Integrating Desono™ loudspeakers and AMP-450BP backpack amplifiers

Hardware overview

Programming

Tesira software and firmware versions 3.11 or later include support for the AMP-450BP. 

The Tesira PoE AMP can be found in the Amplifiers menu, which can be found under the 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 menu for Speaker Count. This selection is equivalent to 8-ohm or 4-ohm in the AMP-450P, where 1 speaker = 8-ohms, 2 speakers = 4-ohms. 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.

A Tesira Library File (.tlf) is available to assist with the deployment and commissioning of systems that include the Desono C-IC6 or C-IC6LP. Th file includes a custom block with Biamp's recommended EQ curves to optimize the sound of the C-IC6 or C-IC6LP loudspeaker. The block should be added just before any output connecting to a C-IC6 or C-IC6LP.

The Desono Loudspeakers Tesira Library File is included in the Processing Library within Tesira software. It can be easily included in any Tesira configuration file by dragging and dropping the desired blocks. Additional information on the Processing Library can be found in the help file.

AMP-450P vs AMP-450BP

AMP-450P was the precursor to the AMP-450BP. Their external dimensions are the same. They feature the same 4 channels of amplification but AMP-450P has (2) 4-pin male Phoenix output connectors rather than (4) RJ-45 jacks.  

• Four channels: 50W (4Ω) or 30W (8Ω) Burst Power per channel
• Software-selectable power vs. channel count:
  • 3W continuous power per channel with 4 channels used (4Ω or 8Ω)
  • 7W continuous power per channel with 2 channels used (4Ω or 8Ω)
  • 15W continuous power per channel with 1 channel used (4Ω or 8Ω) 

TCM-XA and TCM-1A

The Parle ceiling mic models TCM-XA and TCM-1A each offer 2 channels of amplification. They can be a good alternative to the AMP-450P or AMP-450BP when ceiling mics are being used. The TCM-XA comes with (2) RJ-45 connectors. The TCM-1A comes with (1) 4-pin male Phoenix connector. 

• Two channels: 40W (4Ω) or 30W (8Ω) Burst Power per channel
• Software-selectable power vs. channel count:
  • 4W continuous power per channel with 2 channels used (4Ω or 8Ω)
  • 8W continuous power per channel with 1 channel used (4Ω or 8Ω)

Cabling and connections

Category cable and RJ-45 connectors are typically used for network communication and audio/video transport in AV systems. However, they can also be used for 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 on 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 a common 16/2 speaker cable. A 26 AWG CAT cable is equivalent to a 20/2 speaker cable.

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 or C-IC6LP is 40 meters or about 130 feet. At this distance, there will be an approximately a 3dB loss at the speaker. However, this is specified with the worst-case scenario of using a 26AWG CAT cable.

The below table shows the distance at which there would be just 1dB of loss to the speaker. With a 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.

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.

Biamp CCA for non-Desono speakers

The Biamp Category Cable Adapter can be used to simplify wiring when using an AMP-450BP with speakers that do not utilize Biamp’s category cable connectivity. This eliminates the need to terminate and dress multiple conductors to the Euroblock connector in the field while preserving the easy, fast, inexpensive RJ-45/CAT Cable installation experience. 

• Converts category cable to speaker wire by adapting RJ-45 plugs to 4-pin Euroblock connectors.             
• Provides single cable simplicity for all Biamp projects. Can be used for both direct wire or daisy chain installations.
• Choose any speaker you need for the application.
• Plenum Rated
• Verify the pinout of the specific speaker you are using before following the diagrams below. Some speaker pinouts are different than those shown below.

Direct connection using Category Cable Adapter with standard CAT5 cabling.

The CCA will come wired as depicted below making it compatible with both Desono CM-Series and Desono DX-Series loudspeakers.

Daisy Chain connection using Category Cable Adapter with standard CAT5 cabling. 

Parallel connection using CCA requires two adapters per daisy-chained loudspeaker. Remove the Euroblock from one CCA adapter, and attach that RJ-45 cable to the second Euroblock connector matching the manufacturer's pinout for parallel connectivity. End of line speaker can be connected with a single CCA adapter as shown in the diagram below. 

Biamp CCA extender with bare copper tails on each end

A pair of Biamp CCA can be used with category cable to quickly and easily make a standard pigtail-style speaker wire using category cable. Remove the Euroblocks from each Biamp CCA. Run the category cable as needed. Place one Biamp CCA at each end and connect to the speaker and amp. 

Further reading