Line Output Converters (Hi-Low converters)

It can happen to the any one of us. We get the best audio system there is, thinking that it will perform well with other parts we already have- only to realize that our good old amplifier doesn’t take speaker level inputs.  What to do now? Get a new amplifier? Or is there a simple solution to this problem?

There is. And it is called Line output converter, or Hi-Lo converter. This device converts the speaker outputs into a signal which can be fed into the amplifier without the interference of external noises. It will let you listen to your favorite songs in all their glory, without any other noise interference.

Why does one need a Line output converter (LOC)?

If you have an old amplifier, you may need a LOC. Few of modern amplifiers can take speaker level inputs, as they come with built-in level converter. But many amplifiers from old day don’t process speaker level inputs. They only take pre-amp level inputs, which fall in the range of 1-6 volts. So, it’s not possible to connect speaker level inputs to such amplifiers.

If you have a factory fitted audio system, chances are that, you may need a LOC. Many factory fitted systems don’t give out pre-amp outputs (known as RCA connectors in general), and a few provide just a single RCA output for subwoofer. This makes it difficult to use on external amplifiers to power full-range speakers to the front and the rear ends of your vehicle.

There is another important factor to consider: the longevity of the speakers. The speaker output of a high powered HU is designed to operate in a bridged configuration; when the HU is off, the output wires have zero volts, and as soon as it is turned on, each of the output speaker wires get a power surge (the voltage changes from 0 volts DC to 1/2 of the battery voltage). LOCs have a transformer to dampen the effect; if there were no LOC, the turn on pop would be severe; the amplifier gain causes the signal to boost further, resulting in severe damage to the speakers. Speaker may burn out if the amplified signal crosses the Maximum short time power handling capacity of the speakers.

Note. The transformer in the LOC gives a clean ground which isn’t available from the bridged outputs of the head unit, providing in very clean, almost no-noise signal.

Finally, don’t forget to shield ground wires.

LOCs usually contain one or two extra wires, normally used to ground the shield of the RCA output cables to the HU. Some amplifiers work fine without them, others don’t. If the LOC is installed behind the radio (and consequently the wires aren’t required), connecting the shield ground wires to the case of the radio is strongly advised.

Many line output converters have controls which allow you to manage your output signaling completely. A decent line output converter will step down the speaker-level signal, enhancing the sound quality. A quality line output converter gives a great signal, resulting in a fabulous listening experience- even at low listening levels.