Investment Date





Crescent led the management buy out of APT in May 2005 in syndication with Trinity Venture Capital, APT’s management and QUBIS Limited.

APT was formed in 1989 to build upon innovative research into digital audio compression technology carried out at Queens University Belfast. Over the years the company’s range of novel codecs has been expanded to cover the broadcast market and a range of professional audio and consumer applications.

The company looked into two distinct divisions – hardware product servicing the international broadcast market and an IP licensing division focused on providing digital wireless solutions to the professional and consumer audio markets.

APT’s hardware division developed the WorldNet series of hardware audio codecs which incorporated the apt-X® compression technology. These products enable the transport of CD quality audio over a variety of telecom links such as ISDN, IP, X.21 and E1/T1 and achieved international penetration in the world of broadcasting and telecommunications. In March 2009 a successful sale of this business unit to the Audemat Group of France was concluded.

Following the sale of the hardware division, APT’s remaining business focused on IP licensing. The company developed a market leading portfolio of audio codecs focused on the large and growing markets of Bluetooth audio transmission, digital wireless microphones and on-line multi-player gaming. These codecs are increasingly viewed as representing the preferred choice for customers demanding the best audio solutions.

In July 2010, this licensing business was sold to CSR Plc, the market leading bluetooth chip business. The APT division today remains a key and growing repository of audio engineering capability with the CSR group.

Noel McKenna is Chief Executive of APT - Audio Processing Technology, the audio compression specialist. They supply their world renowned suite apt-X® algorithms in a variety of formats to leading professional and consumer audio companies worldwide.