You may not realize this at first when you’re trying to enhance the audio quality of your music and home theater audio, but you really do need a matching amplifier to speakers guide to help you out. That’s because you can’t just get any amplifier to match up well against your set of speakers.
It’s true that for a lot of audio system newbies, speaker amplifier models seem like they’re all the same. You’ve got a box made of metal, with several knobs and switches for you to adjust. That seems to be it right?
It’s for this reason that so many people spend an inordinate amount of time trying to find the right set of speakers, yet somehow put no time and effort and picking the right amplifier to match those speakers.
But this is a mistake. The amplifier you choose can have nearly as great an impact to the overall tone and quality of your home audio as your speakers do.
The fact of the matter is that it is very possible for you to pick terrific speakers, and then get substandard audio quality because you matched those speakers with a mediocre amplifier.
The same goes when you pick the best stereo amplifier, and somehow you get tinny low-quality speakers to work with it. This gives you terrible audio as well.
So you need to match the amplifier with the speakers you choose. Unfortunately, it’s not going to be as easy as just matching up the corresponding specs and finding a match. If you’re looking for complete system compatibility between your amplifier and your speakers, you need proper synergy.
With the right amplifier speaker systems match, you can make sure that the music you play and the sound you get with your movies will be fuller and richer. The amplifier won’t accidentally blow your speakers either.
This matching amplifier to speakers guide won’t be too technical and heavy on various mathematical equations. That’s for advanced gearheads who tend to sell amplifiers and speakers. There won’t be any overly scientific discussions regarding dampening or electromotive force, and slew rate. It’ll be much simpler, as befitting your audio newbie status.
To make sure you pick the right match between your speakers and your amplifier, you can’t escape the task about knowing at least a little regarding certain Hi-Fi terms. Impedance is one of these concepts that you should learn about.
Check out the specifications of your equipment, and you’re likely to find impedance mentioned. Think of impedance as a way of measuring the electrical resistance of your audio components, and it’s measured in ohms. You’ll find the resistance of these components stated with the Ω symbol, so you may find something like 10Ω. Impedance is one way of checking whether your speakers are compatible with your amplifier.
Speakers generally have ohm ratings within a range of 4 to 8 ohms. Amplifiers are also rated within a particular range, typically between 4 (or 6) to 16 ohms. Check the spec sheet for these ranges, and if you’ve lost your owner’s documentation you can always download the spec sheet online.
It’s normally okay if you have higher impedance with your speakers matching up with an amplifier that can operate with a lower impedance minimum.
What you need to avoid is to match up speakers with lower impedance such as 4 ohms with a stereo power amplifier with higher minimum impedance (like a range from 10 to 16 ohms). That’s the basic math you need to remember: the speaker ohm rating must be greater than the minimum amplifier impedance.
Right now, many of the newer amplifiers and speakers explicitly state the ohm ratings with which they’re compatible.
So if you buy an amplifier, you may find the speaker ohm ratings it can work with. The same goes if you buy speakers, as you may find it explicitly stating the kind of impedance range you need to get in your amplifier.
Power is the next consideration you need to factor in. If you’re not exactly mathematically inclined, this can be somewhat complicated though we will try to simplify it as much as we can.
Power, in this case, is electrical energy an electronic device needs. This is then measured in watts. It’s been a rule of thumb held by some people that when you have more wattage in the spec sheet, the more volume you can get out of your audio equipment. This is a gross oversimplification, and it’s not quite accurate.
It’s more accurate to say that the wattage you get in amplifiers is about how much power the amplifier can put out. The wattage in speakers indicates how much power a speaker can handle.
An old method of pairing has been to match up a low-wattage amplifier with a high-wattage set of speakers. This is a rather safe method to be sure, since you can prevent the amplifier from putting out too much power that the speakers can’t handle. But this isn’t exactly the ideal pairing at all.
To find your more appropriate matchup, you need to first familiarize yourself with 2 terms:
Continuous Power. In some spec sheets, this may be referred to as Continuous Power Output or Continuous RMS Power.
Dynamic Power. Sometimes it’s also called Peak Power.
The Continuous Power is more relevant. This indicates the fixed level of wattage that speakers with certain ohms can handle for long periods of time. So for example, the continuous power can be 50 watts per channel into both 4-ohm and 8-ohm speakers.
Dynamic Power tells you the maximum amount of watts that the device can handle. This is needed because music and movie audio aren’t always even. Sometimes there are sudden bursts of loud sound and great power. So you may have Dynamic Power that can put out 150 watts into 4 ohms and 100 watts into 8 ohms. Since this limit is only in effect for a few milliseconds, it’s not the more accurate indicator of the power of the amplifier. The Continuous Power is more relevant.
Speakers can also list their recommended amplification or wattage levels in the spec sheets. These can be listed as Maximum Continuous Power or Minimum Recommended Power, or just a range of recommended wattage levels.
What all these mean is that you really need to check the continuous power wattage the amplifier will put out and then check how it matches up with the recommended wattage levels. The power the 8 ohm amp can put out must be within the range of wattage that the 8-ohm speakers can handle.
Wrong Power Matchups
What happens when you ignore our advice and disregard power wattage ratings?
Bad things happen, that’s what.More specifically, you can end up blowing up your speakers. Even your amplifier isn’t safe.
Here are the 2 most common problematic scenarios regarding speaker wattage amplifier matching:
Your amplifier’s Continuous Power speaker wattage is a lot greater than the power your speakers can handle comfortably for any length of time.
What generally results in this type of scenario is that your speakers are receiving more heat energy from the amplifier than they can handle. The speakers can’t dissipate the excess heat energy at all.
So what happens is that there’s too much speaker power and the excess heat energy burns up the voice coil of the speaker, and damages the suspension too. Basically, you end up wrecking your speaker completely.
Even the dynamic power shifts must be accommodated. Granted, they don’t happen all the time and they only occur in milliseconds. But when you’re watching violent action movies with lots of explosions and gunshots, you’ll have problems. That’s why if you have speakers with a recommended power range of 15 to 75 watts, you really don’t want a Dynamic Power rating that can exceed 150 watts.
The other type of problematic scenario has the opposite imbalance, but with similar disastrous results. This time, you have an overly weak amplifier for your speakers.
Now this may seemingly make sure that you don’t send too much power from the amplifier for the speakers to handle. But the practical result is that you end up trying to crank up the volume just to get the level of loudness you like. You end up setting the volume to max each time just to get a normal volume level (and that’s not enough for a party).
Pumping up the volume constantly will then end up overheating your amplifier. It will then eventually burn itself up and damage the inner components. You’ll end up with an amplifier that sends clipped signals to your speakers. You’ll get horrible distortion. You can also have high frequency energy that can break your speakers—and your amplifier too!
It’s true that having an underpowered amplifier for speakers may seem less likely to cause problems than with an overpowered one. But both scenarios can still cause problems and they’re not ideal matchups at all.
Power Requirements for Certain Types of Music
If you don’t know by now, some music are inherently more powerful than others. That means you need to pick speaker amps that match up with the type of music you normally play.
The general rule for recommended amplifier power for speakers is that if you tend to play audio books or light dance music, the amplifier power should be about 1.6 times the continuous power rating per channel rated for the impedance (in ohms) for the speakers. If you’re a fan of grunge, punk, had rock, or heavy metal, this should be increased to 2.5 times the continuous power rating per channel.
Let’s say your speaker is 4 ohms. Its continuous power rating at 4 ohms is 100W. This means that if you’re a fan of light dance music, your 4 ohm amp should provide 160W continuous power per channel (1.6 times 100W). If you’re a fan of Metallica and Korn, this should be 250W per channel (2.5 times 100W).
You can’t use too much power, because you’re forcing the speaker cone beyond its capabilities and you’re likely to damage the amplifier speaker. But using an amp with very little power is also a problem, because you’re likely to increase the volume level of your music. If you keep on trying to make the speaker sound loud enough by turning the volume dial to 10, clipping can become a problem and you can damage the speakers due to overheating.
This is a unit of measure that pertains to speakers and it measures loudness. More specifically, it measures the loudness of a speaker in decibels, when it is a meter away and it’s powered by 1 watt.
So if you have a speaker with 94dB sensitivity, it means the speaker will be 94 decibels loud from a meter away with just 1 watt of power and that’s way less than the number of watts an amplifier will normally provide.
This means that you can compare one set of speakers with another by checking out the sensitivity ratings. The one with the higher sensitivity will be louder than the speakers with the lower sensitivity, when paired with the same amplifier set at the same volume level.
For a more concrete example, let’s say you have 3 different speakers. Speaker “Alpha” has a sensitivity of 85dB at 1W/1m. Speaker “Bravo” is rated at 88dB, and Speaker “Charlie” has a sensitivity of 91dB.
Now attach them all to the same amplifier and play some music. You will then realize that Speaker Charlie is the loudest of them all, while Speaker Alpha is 6dB quieter.
You have to understand that this does not mean that the speakers with higher sensitivity are necessarily “better” overall. It does mean, though, that the high-sensitivity speakers can potential reach higher volume levels. So if you like to play loud music you can just pick speakers with higher sensitivity rather than buy a more powerful amplifier.
Now you may be thinking: why do I need amplifiers with more wattage when 1 watt is enough to get my speakers to reach 94 decibels? After all, that’s very loud—regular sustained exposure to 90-95 dB levels can cause permanent hearing damage. That’s about the same volume level as a power mower, and you’re not supposed to subject your eardrums to such decibel levels for more than an hour.
But amplifiers need wattage to drive up the volume, which you may need when you’re hosting a large party, for example. You need double the previous wattage to increase the decibel level by 3dB. This means if you need 1 watt for 94 decibels, then you need 2 watts for 97 dB, 4 watts for 100 dB, 8 watts for 103 dB, and so on.
You also have to compensate with wattage when you’re farther away from the speakers. Remember, the sensitivity rating is only when you’re 1 meter away from the speaker. Extend the distance for another meter, and you lose 6dB.
This means that if you take yourself 4 meters away from the speaker with 94 dB sensitivity, you lose 18 dB of volume and you effectively only get 76dB. That’s about the same volume level as ordinary living room music. To get back that 18dB you lose, you’ll need 64 watts (2 to the 6th power)!
Obviously, if you get speakers with higher sensitivity, you’re able to reach the higher volume levels you like. For those who like rock or party music, this ability is crucial.
This is a rather ephemeral subject, and you can’t really find the data in the spec sheets to help you out. What we are talking about is tonal balance for your amplifier and speakers, and you need sensitive audiophile hearing to understand this.
When you’re a real audiophile, you realize for a fact that amplifiers and speakers (especially the high-end premium quality ones) have their own particular tonal characteristics. It’s like the quality of a vocalist in a band.
They each have their own particular and distinct sound, even if they can sound similar to one another.
For example, some amplifiers somehow sound brighter than others. But what happens when you pair this type of amplifier with speakers that also sound a lot brighter too? What happens is that this brightness becomes too much, and then the sound turns overly thin as a result. So to balance things out, you want to match a brighter amplifier with speakers that aren’t as bright and are instead somewhat more lavish in its warmth.
It’s hard to explain various amplifier and speaker characteristics to non-audiophiles. But for those who can differentiate between amplifiers, certain tonal characteristics stand out. The amp can be punchy and articulate. It can be warm or cold. Articulation may be clear or not.
You’ll notice this when you play certain different types of music with your amp. Some amps are great for rock with its screeching guitars. Other amps are better for quiet lounge music with flutes and pianos, lulling you into a sense of serenity.
Regardless, matching up the tonal characteristics of amps and speakers is more like matching up your shirt and your trousers. Often there are no hard and fast rules, but in general you don’t really want to wear the very same color from top to bottom, right? The same goes for amps and speakers—you don’t want them to sound too much alike.
This is more about picking the right speaker amp combo as a whole. While there are some rather confusing complicated calculations you can do, in general you simply need to match the power of the amp to the size of the room.
If you have a very large room, then an underpowered bookshelf speaker amp with a couple of tiny speakers simply just won’t do to fill the room with music and movie sound effects.
At the same time, if you have an extremely powerful amp with large speakers, while you live in a cramped apartment, the results aren’t pretty either. You can end up with too much bass, and annoy yourself and your neighbors. Also, you pay for that extra power and you just wasted your money if you didn’t really need it anyway.
Amplifier Speaker Matching Calculator
You can go online and find an amplifier speaker wattage calculator that can help you determine the power you need for your amplifier. These calculators will ask you to plug in various values, such as your regular distance from the speaker, the level of loudness (SPL or sound pressure level) you want at that distance, the sensitivity of your speaker, and the amplifier headroom (the allowance you need to deal with audio peaks without distortion.
Do remember that these calculators offer estimates only, because they can’t know the general shape and size of your room. In fact, many of them operate under the premise that the room is “open-air”. So the amplifier speaker matching calculator may not take into account the reflective properties of ceilings, walls, and floors.
Buying Amplifiers and Speakers from the Same Manufacturer
Matching up a stereo amp with a set of speakers can be so confusing that some people just go with the recommendation set by the manufacturer of their particular component. Basically, they may buy an amp they like, and then they can just get the speakers that were designed by the manufacturer to work with that amplifier.
There are many advantages to this.
One is that you’re likely to find a great match right away, since they were all expressly designed to work best with one another. The amp won’t be under- or over-powered for the speakers.
Their looks may also complement one another, which is great for your interior design. That’s one problem with mixing and matching amps with speakers from another brand—they can look obviously mismatched.
You may enjoy a lower price, especially if you buy them all as a package.
The setup is much easier, since the manual may have specific instructions on how to set up the stereo amplifiers with the designated speakers.
You only have to call a single customer service for any problems.
The main disadvantage of this arrangement is that you generally limit yourself. Some audiophiles think that part of the fun is finding a match for amplifier and speakers themselves. The challenge adds to the enjoyment.
Another disadvantage to this is that upgrading your equipment may prove to be more expensive later on.
That’s because you may find yourself having to buy a new amplifier and a new set of speakers. Buying just a new amplifier or a new set of speakers may give you a crappier sound, which is the opposite of why you wanted to upgrade in the first place!
Buying the Amp and Speaker According to Price or Quality
This method assumes the (often true) assumption that price and quality in amp and speakers are pretty much in sync. If something’s expensive, then it must be good. Conversely, if it’s good, then you will have to pay for the quality.
What this means is that the price of your amplifier should be similar to the price of your speakers. If you spend $4,000 on your premium, audiophile-grade amplifier, then you really must avoid spending only $50 on your speakers. Also, you can’t spend $2,000 for each speaker and then go with a $200 amplifier.
It’s easy enough to understand the common-sense wisdom of this speaker and amp combo rule. If you have a great amplifier, you won’t really hear how great it is because the speakers aren’t reproducing the sound the way it ought to. It’s going to sound the same as the music you hear from a much cheaper amplifier.
On the other hand, when you have a very cheap speaker amp with crappy sound, you will hear the crappiness of that sound in all their terrible “glory” when you pair it with a fantastic set of speakers. These expensive speakers can articulate very detailed sound, which will really make crappy sound quality very noticeable.
One Last Set of Tips
Here is a condensed version of the tips that have already been mentioned, as well as some new tips that you may need too:
See to it that your amplifier can support the impedance of your speakers.
When you’re checking power ratings, double-check to see if the specs are talking about average (continuous) power, or peak power.
When matching speaker with ampli, it’s better to pick an amplifier with a slightly higher power rating than the power rating of the speaker, rather than go with an underpowered amplifier. That’s because you can always just dial down the amplifier, and you also give yourself some leeway in the future when you upgrade your speakers.
If you have a larger room, go with a more powerful stereo amplifier and the speakers to match that amp.
For the majority of home theater systems in an average-sized room (not to small, not too big), a choice of amp that can give you about 50 to 100 watts per channel (continuous power or RMS) should be fine. Obviously, you need those 100 watt speakers.
Consider getting the best USB DAC under $300. A good digital to analog converter can give you a higher quality conversion of the digital music you download from the Internet.
If you need an amp for live musical performances, look among the best tube amplifier models.
If you want something simpler, consider getting an AV receiver. The best AV receivers under 1000 dollars give you a combo of tuner, preamplifier, and an amplifier. It’s cheaper in general, and easier to install.
Do try to avoid too much equalization in your home speaker amplifier when you boost a frequency. Better to cut down a frequency instead. When you boost a frequency, you may get unwanted (or even harmful) peaks.
Avoid going to the maximum level of the amplifier volume dial. Stay at level 6 or 7 out of 10. If that’s too quiet, you either need more efficient speakers with greater sensitivity or you need to buy a more powerful amplifier.
It all seems somewhat overly technical, doesn’t it? But learning how to choose amplifier for speakers isn’t really an exact science.
You can read lots of stereo amplifier reviews and you’ll find different opinions even among experts.
In the end, don’t sweat it.
As long as you don’t go to extremes (like overly expensive speakers matching with a really cheap amp), matching your amplifier for home speakers will work just fine. This guide is here to help you find the best amp for speakers, but in the end there’s really nothing to worry about. You’ll do fine!