When designing a speaker system for your car or truck, you want to be sure that it sounds as good as possible. You want the high-end to soar, the mids to be strong and crisp, and the low-end to rattle bottoms in their seats.
So, you want to install the ideal combination of subwoofers to get the biggest, baddest bass. However, there are so many setup options out there, including speaker sizes, boxes, sealing or venting, and more.
The question that I hear a lot of people asking is, “Would 3 10s or 2 12s sealed be louder?” As we’re going to find out, the answer to this question isn’t straightforward and depends on a lot of factors. So, let’s look into it and help you make the best decision for your sub setup.
Size Matters for Speaker Cones
While it doesn’t matter for everything, size matters for speaker cones. And the size of your cones makes several differences to the sound of your bass.
The first and best understood impact of size on speaker cones is that, all things being equal, a bigger cone can produce lower frequencies. The frequency response of a 12-inch speaker can get down to anywhere between 30-35Hz.
However, with 10-inch speakers, you will rarely get lower than 35-40Hz. This means that both 10s and 12s will miss out on some of the lowest of the low bass frequencies because human ears can hear down to 20Hz, and only our rears can feel frequencies even lower than that.
However, you can see that 12s will almost always get down to lower frequencies than 10s. So, if you’re a tickler for those lowest tones, 12s may be your best choice. Speakers’ frequency responses are set by their construction, and there’s nothing you can do to a speaker to change it.
It’s pretty straightforward. A speaker with a bigger diameter is going to push more air than one with a smaller diameter. To move the surface of the bigger speaker, you simply need more power. So, a smaller 10” speaker should be louder with the same Watts from your amp than a larger 12” speaker.
Another way of saying this is that a larger speaker needs to use more power to get to the same volume level. That means a larger 12” would use more power than a 10” speaker.
However, if you’re going to wire up two 12s or three 3 10s, the 10s will use a little more power because there are three of them. That said, the difference is pretty small and shouldn’t make an overall difference to your whole setup.
OK, we’re going to have to go back to middle school math for this one. The surface area of a speaker’s cone determines how much air it can push, and pushing more air means making a louder sound. So let’s compare a 10-inch speaker to a 12-inch speaker.
Are you ready? Here comes the math…
The area of a cone is tricky, so generally, we use the area of a circle formula when talking about speakers. The area of a circle is πr2, which is pi (3.1416) times the radius (half the diameter) squared.
For a 10-inch speaker, the radius is only half that diameter at 5 inches. So the area of the speaker is:
- A(10” speaker) = πr2 = 3.1416 * 5 inch * 5 inch = 78.54 inch2
OK, not bad. How about a 12-inch speaker? Here the radius is going to be bigger at 6 inches. But, because the radius is squared, this makes a big difference.
- A(12” speaker) = πr2 = 3.1416 * 6 inch * 6 inch = 103.10 inch2
That’s over 30% bigger, which means 30% more air getting pushed around and (perhaps) 30% more volume, all things being equal.
The question we’re asking here, though, is…
“Would 3 10s or 2 12s sealed be louder?” So, we have to take things one step further. Three 10-inch subs would have a total surface area of 3 * 78.54 inch2 = 235.62 inch2. At the same time, two 12-inch subs would have a total surface area of 2 * 103.10 inch2 = 206.2 inch2.
Uh-oh! Now we realize that three 10s together move more air than two 12s, and therefore three 10s should be louder. Again, if all things are equal.
But are all things equal? Of course not. Different brands and even different models of the same brands are going to have different construction, different power handling capabilities, different resistance, and more. And that can make choosing the right sub speakers for your car a tricky one.
Resistance and Installation
The wattage of your speakers is one thing. But, if you have a 10-inch speaker and a 12-inch speaker with the same RMS wattage, you’re not going to hear a lot of difference in volume. However, the speaker resistance and the way you wire up your speakers are going to make more of a difference.
Take two 12-inch 4-Ohm speakers, for example…
If you wire them up in parallel, the overall load on your amp is half the impedance (resistance) of a single speaker. So, this way, you’ll present the amp with a net 2-Ohm load.
This means you can play these speakers louder with the same amount of wattage since the resistance is lowered by wiring them in parallel.
But not so fast…
If you took three 10-inch speakers that had a resistance of 4 Ohms and wired them in parallel, you would get a lower net impedance of 4/3 = 1.33 Ohms.
This means that the three 10s could get even louder with the same wattage than the 12s. You have a reduced load, so it’s easier to push the power through the three smaller speakers than the two larger ones. Just make sure they can take it.
In general, you’re going to find that three 10s are a little bit louder than two 12s. However, the difference is not going to be a huge one. And there are other factors to consider if you want to choose between three 10s or two 12s car speakers.
We’ve already looked at a couple of the pros and cons of three 10-inch subwoofers in comparison to two 12s. But, there are a bunch more factors to take into consideration. First off, the price. In general, it’s going to be more expensive to buy three 10-inch speakers of a similar make and quality.
Let’s compare two brands…
Skar Audio has their 10” SDR-10 D4 1200 Watt subs priced at about $80 and their 12” SDR-10 D4 1200 Watt subs priced at about $90. If you bought two 12s, you’d pay just $180, but three 10s are going to cost you $240.
Of course, that’s for just the speakers, never mind the extra wiring and any connectors. In general, you’re paying over 30% more for the 3-speaker set-up over the two 12s.
The other main thing to take into account when you’re choosing between three 10s and two 12s speakers is the space they will take up on installation. As we already calculated, the three 10-inch subs have a bigger surface area than two 12s.
However, that’s just the area of the cones added together. This doesn’t take into account the linear space you need to lay out these speakers in a line or a cluster.
We want at least two inches around each speaker for mounting purposes. In that case, a row of the three 10-inch speakers is going to be (2” + 10” + 2” + 10” + 2” +10” + 2”) 38 inches long and 14 inches tall. That’s 38 * 14 = 532 square inches.
With two 12s, we’re going to use less space overall. You’d need only (2” + 12” + 2” + 12” + 2”) 30 inches in length, but 16 inches in height. That’s 30 * 16 = 480 square inches.
These are more or less the minimum linear dimensions you’ll need to mount these speakers. But, of course, you could also put them in separate boxes rather than one big one. While the three 10s will take up more linear space altogether, it’s worth noting that it depends on where you mean to mount them.
So, where are they going in?
If you’re going for under car seats or truck bench seats, the 12s might not fit into places that the 10s can. If your spaces are tight, you might need to go with the smaller 10-inch speakers simply because they’ll fit.
Since we’re talking about sealed boxes here, we also have to think about what’s recommended for the speakers.
Going back to the Skar Audio subs, I would recommend that you put the 10” SDR-10 D4 1200 Watt subs in sealed boxes providing 0.95 cubic feet of space, while the 12” SDR-10 D4 1200 Watt subs need only a little more at between 1.00-1.25 cubic feet.
So even if you went big with the 12s…
You still need a max of 2.5 cubic feet volume of boxes. But, for three 10s, you’re going to be looking at 2.85 cubic feet. So again, the two 12s save space overall. Of course, you will also need a larger 3-speaker box for the three 10s or three individual boxes, which will cost more than two.
You can get this triple 10-inch sealed subwoofer enclosure from American Sound Connection for $150. But, a similar quality double 12-inch sealed enclosure from BBox costs just $100 and is smaller overall as well.
How About Sound Quality?
If you’re not only concerned with volume but also want to get the best sound quality, the differences between 3 10s and 2 12s are important.
On the one hand, the 12s should get down to deeper frequencies in their response curve. This means that you’re going to scoop up more of the precious deep tones that define the bottom end. You’ll find 12s juicer and more robust. You can also generally set your low-pass filter cut-off frequency lower and focus 12s more on the low end. This generally produces clearer bass.
But at the same time…
Three speakers working together can do something different than two. With three 10-inch speakers in three different locations or mounted on angles so that they’re directed in different directions, three 10s can give you more reflections, more ‘pings,’ inside your car.
Is this a good thing?
That’s open to your taste. More pings will give a fuller sound, packing the bass all over your car’s interior. But, the reflections can also bounce around and cause more interference. And that can muddy your low-end more than two speakers will.
So, in the end, the sound of three 10-inch speakers compared to two 12-inch speakers comes down to personal preference. The three 10s might be able to get a bit louder, but that’s not always the only thing to think about.
Want To Improve Your Car’s Audio?
We can help with that. Check out our in-depth reviews of the Best 12-Inch Subwoofers, the Best 15-inch Subwoofers, the Best Car Subwoofers, the Best Under Seat Subwoofers, and the Best Subwoofers for Single Cab Truck you can buy in 2023.
Also, take a look at our detailed reviews of the Best 6.5 Speakers, the Best 6×8 Speakers, the Best Car Amplifiers, the Best 3000 Watt Amps, the Best 2000 Watt RMS Amps, and the Best Monoblock Car Amplifiers currently on the market.
Would 3 10s or 2 12s Sealed Be Louder? – The Verdict
In the end, the very basic, straightforward answer is that installing 3 10-inch speakers in your car audio system will be a bit louder than putting in two 12-inchers. If volume is your only concern, then go ahead and get yourself a trifecta of the most gnarly 10-inch speakers you can find.
At the same time, three 10s will cost more than two 12s right off the bat. Plus, installation and boxing them will also cost more. The three 10s will also take up more space in your ride and possibly have a less juicy, deep, and clear sound than you can get from a pair of 12-inch subs.
But in the end, the choice is yours. And you need to choose the best setup to shake your rearview mirror right off the windshield.
Until next time, good luck with your decision, and happy listening.