Are Dual Subwoofers Worth It?

Who needs two subwoofers? What do more subs do to the overall sound of your music or home theater system? If you've been troubled by not enough bass, or surprisingly if you have too much bass, you might want to take a look at adding a second sub. Andrew explains why.

Are Dual Subwoofers Worth It?

If you've spent any time researching home theater and home theater systems, whether it's online or talking to friends or relatives that have systems, you've probably heard terminology like 5.1 or 7.1. The 0.1 in those cases is the sub-woofer, is the LFE, or low-frequency effects, channel.

And all home theater receivers have a sub-woofer output, a dedicated sub-woofer output for sending the bass signals that you tell the receiver to send to your sub-woofer. Now, you also might have heard 7.2 or 5.2. Well, the 0.1 has become a 0.2 which means two sub-woofers.

So as more and more home theater receivers are starting to have dual sub-woofer outputs people are starting to ask questions. "Well, should I have two sub-woofers? When would I want two sub-woofers?" Now the question's very, very interesting because if you tell somebody, you know, you should have two sub-woofers or four sub-woofers in a system, they'll go, "Oh, no. I have one sub-woofer and there's already too much bass or the all the bass that I need."

Well, having more than one sub-woofer in a home theater system is not about producing more bass or more output necessarily. The important thing that you want to think about is how the sub-woofer and how the bass is going to be produced in your room. And the benefit of having more than one sub-woofer is to smoothen out and have more linear bass frequencies.

The reason for that is that when we have more than one source of bass like a sub-woofer in a room, we are driving different room nodes and room modes that can impact how flat the bass is going to be in a particular listening room. So for instance, if you have, you know, in the front left and right corner of your home theater system, you've got a sub-woofer, those two sub-woofers are going to interact in different ways with the rest of the room at bass frequencies.

And what will tend to happen is you'll get flatter, more linear bass. Now you can extrapolate this to any number of sub-woofers you want, you know, 4, 10, 50, 100. And actually, there's companies that have done research and mathematical models showing that when you drill down to it, the best most reasonable performance improvement is from four sub-woofers.

Now I know a lot of you are probably saying, "Four sub-woofers? I never want four sub-woofers in my room." But the research that we conducted about a decade ago where we measured four and two sub-woofers in different placements in a whole different range of rooms sizes, and floor treatments, furniture, etc showed that yes, four sub-woofers will give you the most linear accurate bass in your room.

Two did a very, very good job of improving on the performance of one sub-woofer. So it's something to consider if you have the space and you have the budget, adding at least a second sub-woofer to your home theater system can make a massive improvement in how flat and linear the bass is going to be so that you don't have those hills and valleys that, you know, typical rooms suffer from at bass frequencies.

One note about correction algorithms like Odyssey and a number of others. Yes, you can do some things to flatten out the bass, but you don't want to boost frequencies. Trying to put more energy and boosting into specific areas is not the right way to go about it.

Because you're just throwing sub-woofer power away for nothing. You can't fill in a dip. What you can do is bring a peak down. By having more than one sub-woofer you're doing that naturally without any EQ. So it's something to think about for the next upgrade to your theater system.



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