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Documentation & downloads
What exists today, where it is, and what is still being produced — stated plainly, because a specifier needs to know which of those they are looking at.
- Model covered
- SD125.4
- Firmware described
- V1.8.0
Documentation
The SD125.4 is the first amplifier in the range and its document set is still being produced. Rather than list files that do not exist, this page says which of them are finished, where the reference material that already exists lives, and what to do in the meantime.
Nothing here is a dead link. Every item marked on this site goes somewhere real; every item marked in production is exactly that. If you need one of the latter before it is published, ask — we will send what exists today.
Every published figure
Output, performance, distribution, connectors, power and physical data for the SD125.4, with the source of each figure stated.
Specifications page Wiring & cable reference On this siteGauge, runs and the Hi-Z rule
Maximum cable runs by gauge for low-impedance and constant-voltage wiring, on this page. How a 70/100 V line connects across an output pair, and the high-pass that keeps line transformers out of saturation, on the technology page.
Cable gauge tables Rack & thermal planning On this siteClearances, draw and heat
Ventilation clearances, mains and idle draw, thermal loss in BTU at the continuous-programme approximation, and the standby behaviour to plan a cupboard around.
Technology page Front-panel indicators On this siteWhat each of the five reports
The manufacturer's indicator table — Status, Input, Output, Network and WiFi — reproduced in one place on the product page.
SD125.4 pageA one-page PDF
A Selective-branded sheet to attach to a tender or a system drawing. Until it exists, the full specification above is the authoritative version and we will send what we have on request.
Rack, connect, power up
The short version of the sequence below, in a form that can go in a toolbox rather than on a phone screen.
The full document
The complete installation and user manual, covering every parameter in the configuration interface. It exists; the public edition is not released yet. Ask and we will tell you where it stands.
Selective Control, screen by screen
An illustrated walkthrough of the four configuration tabs. The commissioning sequence below is the interim version.
Versions and release notes
Not published on this site yet. The amplifier reports and updates its own firmware from its configuration interface — see below.
Held by your supplier
Warranty terms are the responsibility of the amplifier re-seller, so the applicable terms come from whoever supplied the unit. No period is published here.
Cable gauge
Maximum run by conductor size
Published maximum lengths, for less than 0.5 dB of loss on a low-impedance run and less than 1.0 dB on a constant-voltage run of 20 evenly distributed speakers. Hi-Z lengths should not exceed 250 m in any case.
| mm² | AWG | 4 Ω | 8 Ω |
|---|---|---|---|
| 0.75 | ≈18 | 5 m | 10 m |
| 1.5 | ≈16 | 10 m | 20 m |
| 2.5 | ≈14 | 17 m | 35 m |
| 4.0 | ≈12 | 28 m | 55 m |
| mm² | AWG | 125 W/ch | 250 W/ch |
|---|---|---|---|
| 0.75 | ≈18 | 90 m | 45 m |
| 1.5 | ≈16 | 180 m | 90 m |
| 2.0 | ≈14 | < 250 m | 150 m |
| 3.5 | ≈12 | < 250 m | < 250 m |
| mm² | AWG | 125 W/ch | 250 W/ch |
|---|---|---|---|
| 0.75 | ≈18 | 190 m | 90 m |
| 1.5 | ≈16 | < 250 m | 180 m |
| 2.0 | ≈14 | < 250 m | < 250 m |
| 3.5 | ≈12 | < 250 m | < 250 m |
Commissioning, in the order it is meant to happen
The interim version of the configuration walkthrough: the sequence an installer works through, with the detail behind each step linked rather than repeated.
Steps four to six follow the manufacturer's own recommended order for configuring the amplifier — inputs, then zones and routing, then outputs. Working it in that order matters, because each stage is what the next one has to assign.
Set-up happens over the amplifier's own network or the building's, in a browser, with nothing to install on the laptop you brought. What the interface contains is on the technology page.
- Rack it, with the clearances. Ventilation apertures sit on the sides and the rear panel and the unit is fan-cooled — the published free-air figures are on the technology page, and they are easier to honour before the rack is full than after.
- Make every connection before mains. There is no power switch: the amplifier is operational the moment mains is connected. Signal, speaker, GPIO and network connections all belong to the unpowered unit. It is a Class I product and needs an earthed mains cable.
- Power up and read the front panel. Status, Network and WiFi tell you where the amplifier has got to before you have opened anything. What each indicator reports is documented on the product page.
- Connect and open the interface. Either join the amplifier's own wireless access point, or reach it over the building network on the rear-panel Ethernet socket. The configuration interface is served by the amplifier itself to any browser.
- Inputs, then zones, then outputs. Set input sensitivity and gain; assign inputs to zones and zones to outputs; set each output's mode — low impedance or 70/100 V — and its processing. Power Share needs no step of its own: sharing across each pair is automatic.
- Set a password, then check the firmware. The interface can hold its own password, which is worth setting on any amplifier reachable from a wired network. Check the installed firmware version while you are there — see below.
- Back up the configuration before you leave. A configuration can be exported to a file and restored onto the same unit or another one. On a multi-amplifier install that is the difference between a repeatable system and a retyped one, and it is what makes a service call cheap.
Checked and updated by the amplifier itself
The documentation on this site describes firmware V1.8.0. The version installed in a given unit is shown in its own configuration interface, under the device options in the Settings tab, and it is updated from the same place.
The manufacturer's guidance is worth following literally: check the installed version when the amplifier is commissioned, check it regularly after that, and if a newer version is available, treat the update as a priority rather than as maintenance to get to eventually.
In production
Firmware files and release notes are not published on this site yet. If you need to confirm whether the unit in front of you is current, ask us and we will tell you the current version.
Questions about a specific install
Configuration, installation and operation questions go to the same place, and a real answer is better than a document you have to interpret. If you are specifying rather than installing, the dealer route is the faster one.
Servicing is not a field operation: refer it to qualified service personnel, and to your supplying dealer in the first instance.