What Size Amp Do I Need For Different Sized Subs?

If you are an automobile user, you consider a lot of things for your car. And being passionate about it makes you even more sophisticated about its stuff. Subwoofers are something you must be concerned about. 

So, what size amp do I need for different sized subs?

You can not directly choose the right amp for your subs. You need to follow a 3-step method for this. First, find out the total RMS ratings. Then identify the right impedance. Finally, take the amps according to the chart properly. And that is how you can get the right size amp for your subs.

This is actually a peek through to the actual part. We have covered it in-depth in the article. So, read along.

Get started now!

Most Common Sized Subs

There are many subs in the market currently. However, there are 4 main and most common sized subs. These are discussed briefly here:

After the brief, we also got a chart. Over there, you can find the compatible amp for the respective subs.

8 Inch Subs

8 inch subs are generally the smallest ones of the subs. Although these are low in size, the amp is not that low. 

The watt this amp needs is about 600. The 8-inch subs give you a clean bass. But these are not as good as 10-inch subs.

I’ve curated some of the best 600W amps for you here.

10 Inch Subs

The watt amp it needs for a 10-inch sub is 300. Although the amp is not that high, the performance is not negligible. 

In fact, the 10-inch subs are even better than the 8-inch subs. These are better in terms of the bass.

And when paired with Rockford Fosgate P300 it works like a wonder. If you don’t believe me then check out this setup.

12 Inch Subs

For 12-inch subs, a 500-watt amp is a minimum that would work. You can definitely get up to 1000 watts. But do not try to go over that.

Because amps more than 1000 watts can damage your subs. No worries! Check out these amazing amps to complement your subs.

15 Inch Subs

With a 15-inch sub, you can get up to 1200 watt amps at max. The minimum amp it needs is 400. However, we do not recommend this low amp.

The 15-inch subs are generally considered the best with their beats and bass.

Now, here is a chart to get the information at a glance.

8 Inch10 Inch12 Inch15 Inch
Amp Size600150500-750400-1200

This chart hopefully helps you, giving a good brief in short. 

What Size Amp Should I Choose for Different Sized Subs?

Choosing the right amp for different subs is important like doing it for different powered subs. This is in fact quite crucial for your subwoofers.

You know subs come in different sizes like 2 10 inch or 2 12 inch subs.

The subwoofer’s parameters must be met by the amplifier’s capability. For example, a sound digital amp might or might not work for just any sub. For both the amps and the subs, your objective is to have these two parameters coincide. 

The coil size and resistance of many subs connected together should be the same. If they aren’t, power will not be distributed equally. 

And some subs would almost certainly be robust, whereas others likely are underpowered. In a system, you could want to operate multiple types of subs. 

Source : The Wire Realm

In such a situation, each variety will require its own amplifier. For example the 5E3 amplifier can be paired with some selected speakers only. You may also measure the amplifier using an amplifier matching calculator.

Now, take a look here to ascertain the amp size is compatible with the sub. We have got here the steps to follow to match the subs.

Step 1: Find Out The Total RMS Rating

To begin, multiply the number of subs it has by each one’s RMS grade. This will aid in determining their full RMS rating. 

You have to be certain about one thing. The amp must not deliver more than the entire RMS rating of the subsystem. 

Source: Bluetooth speakers

If you fail to ensure it, you may face remote issues with your subs. However, if the remote is bad, you may replace it.

Step 2: Identify The Impedance

Now, this one is one of the most crucial parts for the right size of amp. Because you need to find out the total impedance for attaching the subs together. 

If you fail to do it properly, there might be massive failures. And you would definitely not like the consequences. 

We would like to cover it with the bullet points below. Because a table chart might be too lengthy and confusing to keep up the follow-up. Take a look now.

  • One single voice coil with 2 ohms could have an impedance of 2 ohms maximum.
  • One single voice coil with 4 ohms could have an impedance of 4 ohms maximum.
  • One dual voice coil with 2 ohms could have an impedance of 1 ohm. But it can also have an impedance of 4 ohms too.
  • One dual voice coil with 4 ohms could have an impedance of 2 ohms maximum. But it can also have an impedance of 8 ohms too
  • Two single voice coils with 2 ohms could have an impedance of 1 ohm. But it can also have an impedance of 4 ohms too
  • Two single voice coils with 4 ohms could have an impedance of 2 ohms. But it can also have an impedance of 8 ohms too
  • Two dual voice coils with 2 ohms could have an impedance of 2 ohms. But it can also have an impedance of 8 ohms too
  • Two dual voice coils with 4 ohms could have an impedance of 1 ohm. But it can also have an impedance of 4 ohms too
  • Three single voice coils with 2 ohms could have an impedance of 6 ohms maximum.
  • Three single voice coils with 4 ohms could have an impedance of 1.3 ohms maximum.
  • Three dual voice coils with 2 ohms could have an impedance of 1.3 ohms. But it can also have an impedance of 3 ohms too.
  • Three dual voice coils with 4 ohms could have an impedance of 2.7 ohms. But it can also have an impedance of 6 ohms too.
  • Four single voice coils with 2 ohms could have an impedance of 2 ohms. But it can also have an impedance of 8 ohms too.
  • Four single voice coils with 4 ohms could have an impedance of 1 ohm. But it can also have an impedance of 4 ohms too.

Speaking of impedance, you need to make sure you have set your amplifier properly to high or low gain. Some users think this is not an important thing to consider. But make sure you definitely count on these to choose the right amp.

As a good user, you must want to be safe while using subs.

Step 3: Take The Amps

At this point, you need to pick up the amp for your subs. Take a look at our chart to get an easy idea.

1 Ohm2 Ohms4 Ohms
1 SubDVC 2-ohmsSVC 2-ohmsDVC 4 ohmsSVC 4-ohmsDVC 2-ohms
2 SubsSVC 2-ohmsDVC 4-ohmsSVC 4-ohmsDVC 2-ohmsSVC 2-ohmsDVC 4-ohms
3 Subs(1.3 ohms)*SVC 4-ohmsDVC 2-ohms(3 or 2.7 ohms)*DVC 2-ohmsDVC 4-ohms(6 ohms)*SVC 2-ohmsDVC 4-ohms
4 SubsSVC 4-ohmsDVC 2-ohmsSVC 2-ohmsDVC 4 ohmsSVC 4-ohmsDVC 2-ohms

You may get confused with the abbreviations. So, we have clarified it here for you.

  • SVC- Single Voice Coil
  • DVC- Dual Voice Coil

Finally, you are done choosing the right amp size for your subs.

FAQs

What factors to consider for the ideal sized amp for my subs?

You need to do a bit of calculation to find out this. First of all, reckon the watts RMS rating of your sub. Then find the product of sub ratings of each one and the quantity of the subs. And then you would be able to find out the total RMS rating. Then choose the amp that is within the range of this.

Will there be a problem using different amps for subs?

No, you can not use different amps for your subs without a valid measurement. But if you are planning to install 2 different amps for one sub, you can. However, you have to make sure that the requirements are met accordingly. Without following that, there would be problems.

Is it impossible to make amps greater than the subs?

Well, you can actually install amps greater than the subs if you want. But it is recommended not to do that so. Although it can be good at times like in passive sub, it is better not to do so. Because there could be a few internal issues that you might not be aware of.

Final Words

Now you got your answer, what size amp do I need for different sized subs! We believe you now have a detailed idea about their different sizes.

Make sure you ascertain the compatibility sizes prior to making the purchase. Because you would not like to waste your money on it.

Best of luck!

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