What Subwoofer Input Should You Use?
RCA, XLR, multi? How do you know which connection is best for your subwoofer? Andrew Welker explains in this video.
One question we get a lot is about connecting your subwoofer.
Connecting a subwoofer is not very difficult, particularly as most home theater receivers have got dedicated subwoofer outputs on them.
The first thing that we should mention is before you make any connections to your system, it's a good idea to make sure that the power is off to the receiver and to the subwoofer. You're not necessarily going to damage anything, but it can cause some startling bangs and noises if things are not right.
Once that is done, go to the back of your home theater receiver or processor and locate the output labeled sub out. Most of the time you're going to find a common connection called an RCA connection.
On most receivers, there is going to be one sub output, on some there'll be two, but you're simply going to plug your RCA cable into that sub out on your receiver or processor, and then the other end is going to connect to your subwoofer.
Now, depending on what vintage of our subwoofer that you own, you may have a multi plug which requires a quarter phone to RCA adapter, which is included with the subwoofer. If you have one of those amplifiers, you simply plug the adapter in and then you plug the other end of your RCA cable from your receiver's sub out into that input connection, and now, the subwoofer is connected.
If you don't have one of these multi jacks on your subwoofer, you'll have just the standard RCA jack, and it's just a matter of plugging into the RCA that's labeled low level input. On some home theater processors, you're going to find a different connection as an option, which is called an XLR connection. It's typically found on higher-end equipment and it gives you the benefit of being able to run longer runs of these cables with lower noise and interference.
In the case that you've got an XLR subwoofer output on your processor, it's exactly the same as the RCA connection.
If you have a multi jack, it plugs into the same connector that held the RCA adapter, and if you have a version with a dedicated XLR input, it simply plugs into that input there.
In case you're not using a home theater receiver processor and have a stereo system or two channel system with an integrated amplifier or a dedicated preamp and amplifier, obviously, you're not going to find this dedicated subwoofer output in almost all cases with those electronics. So the question then is, how can you hook up your subwoofers?
In the case where you've got an amplifier that you need to hook up to the subwoofer, you're going to use what's called the high level connections, and these are identical to the speaker connections that you would use on a typical amplifier. Now, you have a couple of options here. You can either run your amplifier connections to the main speakers and then run another set of speaker cables to the subwoofer. Alternatively, you can either wire from the amplifier to the subwoofer and then jump off to your main speakers, or vice versa. You can go to the speakers from the amplifier and then from the main left and right speakers, you can jumper to the subwoofer. In any case, what you're going to be doing is you're simply going to connect both the left and right speaker outputs wherever they're coming from to the input of the subwoofer amp. And now, you have available the same signal that you would coming from a sub out on a processor. Now that you've got your subwoofer connected up in the manner that works with the electronics that you own, now is the time that you can power up your electronics, plug in the subwoofer, power it on, and then go towards making the adjustments and set up.
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About the Author
After graduating with a degree in Electrical Engineering Andrew went on to join the R&D team at API (Audio Products International) makers of Energy and Mirage product lines. He was working directly for API's head of engineering Ian Paisley, who was also a member of that handful of loudspeaker designers who participated in the NRC research project, and to quote Ian Colquhoun "one of the finest loudspeaker designers to ever grace this planet". Andrew spent over 10 years at API and ended up being the head designer for all the Mirage products. Andrew is a brilliant loudspeaker designer who has a broad knowledge of everything audio and a particular expertise in the science relating to the omni-directional psychoacoustical effects of loudspeaker reproduction. Andrew joined Axiom in 2009.