

The job of a speaker is to reproduce the input signal as accurately as possible. It should eliminate as far as possible any distortion and faithfully reproduce what the sound engineer has worked hard to create. However, don’t forget that loudspeakers can only ever represent the music they play, because they are transducers. What that means is they convert one type of input - the electrical signal - into a different output - acoustic sound waves.

What you should be listening for in a broad selection of different music is a balanced, natural tonal presentation. The sound should have a wide range, with distinct instruments and voices, a deep, solid bass and really sparkling treble register. It’s a bit of a cliché, but it ought to feel as if you’re in the same room as the performers, with a natural sound and balanced tonal areas where nothing dominates.

Listening to synthesizers and other electronic instruments isn’t always a good test of sound quality because they don’t have an inherent naturalness, so you have no external point of reference. Kratfwerk are still rated as the godfathers of electronic music, but if you test how a pair of speakers sounds by listening to Autobahn or Trans Europe Express, you’re really only going to find out how well the speakers deliver those pieces.

We find that acoustic instruments and vocals are much more effective as test material. This is mainly because the sounds they make are familiar to the ear, natural and pretty universal. The same goes for movie sound effects: real-world sounds like birdsong and traffic are a better guide than the sound of the Millennium Falcon’s engines.

Whatever you’re listening to, make sure you hear it in two-channel stereo. It’s easy to be persuaded by the novelty of a surround sound system that you’re experiencing something amazing. In fact, this is a kind of gimmickry with clever but empty tricks like the guitarist suddenly sounding like they are right behind your left shoulder. It’s wizardry that distracts from the real sound quality you’re looking for.

Take special notice of the bass. Not just in heavy funk or reggae but in music that isn’t renowned for prominent bass. It’s a very good guide to the speaker’s breadth of frequency response, and it’s often the bass that really supplies the power of live music. It should be clean and crisp, each note distinct and articulate, not descending into a muddy rumble. A very useful exercise is to listen through an entire track concentrating just on the bass. If you can follow every note no matter how much is going on in the higher frequencies, that’s a very good indicator of quality. Try an upright acoustic bass in a jazz quartet - Miles Davis’s ‘It’s About That Time’ for example. U Roy’s ‘Natty Rebel’ or Bob Marley’s ‘Exodus’ represent reggae bass very well, disco/funk doesn’t get bassier than Chic’s ‘Good Times’ while for rock music the Herbie Flowers bass on Lou Reed’s ‘Walk on the Wild Side’ or Fleetwood Mac’s ‘The Chain’ tell you all you need to know.

The midrange is where we find vocals, guitars, saxophones and violins, while in movies, it covers everyday sounds like footsteps, doors slamming and conversation. A good speaker will render all these sounds realistically. Singers should sound natural, not muffled or distorted. Saxophones should be sharp but not shrill. Guitars should be rich but not overpowering. Even Bob Mould and Tom Morello shouldn’t sound like an onslaught, while every lingering note of a Richard Lloyd or John Perry solo should be crystal clear. The same goes for the vocals, even when they’re low in the mix. Close harmonies should play clearly enough for you to follow one or other of the lines - try anything by The Everly Brothers or ‘If I Fell’ by The Beatles.

Don’t underestimate the importance of the treble, where all the really high tones exist. Some guitar solos, all falsettos (e.g. Smokey Robinson) and singers like Eddi Reader and Joni Mitchell will put that to the definitive test.

Sound engineers refer to speakers with good high frequency response as providing good dispersion. This means the high registers are just as clear if you’re positioned to the side of the speaker or right in the centre. Dispersion is an important part of the space that we prize so much in good speakers. The amount of power in their output is only one measure of their capacity - it needs to be focused and controlled but also spread broadly and evenly.

We should say a word about the varying ability of the human ear to hear sound waves. These are waves that vibrate through the air, measured in cycles per second, known as Hertz. Humans can hear sound waves in the range from 20Hz in the bass to 20kHz in the treble. However, as you get older, this range gets narrower so that in middle age you might only get as high as 14kHz and by old age, no more than about 3kHz. This really doesn’t matter, because you’re buying speakers that suit you, first and foremost. What you can’t hear isn’t important - it’s what you can hear that counts. In any case, it’s in the mid-range from 200Hz to 3kHz that most of the serious action happens.

So, we think that covers everything. Make sure you’re happy with the specifications of any pair of speakers you buy, but the real test is in the listening, of course. Take your selection into the listening room, set them up side by side and get them working. We hope these pointers will get you primed and ready to enter the thrilling world of the audiophile.