REL Subwoofer Input Options

To connect a subwoofer, you have to use the right inputs to create the best home theater experience. Customers, especially those new to high performance audio, can get confused by the several methods of connection available before they hook up their new subwoofer. We’re here to help you sort these things out.

There are essentially three ways to connect your subwoofer: RCA and XLR are two methods that involve variations of low level connection—which involves transmitting a small voltage signal operating below 2 volts—and the third uses a “High Level” connection wherein one or more channels of your receiver or amplifier’s speaker connections are through the input of the subwoofer using a special cable.

212 Black Label rear panel

RCA-RCA Low Level

RCA-RCA is the simplest method of connection, a tried-and-true method that connects using a low level signal; RCA is used for the vast majority of more modestly configured systems. It takes a very small signal from the .1/LFE subwoofer output (on the rear of your receiver) and outputs, typically, a theater-centric signal to your new subwoofer.

Using the ubiquitous RCA cable, this method plugs in similar to how tuners or CD players have done so for decades. RCA is easy and works fine for relatively short runs of, say, 25′ or so. So then, why would anyone use another method of connection besides RCA? Well, getting better quality of sound and quietness, or unlocking the ability to keep the signal robust and the noise down to a minimum, are big reasons to move up from this basic standard.

REL Commander .1/LFE Subwoofer Cable

Balanced XLA-XLR Connection

XLA-XLR is another low level signal method of connection that is more conducive for music. Balanced XLR connections have been the standard method of connection in the music making industry for years, providing a better connection than .1/LFE due to transmitting an inherently stronger signal—plus it rejects noise and hum better.

First, the mechanical connector itself for XLR is a far more secure locking connector. Second, the method of sending the signal is more robust: Instead of one very low level positive signal being transmitted to the subwoofer, and all other energy being wasted as if simply dumping to ground (think of a garden hose in the desert trickling water onto the sand), this balanced circuit actually uses two much stronger signals, both transmitting signals at different times. This signal is more like a fire hose, sending out a much stronger signal that rejects noise and hum better, then adding a second identical but reverse phase signal that cancels any noise that can get on the line. 

So, XLR connection can be a nice step up; many of the better receivers on the market and virtually all high-end AV processors offer this connection on their rear panel.

High Level Connection

REL’s “High Level” connection is preferred by many of the most experienced listeners due to the performance gains available from this type of design. This connection method has been used by REL Acoustics for over thirty years and offers several performance benefits. But it does require paying a little more attention because the receiver you are using has its own amp, and depending upon what type of amplifier class it uses, you’ll want to connect it through one of a few different ways. We’ll explore this further in just a moment, as we answer a few commonly asked questions:

Why do the world’s most careful listeners insist on using only this method?

Experience has taught us that when we connect to a REL using our “High Level” connection, the sound takes on all the sonic qualities of your main system. This means that all the musical qualities present in your main system feed forward into the sound produced by your REL—completely integrating your subwoofer with the entire sound system and ensuring each and every sound produced is accentuated by your REL.

Well, why is this experience remarkable?

The most difficult thing for a sub to do is to blend perfectly with the main speakers. In contrast to the normal speaker/sub system, a REL “High Level” connection ensures that your subwoofer is fed by ALL the elements of your existing system, rather than just the major components. In a normal system, the sound acts a little like a marching band moving past, with the bass instruments and drums lagging at the rear of the band; with a REL “High Level” connection, you are suddenly able to hear the entire ensemble playing at once, rhythm and tempo in correct timing—suddenly, music makes wonderfully toe-tapping sense.

But wait, I really only bought a subwoofer so I could experience big bass for all the cool special effects for movies!?

REL subwoofers have bass covered too. RELs that offer a “High Level” connection—not all of them do, our mostly-for-theater HT range only offers conventional low level .1/LFE—also offer a complete, dedicated .1/LFE input for theater sub bass, including its own volume control so you can set it for the perfect level and still use our “High Level” connection.

I thought you said High Level connection was all about music?

REL’s “High Level” connection definitely creates a better listening experience when music is the preferred art form you’re taking in. That said, when movies are being played, High Level does this wonderful trick of improving every single sound in the movie—not just the special effects, but the music and the dialogue, creating a richer and more full theater experience. 

Commodore .1/LFE Subwoofer Cable