Finally, A-BUS Cat 5 Audio Distribution Boosts Power Output

New Dynamic Efficiency (DE) amplifier from Forté increases A-BUS multiroom audio distribution power by 47% to improve sound quality, overcoming the long-time limitation of the technology.


When it first hit the scene well over a decade ago, A-BUS technology became a popular choice for structured wiring installations and tract home developments, where Cat 5 is common.

The technology was developed to eliminate the sonic losses caused by long runs of speaker cable, instead using Cat 5 to reproduce clean, clear sound. Its popularity was driven by ease of installation, flexibility and low cost… it can be installed by anyone capable of terminating a Cat 5 cable. 

But the original technology was always hampered by one limitation: the need for higher power to improve sound quality.

Well, engineers at A-BUS, which was pioneered by Russound and then adopted by several other manufacturers over the years, finally addressed that missing ingredient.

LeisureTech Electronics, the Australian inventors of A-BUS Cat 5 technology, has introduced new Dynamic Efficiency (DE) amplifier technology into its Forté brand delivering a 47 percent increase in output power and a significant improvement in sound quality. 

There are two new keypad models the AB-44 for single source applications and the AB-46 for multi-source control. 

Andrew Goldfinch, president of LeisureTech Electronics, says the key to boosting the power output of A-BUS was limiting the distortion.

For many integrators, the lack of power has been a long-time limitation to using A-BUS. Andrew Goldfinch, president of LeisureTech, always rejected that concern claiming that there is plenty of power for the great majority of installations and the more important consideration is the sound quality. 

“You will find A-BUS systems get more use because the sound quality at normal listening level is better and more entertaining than traditional systems,” he notes.

But Goldfinch has listened to the market with the advent of the new DE amplification.

“In normal amplification, distortion rises as the output increases. This distortion consumes valuable current at a time when it is most needed, limiting peak power output. Dynamic Efficiency technology reduces the amplifier distortion by 90 percent. But most importantly, it does so at peak power, so a lot more musical power can be delivered, greatly improving dynamics and stereo image.

“While this may not be as noticeable when the audio signal has been degraded by a long run of cheap 16/4 speaker cable, the high quality audio signal delivered by Cat 5 to the A-BUS amplifier results in true audiophile quality sound,” he says.

‘Turbo-charged’ A-BUS

There is another twist to the DE format in that the new amplifier can actually deliver more power than a single Cat 5 can supply.

So the engineering team at Forté incorporated an additional RJ-45 socket on the back of the keypad to allow a second Cat 5 to be connected from the hub, doubling the amplifier’s power output.

The rear of a Forté AB46 keypad with the new power module.

This capability for creating a “turbo-charged” A-BUS system adds a bit more flexibility for system design in large rooms or when using encountering inefficient loudspeakers. It also enables A-BUS platforms to power a main pair of speakers in formal living areas and family rooms.

The second cable can be connected to any A-BUS output. Forté multi-source hubs already include two A-BUS outputs per zone.  Also, the DE amplification design reduces current consumption by half. 

Several years ago, A-BUS added a Bluetooth module which can be installed in individual rooms or as a main source that is powered by the Cat 5 cable, thus not requiring a power supply. The system allows a user to simply “pair” their iPhone or iPad to the system to access their personal music collections.  

The new DE keypads can be retrofit to any existing A-BUS system, regardless of age or brand.

About the Author

Jason Knott
Jason Knott:

Jason Knott is Chief Content Officer for Emerald's Connected Brands. Jason has covered low-voltage electronics as an editor since 1990, serving as editor and publisher of Security Sales & Integration. He joined CE Pro in 2000 and serves as Editor-in-Chief of that brand. He served as chairman of the Security Industry Association’s Education Committee from 2000-2004 and sat on the board of that association from 1998-2002. He is also a former board member of the Alarm Industry Research and Educational Foundation. He has been a member of the CEDIA Business Working Group since 2010. Jason graduated from the University of Southern California.


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