Running the TV sound through the ceiling speakers is one of the most common applications of the AMP4X15BT — and at the same time the application with the most noise-related questions in our support archive. Here is what works, what does not, and why.
Two routes from the TV to the amplifier
The amplifier accepts sound via Bluetooth or the AUX input (3.5 mm jack). Bluetooth is convenient but depends on the TV software — after a manufacturer update, a pairing can falter. The cable is the robust solution: it works with any TV that has a headphone or adjustable audio output. Both in parallel works too, by the way — Bluetooth for the smartphone and AUX for the TV, for example.
Bluetooth takes priority — but only while playing
If a signal is present on AUX and a Bluetooth device starts playing music at the same time, Bluetooth wins: the amplifier switches over dominantly. What matters is the active playback — a Bluetooth device that is merely paired or connected but silent does not disturb AUX playback. So if you run both in parallel, be aware: as soon as someone presses play on their phone, the TV sound is gone.
When the amplifier will not go into standby
The amplifier wakes up automatically as soon as a signal is present and goes back to sleep after about ten minutes of silence. The AUX input is very sensitive by design: even the tiny residual voltage many TVs and radios leave on their output in standby is interpreted as a signal — the amplifier stays awake, sometimes with audible hiss or hum. The simplest test: unplug the AUX cable. If the device then enters standby after a short while (the LED in the housing flashes), the source is the trigger. Remedies are a jack cable with a built-in volume control (to interrupt the idle signal), an in-line switch at the socket — or simply a source that genuinely switches its output off in standby.
Getting rid of hum and hiss
The amplifier’s AUX input is galvanically isolated via input transformers — a legacy of its origins in caravan equipment, where TVs are notorious hum sources. Hence: an AUX cable dangling around unconnected may make noises — that is normal. For interference-free operation, these have proven themselves:
- Use a well-shielded cable — ideally from the musician supplies — and keep the runs short; do not route AUX lines parallel to mains cables.
- Same mains circuit: amplifier and source into the same power strip. If it hums regardless of the source’s volume, a ground loop is usually at play — more on this in the classic Hum caused by ground loops.
- Flush-mounted radios (Jung, Busch-Jaeger and the like) are tricky sources in our experience — their outputs are often not built for this. Test before anything is plastered in.
Setting the volume correctly
The amplifier itself has no volume control — the level is always set at the source. A fixed line output without regulation is therefore unsuitable; use the headphone output or an adjustable output. Two practical values: room level is often only reached from about half the control range, with plenty of reserve above. And if the smartphone’s Bluetooth volume steps jump too coarsely, the fine adjustment in the operating system helps (iOS and Android both offer options) — it cannot be changed on the device.
Adding a subwoofer
For more depth, a subwoofer of 4 to 8 ohms can be run on a free speaker output; connect active subwoofers to their high-level input. The ground-loop rule applies here too: run subwoofer and amplifier on the same mains circuit if possible. We do not carry a dedicated in-ceiling subwoofer.
When the TV will not pair
If a smart TV will not pair via Bluetooth (any more): delete the old pairing in the TV menu, briefly power-cycle the amplifier, search again. If it stays that way, it is almost always the TV software — which is why we cannot guarantee compatibility with smart devices. The jack cable always works.
More on pairing, PIN and unwanted access: Pairing Bluetooth ceiling speakers. The invisible cabling of the whole setup is described in Cabling home cinema, TV and projector invisibly.
