How Much Guitar Amp Power Do I Need

how much guitar amp power do i need

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Are you an aspiring guitarist looking to take your playing to the next level? Are you ready to rock out with a powerful guitar amp, but not sure how much power you need? Look no further! This article will answer all of your questions and show you how to get the most out of your amp.

It is usually recommended to have an amplifier that is at least double the highest volume you will require. For example, if you would like to reach 100 Watts of volume, find an amplifier with a minimum of 200 Watts. This will make sure that the sound does not become distorted or muddled when it is played loudly.

What are the different guitar amp power options?

There’s a big misconception when it comes to guitar amps. Having more power and more watts isn’t necessarily the better thing all the time. Bigger amps might be great for on-stage use, but they aren’t that handy during home practice. No one wants to have angry neighbors knocking on their doors each time you play your guitar. When talking about practice amps, it’ll mean that they have smaller power and wattage. For that reason, no one takes practice amps seriously, which is wrong in more ways than one.

Practice amps shouldn’t be looked down upon as they’re also capable of producing a decent sound. They sound amazing as well and are more than enough for occasional performances and home utilization. There is a wide variety of choices with amps, with options ranging from 1 to 240W and more. Before understanding how much guitar amp power do I need, it’ll be important to look at different options.

1 to 10W guitar amplifiers

This category is more leaning toward portable, small amps instead of proper practice amps. However, due to their features, they can easily be utilized at home. These units typically range from 1 to 10W of power capacity and can easily pack smaller speakers. Although their sound isn’t as clear and defined as other bigger amps, they’re still capable of producing a great tone for your needs.

Moreover, they usually have different features like onboard effects and tuners. These features help you in figuring out what you’re looking for in the sound and make the purchase accordingly. Amps having 1 to 10W power will be a great route to understanding sonic preferences and your guitar amp requirements. This will help you make thoughtful decisions and acquire details that’ll help you keep a permanent amp in your rig.

10 to 30W guitar amplifiers

If you aren’t looking to spend a huge amount and want a simple amp on your way to a bigger amp, you can decide to go for an amp with 10-30W power. These amps are good enough to drive 8-12” speakers and create a high-quality tone without any background noise. With such devices, you can go very loud without the sound getting distorted while experimenting with its sonic features. 10 to 30W amps come with more onboard effects, and they’re straightforward to use.

Overall, you’ll be getting delay, reverb, and distortion among others. Such combos will give you more than enough for your bedroom studios. Moreover, the amps in this category are also capable of handling smaller venues like cafés and coffee shops.

30 to 50W guitar amplifiers

This category can also be referred to as the category for “professional” practicing and playing guitar amps. The combos having 30 to 50W power will not only be useful at home, but they’ll also allow you to rock any small or medium stage. In that sense, you’re essentially getting something that’ll let you perfect your craftsmanship and perform in front of decent crowds.

Most guitarists, especially beginners, will want to practice to the point where they’re able to perform in front of a live crowd. The guitar amps having 30-50W power are perfect for guitarists who are looking to become professionals but still need practicing. If you’re looking to record at home or play occasional gigs, a 50W amp will be a great option.

Such amps offer a cleaner, more defined, and perfected sound. It’ll allow you to easily discern all the tonal mistakes that you’re making. Moreover, you can experiment with different styles/techniques without needing to worry about the tracking capabilities of your amp. Although these amps at this wattage are comparatively expensive, they’ll ultimately be a better investment as they can be used on stage too.

How much guitar amp power do I need

To answer this question, you should clearly define your goal. Are you looking to power loudspeakers such that they’re able to play as loud as possible without burning out? First, you’ll need to determine how much power your speakers can handle

You can determine it by checking the speaker’s datasheet. Look for nominal impedance spec, which will typically be at 2, 4, 8, or 16 ohms. After that, look for the loudspeaker spec referred to as Continuous Power Handling or Continuous Power Rating. It may be called Power Capacity or IEC rating.

If you can prevent the amp from clipping, you should use a power amp that can supply 2-4x the speaker’s continuous power rating per channel. This will allow 3-6dB of headroom for peaks in your audio signal. The speakers are designed to handle short-term peaks. If you cannot keep the power amp from clipping, the amp power should be equal to the speaker’s continuous power rating. This way, the speaker wouldn’t get damaged in case the amp clips by overdriving the input. In such cases, there won’t be any headroom for peaks. You’ll need to drive the speaker at slightly under the full rated power for avoiding any distortion.

For doing light vocal sessions, it’s recommended that the amp’s power should be 1.6x the Continuous Power rating per channel. If you’re doing heavy metal/grunge sessions, you should have 2.5x the Continuous Power rating per channel. The amp power needs to be rated for the impedance of the speaker.

Say that the impedance of the speaker is 4-ohm and its Continuous Power Handling is 100W. If you’re having light vocal sessions, the amp’s 4-ohm power must be 1.6 x 100W or 160W continuous per channel. For handing heavy metal/grunge, the amp’s 4-ohm power must be2.5 x 100W or 250W continuous per channel.

If you use too much power, you could end up damaging the speaker. You’ll essentially be forcing the speaker cone to its limits. If you’re less power, you will probably turn up the amp until it clips as you’ll try to make the speaker loud enough. Clipping might damage the speakers because of overheating. This is why you should stay with 1.6-2.5 times your speaker’s continuous power rating.

Power vs. Application

Another important consideration to consider is how big an amp you’ll need for filling the venue with clear, loud sounds. Remember, there are certain drawbacks if you use power amps that are too small. The bigger the room and the louder the sound system, the more power will be needed. Loudspeakers that have high sensitivity will require less power than loudspeakers having low sensitivity.

Even though a rock concert in an arena can be powered by 15,000W, you might see large touring labels using 80,000 to 400,000W total. Around that, much power will be required for handling 20 to 24dB peaks without clipping and for powering extra speakers for better coverage of a large area.

If one loudspeaker isn’t able to handle the total power needed, you can easily divide the total power among multiple amp channels and multiple loudspeakers. Say that you require 1000W for achieving the desired average loudness, but your speaker’s power handling is 250W continuous. You can use a power amp of 500W per channel while connecting two loudspeakers in parallel to each channel. This way, each speaker will be receiving 250W (not considering cable losses).

If the parallel has multiple speakers, their total impedance will be halved. For instance, two 8-ohm speakers in parallel will have the impedance of 4-ohm. In this case, each speaker will receive half of the amp’s 4-ohm power.

Sensitivity

The sensitivity specifications will be present in the loudspeaker’s data sheet. The typical sensitivity for a PA loudspeaker is 95 to 110dB SPL/W/meter. Bigger speakers generally come with higher sensitivity than smaller speakers, and high-frequency drivers with higher sensitivity than low-frequency drivers.

Peak headroom

As music has transient peaks that are 6 to 25dB above the average level, the power amp has to produce enough power for handling the peaks without distortion.

For instance, if you require 100W continuous power to achieve the desired average SPL (Sound Pressure Levels), you’ll require 1,000W continuous to handle 10dB peaks. Meanwhile, you’ll need 3,162W to handle 15dB and 10,000W for handling 20dB peaks. Clearly, the peaks will need more power than the average levels. 

Listener’s distance from the source

This will be the distance from the loudspeaker to the farthest listener. If you’re using multiple loudspeakers that extend into the audience, this distance will be from the nearest loudspeaker. For example, if your audience is 100 feet, and you’re having speakers at 0 feet and 50 feet, the listener distance will be 50 feet.

If you’re unsure about this distance, you can always make a rough estimate from the values mentioned below. Be sure that you’re entering the distance in meters.

  • Coffee house – 4.8m or 9.8m or 16 to 32 feet
  • Small-sized clubs – 9.8m or 32 feet
  • Medium-sized clubs – 13.7m or 45 feet
  • Small outdoor festivals – 15.2m or 50 feet 
  • 2,000-seat concert hall – 33.5m or 100 feet 
  • Stadium or arena – 30.5m or 91.4m or 100 to 300 feet

Other considerations to consider

The calculations above will apply to outdoor or anechoic conditions. If the sound system is present inside the venue, the reverberation increases the SPL, typically by 6dB. You’ll be able to use this room gain as extra headroom.

Say that you require 1,000W for peaks and the speaker’s continuous power handling is 250W. A speaker’s peak power handling should typically be 4x its continuous power handling. The speaker will probably be able to handle a 1,000W peak. It means that you’ll be able to use a 1,000W amp for driving the speaker. This applies as long as you’re using the power for peaks and not driving the speaker continuously with 1,000W. In simple words, you shouldn’t turn up your amp so high that it starts clipping. 

What if the sound system is using an active crossover and separate power amp channels for each driver? Say that you’ve got a 3-way system. You should determine the power separately for every sub, mid-range driver, and high-frequency driver. All three types of drivers will produce the same SPL at the same distance. It’s worth noting that horn-loaded drivers normally have higher sensitivity than subwoofers. The horns will require less power to produce the same SPL as the subwoofers.

How much guitar amp power do I need to gig

electric guitar and amps on stage

After playing the guitar for some time, you’ll feel that the hours of practicing have been worth it. You’ll notice that you’ve improved a lot, and you’re ready to start gigging. At that moment, you’re already fantasizing about playing as part of a band or as a solo act. You’ll be contemplating whether your 20W amp is enough to play on stage or not? But how much guitar power do I need to gig?

Playing live with a drummer will need you to use at least 50W of amp power for matching the volume. Headroom will be important too, as you might struggle to get clean sounds at high volumes with 50W. To get clean tones, having 100W will be the standard. Moreover, you should remember that you can always mic up smaller amps or go through the PA. 

Watts aren’t necessarily a symptom of volume

Even though watts are related to volume, it isn’t necessarily the only aspect. Wattage is more related to power, which isn’t the same as volume. The number of watts in your amp determines the power. Some guitarists feel that if they double the wattage, they’re doubling the volume, but this isn’t always true.

Watts and volume are actually related exponentially instead of linearly. If you’re looking to double the volume, what you need to do is multiply the number of watts by 10. Moreover, a 10W amp wouldn’t have a major difference from a 20W amp. Going from 50W to 100W will only result in a 3dB rise in loudness.

Is it possible to gig with a 5W amp?

A 5W amp commonly has a 1×12 speaker, and the gears aren’t able to achieve enough volume to play with a drummer for practicing or gigs on stage without PA support. This type of amp might sound small even if it’s hooked up to a PA system through a microphone. 5W amps are designed for playing at suitable volumes needed within a bedroom or at home.

If you’re looking to get bigger sounds using this gear, you can look to get additional speakers. Although these cabinets give thicker tones, and you’ll notice a major difference, the volume will still not be enough for gigging.

Will 10W amps be loud enough for gigging?

10W amps are also considered to be beginner gear for practicing at home. These amps will require you to have PA support. If you’ve got a 10W amp, you should think of playing alone without any bandmates. Small 10W amps will also be decent for busking. It’ll depend on your expectations, but they’ll be useful for small gatherings of an audience who wants to listen to you.

Will 25W amps be enough for gigging?

Assuming that you don’t require crystal-clear sound, 25W amps might be enough, but they might make unwanted noises while playing. Needless to say, it’ll depend on the style of music that you’re looking to play and the tone that you want to achieve. Generally, these amps might be too thin to play with other musicians.

Audience drum kits are loud, especially if you’re playing music genres that need hard-hitting drummers, like metal or hard rock. Standard bass amps can sometimes drown your low-wattage guitar amps. If you’re in a band having another guitarist who cranks their higher wattage amp up, you’ll be having serious sound issues.

The audiences might have a hard time making up what you’re performing. What’s worse is that you won’t be able to hear yourself playing.

Are 50W enough for guitarists to gig?

50W amps are widely considered to be the starting point for gigging amplifiers without the help of any mic. This is the wattage for the minimum threshold for playing live. Up to this point, the difference between tube amps and solid-state amps will be pretty irrelevant. 

If your end goal is to use solid-state amps, the higher the wattage, the better it’ll be. This is the case as you’re intending to sound loud, you won’t want to crank up the amp as you’ll need leftover headroom. It’ll help you maintain a clean tone, as you won’t have to push your gear to its limits. 

Tube amps, on the other hand, will reach their best tone once they’re pushed. In this case, you’ll want to break up the amp to its limits. With tube amps, they’ll be enough as you’ll be looking for the amp to crank up.

The 50W solid-state amps are unlikely to be enough for the same situation. You’ll have to push the amp to its limits for it to be heard. Moreover, the sound produced will likely be poor, and it could potentially damage your equipment. Remember, 50W isn’t really recommended if you want to achieve clean tones.

Will 100W or more be enough for gigs?

100W will be the gold standard if you’re looking for gigging amps. These are the big boys that’ll pummel your audiences with amazing tones and their power. These types of amps will offer enough volume for gigging. Moreover, you won’t have any trouble pushing them to the limit because of the headroom provided. 

You wouldn’t have to deal with any unwanted distortion or clipping. Additionally, you can even play maintaining a fine clean tone in both types of amps, tube amps or solid-state amps.

Why is headroom needed for gigging?

Headroom is essentially the slack that the amp has to keep clean tones clean. Guitar amps, when they’re cranked, start distortion. A high watt amp isn’t always required to be cranked for the amp to sound loud for gigging with. This way, you’ll still be able to play clean tones at high volumes.

Headroom is a term that describes the power that your amp can provide before you start cranking or sounding distorted. Some guitar amps are intended for providing a lot of clean headroom. It’ll be great for keeping a pure, clean sound even at high volumes. Contrarily, some other amplifiers are created for providing a distorted sound before it cranks up.

This is because they’re designed for providing less headroom, as the distorted sound produced is perceived to be something good by the human ear. Further, amps that possess a high wattage won’t have to be cranked to sound loud enough for gigging. This way, you’ll be having loud enough tones despite having high volumes when you’re playing.

How Much Amplifier Power Do I Need?

Conclusion

Thank you for reading. Hopefully, now you know a lot more about guitar amp power, how much guitar amp power do I need, how much power should your amp have for gigging, and more. For musicians and guitarists who are practicing and have to play occasional gigs at small venues, having an amp with 50W power will be good enough. However, for getting clean tones, having an amp with 100W will be the golden number for playing live gigs. If you ever feel that you’re having less sound, you always can mic up smaller amps and use a PA for getting a louder sound.

Rick Pena

Rick Pena

Rick is the founder of All Stringed. He started playing with a classical guitar when he was 10, but changed soon to electric guitar and later also to an acoustic. You can find more about him here.