Using KEF LS50 Wireless II with a Subwoofer

Big thanks to @Ben_Hagens for getting us the final answer on the LPF and HPF slopes. That’s a very nice thing to have for those of us with the passive Metas. Good on KEF for supplying that info to customers.

Hi Ben,

It works here too but what sense is the KC62 profile in the KEF app when manual adjustment is necessary afterall?. Or is this a workaround until the next update?

Best regards,

@Ben_Hagens :slight_smile:

Ben, your input here is extremely valuable to all of us - thank you Ben. Here are a few additional questions:

  1. From user JohnnyZeroSix in AvForums: he does not see the 18ms delay appear when selecting the KW1 in the Kef control app - is someone able to test/verify this?

  2. From user PatSurf70 in Avforums: Found another ‘bug’ or feature today in the app: When no subwoofer is selected (and connected) the high pass filter setting still works. Resulting in less bass when its enabled.I would assume when if there is no subwoofer connected the high pass filder doesnt need to work. But i could be wrong. I already had the setting of none subwoofer connected. Now i also disabled the high pass filter. (Think its default set to 70)

  3. There seems to be a (global?) delay in KC62 delivery - including my order :frowning: Is there any specific reason for this? If it is fixing the issues i am more than happy with the delay :- :wink:

@Ben_Hagens Would you be so kind to have Kef engineers check the above please? I have put both (potential) issues on the bug tracker list located here >> KC62 Issue list <<

Hoping it is ok to ask here:
I have my KEF LS50 W2 connected to Samsung TV via eARC HDMI; two questions:

  1. The volume when playing music directly Spotify to KEF via phone at 40 is good volume, but when I switch to TV input; 40 seems too low and I have to volume up to around 48 to 50 to match the same level as audio via phone (Spotify) - is this expected?

  2. Even when KEF is in stand-by and switch on the TV I still get sound from KEF (although in believe in this case the TV speakers are also play the sound) - is this ok?

Thanks for your inputs in advance.

@Ben_Hagens apologies if you’ve answered this earlier; can we select stereo for subwoofers on the LS50 WII now? One KC62 per channel…? :slight_smile:

Fabulous! Thanks @RBM

Aye, was added a little while ago. Can’t remember if it was at the same time as the sub profiles were added.

Either way, I tend to go stereo, I find the imaging/soundstage is improved for the most part.

Hi, found this topic because the KF92 I just got in test for my LS50 wireless II sometimes stays off with the red LED. I have a few questions:

  • Is this still being investigate and will it be improved with a new firmware?
  • I have a RCA cable 1 male to 2 male, is that OK? I see in the manual they advise a 1 to 1 in the left input on the sub
  • My KF92 is in a corner, just on the left side of the two speakers. Is corner mode still advised? In the manual it seems intended for a corner behind the speakers.
  • Is it worth trying to change the HP70 / LP50 recommended settings? changing LP to 250Hz and you hear a lot more things in the basses but it sounds weird.
  • How am I supposed to know if phase should be zero or 180?
  • Is there a way to instantly switch between sub activated and LS50WII only to accurately hear the difference between the two?

Hi all, Ben.

I’ve received my KC62 early july & KW1 in de mid of august. Two topics are relevant

  1. The upper internal screw-thread of the screw to attach the KW1 to the KC62 is damaged - preventing the screw to go in all the way (see pictured below). Despite several attempts to contact KEF NL there is no response yet. It seems that the inner screw-thread of the kc62 damages the screw too - so i refrained from using any force to proceed. As i used to own a mechanics workshop i know what i am talking about here.

  2. i have received different EQ settings from KEF NL. Attaching for your reference.

  3. KC62 Wakeup using the KW1: there is no difference in volume settings compared to using a cable.

Screw thread problem pictures:

EQ Settings

  1. Set Crossover Frequency to max
  2. Set the volume knob on the KC62 on 50 (adjust afterwards)
  3. Set High Pass frequencies and Low Pass frequencies to the same value in the app. Normally from 70Hz
  4. Optional: set subwoofer gain on +5 or +6.

Hello, what have you set for the crossover on the sub?
Greetings from Switzerland.

Enclosed KEF’s answer to my official inquiry: We are sorry to hear that there are difficulties using your LS50WII / KC62.

The KC62 subwoofer switches on depending on the input level.
It does not have a manual option to switch it on permanently in order to meet the EU directives on energy saving.

The switch-on behavior can also be improved at lower levels with the following “workaround”:

  1. Set the mode switch of the KC62 to “Manual”
  2. In the Connect App, please select the KC62 as the connected subwoofer
  3. Configure the high pass filter in the app to 70 Hz
  4. Set the low pass filter for the sub in the app to 250Hz
  5. Set the crossover control on the subwoofer itself to 45 Hz
  6. Turn the volume control on the subwoofer to the 3 o’clock position

If the switch-on behavior continues to cause problems, you can increase the output level (subwoofer gain) in the app and reduce the volume accordingly with the control on the subwoofer.

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These are the exact settings I’ve been using for the last few months (apart from volume – mine is at 1 o’clock). These work perfectly for me (sub switches on without failing when bass is present at low or moderate volume ranges).

Oh – and it all sounds bl**dy glorious… :smiley:

Anyone using two KC62 with stereo setting in the KEF Control app, rca sub out from each LS50 WII speaker to the KC 62’s ? Whats the experience ? I’m seriously thinking trying this.

Hi Urs
Sorry for delay in replying - I’ve been on holiday!

My Kef settings - as per the Kef app (latest version):
High pass filter = 70 Hz
Sub out low-pass frequency = 250 Hz
Sub gain = 0 dB
Volume control on subwoofer = 3 o’clock
Sub polarity = ON

This last setting is VITAL if you have an early example of the KC62 - as the polarity seems to have been wired incorrectly? Do try this, it made a massive difference to the sound, which I can now only describe as awesome!

Good luck

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Thank you :+1:

Not sure if this is true in every case – my KC62 is an early model (March 2021), but definitely needs polarity set to off. It’s placed along the same wall as the main speakers are:


Oh well – just listen and you’ll hear soon enough… :wink:


Yes, you could well be right about that.

I received my KC-62 on 5 March, but the LS50 WII’s arrived on 18/11/20, so I guess one of them is wrongly wired somewhere?

I only discovered the phase setting by accident - I was trying all sorts of combinations to get the KC-62 to fired up - and boy, what a difference I heard; obviously they weren’t working correctly out of phase. Who knew?

Terry :rofl:

I bought the LS50 / KC62 both on 09.2021. I don’t hear any difference. :worried:

Phase is down to a few things - room, positioning and preference. Plenty of times I’ve set the exact same sub (not just KEF, but back in my retailer days) in different rooms and ended up using different phase settings.

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