How Long Can a Subwoofer Cable Be?

Audio enthusiasts know that having the right cables can make all the difference in sound quality. Subwoofer cables are an essential component of any audio system, and they come in various sizes and lengths.

But how long can a subwoofer cable be? People think they can use any length of RCAs to connect their subwoofers (home and car setup) with the stereos.

But that’s not true! I always recommend choosing the right cable length. Otherwise, you will reduce your subwoofer’s performance.

You need to understand the below factors to get excellent sound quality without introducing distortion or noise (because of the wrong size) into your system. Let’s begin!

How Can Cable Length Really Affect the Subwoofer?

Please read the below points so that you can clearly understand the potential risks of choosing a long cable:

1. Signal Loss or Disruption:

Many factors can cause signal loss or disruption in the audio setup. But I’ve also discovered one of the most common factors can be the cable’s length itself.

Frankly speaking, longer than 25 feet of cables may lead to signal degradation due to the increased resistance that comes with it.

In simple words, the longer a wire or cable is, the more likely there will be disruptions and losses in signal transmission.

2. Susceptible to Interference and Noise:

Coaxial subwoofer cables can also create Electromagnetic Interference (EMI) and other noises, such as subwoofer hum.

You may also hear the unwanted hum, hiss, or other annoying background noise from the subwoofer (occurring due to a lousy audio signal).

This can be particularly problematic in high-gain systems, where background noise can be amplified and made even more noticeable.

The primary source of EMI-related problems comes from power supplies used by nearby equipment interfering with electrical signals traveling through cable runs between devices.

3. Phase Shift:

Phase shift is an acoustic phenomenon whereby audio signals are delayed, causing a timing difference between the subwoofer and other speakers in the system.

You may face a phase shift in your audio setup if you have such a long coaxial cable. However, this issue becomes increasingly problematic with longer cables because of the extra length that needs to absorb the signal’s energy before being passed on to the next component in line.

The longer it takes for that signal to reach its destination, the more time there is for interference and delay (causing phase shifts).

What Should Be the Maximum Length for a Subwoofer Cable?

However, I suggest using the as much as shorter RCA cable to connect your subwoofer to your audio system.

However, up to 15 feet (4.5 meters) may be acceptable for low-powered systems. However, for high-quality systems with more powerful amplifiers, thicker gauge wires are needed, and a shorter cable would be necessary – 25 feet (7.6 meters) or less is recommended in this case.

• For Car Subwoofer: The ideal length for a car subwoofer cable ranges from 5 ft. to 23ft.
• For Home Subwoofer: The ideal length for the subwoofer cable should be from 5 ft. to 25 ft. But in most cases, you can use up to 40 ft. (depending on the cable quality).

4 Tips to Choose the Right Cable Length for Your Subwoofer:

Here are my favorite and most professional ways to choose the right size for coaxial cables:

1. Measure the Length Between the Sub and Audio Receiver:

First, you need to measure the distance between your subwoofer and the audio receiver. Place your subwoofer and receiver in your desired places so that you can get the correct measurement.

The length will help you determine how much cable you need to connect your speakers to your receiver. To measure, use a measuring tape, take measurements from both ends of the projected route, and add them together for length.

Once this is done, it’s time to decide which cable type suits your needs best before purchasing.

2. Get a Slightly Longer Cable:

Hold on! You should always get a slightly longer RCA cable than the exact measurements. This will give you more flexibility when positioning your subwoofer and audio receiver.

Additionally, having some extra slack can help with cable routing or connecting components further away from each other.

Longer cables also have less strain on the connectors which can reduce wear over time and improve signal transmission quality. An overly long line may result in excess clutter, so balancing length and performance needs is crucial.

3. Choose a High-Quality Cable:

Choosing high-quality audio cables is essential to ensure that the sound quality from your subwoofer is not compromised.

High-quality cables are designed with shielding, low resistance, and good insulation to reduce signal loss or interference that can degrade the sound.

Additionally, look for heavy-duty construction with gold connectors since these will provide better conductivity for clear audio signal transmission.

4. Avoid Excessively Long Cables:

I am repeating it! Regarding subwoofer cables, the longer the cable is, the greater the chance of signal degradation and interference.

Sound quality can be significantly reduced if these cables are too long, so a recommended maximum length is 25 feet.

To ensure optimal sound quality, choose a cable length suitable for your setup and leave some slack to prevent damage from pulling or stretching forces.

To minimize the risk of signal loss, focus on using high-quality shielded cables to protect against noise interference.

How to Prevent Subwoofer Hum Due to Cable Length?

If you’re experiencing subwoofer hum due to cable length, there are a few preventive measures you can take:

1. Try to use shorter cables whenever possible; longer cables may sometimes be required, but keep the length as short as possible.
2. Consider using shielded or low-capacitance cables with good-quality connectors; this will help reduce interference from nearby power lines and other sources of electromagnetic noise.
3. Make sure all your components are grounded properly; an incorrect ground connection can cause RF interference that leads to distracting noise from your subwoofer.

If these measures don’t work, it may be necessary to look into additional shielding materials like ferrite cores for your cabling or even different wiring solutions such as balanced line cabling, significantly reducing the chances of picking up external noises.

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