Audio cable for projector: How to boost the audio in the projector.

FACTS CHECKED BY  Jose George​

Projectors play a vital role in delivering presentations, films, and other media in both professional and academic settings. However, the pleasure of watching a movie on a smart home projector isn’t complete without perfectly timed sound. Now, how do you hook speakers up to the projector? Is an appropriate audio cable for projector enough? Let’s look into more details.

How will a projector receive and send audio (sound)?

The primary purpose of a projector is to transmit and playback video. Modern projectors are equipped with various video and audio transmission ports, including HDMI, MHL, USB, and RCA composite.

Some older projectors may only have a VGA port for communication and cannot receive sound as they display moving images. Projectors may support many video connections at once, including but not limited to;

  • Component Video (which has three different signals)
  • Composite Video System (that has data traveling in one cable like the original video signal)
  • S-video (that is an outdated sort of analog video stream) 

Unfortunately, if the projector only has video inputs, you’ll have to find an alternative method of speaker setup.

Projector connected to laptop

Projector connected to a laptop

The way to connect the projector and speakers

There are three methods of speaker setup.

Using audio cables 

Most projectors have A/V plugs that can pass through the audio signals, including

3.5mm jack inputs and outputs: You should verify the sort of 3.5mm jack the projectors has, as some only have one (either the output or input). Thus, if this access point can only take in sound, you can only use it to listen to audio. For audio, many projectors contain two 3.5mm connections, one for transmission and one for the reception. Remember that the 3.5mm jack is used for analog audio transmission and reception.

Composite or Component Audio/RCA connection types: RCA connectors are a step up from 3.5mm jacks for inputs and output. However, the 3.5mm jack and the RCA cable both transmit an analog signal and are susceptible to the same amount of outside interference. These cables have split signal features that produce stereo sound. The difference in their real structure makes one superior to the other under certain circumstances. It’s also important to remember that some projectors may only have RCA connections, so you’ll want to double-check before making a purchase. 

S/PDIF connection types:

S/PDIF adapters convert analog audio to digital and then use a coaxial cable to deliver the digital signal. Hence, if your projector has S/PDIF compatibility, you’re in luck since the sound you receive will be of the greatest quality. You should know that, like RCA or a 3.5mm jack, S/PDIF can function as either an output or input connection type. Also, speakers’ S/PDIF connections are not standard since analog sound principles use electrical current rather than binary code to inform speaker design.

Optical or TOSLINK: There have been optical cables like TOSLINK before HDMI. Only the two-in-one audio-visual HDMI cable and the TOSLINK protocol use optical cables to transmit high-quality digital sound streams. An AVR can decode the compressed surrounding sound or uncompressed PCM output from your DVDs, CD players, personal computers, gaming systems, and DAT recorders.

For these projectors, you can use the following setups. 

Active speaker setups (without using an A/V receiver)

The connection is simple if your speakers are active (meaning they have their own internal powered amplifiers). Active speakers can have different connection types, not only the terminal connectors seen on regular passive speakers. In most cases, your active speakers will have XLR connections, ¼-inch jack connections, and RCA connections.

However, active speakers are unlikely to be included with digital audio connection options. Active speakers have an amplifier built right in, so if your projector uses a different connection type from the speakers, you must buy an adapter and perhaps some extra cords.

You will come across the most likely options (in terms of cables and adapters).

  • RCA to RCA Cable
  • RCA to 3.5mm Cable
  • ¼ inch Jack to 3.5mm Jack Cable
  • XLR to 3.5mm Cable

Passive speaker setup (using an A/V receiver)

There will be some added complexity with passive speakers compared to active ones. You’ll need an AV receiver or amplifier to connect a projector to speakers through speaker cables

The main feature that sets an AV receiver apart from a powerful stereo amplifier is the ability to send over video signals in addition to audio. Compared to this, a conventional stereo amplifier’s main function is to boost the volume of the sound coming out of the speakers. As a result, you’ll need to hook up your AV receiver or power stereo amplifier with your passive speakers before you can use them with your projector.

 Listed below are the most standard cables and adapters you would need.

  • S/PDIF Cable
  • Digital to Analog Audio Converter
  • Analog to Digital Audio Converter

Wireless Connection 

If your projector supports Bluetooth, you’re in luck: that’s the simplest way to hook up speakers. For wireless setup, you can purchase the following;

  • Bluetooth Speaker: A set of wireless speakers and a projector with Bluetooth functionality are all you need to get started. With this setup, you can stream music to the speakers without wires.
  • Bluetooth audio adapter: Attach an RCA connection from this device to your AV receiver, active speakers, or power amplifier to begin using it. Buying these receivers also lets you connect and receive audio from other portable devices, such as your tablet or smartphone.

Built-in speakers or soundbars

Some projectors now include speakers, and higher-quality projectors often include soundbars. If you are fortunate enough to buy or already own one, you can rest easy knowing that your projector doesn’t need any additional audio output connectors. However, remember that you’ll need to position your projector within listening distance of your audience or use alternate methods of connecting audio to more speakers. 

Projector wire harness

Projector wire harness

How to set up audio for a projector with no audio connections?

Sometimes, you will come across old projectors that need audio connections. For that, you have to choose some external aid for audio projection, such as the following options.

External AV Receiver

The setup is different in the earlier cases when we used an AV receiver to link a speaker to your projector. In this configuration, your projector would send audio signals to either an AV receiver or a controlled amplifier, which would then power your speakers.

Since your projector lacks audio outputs, you’ll need to route all media by the AV receiver before sending it to the projector. That is possible as an AV receiver allows for audio and video throughput. Nevertheless, a powered amplifier would be useless in such a case because it only boosts audio and never allows for visual pass-through.

Then, how to make the connection?

You can send the data stream (containing sound and video) to your AV receiver, where it can be decoded and played back from your chosen source device with an HDMI cable. You’d connect the projector to the AV recipient’s video output and the recipient’s audio output to the speakers. You only need to recall the specific sequence in which you connected each item.

HDMI audio splitter

Investing in an HDMI sound splitter would be necessary if you possessed devices incompatible with an AV receiver. In this case, a computer, laptop, Macbook, or camera might be useful.

Remember that the signal will be divided depending on the order and chain of equipment so that you might get sound from your loudspeakers and video from your projector.

Although a laptop is used in the example, any equipment with an HDMI output will do. With a laptop that supports HDMI out and an HDMI audio splitter, you may transfer the video signal from your laptop to the projector without interrupting the audio.

AV receiver-powered audio amplifiers or active loudspeakers might take the audio stream via the HDMI splitter’s RCA outputs.

Conclusion

Although a projector’s primary function is to reproduce video, many models now include stereo speakers, sound systems, and audio inputs/outputs. Thus, we need to consider whether your speaker and projector are compatible. Moreover, you should know the setting up method or contact professionals. Contact us now if you need help with the audio cables for projectors.

Need a buying guide?