At a glance
- Client: County of Placer, whose Board of Supervisors meets in a chamber staff call the Domes
- Location: 175 Fulweiler Avenue, Auburn, California — chamber floor and adjoining control room
- Scope: One-for-one audio hardware refresh across 15 microphone paths, built on a Biamp TesiraFORTE AVB CI with 13 Shure MX418S/C gooseneck microphones, two Biamp AMP-A460H amplifiers and a LEA Professional CS168N eight-channel amplifier
- Platform: Biamp Tesira over AVB, with Dante to the house amplifier
The situation
Placer County runs its Board of Supervisors meetings out of a chamber in Auburn that everyone on staff calls the Domes. Fifteen microphone paths feed it. Seven sit at the dais, one at the clerk's desk, four across two department-head tables, one at the public podium, and one is a wireless channel. Whatever those microphones capture becomes the public record. It goes to the room, to the assistive listening system, to a Denon network recorder and out to the meeting feed.
The room falls under our boardroom and council chamber AV work, and its rack sits in an adjoining control room. The audio hardware behind it had been in service for several years. The county did not ask for new capability. It asked for the same system, built from parts that are still supported, with better clarity and fewer things left to fail. The scope of work states the goal plainly: replace the legacy hardware one for one, keep the signal flow and the user experience consistent, and improve reliability and audio clarity.
That constraint shaped everything. Nobody in that chamber was going to be retrained. The clerk who mutes a microphone before a closed session had to find the same button in the same place after the work. It is the kind of brief we see often in government AV, and it is the same chamber where we also replaced the touch panels.
What made it hard
A one-for-one refresh is harder than a new build, not easier. A new room gets designed around the equipment. A refresh has to land inside cable, conduit, rack space and mounting positions that were chosen years ago for different boxes. It also has to reproduce behaviour nobody wrote down.
The split of work added a second constraint. The county performed the physical deployment itself. County staff removed the legacy equipment and installed the new hardware into the existing racks and mounting locations, using existing or new cabling. The county also provided the network connectivity the Tesira system needed. Creation Networks supplied the hardware, wrote and configured the programming, then commissioned and tuned the room. That division means the design has to be right on paper before anyone else touches it, because the integrator is not the one holding the screwdriver.
Several devices in the room were staying. The lobby and exterior speakers, the Denon network recorder, the Constellation switcher, the assistive listening feed, the program audio path and the press plate XLR all had to reconnect to the new core and behave exactly as before.
How did we design a one-for-one chamber audio refresh?
We drew the system as a full design and engineering set before any hardware moved, because the county's own staff would be installing it. The core is a single Biamp TesiraFORTE AVB CI. It carries twelve analog inputs with acoustic echo cancellation on every one, eight analog outputs and 128 by 128 AVB channels in one rack unit. Two Tesira EX-IN expanders and one EX-OUT expander extend that I/O over the network rather than over new copper. That is what made the existing cable plant usable.
Chamber microphones are 13 Shure MX418S/C gooseneck condensers. They are 18-inch cardioid models with the integral mute switch and LED that the dais already used. Matching the switch behaviour mattered more than the capsule specification. The Tesira program replicates the existing gating and the existing mute and LED logic rather than introducing a new convention. A Shure SLXD24D dual digital wireless system covers the roaming channel. Plenty of the conference and chamber microphones we carry would pick up speech well. Only a like-for-like gooseneck kept the dais unchanged.
Loudspeakers split by zone. Six Biamp Desono DX-IC6LP low-profile ceiling speakers cover the chamber floor and control room. Two Biamp ENTASYS ENT-FR column loudspeakers on ENT-PB pan brackets handle front-of-house reinforcement. A column array keeps energy on the seating and off the hard chamber surfaces. Both models sit in our commercial loudspeaker range.
Amplification is two Biamp Tesira AMP-A460H four-channel amplifiers for the distributed zones, plus one eight-channel commercial audio amplifier for the house. Tuning the zones against the chamber's hard surfaces is part of our acoustical design and tuning services. It is the reason a hardware-only refresh still needs a tuning day.
Two design decisions are worth recording because both changed on paper. The large amplifier was specified three times. It started as a Biamp TesiraXEL 1200.1, moved to a Biamp Voltera D 1200.4 in a later revision, and finished as a LEA Professional CS168N. The as-built drawing records the LEA unit, which brings web-based configuration, load monitoring and fault reporting to a rack that sits behind a locked door. Separately, a Tesira EX-LOGIC expander was removed from the scope by change order. The mute and LED logic now runs on the core and the existing control path rather than on a dedicated logic box.
The system, part by part
Every model below is what the closeout records: the serial sheet where it lists the part, and the as-built drawing where it does not. Equipment the county already owned and kept is marked owner-furnished. We did not supply it, so it is listed without a link.
| Function | Model | Qty | Notes |
|---|---|---|---|
| Audio DSP core | Biamp TesiraFORTE AVB CI | 1 | 12 analog in with AEC, 8 analog out, 128x128 AVB |
| Chamber microphones | Shure MX418S/C | 13 | Dais, clerk, department-head tables, podium; mute switch and LED |
| Wireless microphone system | Shure SLXD24D/SM58-G58 | 1 | Dual channel, SM58 handheld |
| Ceiling loudspeakers | Biamp Desono DX-IC6LP-TAA | 6 | 6.5 inch coaxial, low profile, 70V/100V |
| Front-of-house loudspeakers | Biamp Desono ENT-FR | 2 | ENTASYS full-range 3-way column, black |
| Loudspeaker brackets | Biamp Desono ENT-PB | 2 | ENTASYS pan bracket, black |
| Zone amplifiers | Biamp Tesira AMP-A460H | 2 | 4 channel, 60W, half rack |
| House amplifier | LEA Professional CS168N | 1 | 8 channel, Dante primary and secondary, load and fault monitoring |
| Input expanders | Biamp Tesira EX-IN | 2 | 4 channel mic/line in, PoE+ |
| Output expander | Biamp Tesira EX-OUT | 1 | 4 channel mic/line out, PoE+ |
| AV network switch | Netgear GSM4230P-100NAS | 1 | M4250-26G4F-PoE+, 300W |
| Lobby and exterior speakers | Owner-furnished | — | Existing distributed zones, re-fed from the new amplifiers |
| Recorder, switcher, assistive listening, press feed | Owner-furnished | — | Denon network recorder, Constellation switcher, ALS, press plate XLR |
The Tesira EX-IN and EX-OUT expanders, the LEA CS168N and the SLXD24D/SM58 wireless kit have no exact product page on this site, so those model names stay plain text. The rest of the Biamp range we carry covers the core, the loudspeakers and the zone amplifiers.
What did the network and county IT need?
The audio network is a single Netgear M4250-26G4F-PoE+ switch, the AV Line model with the 300W power budget. Tesira devices ride AVB. The FORTE core, both EX-IN expanders and the EX-OUT expander are AVB endpoints. The expanders draw PoE+ from the same switch, so each one is a single cable to a rack port rather than a power supply plus a signal run. The house amplifier is drawn with Dante primary, Dante secondary and a separate control Ethernet connection.
The county provided the network connectivity for Tesira communication, and the as-built shows the AV switch uplinking to county network ports. That division is worth stating in a proposal rather than assuming it. On a government project the AV integrator rarely owns the switch fabric, and the schedule depends on somebody from IT being available on the day the DSP needs an address. What the closeout does not carry is a VLAN and IP schedule. The serial sheet records device serials but leaves the MAC column empty. That is a documentation gap we would rather close before a future technician has to trace a port by hand.
The rollout
Because the county did the removal and the physical installation, our on-site time was short and specific. The daily log records two consecutive weekdays, both starting early. The first day went to identifying cable in the rack and beginning rack work. The second went to finishing the rack and testing every cable. The room was then ready for commissioning, which is the step the scope of work reserves for us. That meant replicating the existing system logic in Tesira, keeping the existing gain structure and microphone gating, and mirroring the mute and LED behaviour. It also meant tuning for the chamber's acoustics and validating all 15 microphone paths and every speaker zone.
Status Controls wrote the DSP and control programming as a specialist subcontract, against the same brief: reproduce the room, do not reinvent it. The touch panel projects for the dais, the clerk position and the podium all carried forward.
Support from here
The workmanship guarantee on this project runs one year from the date of first use recorded on the certificate. It covers installation workmanship and the programming source code, not just the boxes. Manufacturer warranties on the hardware run from one to five years depending on the line, and we broker those claims rather than handing the county a phone number. Service requests open as a ticket in the support portal before a technician is dispatched. Every visit closes with an electronic report the county replies to in the same portal, so the history of the room lives in one place.
What a chamber like this needs is someone watching it between meetings. The LEA amplifier reports load and fault status over the network. The Tesira core will show when a microphone channel stops behaving, but only if somebody is subscribed to the answer. Our maintenance and support programme covers that with scheduled sweeps, firmware management and remote diagnosis before a meeting rather than during one. Rooms drift out of spec quietly. A gain change made in a hurry, a firmware update that resets a mute group, a microphone that starts gating late: none of those announce themselves, and all of them turn up on camera in a public meeting if nobody is looking.
Frequently Asked Questions — Council Chamber Audio System Refresh
Answers to the questions county IT managers, clerks and facilities teams ask most often about refreshing chamber audio.
Why replace a chamber audio system one for one instead of redesigning it?
A one-for-one refresh keeps the operating behaviour of the chamber identical while removing the failure risk of unsupported hardware, which is why Creation Networks rebuilt the Placer County signal flow, gain structure, microphone gating and mute and LED logic inside a new Biamp TesiraFORTE AVB CI so no clerk or supervisor had to relearn a control.
It is the right approach when the room works and the equipment is aging. It is the wrong approach when the room itself has changed, for example a hybrid meeting workflow or a new streaming requirement. Then you would be paying to reproduce a design that no longer fits.
How many microphone paths does a board of supervisors chamber like the Domes use?
The Placer County Board of Supervisors chamber in Auburn runs 15 microphone paths into its Biamp Tesira core: seven dais positions, one clerk microphone, four department-head table positions, one public podium microphone and one wireless channel, each with its own gating and mute state so the record is selectable position by position.
The count follows the seating chart and the meeting procedure, not the size of the room. The podium and wireless channels cover the public and presenters.
Can existing loudspeakers and recorders stay when the audio DSP is replaced?
Yes, and on the Placer County chamber they did, because the lobby and exterior speaker zones, the Denon network recorder, the Constellation switcher, the assistive listening feed and the press plate XLR were all owner-furnished devices that Creation Networks reconnected to the new Biamp Tesira core instead of replacing them.
The test is whether a retained device has a clean interface to the new core and a supportable future of its own. Passive speaker zones usually pass that test.
How long was the chamber out of service for the audio refresh?
The field work on the Placer County chamber took two consecutive weekdays on site, followed by commissioning, because county staff removed the legacy equipment and installed the new hardware themselves, leaving Creation Networks with rack work, cable verification, programming, tuning and validation of all 15 microphone paths.
The scheduling risk on a job like this is rarely the install itself. It is waiting on network access and on a quiet room to tune in.
Who does what when the county installs the audio hardware itself?
The scope of work split it explicitly: the County of Placer removed legacy equipment, installed the new hardware into existing racks and mounts, provided cabling and supplied network connectivity for Tesira, while Creation Networks supplied the hardware, wrote the programming, and commissioned and tuned the room.
That model reduces the integrator's time on site. It also raises the cost of a design error, because the drawings have to be right before anyone else starts work.
Does a Biamp Tesira chamber system need its own network switch?
It does on the Placer County chamber, where the Tesira system runs on its own managed switch, a Netgear M4250-26G4F-PoE+ with a 300W power budget, and the TesiraFORTE AVB CI core plus its EX-IN and EX-OUT expanders are AVB endpoints that draw PoE+ from that switch over a single cable each.
A dedicated AV switch keeps AVB clocking and bandwidth predictable. It also keeps AV changes out of the county IT change window.
What does a county IT department need to provide for a chamber audio refresh?
On the Placer County chamber the county provided the network connectivity for Tesira communication, and the as-built drawing shows the Netgear AV switch uplinking into county network ports, so county IT had to have those ports live before Creation Networks could commission the Biamp system.
Ask for the VLAN and IP scheme in writing before install. The closeout on this job has no address schedule, and that costs the next technician time tracing ports.
What happens when the specified amplifier changes during design?
It gets substituted on paper before it is bought, and the closeout records which unit went in: the Placer County house amplifier was specified as a Biamp TesiraXEL 1200.1, revised to a Biamp Voltera D 1200.4, and installed as a LEA Professional CS168N, which is the model the as-built drawing shows.
What matters is that the documentation matches the rack. A drawing that still shows the original part number is how the next technician orders the wrong spare.
Why was the Tesira EX-LOGIC expander removed from the chamber design?
A change order removed the Biamp Tesira EX-LOGIC expander from the Placer County scope, so the dais mute buttons and LED indicators are driven by the TesiraFORTE AVB CI core and the existing control path instead of by a dedicated logic box in the control room.
One less device in the rack is one less device to fail, power and document. The operator sees no difference at the dais.
What does the workmanship warranty cover on the chamber audio system?
The Creation Networks workmanship guarantee on the Placer County chamber runs one year from the date of first use recorded on the certificate, and it covers installation workmanship and the programming source code, while manufacturer hardware warranties of one to five years run separately and Creation Networks brokers those claims.
Service requests open as a ticket in the support help desk portal before a technician is dispatched.
How do you keep a chamber audio system from drifting out of spec between meetings?
Scheduled attention keeps a chamber in spec, so Creation Networks maintenance covers firmware management, periodic sweeps and remote diagnosis, and the LEA Professional CS168N in the Placer County rack reports load and fault status over the network so a failed speaker line surfaces before a meeting.
Gain changes, firmware updates and late-gating microphones do not announce themselves. In a chamber that is filmed, the public notices first.
Technology partners on this project
If your chamber runs audio hardware that is no longer supported, the useful first step is a room walk: a look at the rack, the microphone count and the existing cable, and a straight answer about what has to be replaced and what can stay.
Creation Networks, Inc. — nationwide commercial AV integrator, CTS-D certified, based in Concord, CA and Incline Village, NV. Design, engineering, programming, installation, and support from a single point of contact. Call 888-230-3661 or email sales@creationnetworks.net.
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