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300 Watt Speakers: What Size AMP? (Updated 2023 Guide)


Passive speakers can’t produce sounds without an AMP.

But picking out the right amplifier for your audio setup can be intimidating.

Don’t worry, though.

I’ll guide you in choosing the right AMP for your 300-watt speakers. 

And trust me, it’ll be much easier than you think.

Continue reading to find out:

  • What AMP you should get for 300-watt speakers.
  • 3 helpful tips for using your AMP and speakers safely. 
  • 5 simple steps to match your speakers to an amplifier. 
  • And this is just the beginning… 

What size AMP for 300-watt speakers?

A 450-watt AMP is best for 300-watt speakers. That’s because you won’t overwork your amplifier if it’s more powerful than your speakers. However, you should also match the impedance or ohms of your devices. Otherwise, 1 of them may fail. 

What does 300-watt AMP mean?

A 300-AMP means that your device can produce a power output of 300 watts. 

“What’s a watt?”

Well, it’s a measurement of electricity. 

And it signifies the amount of power an amplifier can generate. Or how much electricity your speakers need to work. 

Now, some speakers absolutely need amplifiers to function. 

But you should never connect active speakers to an AMP.

So before you decide on what kind of amplifier you need… 

Figure out if your speakers actually need an AMP

Speakers are divided into 2 different types:

  1. Active.
  2. Passive.

Now, simply speaking, passive speakers need an AMP to work. 

Otherwise, they won’t be able to produce sounds.

On the other hand…

Active speakers don’t need amplifiers. And they should never be connected to one. That’s because they already have a built-in AMP in their system.

Warning: You shouldn’t connect active speakers to an external AMP. Because you’ll fry or destroy the former if you do so. 

And now, if you’re wondering: 

“How can I know which category my speakers fall into?”

Simple. Just check the back of your device.

And look if it has a power port. 

If it does, that means your speakers already have built-in amplifiers so they’re active. 

You might also want to know: 2 Ways To Wire A 4-Channel Amp To 6 Speakers (How-To)

How do I match my speakers to my AMP

To match your speakers to your AMP, figure out the power capacity of your speakers. Then add 50% to this value to know how powerful your AMP should be. Afterward, match the nominal impedance of your devices. 

Let me explain this process in detail with these…

5 simple steps to match your speakers to the right amplifier

Note: You should only follow these instructions if you have passive speakers. 

#1: Find your speakers’ power capacity

“What’s that?”

The power capacity of your speakers is how much electricity your device needs.

As I said earlier…

Speakers are usually measured by how many watts they can handle.

And power capacity is the official term for this measurement.

You can usually find this value on your device’s user manual or specifications. 

So once you know how many watts your speakers can handle, proceed to the next step.

Note: This is also called RMS or program watts

Warning: Record your speakers’ power capacity, not its peak power capacity. The latter refers to the maximum electricity your device can handle in short periods. So using this value for the equation later will damage your speakers. 

#2: Identify your speakers’ nominal impedance 

Now that you know the amount of power your speakers can handle…

It’s time to figure out your speakers’ nominal impedance (in ohms). Or how much they can resist electricity’s current. 

Note: You’ll see this on your speakers’ specifications or user manual. 

#3: Calculate the watts your AMP needs

Just multiply your speakers’ wattage by 1.5. 

Then, take note of the product.

For example, if your speakers have 300 watts… 

Multiply 300 x 1.5, and you’ll get 450.

Important: The number you’ll get is how much your amplifier’s watts need to be. So if your speakers have 300 watts, buy an AMP with 450 watts per channel. 

Now, many people worry that a more powerful amplifier will destroy their speakers.

But fret not. 

Your speakers will be safer with an AMP that has more wattage than the other way around. 

As I said, the power capacity of your speakers is how much electricity it needs to work.

On the other hand, the wattage of your AMP is how powerful it is.

Now, if your amplifier only has just as many watts as your speakers…

The former will have a hard time generating enough power for the latter.

However, if your AMP is stronger…

It’ll have a much easier time carrying electricity to your speakers. 

That’s because it brings enough power and will always have extra if needed. 

However, this doesn’t mean you can simply use any amplifier with more watts. 

Warning: Stick to the calculation you made earlier. Never use an AMP that’s 200% more powerful than your speakers. Because you might overpower the latter and destroy its components. 

#4: Match your devices’ nominal impedance 

As I’ve said earlier, your speakers and amplifier should have the same nominal impedance. 

Or else, you’ll risk destroying your devices. 

Let me give you an example:

If your speakers have 4 ohms and your AMP has 8…

You’ll fry your amplifiers’ components and blow your speakers out.

That’s because your AMP will be more resistant to electricity than the latter. 

On the other hand, if your speakers’ ohms are higher than your amplifier’s…

Your AMP won’t be able to power your speakers efficiently.

So you’ll get much weaker audio than you’re supposed to.

That said, if you have a 300-watt speaker with 4 ohms…

You should find a 450-watt amplifier with the same nominal impedance.

This way, none of your devices will be overworked.

And they’ll function efficiently and safely. 

Want to learn more about how the nominal impedance affects your speakers? Watch this:

#5: Connect your devices

You already know what the right amplifier for your speakers is by now. 

With that, all that’s left to do is connect them. 

But before you do so, I have these… 

3 tips for connecting your speakers to your AMP safely:

#1: Always start at the lowest volume

Before you turn ON your AMP and speakers… 

Always set your volume at the lowest settings or 0.

Then, increase your AMP gain gradually while a song plays. 

This way, you’ll avoid blowing your speakers out. Which usually happens if you accidentally let them play too loud. 

Note: Blown-out speakers will start producing unwanted buzzing and scratching sounds. 

“If I accidentally blow my speakers out, can they still be fixed?”

Yes, they can.

However, this process can be complicated. So most of the time, only professionals can fix them. 

#2: Don’t let your speakers play too loudly 

Don't Let Your Speakers Play Too Loudly

Your AMP is already more powerful than your speakers.

So just a small gain increase will be enough to make your audio much louder.

That said, there’s no need to set your amplifier’s volume to the highest values. 

Warning: Turn down your AMP’s volume when you start to hear audio distortion or clipping. Because if you let your speakers play like this for long durations, you’ll risk blowing them out. Or worse, you might fry their components. 

#3: Be careful about adding new speakers to your setup

If you want to add more speakers to your setup… 

Only use those that match the ohms of your current devices. 

However, don’t just plug your new units into your amplifier immediately. 

That’s because connecting more than 2 speakers into an AMP requires an extra step. 

And that’s to calculate the new impedance load of your speakers.

You can do this by:

Dividing the ohm value of your devices by the number of speaker units you have per channel. 

Here’s an example: 

If you want to use 4 speakers together in a parallel connection (2 units per AMP channel)… 

Their new impedance value will be 2 if they each have 4 ohms. 

Note: 4 ohms divided by 2 speakers (per channel) is 2. 

So you should connect them to an AMP that can also handle the nominal impedance of 2 ohms. 

Because if you use a model with 4 ohms…

Your speakers won’t be safe in this kind of setup.