How To Connect A Subwoofer To A Receiver Without A Subwoofer Output

So your receiver doesn’t have a subwoofer output. You’re probably wondering what the heck you can do about it, and you might be worried if you’ll have to spend a lot of money for either a new receiver, subwoofer, or both!

I’ve got great news – there are several simple ways to connect a subwoofer to a receiver without a subwoofer output.

Read on and I’ll show you several options along with easy and clear diagrams to help. There’s no need to throw away your old receiver or break the bank!

Home stereo subwoofers explained

Passive vs active home subwoofers diagram

Comparison of non-powered (passive) vs powered (active) home stereo subwoofer enclosures.

Home stereo subwoofers are available in two different types: powered (“active”) and non-powered (“passive”).

  • Powered subwoofers use a low-signal signal which is boosted greatly using the built-in speaker amplifier, power supply, and crossover. These types are one of the most common and in many cases use an RCA type input jack to connect to the receiver for sound.
  • Passive (non-powered) subwoofers are simply a subwoofer speaker inside the bass enclosure which is directly wired to the speaker terminals or a passive bass crossover inside. These types are less common.

How a subwoofer produces bass

The subwoofer works by resting inside of an enclosure designed for it and to produce deep bass when playing music limited to low-end bass sounds.

In order to produce clean-sounding bass without vocals or other sounds a subwoofer can’t properly produce, a low-pass crossover is used to allow only bass frequencies to pass & be produced. The problem comes when you try to connect a subwoofer to a signal without a crossover – it sounds terrible!

The subwoofer output jack on a receiver is normally limited to passing bass only, either from stereo music production or from the “.1” subwoofer channel (dedicated subwoofer music content) of a surround sound system.

For example, when you hear references to “5.1” or “2.1” speaker systems or surround sound audio for movies, the first number represents the number of main speakers. The “.1” is used to represent a sound channel limited to only bass for optional subwoofer use.

Powered subwoofer inputs & controls you may (or may not) have

Powered subwoofer example with inputs and controls labeled

Example of a powered subwoofer with 2 types of signal inputs (speaker level and RCA jacks) along with sound controls. Note: Not all subwoofers have speaker level inputs, which makes it a problem connecting them to a receiver without a subwoofer output.

Powered subwoofers usually have several inputs and controls, but it always depends on the brand and model. Here’s an example of what you’ll usually find:

  • Power input (AC outlet power)
  • On/off switch
  • RCA input jack or a pair of jacks
  • Subwoofer crossover adjustment
  • Subwoofer level adjustment know (the amplifier’s boost level)

The subwoofer input jack usually connects to a single mono (monaural, meaning both stereo channels are combined into one) output jack on the receiver.

Receiver subwoofer output jack example

Example of the mono RCA subwoofer output jack found on many home receivers. These connect with a single male to male RCA cable to a powered subwoofer.

Some models also include speaker level inputs, meaning they can be used with any modern or old home stereo receiver without a subwoofer output.

While that’s nice, if yours doesn’t have that feature, ordinarily you’d need to buy a different subwoofer and waste money.

In fact, some of the information you’ll find right now on the internet says that you have to buy another subwoofer if you don’t have a receiver with an output jack. That’s simply not true.

As I mentioned at the beginning of my article there are several ways to work around this problem.

Diagram & examples: Connecting a subwoofer to a receiver without a subwoofer output

Diagram showing how to connect a subwoofer to receiver with no subwoofer output

1. Connecting a receiver to a subwoofer with RCA input jacks

Example of a powered subwoofer RCA jacks & RCA Y adapter cable

Left: Example of a powered subwoofer with 2, instead of the typical 1, RCA input jacks. Right: An RCA Y adapter that can be used with a line level converter to connect to a subwoofer with a single RCA input jack.

For subwoofers with only 1 or more RCA input jacks (no speaker level inputs), a simple way to connect them to a receiver with no subwoofer output is by using a line level converter.

What is a line level converter, and how do they help?

Line level converters are small devices that accept speaker wire connections and scale down the speaker level signal to a low level signal (RCA jack) type output that the subwoofer can accept. They’re extremely handy in the car stereo world because they make it possible to connect a stereo without RCA outputs to any amplifier.

They’re not commonly used for home stereos but still really useful there, too.

Image showing examples of line level RCA converters

Shown here are two examples of line level/RCA speaker level converters that work well for home receiver/amp to subwoofer use. A line level converter takes the higher voltage speaker signal from an amplifier or home receiver and scales it down significantly so it’s safe to use with RCA inputs.

How much do line level converters cost?

Line level converters range in price (for a good one) of about $15-$25 each. They’re connected to the speaker leads of a radio, receiver, or amplifier. RCA cables are then connected to the jacks provided. The internal electronics not only scale down the speaker output voltage from a receiver but also help prevent noise from the audio path, too.

If you’re using a subwoofer with a single RCA subwoofer input jack, you may want to pick up a “Y” RCA adapter to combine both receiver channels on the output side into one.

Subwoofers with 2 (stereo) RCA jack inputs, however, will need a standard male-male RCA cable.

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2. Subwoofers with speaker level inputs

Example of subwoofer speaker level inputs

If you own a subwoofer with speaker level inputs you’re in luck! You can connect these directly to your receiver’s speaker outputs, either by themselves (on unused speaker terminals) or at the same time with speakers connected to the receiver.

These subwoofers with this feature contain internal electronics that scale down the speaker signal from the receiver before it reaches the internal amp that powers the sub.

Additionally, there’s a low-pass crossover built in as well to produce great-sounding bass and no unpleasant parts of the music – just pure, low-end bass.

Connect these directly to the receiver just like you would another pair of speakers. 

Note: Subwoofers with speaker level inputs and outputs provide a way to easily connect both at the same time. The outputs are internally connected to the input connectors, making it easier to add speakers and the subwoofer to a receiver simultaneously.

3. Connecting a receiver to a passive (non-powered) subwoofer

Example of a passive subwoofer low pass crossover

Example of a passive subwoofer low-pass crossover. Passive crossovers, unlike electronic crossovers, work using capacitors and inductor coils instead of electronic components.

If you’re wanting to use a non-powered (passive) type of subwoofer, there’s still hope, although it can be a bit harder to find the right parts and set up vs using a powered subwoofer.

To use a non-powered subwoofer, as shown in my diagram above, you’ll use a low-pass subwoofer speaker crossover which is connected between the receiver and the subwoofer enclosure. These filter out higher frequency sounds before they reach the sub to help provide clear & nice-sounding bass only.

How to choose subwoofer crossovers and where to find them

Speaker crossovers such as this are sold both in a single (one speaker) or dual (2-speaker) model, depending on the brand & supplier. They also have to be matched correctly to the impedance (Ohms rating) of the sub.

For example, subwoofer crossovers designed for 8 ohm speakers must be used only with those. Otherwise, the sound filtering is radically different and won’t sound as expected since the speaker load will react differently with the design.

Normally you’d choose one with a low-pass frequency of close to 100Hz or in that range. Speaker crossovers are sold where speaker parts & related components are sold as well as marketplaces like Amazon or Parts Express.

Stereo vs surround sound receiver subwoofer output differences

Stereo vs surround sound receiver differences diagram

Unlike older or standard stereo receivers, surround sound receivers have a unique output that comes from the surround sound movie or music source. However, in regular stereo listening mode, they act the same as regular receivers.

One thing to bear in mind is that when connecting a subwoofer to a receiver without a subwoofer output, you can’t get a separate “.1” bass channel as you can with surround sound receivers.

On the other hand, it may not even be an issue. In fact, the surround sound receiver “LFE” (low-frequency) output is considered optional – hence the “.1” name. There is a drawback, though: for some movies, especially action or other types, the bass channel can be very enjoyable.

Using a receiver without that output means you can’t get the same effect, but that’s only for surround sound mode. The good news is that in stereo mode, both new and old receivers have very similar subwoofer behavior when connected as you’ve seen here.

Just something to be aware of if you’ve ever considered upgrading later.

More helpful speaker info & diagrams

I’ve got lots more information to help you get your sound system going:

Your comments are welcome!

  1. Hey Marty. Great article and advice. I currently own a Sony DH190 Stereo Reciever. It has A/B bare wire speaker connections no Sub out. Meaning I can hook up 2 sets of speakers. I have an old passive Sub that only has 1 lamp fixed type wire coming out of it spilt into 1 +/- wire. How can I hook this up to my reciever? Meaning the B speaker obviously require 2 sets of wires to work and I only have one. I currently have it hooked up to the B speaker clips but only in the R side meaning I am getting some bass but also have some right speaker audio leakage. Is there a way I can hook just 1 set of bare wires to 2 speaker terminals. Sorry if this all sounds confusing I’m not that great at communicating…ha ha. Any advice would be much appreciated. Thank you. Dom

    Reply
    • Hi there, no problem I understand what you are describing. Passive subwoofers can definitely be a hassle to use because of exactly what you’re dealing with. While you could wire it to both channels IF the receiver was bridgeable, most receivers usually aren’t. :(

      Honestly, the most practical ways are:
      1. Replace the passive subwoofer driver with a dual voice coil (DVC) model. You can connect both speaker channels then. Obviously not the easiest solution.

      2. Use a mini amplifier with a low-pass mono output (woofer) channel like this one at Parts Express.

      #2 should sound great and won’t be hard to do. You’ll still need a line-level converter like the examples in the article, but they’re relatively cheap and easy to use too.

      Good question and I’ll need to update the article as I’m sure it’ll come up again. Thanks!

      Reply
      • Dear Marty,
        You should update the article- use those pretty drawings you do too- as this problem is exactly what I am facing. Passive sub, single voice coil, vintage gear.

        Great article and my search engine seems to be preferring your drawings when I’m searching for solutions.

        Reply
  2. Hello Marty,

    I have the Yamaha AS301 amplifier (looks exactly like the image you have listed above in fact) which my Yamaha NS10’s are connected to using bare wire method. However, I want to purchase a Neumann KH750 subwoofer wIth DSP and I want to know how best to connect it to the Amp especially for the alignment process? I was advised that I need to come out of the KH750 (which uses xlr connections) and go into AMP and this is where I am stumped, as I cannot use bare wire method to connect the sub and the amp only has a sub out, but I see no options for inputs. My question is could I perhaps use any of the aux inputs on the amp? Would this work?

    Any help or advice you can provide with greatly appreciated.

    Many thanks in advance

    Reply
    • Hi, you may be able to just use the Neumman’s optical digital input since the Yamaha amplifier has an optical output. Those cables are inexpensive so it’s worth a try. Aside from that you may be able to find an speaker level to XLR converter like the Jensen SP-2SX (or use 2 converters together). I’m a bit confused about the question about using inputs to the amp and you won’t use inputs – only outputs to the subwoofer.

      Reply
  3. HDMI, Optical out, Soundbar with crappy bass and meantime my awesome Velodyne powered sub is sitting in the corner with nothing to do because there is no longer a giant receiver with a rca powered sub out. I did not see any option in your article that would help me out with no rca out. Is there any way I can get my bass, that rattles my house, hooked back up to all this new stuff?? My Velodyne only has RCA input but all this new stuff only has HDMI and Optical output.

    Reply
    • Hello, yes ideally you can do similar to modern TVs with an optical output: by using an optical to RCA converter box. They’re pretty affordable. That should work as long as the optical output is active in whatever listening mode you’re using on the receiver.

      Reply
  4. I am wondering, because I want to learn all the wiring to standard circuit boards, is the a way to connect my Sony stereo receiver to a Sony home theater Bluetooth subwoofer that has had the amplifier and sub removed from the box.

    Reply
    • You mean to the bare subwoofer speaker itself? Yes, but if the amplifier and subwoofer have been removed you can use example #3 in the diagram or a separate amplifier to drive it.

      Reply
  5. Marty, need some help. I have an old receiver- a and b speaker outputs capable and no LFE or line level output for subwoofer. I have already parallel wired 2 sets of speakers to the “a“ speaker output and would like to add 2 additional self powered subs (high level inout only) to the B output from the same receiver.
    How should I wire (parallel wire ?) the self powered subs and treat them the same way as the regular speakers and will it put additional stress on the receiver even though the subwoofers are already self powered (receiving signal only) is this true? Please help !

    Reply
  6. Hi Marty,
    I have a 5.0 Stereo receiver with a single RCA output. On the other hand I have an LG 4.1 speaker system. My woofer is self amplified but power cable (coaxial type) was configured for original reciever. Now I have connected woofer to reciever via black and red cable. It plays but it seems I have lost some fidelity in sound. How do I power it can I just change cable and put in a plug or do I connect the speakers to RCA sound out. I hope it makes sense.

    Reply
      • Hi sorry not very good with electronics. My amp stereo has 5 channels with stereo level put red and black and an additional output with AV cable output red and white. My sub woofer is active with a din type 13 pin power cable. I have connected the sub to amp on a spare stereo level put. The sub woofer is playing but has lost the lower frequency and does not power up. Does the AV connection offer more power or can I replace the power cable and connect it directly to power source. The sub woofer was originally connected to a hifi system by 13 pin din cable.

        Reply
        • Hello there “Innocent.” The RCA jacks offer a line-level signal so it doesn’t really relate to power, but rather an audio signal that’s useable by a powered subwoofer. However, if you have 13-pin DIN connector there may be other factors at play.

          I can’t really add more without specific information to help – especially if the 13 pin DIN connector is unique to the manufacturer as it is not a standard type of connection.

          Reply
  7. Thanks it’s I salvaged from a LG hifi and sub was specific to hifi. So having connected it via spare stereo output. It plays low frequency but omph is missing because it’s not powered. The din connector is for the power supply. So because it’s not powered I can’t control the speaker control. Is it necessary to power it anyway. It’s on a 80 watt pmpo out put for main speaker while sub is a 200 watt 85 dB per metre

    Reply
    • I’m afraid I’m not able to help much as this sounds like it uses a proprietary connection. If you’re good with electronics you can perhaps open it and tap off the wiring needed as a work-around, but otherwise you’re probably better off getting a standard powered subwoofer to replace it.

      Reply
  8. Mate love your work,. Thank U,.
    Question I have this klipsc cs700 sub on its own, would it be possible to hook this up to a Bluetooth receiver to work

    Reply
    • Hi Lenmar. To the best of my knowledge at this moment I believe it’s not possible. It’s likely using a proprietary wireless connection or some other format where it cannot be paired to anything else.

      I’m fairly certain about that. These “home theater in a box” speaker systems often have a subwoofer (wired or wireless) that will only work with the original set.

      Reply

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