A museum order is signed on a calm afternoon. The language list is printed, the room counts agreed, and the quantity column looks final. Then a temporary exhibition arrives with captions in a language nobody planned for, a sponsor from a new market asks for a version of their own, or a sister site adds one more. The building has not changed. The order has.
For anyone assembling a museum wireless audio solution, the useful question is not how many languages the venue runs today but what one more will cost tomorrow. That is settled neither by brand nor by the figure printed largest in a brochure, but by where the language physically sits inside the kit.
🗺️ Two Ways a Spoken Commentary Reaches a Visitor
In the first arrangement the commentary is carried. A transmitter holds the audio and puts it out on a radio channel; the unit in the visitor's hand is a tuner that contains no commentary at all. Change the language and the receiver does not care, because it was never holding one; it only has to know which channel to sit on.
In the second arrangement the commentary is stored. There is no radio link and no transmitter in the chain. The recording lives on the handset itself and the visitor selects it with a keypad. That device is not a tuner but the carrier: the language is not something the system tunes to but something the system is made of.
The Route That Puts the Commentary on a Carrier
The RC9150 is the carried arrangement with the widest ceiling: the 2.4 GHz band between 2403 and 2483 MHz, 100 channels, ten milliwatts of output, PLL frequency synthesis, fifteen hours on the transmitter and thirty-five or more on the receiver, both packs rated 3.7V 1800mAh, charged over Type-C, and 97.5g in the hand at each end.
A second option on the same logic is the RC2406, working the identical way with a lower ceiling: the same band, 80 channels, ten milliwatts, ten hours on the transmitter and twenty on the receiver, a 3.7V 1500mAh transmitter pack against a 1000mAh receiver, and a 50g handset charged from a DC port. The RC9150 buys endurance and channel headroom; the RC2406 buys the same architecture for buildings that never run many languages at once.
The number that decides everything here is the channel count: on a radio system a language occupies a channel. One hundred channels on the RC9150 and eighty on the RC2406 are not a technical footnote; they are the language budget, and the receivers the museum already owns can be pointed at any of them.
The Route That Puts the Commentary on the Handset
The 2.8-Inch Semi-Auto Digital Audio Guide carries no radio link at all. The visitor punches an exhibit number on a 0-9 keypad and the matching commentary plays. What makes it work is capacity on board: sixteen languages and up to 9999 audio files in 2 GB of built-in memory, eighteen hours per charge over Micro USB, earphones included, and units tested individually before shipping.
The advantages are genuine: a visitor needs no guide and no briefing, and the museum needs no transmitter and no frequency decision. The cost is structural - every language has to exist on the machines people are holding, so the fleet is not a container for languages but the language library.
What the Quantity Column Is Really Counting
On the carried route the quantity column counts receivers, and receivers are language-neutral, so one figure covers every language the venue will run. The language-bearing item is the transmitter, and a venue needs only as many of those as languages running at the same time. Three languages in rotation with one group each means three transmitters and one receiver pool; a fourth does not change the pool.
On the stored route the same column counts machines that each belong to a language set, so a modest visitor figure can multiply into a much larger order. Two museums with identical footfall can write orders of very different size and both be correct, because the column header means something different in each.
The Morning a New Language Arrives
On the carried route the new language needs a channel and a transmitter sitting on it. The receivers already in the cabinet tune to that channel; nothing is replaced and no second set of machines is bought. The work is administrative: confirm the channel is free, run the check, and write the channel list down so the next session does not re-tune from scratch.
On the stored route the new language has to be on the machine before the visitor arrives. Physically there is room for it, since sixteen languages and 9999 files is a generous ceiling, so the work is a reload across the fleet in a window when no group is waiting. The alternative is a second set of handsets, and that option quietly doubles the storage footprint, the charging load and the labelling work in the handout room.
Reading the Specification Before the Number Is Fixed
Three lines settle which route an order is on. The first is whether the commentary is carried or stored, usually obvious from whether the page lists a frequency band at all. The second is the channel count on the radio side, because that figure is the language budget and not a piece of engineering trivia. The third is receiver runtime against a real session, since a handset that runs flat during a tour costs more than any difference on a data sheet.
| What the order turns on | Carried route (RC9150, RC2406) | Stored route (2.8-Inch guide) |
|---|---|---|
| Where the language physically sits | A channel on the transmitter | Audio files inside the handset |
| What one more language costs | A channel and a transmitter | More handsets, or a fleet reload |
| What the quantity column counts | Receivers, which are language-neutral | Machines, each tied to a language set |
| What the venue stores and charges | One receiver pool, plus transmitters | One machine set per language |
| Where the ceiling shows up | Channel count and receiver endurance | On-board languages and stored files |
| What happens at the handout desk | Same routine whatever the language | Routine splits by language set |
A radio system and a point-and-play player share no comparable numeric fields; forcing them into one grid would produce numbers that look comparable and are not.
The Two Orders Side by Side
Set the published figures side by side and the split becomes concrete. One unit publishes a frequency band and a channel count; the other publishes neither, because it has neither. One publishes eighteen hours from an on-board battery; the other publishes fifteen on its transmitter and thirty-five or more on its receiver - two different questions being answered.
| Published figure | RC9150 | RC2406 | 2.8-Inch Semi-Auto Digital Audio Guide |
|---|---|---|---|
| Frequency band | 2403-2483 MHz | 2403-2483 MHz | Not applicable - no radio link |
| Channels | 100 | 80 | Not applicable |
| Language or file capacity | One channel per language | One channel per language | 16 languages, 9999 files |
| On-board memory | Not published | Not published | 2 GB |
| Transmitter battery life | 15h | 10h | No transmitter |
| Receiver battery life | 35+h | 20h | 18h per charge |
| Charging port | Type-C | DC port | Micro USB |
| Warranty | 3 years, mainboard only | 3 years, mainboard only | 1 year, accessories excluded |
Two entries deserve a note. The three-year term on the radio units covers the mainboard and leaves headset, microphone and battery outside it, which matters where a receiver passes through hundreds of hands a week; the player carries a one-year term excluding accessories. Read either as a measure of how the manufacturer expects the product to be used, not as a warranty comparison. For the wider picture across the range of wireless tour guide systems, the series comparison puts the channel counts and runtimes of every model on one page.
What to Settle Before the Order Sheet Is Written
Three questions are worth answering in writing before the quantity column is filled in, because each changes the figure rather than the wording. How many languages run at the same time on the busiest morning, as opposed to how many exist across the year? How long is the longest single session, from first handout to last return? And who owns the growth problem when a language is added - the shelf that holds transmitters, or the cabinet that holds handsets?
A venue that can answer those three will not be surprised by a fourth language arriving early. Start from the hardware instead, and the same list produces an order that looks complete and fails at the first temporary exhibition. The language list is the one item on a museum specification that is certain to change; writing the order around where the language sits keeps that change small.
