Canford: Overcoming Audio Install Problems

Canford has been helping engineers overcome issues with audio and video installs and equipment for over 35 years, whether something as simple as a call to the free technical support team or deploying one of the many products that have been developed to identify or overcome the myriad of potential pit falls, write Marketing Manager Paul Vickers and Paul Carlisle, Head of Tech Support.

Audio out of phase: If you've ever had a mixer or speaker that doesn't sound 'quite right', this could mean that the signals are out of phase. Identifying and finding the problem can be a time consuming issue. One way to do this is with a Phase Check System, which allows fast testing of the polarity of acoustic transducers, microphones and electronic devices. To check acoustical or electrical phasing, the generator is connected to the input of the device under test, and the detector to the output signal.
Subsequent signal processing enables the detector to decide whether the device under test reverses signal phase or not. The result of the test procedure is displayed via two LEDs, the green one indicating 'in phase' and the red one indicating 'out of phase' condition.

Faulty cables: Because not all cables are created equal or indeed treated with the care they may deserve, faults will invariably occur. An automatic cable tester can be used for testing either long cable runs or short lengths, balanced or unbalanced.
The Canford Mk. 4 cable tester provides a comprehensive visual indication of most commonly found faults. The unit will display the fault as soon as a cable is connected to tester. If the cable needs a quick repair, the Canford Bodge Plugs have spring loaded connections on XLR's, Jack's and Phone's that can be used without the need to solder.

No audio signal or testing a new install: A Tone Generator can output three test levels making it suitable for a variety of test and circuit identification purposes at both microphone and line level. This can be used for passing a calibrated tone through a new install to check speakers and equipment. Or to see if a microphone is damaged, if everything is plugged in but there is no audio the tone generator can be inserted at various points in the circuit to identify where the fault is.

Balanced to unbalanced conversion: When the need arises to interface 'domestic' with 'pro' or 'semi-pro' equipment, the Canford Pro-Interface allow the interfacing of equipment with higher audio levels and differing connection to professional equipment, or vice versa, due to the bi-directional stereo interface.

Powering microphones: Not all recording or amplifying equipment has a phantom power supply, which means condenser type microphones will either have to rely on internal power which can run out at the wrong time, or just not work at all. Phantom power supplies work from either mains power or larger batteries to supply a constant 48V and also have a low battery indicator to help avoid those embarrassing moments.

Lapel mics but no radio pack: The use of lapel microphones is becoming ever popular and these little mics require a smaller voltage to their larger counterparts. Electret mics typically use nine volts and get their power from a radio transmitter belt pack. If you want to wire them direct to a recorder or mixer, an electret microphone adaptor can be used. The adapters take the place of the pack, plugging directly into a standard XLR-3 microphone connection to give a balanced output.

Blowing fuses: This can be a wide range of things, but one reason is that the equipment at switch on is drawing more power than the steady state current can supply. This surge can trip fuses or circuit breakers, by fitting a mains power inrush current limiter this problem is instantly eliminated.  The unit has IEC input and output connectors and limits the current at switch-on to an acceptable level for 200mS–400mS. Two LEDs on the front panel indicate the status of the unit. A voltage dependent resistor is included for transient suppression. 

The article is also available to read in BFV online.

(IT/JP)