Guide to connect the red and black wires of a Hi-Fi system to the PC or TV.

Hi-Fi speakers
On old Hi-Fi stereo systems, the audio speakers were connected to the central unit by means of simply exposed wires (without plugs and without sockets), to be inserted into the appropriate terminals on the rear of the unit.
This type of speakers still have a beautiful and clean sound and it is a shame to throw them away or let them accumulate dust unnecessarily: we can, in fact, reuse them to recreate a powerful 2.1 stereo system to be connected to the PC or TV to listen to music, movies and games with a yield never seen before!
But how to connect speakers with red and black wire to modern devices that only support audio on 3.5mm jack or RCA cables? In this guide we will show you how to quickly solve this problem on both PC and TV, using amplifiers designed for use with this type of speaker.

How to connect old Hi-Fi systems to PC or TV

If we have never seen an old Hi-Fi system before, it is worth getting a used one right away eBay or asking uncles, fathers or grandparents if they have one to give you, since they belong to a generation that will never come back (and honestly the speakers were made with much higher quality than the current ones).
After getting the system, let’s see together how it works and how to connect it to both the PC and the TV.

How do old Hi-Fi speakers work?

The old-fashioned speakers feature a red thread and a bare black thread (i.e. without any plug) and must be connected to an amplifier with dedicated terminals since they cannot manage the audio signal independently.
Speaker amplifier

Being passive speakers we will therefore have to get an amplifier with audio terminals and various modern audio inputs (such as RCA, 3.5mm Jack or better still digital optical inputs), so as to be able to take the output signal from the PC or TV, send it to the amplifier and thus take advantage of the old audio speakers.

Whatever device we want to use them on, we will need to get a compatible amplifier, such as the do cooler Mini Audio Power Amplifier, sold for less than 40 €.

The speakers can be connected to the terminals on the back (respecting the orders indicated by the labels) and using a power socket to operate the amplifier correctly.

If we want something even more powerful and professional, we can also see the DENON Pma-800 amplifier, available for less than 500 €.
DENON Pma-800

With this amplifier, we will be able to connect more than one Hi-Fi speaker and also use it to obtain the audio from PC or TV via the digital optical output.

If our computer does not have a dedicated subwoofer output (essential to recreate the 5.1 Surround effect), we will have to focus on an amplifier with a subwoofer output such as the DENON Pma-600, on sale for less than 400 €.
DENON amplifier

Also in this case we will be able to connect the speakers in the dedicated sockets and take advantage of one of the many input ports to amplify the signal of the computer or Smart TV.

How to connect Hi-Fi speakers to PC

To connect the Hi-Fi speakers to the PC we will first have to place the amplifier chosen in the previous chapter, connect the speakers to the terminals of the chosen amplifier and finally choose the type of connection to be made between the amplifier and the computer.
The simplest connection involves the use of a 3.5mm-RCA jack plug such as the Beikell RCA Jack Adapter Cable (2M), 3.5mm to 2RCA, available for less than 10 €.
RCA Jack

The 3.5mm jack plug will be connected to the audio output of the computer (usually present as the green plug on the back of desktop PCs) or at the exit Hearphones (on laptops), while the two white and red RCA cables we will have to connect them to the plugs LINE IN or AUDIO IN of the amplifiers presented above.
With this configuration we will not be able to correctly manage the bass, which will be reproduced by the audio speakers in an approximate way; if our sound card allows it, we can connect the subwoofer separately using the channel Center / Subwoofer, present between the pins on the back of the PC (usually colored Orange) and can be connected with a simple Jack-Jack cable.

If our sound card allows it, we can get the highest possible quality for sound by using a TOSLINK optical cable such as the iVANKY 1.8m Toslink Optical Digital Audio Cable, on sale for less than € 15.
Optical Cable

In this case, just connect the cable to the optical audio output (SPDIF OUT or OPTICAL OUT) of the PC with the optical input present on the more expensive amplifiers (indicated as DIGITAL AUDIO IN or OPTICAL IN).

How to connect Hi-Fi speakers to the TV

On a modern Smart TV, it is convenient to take advantage of the digital optical audio output, so you don’t have to waste time with cables that are not found or adapters for RCA plugs (since many TVs have removed them in the audio supply).
Audio output

All we have to do is identify the door on the back of our TV DIGITAL AUDIO OUT (OPTICAL) or similar and use the same TOSLINK cable seen in the previous chapter to connect it to one of the more expensive amplifiers already recommended.

If we want to recreate a 5.1 or 7.1 system with old Hi-Fi speakers, we can also consider home theater amplifiers such as the ONKYO TX-NR686 7.2channels Surround Black AV, available for less than 500 €.

With this amplifier, we will be able to connect a large number of old-fashioned Hi-Fi speakers and recreate our Home Theater configuration without having to spend thousands of euros for satellites and subwoofers.


As we have seen, even the old audio speakers of the Hi-Fi systems of the 70s and 80s can be recycled on modern PCs and Smart TVs, all we have to do is choose the right amplifier for our needs and the type of connection to be made. , being able to choose between analog solutions and digital solutions (the latter definitely more suitable for high-quality audio).

Always remaining on the subject of connecting the audio speakers to the computer or other devices, we invite you to continue reading also on our articles How to connect TV speakers and audio systems to Smart TV is Wireless speaker boxes to bring audio to any room or outside, so you can independently choose the type of connection to be made.


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