AV for Hotel Ballrooms: Technical Considerations for Events Teams

Hotel ballrooms are some of the most technically complex event spaces to work in. They are large, acoustically variable, often listed or architecturally significant, and used for completely different event formats on consecutive days. A conference that ends at 17:00 and a gala dinner that starts at 19:00 are two different technical setups in the same room, two hours apart.

For an events team, the challenge is knowing what is possible in your specific space before a client asks. A client who has attended an event at a purpose-built conference centre and expects the same production capability in a converted Victorian ballroom needs to be briefed accurately before they sign a contract, not after.

• ✓Reverberation time — Ornate plaster ceilings and hard reflective surfaces in ballrooms often produce reverb times of 1.5–2.5 seconds. This is fine for music but significantly degrades speech intelligibility. A distributed PA system with multiple smaller speakers keeps sound close to the audience rather than relying on point-source speakers at the front of the room, which fire into a reverberant space.
• ✓Column arrays for ballroom PA — Column array speakers (line arrays in a compact vertical housing) provide tight vertical dispersion that reduces floor and ceiling reflections while covering the full audience width. They work well in rooms with difficult acoustic properties without requiring permanent installation.
• ✓Under-table subwoofers for gala dinners — For events where the PA needs to cover a fully laid banqueting set without being visible at table level, under-table bass cabinets can be installed discreetly. Requires planning but is achievable in most ballrooms.
• ✓Wireless microphone frequency planning — Hotel ballrooms in city centres sit inside dense RF environments. Multiple wireless microphone systems need frequency planning to avoid interference. This is not something that can be handed to the catering manager to sort out.

The single most common technical problem in hotel ballroom events is screen visibility for a seated audience around circular tables. The room layout that works for dinner does not work for projection in the way it does for theatre-style conference seating.

• ✓Screen height and size for banqueting rounds — A 16:9 screen needs to be significantly larger in a banqueting configuration than in theatre-style seating because audience sightlines are not focused forward. The bottom of the screen needs to clear seated guests' heads at the furthest tables, which typically means a screen base height of 2.0–2.4 metres and a screen height of at least 3.0 metres for rooms over 20 metres deep.
• ✓Ambient light and projection contrast — Hotel ballrooms often have chandeliers or decorative lighting that cannot be fully extinguished without removing the atmosphere. This reduces projected image contrast. For events in high ambient light conditions, LED screens outperform projectors significantly, though their scale, weight and rigging requirements are different.
• ✓Multiple screen positions for large rooms — A room over 30 metres deep will have audience members for whom a single frontal screen is impractical. Two screens flanking a rear-lit podium, or repeater screens on side walls, ensure full room coverage without requiring a screen size that interrupts the ceiling architecture.

• ✓Rigging points and ceiling loading — Listed ballrooms rarely have purpose-built rigging infrastructure. Productions that want to fly speakers, screens or lighting trusses need to assess the structural loading capacity of the ceiling or available architectural features. Never assume it is possible without a structural assessment for significant loads.
• ✓Available power and distribution — Most hotel ballrooms have 63A three-phase power available at a distribution panel. For large productions with high lighting and PA loads, confirm the available power well in advance. A distribution board that can only service half the planned production is a problem that appears late in the load-in.
• ✓Heritage and listed building constraints — Some hotels in period buildings have restrictions on surface mounting, floor cutting, or any work that touches the building fabric. Know these constraints. They affect what the production company can do and how they do it.