This article is intended to provide supporting information and application notes for the AMP-450BP PoE-powered Backpack Amplifier, and its integration with the desono™ C-IC6 Conferencing Loudspeaker. Additional information and specifications can be found in the appropriate Installation & Operation Guide.
AMP-450BP Backpack Amplifier
The AMP-450BP is a 4-channel, AVB-enabled, PoE+ powered (IEEE 802.3at Class 4, 30W) audio amplifier designed specifically for use with the desono™ C-IC6 conferencing loudspeaker. It has the same specifications and patent-pending Burst Power found in the Biamp AMP-450P amplifier; however, rather than the euroblock connectors, the "BP" version utilizes RJ-45 connectors and standard CAT cable for terminating speaker connections.
The AMP-450BP mounts directly to the top of the C-IC6 in a "backpack" style and includes an optional cover for protecting connections at both the amplifier and loudspeaker.
desono C-IC6 Conferencing Loudspeaker
The desono™ C-IC6 conferencing loudspeaker is a 6.5" 2-way 8-ohm loudspeaker optimized for use with the AMP-450BP. It includes RJ-45 connectors for quick and simple installation when using the AMP-450BP or TCM-XA amplifiers. There is also a 4-pin euroblock connector to support integration with the AMP-450P, TCM-1A, or other traditional amplifier solutions.
Cabling and connections
Category cable and RJ-45 connectors are certainly not unique to A/V installations, but have been typically used for network communication and audio/video transport. But why not loudspeaker connections?
The ANSI TIA/EIA 568 standard indicates that the individual conductors in a CAT cable are required to be between 22 AWG and 26 AWG. AWG wire gauges are based on the cross sectional area of the wire. When multiple wires are used in parallel the resulting AWG is based off the total cross sectional area of all wires summed together.
Standard CAT cable has 4 pairs of conductors (8 wires). The table below shows the equivalent gauge with 4 of these conductors in parallel. By using 2 sets of 4 conductors in parallel, 22 AWG CAT cable is equivalent to common 16/2 speaker cable. Even 26 AWG CAT cable is still equivalent to 20/2 speaker cable..
|CAT Wire Gauge||4x Equivalent Gauge|
|26 AWG||20 AWG|
|24 AWG||18 AWG|
|23 AWG||17 AWG|
|22 AWG||16 AWG|
Both the C-IC6 and AMP-450BP utilize pins 1,2,3, and 6 for speaker (+) and pins 4,5,7, and 8 for speaker (-).
This equates to pairs 1 and 4 (Blue/Brown) for speaker (-) and pairs 2 and 3 (Orange/Green) for speaker (+). Due to this assignment, the resultant connection will be correct regardless of whether T568-A or T-568-B is used. Even a crossover cable will end up with the same pairs utilized for speaker (+) and speaker (-).
The maximum recommended distance from the AMP-450BP to the C-IC6 is 40 meters, or about 130 feet. At this distance there will be almost 3dB loss at the speaker. However, this is specified with the worst case scenario of using 26AWG CAT cable.
The below table shows the distance at which there would be just 1dB of loss to the speaker. With 26 AWG CAT cable the distance before 1dB of loss is almost 15 meters (50 feet). With the AMP-450BP mounted at the speaker location, cable lengths are usually shorter than when having to make it back to a rack mounted amplifier in a remote location. Standard CAT-5e cable generally uses 24 AWG conductors, which will allow for runs up to 23 meters (75 feet) before a loss of 1dB is incurred.
|CAT Wire Gauge||4x Equivalent Gauge||Length (1dB loss to 8Ω speaker)|
|26 AWG||20 AWG||46.25 ft.|
|24 AWG||18 AWG||75.09 ft.|
|23 AWG||17 AWG||92.90 ft.|
|22 AWG||16 AWG||119.3 ft.|
Please note that there is no designation or recommendation made regarding the type of CAT cable to use outside of wire gauge. Shielded cable is NOT required. CAT5e or CAT6a will work just fine, but so will any other standards based category cable terminated with RJ-45 connectors.
The RJ-45 and euroblock connectors are all wired in parallel. Either one or a mix of each could be used depending on the requirements of the installation.
Tesira software and firmware versions 3.11 or later include support the AMP-450BP. The C-IC6 does not have a corresponding DSP block within software.
The Tesira PoE AMP can be found in the Amplifiers menu, which can be found under I/O Blocks section of the Object Toolbar. When adding this to a Tesira layout, a PoE AMP Initialization dialog will appear, where Channel Count and Device Type can be selected.
Channel Count allows for 1-4 channels to be designated and indicates the corresponding power available per output channel with each configuration.
Device Type allows for selection of either the AMP-450P or AMP-450BP.
Once you select OK on the Initialization dialog, the corresponding block will be added to the file. Below is an image of the block and Control dialog. The last column to the right includes a drop down for Speaker Count. The AMP-450BP will support up to 2 speakers daisy chained off of a single output and this setting should be configured accordingly. Additional information on the controls and monitoring available from this block can be found in the Tesira Help File.
To assist with deployment and commissioning of systems which include the desono C-IC6, a Tesira Library File (.tlf) has bee created. This includes a custom block with Biamp's recommended EQ curves to optimize the sound of the C-IC6 loudspeaker. This custom block should be added just before any output connecting to a C-IC6.
The Tesira Library File and can be downloaded from the above link and imported into the Processing Library within Tesira software. From there, it can be easily included in any Tesira configuration file. Additional information on the Processing Library can be found in the help file.
- Burst Mode in Biamp PoE+ amplifiers
- Desono speaker calculator
- Equalizing loudspeakers in a sound system
- AMP-450BP PoE+ Amplifier Installation & Operation Guide
- desono™ C-IC6 Loudspeaker Installation & Operation Guide
- desono™ C-IC6 Data Sheet
- Tesira AMP-450BP Data Sheet
- desono™ C-IC6 GLL/CLF/DWG Files