Subwoofer settings? KEF LS50 Meta + KEF KC62 + WiiM Amp

[PeterHans]

Hi there,

I am a bit confused right now and have some questions regarding the setup.
I bought a WiiM Amp, a pair of LS50 Meta and the KC62.

KEF recommends the following settings for the LS50 Wireless II (which should be almost identical to the passive LS50 Meta) in combination with the KC62:

• low-pass frequency (filter?): 45 Hz
• high-pass frequency (filter?): 70 Hz

If I want to use this settings with the WiiM Amp what exactly do I have to do?

These are the options in the subwoofer menu:

To my understanding the "Crossover Frequency" in the WiiM amp is the high-pass filter, is that correct?
In that case I set it to 70 Hz, I can clearly notice that there is now almost no more "bass" coming from the LS50, which would be exactly what I want.

The sub is connected via cable to the WiiM Amp (Sub Out), I switched the "Mode" to LFE on the KC62, is that correct?

Is it possible get a low-pass filter also? My thought was that I could physically dial the "Crossover" on the KC62 to about 45Hz or would that be wrong? (or does LFE deactivate the "Crossover" dial on the back and I would have to switch to the "Mode" Manual?)
To be honest, I don't understand what LFE is doing exactly?

Thanks a lot, I know lots of questions any help is appreciated!

 

[PeterHans]

Short update, I had a talk with ChatGPT and it came to the following conclusion:

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You asked about the LFE switch on the KEF KC62 subwoofer, and we discussed how it works:

• The LFE mode is used when connecting the subwoofer to an AV receiver with its own bass management. In this mode, the internal lowpass filter of the KC62 is bypassed, and crossover control on the subwoofer is disabled.
• The LINE mode (Mode: Manual, as labeled on the back of the KC62) activates the KC62’s internal lowpass filter, controlled by the Crossover dial on the back of the unit. This mode is used when the connected system (e.g., a stereo amp or DAC) does not manage bass frequencies.

You then mentioned using a WiiM Amp, which has a software-controlled highpass filter for the main speakers. We concluded:

• If the KC62 is set to LINE mode (Mode: Manual), you can use the physical crossover dial as a lowpass filter.
• Simultaneously, the WiiM Amp applies a highpass filter to the main speakers in software.
• This setup allows you to define both ends of the crossover range:
  
  • Highpass (WiiM Amp) → limits what the main speakers play
  • Lowpass (KC62) → limits what the subwoofer plays
• This gives you precise control over the frequency split between subwoofer and main speakers, improving integration and avoiding overlaps or gaps.

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[staticV3]

To my understanding the "Crossover Frequency" in the WiiM amp is the high-pass filter, is that correct?

It is both the low pass and high pass frequency:


These should be matched in a Linkwitz Riley crossover. I would forget about KEFs mismatched recommendation.

The sub is connected via cable to the WiiM Amp (Sub Out), I switched the "Mode" to LFE on the KC62, is that correct?

Yes. That disables all crossover processing on the KC62 and lets the WiiM handle it.