BREAKING DOWN THE MEANINGS BEHIND FIVE AMP SPECS SO YOU KNOW WHAT YOU’RE GETTING INTO BEFORE YOU BUY

Whether you’re a newbie dipping a toe into the pool of home theater or you’re an expert who’s built several sound systems over the years, choosing an amplifier first is usually the best move. It can be fun, confusing, stressful…but as an amplifier is the “home base” of an audio setup, it’s vital to have one that’s going to work for you.

Each amplifier will have different features - Dolby Surround, Bluetooth, dual-room output, HDMI standby pass-through, AM/FM tuning, and more. But while these features are important, it’s just as important to look at the specifications that make the real difference in the sound you’ll get. 

So we’ve broken down five of the most important specs you're likely to run into. This way you'll know exactly what they mean when you see them!

(And if you’re a true beginner, we recommend first reading our simple Stereo Gear Jargon article, which breaks down the basic words and terms you should know before choosing an amplifier. You can find that here.)

POWER OUTPUT

The power output is typically proportional to the loudness of the music an amp can produce. Generally, larger speakers or bigger spaces require more power. If you’re wanting an amp for an outdoor party or to take revenge on some loud neighbors, then be sure the power output is high!

However, it is also important to note that you may not need as much power as you initially thought. In most cases, 15 watts is sufficient for average listening, and 100 watts is more than enough to create an unforgettable party atmosphere. Quite a few of the older silver-face receivers from the ‘60s and ‘70s will be rated between 20 and 50 watts, which is usually all you need for your basic stereo system.

THD (TOTAL HARMONIC DISTORTION)

When looking at specs, it is also important to consider the Total Harmonic Distortion (THD). THD is the measure of how much of an effect the amplifier has on the sound. Generally, the higher the distortion, the more altered the sound will be compared to the original recording. The lower the distortion, the more faithful the sound. So lower numbers are better when it comes to THD.

Pro Tip: Speakers have the biggest effect on sound, so choose speakers that are well-suited to your listening preferences!

SNR (SIGNAL TO NOISE RATIO)

Signal-to-noise ratio (SNR) is a measurement that compares the level of a signal to the level of background noise. So as its name suggests, it’s literally the ratio of signal power to noise power. Written in decibels, SNR indicates the level of noise from the amplifier - it’s always just background noise, the same way you occasionally hear the hum of the radiator. However, you don’t want this noise to be too perceptible as that will distract away from the music.

Higher SNR means clearer audio, so the bigger the number, the better!

CROSSTALK

Crosstalk is another crucial factor in amplifier performance, as it measures the amount of interference between left and right signals. Despite being housed in a single box, amplifiers work to keep each channel's signal separate, which allows for accurate soundstage imaging (where, for instance, you can tell that the main singer is standing near the left of the stage while the instruments are positioned towards the right).

Higher levels of crosstalk can affect stereo separation, making it difficult to discern the positions of special effects, speakers, singers, and instruments. So for the crosstalk, the larger the number that follows the minus sign, the greater the stereo separation (for example, -100dB is better than -60dB).

CONNECTIONS

While this one isn’t listed as a single number in the specifications, it’s important to keep an eye on. After all, it doesn’t matter how good the power output, THD, SNR, and crosstalk are if you can’t plug in your components! You’ll want to keep an eye on two things: the number of connections and the type of connections.

You’ll need enough hookups for your gear: for example, if you have a CD player, turntable, and cassette deck, you’ll need at least three analog audio hookups (and at least one of those should be a “phono” hookup for that turntable). You’ll also need different types of connections depending on your gear: S-Video for a higher-quality SVHS player or Laserdisc player, USB for a laptop, 3.5mm for an iPod, composite for a DVD player, HDMI for a Blu-ray player, etc. Similarly, if you’re going to be sticking with a simple stereo setup, you only need enough speaker terminals for a couple speakers; if you want a 5.1-channel surround system, you’ll need an amp with hookups for at least five speakers and a subwoofer.

SUMMARY

There you have it! Five important specs you should keep an eye on when you’re on the lookout for an amp. Whether you’re going vintage or modern, silver-faced or Bluetooth, knowing what these numbers mean will help you choose the amplifier of your dreams.

Thanks for reading! We hope this guide helps mitigate any stress or confusion you feel while shopping for amplifiers. And if you’re interested in our large selection of amps, we’ve got everything from preamps to power amps to integrated amps to receivers. You can find them all here. Have a great day!

https://spencertified.com/collections/home-audio-amplifiers