For pubs, clubs and other entertainment venues with permanent or semi-permanently installed music systems.
The AVC2 Automatic Volume Control is a standard 19" rack mounted unit that connects between the mixer (or preamplifier) and the amplifiers. When the average level gets higher than the threshold, it is reduced in discreet steps that should be undetected by anybody listening to the music. This ensures that the enjoyment of visitors to the entertainment venue is not sacrificed. The unit does not reduce the dynamic range of the music, again protecting the enjoyment factor.
Another benefit of the AVC2 is that it protects the speakers from the damage that can occur when over-driven.
The Automatic Volume Control is extremely easy to use. It has no external controls, just a display that shows the amount of attenuation that the unit is applying when the threshold has been exceeded.
Noise measurement and control is usually carried out using the "A" frequency weighting. This is similar to the response of the human ear and is particularly important for noise nuisance and hearing protection applications. However, it is usually the low frequency noise (thumping bass) that can be heard from outside the venue and in nearby properties. It is therefore important to monitor these low frequencies that are effectively removed by the usual "A" weighting.
The Automatic Volume Control can use both "A" weighting and a Linear response. In its default configuration it uses both the "A" weighting and the Linear response, using the higher of the two to check against the threshold. This ensures that the controller will help to protect against both damaging and annoying noise content. It is possible to configure the unit to use either the "A" weighting or the Linear response instead of both.
Connection to the Automatic Volume Control is by XLR connectors for inputs left and right, outputs left and right and for auxiliary connections.
A security cover protects against the connections simply being removed to bypass the volume controller.
Once installed (connected between the mixer and the amplifier), the AVC2 is extremely easy to use. In normal operation, with the volume level below the threshold, the AVC2 has no effect.
If the average level exceeds the threshold then the output is reduced in small steps, which are clearly indicated on the front panel. The more the volume is increased, the more the AVC2 attenuates.
Ideally, the Automatic Volume Control should be mounted where its LED display can be seen by the operator. It should be installed in the signal chain, either between the mixer or preamp and the amplifiers, or between the mixer/preamp and the electronic crossover.
Connection is via XLR connectors - for inputs left and right, outputs left and right, and for auxiliary connections.
The unit is factory configured to operate at an average nominal line level of 0Vu ( 4dBu) and in most cases will not need any adjustment.
The output level can be adjusted by a pot accessible through a small hole between the input and output terminal blocks. A black plastic snap rivet is provided to blank the hole after the initial set up. Further adjustments are possible and these are covered in detail in the User Manual.
Technical specifications for the Formula Sound AVC2 Automatic Volume Control.
|Frequency Response||20Hz - 30kHz ±0.5dB|
|Noise 20Hz to 20kHz||Equiv. input noise < -90dBu|
|Inputs||Electronically balanced, connect negative screen for unbalanced use|
|Input impedance: Balanced 20 kΩ, Unbalanced 10 kΩ|
|Maximum input level: 22 dBu|
|Clip indicator: Indicates @ 20dBu|
|Outputs||Electronically balanced, connect negative screen for unbalanced use|
|Source impedance: 100 Ω|
|Min load impedance: 600 Ω|
|Threshold Range||High range: Average level adjustable 5dBu -2dBu|
|Low range: Average level adjustable -8dBu -14dBu|
|Attenuator Range||-3dB -6dB -9dB -12dB -15dB -18dB -24dB -30dB|
|Control Chain||A control chain with a flat frequency response Linear, "A" weighted, or a combination of both may be selected to control the attenuators.|
|Power||220 - 240V AC. IEC mains connector.|
|Finish||Front and read panels - black anodised aluminium with etched silver notation.|
|Case - black plastic-coated steel|
|Dimensions||19" rack mounting. 1RU|
|Width 482 mm (19"), depth 200 mm (7.9"), height 44 mm (1.75")|