How To Bridge Subwoofers 2023? Top Full Guide

How To Bridge Subwoofers 2023? Top Full Guide
  • Anthony

How to bridge Subwoofers is the top search question on Google. The subwoofer is the most important component in home theater systems because it produces deep bass sounds. However, subwoofers are normally placed at the back of the room. This means they are too far away from the listener’s ears to fully take advantage of them.

Building a subwoofer bridge or completing the so-called “sub crawl” will allow you to bring the active subwoofer closer to your listening spot, saving you time and frustration.

Let’s be with Hooke Audio to learn the ways to bridge subwoofers in this article.

What Is Car Amp Bridging?

Bridging allows you to get the most power from your amplifiers by using a built-in channel-sharing design. In car audio applications, bridging is often used to provide more power to sub-woofers or larger full-range speakers.

This refers to using two amplifier channels together to drive speaker wires or a set of door speakers. The power is normally split between two channels.

This is a fascinating topic and extremely useful! For example, I used to own many amplifiers. I usually used a 4-channel amp or 5-channel amplifier. In bridged mode, I drove a single subwoofer in my trunk or two subwoofers on the car’s 2 amp channels.

This allowed me to have more power and flexibility, even if my speaker cables configuration was changed later.

How To Bridge Subwoofers – Connecting to a Bridgeable Amplifier

Method 1: Preparing to Wire Your Subs to Bridged Amp

Wire Your Subs to Bridged Amp

Find the specification labels for your system. An amp label should be placed near the speaker output jack. It should indicate the amp’s output power (measured as Watts) along with the minimum impedance, measured in Ohms.

The bridged mode should have a label near the speaker output jack that indicates the maximum output power (measured in Watts) and the minimum impedance (measured in Ohms). This is because you will need to use a higher impedance to run a bridged setup. You should label your sub-woofers with an impedance (in Ohms), and a power input (in Watts).

A two channel amp can be bridged to one channel, and a four channel amp into two channels. Bridging the amplifier channel increases the power output. Most of the time, you connect an amplifier to use two channels to power one subwoofer or four channels to power two subwoofers.

Most amps for home theater are stable at 4 ohms when they are bridged. Most car amplifiers are capable of 2 ohms.

These values should be written down. At least Four Channel Amplifiers values should be written down.

  • Amp Bridged Output Power
  • Bridged Amplifier Minimum Impedance
  • Speaker Power Rating
  • Speaker impedance number

Calculate the impedance total of all your speakers. Add up the speaker impedance numbers for each speaker to get this figure. The impedance should be equal to or less than the channel’s minimum impedance. It shouldn’t exceed 16 Ohms unless the amp is specifically rated for higher impedance values.

For speakers wired in series, the formula to find total impedance is Z1 +Z2 + Z3 …. = Ztotal. Where Z is the impedance for a speaker.

If you have three speakers that have impedance values 4 Ohms 6 Ohms and 8 Ohms respectively, your total impedance wired together would be 18 Ohms (4+6+8=18).

It is slightly more difficult to find the total impedance of speakers wired together. It is (Z1xZ2xZ3 …)/ (Z1+Z2 + Z3 …) = Ztotal.

Let’s say that you have speakers with impedances of 6 Ohms and 8. It would look something like this: 1) Multiply both the values. 6 x 8 = 48 Ohms 2. Add the values. 6 + 8 = 48 Ohms 2) Add the values. 48/14 = 3.43 Ohms (rounded).

Determine the power that each speaker will receive based on the amplifier’s power output and total impedance. Alterations of Ohm’s Law can be used to calculate the power or you can use the online calculator. You don’t want to overload your speakers.

Make sure your amp is able to power your subs. Measure the output power in Watts. The wattage should be included on the label of your speakers. Your speakers should be labeled with a wattage.

It must equal or exceed their total output wattage. If you have subs that pull 200 W each, an amp should produce at least 400 W. This is called “headroom” and helps avoid clipping.

Unplug equipment. Wiring powered devices could be dangerous. You can unplug the battery amp terminals if you’re working on a car audio system.

Method 2: Wiring Single Voice Coil Subs to a Bridged Amp

Wiring Single Voice Coil Subs to Bridge Amp

Get a roll stereo wire. This speaker wire is needed to connect your amplifier to the sub-woofers.

Subwoofers can be used with speaker wire in the 12- to the 16-gauge range.

Connect the amplifier to the subwoofers. Make sure to check which amp terminals are used to switch to bridge mode. These will be marked on the amp. Run a wire from your amp’s positive terminal to the sub’s positive bridge terminal.

Connect the second subwoofer with the first. Run one wire from the negative end of the first subwoofer to link to the positive end of the second. You can wire them to parallel by running two speaker wires between each sub. The first will link to the positive terminals and the second to the negative terminals.

Complete the circuit. Connect the wire from the second sub’s negative terminal to the negative bridged terminal of the amp. This completes the circuit, regardless of whether you’re wiring in parallel or series.

Method 3: Wiring Dual Voice Coil Subs to a Bridged Amp

Wiring Dual Voice Coil Subs to a Bridged Amp

Connect the amplifier to the subwoofer. This wiring will be the same as wiring a single voice coil (SVC) subwoofer. You should keep in mind that dual voice coil (DVC) subs, have second sub’s coils and therefore four input terminals. Two are positive terminals, and two are negative terminals.

Connect one of the positive terminals to the positive bridged terminal on the amplifier. Connect the coils. The two coils in your DVC can either be wired in parallel or in series, just like two speakers.

If wiring coils are in series, run a wire from one coil’s positive terminal (the one wired directly to the amp) to another coil’s negative terminal. Then, run a wire again from the first coil’s negative terminal to the second coil.

If wiring parallel coils, run one wire from the first to the second positive terminal, and another from the first to the second negative terminal.

Connect the second subwoofer to your first subwoofer. You have again the series verses parallel debate.

If you elect to wire the subs together, connect the negative terminal of the second coil of the first sub to that of the first coil of the second sub. These circuits can be complicated quickly. Next, link your negative coil’s end to the positive coil’s end. Connect the negative end of the second coil to its bridged terminal.

If wiring parallel, link both the negative and positive ends of the second sub’s second coils. Connect the positive coil end of the first subwoofer to the coil end of the second sub.

Connect the second coil to the sub. Use the same instructions as the first coil.

Finish the circuit. Now, the fun part. No matter how you used parallels and series above to get the right impedance or power distribution, ending the circuit is a simple step. To link the second coil of your second sub to its negative bridged terminal, run a wire.

Check for inconsistencies. Turn on your system and try it out. You can start at a low volume, then gradually increase it until you hear any unusual sounds. You may have miswired sub-bass or bass.


What Is Bridging A Subwoofer?

Two of the amplifier’s four channels are combined into one or two channels with half the ohms. This is called a “bridged amplifier.” The method is very popular among car drivers because it lets amplifiers send more power to the subwoofer or speakers for a mono signal.

What Happens If You Bridge Non-bridgeable Amplifiers?

Bridging them will work but won’t change output voltage – therefore won’t change power output. In order to bridge the car amplifier phase of one channel amp has to be inverted.

Does Bridging An Amp Make It Louder?

Yep, the distortion specs generally get worse with bridged amps — standard PA deal. Get a bigger amp. Note that a 50-watt amp is only 3dB louder than a 100-watt amp. You need ten times the power for a channel amp to sound twice as loud as a smaller amp.

What Makes An Amp More Powerful When It Is Bridged?

It is important to remember that we are assuming certain things, such as that the amplifier can provide this much power.

Some amps are not capable of delivering that much. It all depends on the limitations of each amp and how it was designed.

You should also note that each amplifier channel handles a lot more electrical current than it did before. It will therefore draw more power from your car’s battery.

How Can Car Amplifiers Make It Possible?

This is because today’s car amplifiers have, a design where one of the 2 audio channels is inverted (or 180 degrees out-of-phase). However, it is connected to the output in an inverted manner.

This is because it doesn’t have any effect on the end-user.

This means that bridge mode uses a bridge connection so that amp four channels have a difference from the output voltage. This voltage difference is twice as large as the one-channel.

Can You Bridge One Sub?

You may connect two channels for that one sub, but you must first determine the impedance of your sub. You don’t want to go any lower than 4 ohms steady bridged for most amps.

Does Bridging An Amp Double The Wattage?

By connecting two amplifiers together, you can give more power to a single microphone, but you don’t get more power from the amplifier as a whole. Because bridge amplifiers only work in mono mode, they need a second similar amplifier to work in stereo

What Hits Harder, 2ohm or 4ohm?

A lower electrical resistance subwoofer generates a louder sound than a higher electrical resistance subwoofer; hence 2ohm subwoofers are louder than 4ohm subwoofers. Due to their higher power consumption, 2 ohm subwoofers are more likely to generate a worse sound quality.


If you’re looking to improve the audio in your car, one way to do it is to bridge your subwoofers. This will allow you to get more power and better sound quality from your subs. It’s not a difficult process, but there are a few things you need to note before you get started. Thanks for reading!

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