Silent Angel LF-SP Network Filter

The Silent Angel LF-SP is a passive network filter that clears the Ethernet signal between switch and streamer of interference.

Sometimes the most effective component is the one that does nothing at all, except create calm. The LF-SP works completely unpowered and sits as the final filter stage right in front of your streamer.

Why the LF-SP?

Interference builds up on the last stretch of network before your system that no datasheet shows, but every good ear hears.

• Passive and unpowered: The LF-SP needs no power supply and therefore introduces no interference source of its own. It only filters, instead of adding its own clocking.
• Reduces ground loops and EMI: It dampens ground-loop effects and electromagnetic interference as well as noise carried over from your home network.
• Final stage before the streamer: Placed between switch and playback device, it refines the signal right before it counts.
• Simplest integration: Plug in, done. No app, no configuration, no power supply.

What you hear

The effect is fine polish: a slightly blacker background, calmer voices, and a touch more order in the sound. It's easiest to notice on an already clean streaming chain, especially with calm, high-resolution recordings.

Who is the LF-SP for?

The LF-SP is for anyone who already takes their network audio seriously and wants to optimize the final stage. Bottom line: if you only listen occasionally over Bluetooth, you won't notice much. In a chain with a good streamer and audio switch, it's an affordable, sensible finishing touch.

Our verdict

A small, passive component with a clear job, picking up exactly where active components leave off. Whether the LF-SP brings the last bit of calm to your chain is something we'll assess honestly with you at HD Zürisee in Wädenswil.

Technical data

• Principle: passive, unpowered network filter (inline)
• Connection: 2 × RJ-45 (Ethernet), between switch and streamer
• Data rate: up to 2.5 GbE (2500/1000/100/10 Mbps, auto-negotiation)
• Function: reduction of ground-loop and EMI interference as well as carried-over noise
• Power supply: none required
• Dimensions (W × H × D): 108 × 32 × 26 mm

Frequently asked questions

Does the LF-SP need a power supply?

No. The LF-SP is a passive, unpowered filter. You simply place it in the network run between switch and streamer, it needs no power, and so it introduces no interference source of its own. Plugging it in is enough.

Where's the best place to put the LF-SP?

As close as possible to the playback device, ideally right in front of the streamer. That's where it filters out the last carried-over interference and ground-loop effects before the signal reaches the sensitive audio electronics.

Does the LF-SP replace an audio switch?

No, it complements one. A switch like the Bonn N8 actively clocks and separates the signal, while the LF-SP filters passively as the last stage before it. You get the most out of it when both work together.

Why buy the LF-SP from HD Zürisee?

Because network audio lives from how components interact, and we'll tell you honestly where a passive filter helps in your chain. Here in Wädenswil, we assess it with the whole system in mind, instead of just selling you a part.

Goes well with

The LF-SP performs best in a clean network chain. Discover the world of Silent Angel, the matching network switch, and high-quality network cables.