Using KEF LS50 Wireless II with a Subwoofer

Paul, the sub does not come out of Standby and play until it receives a loud enough bass signal from the amp. I have to turn up the volume to the main speakers for the sub to start playing

When powered On, the sub stays in Standby until the volume is sufficiently loud, then it turns On and plays. Also, after playing a relatively short period of less loud sound (classical music) the sub stops playing and drops back into Standby.

The sub is not On all the time by design to conserve power iaw EU directives, I have read.

Ugh that doesn’t seem very good then. I like listening at relatively low sound levels. Hopefully they will fix this.

I’ve had similar issues with my JL Audio subs not coming on as soon as I would like.

I know, different subs different animal, but the aggravation is the same. Not enough LF to wake em up and if your playing something with little to no LF they go back to sleep after about 30 minutes.

JL Audio support advised to use standby to prolong the life of the subs and use both left and right inputs to double the gain being received. That works if it doesn’t double up on hum.

Another option is the turn the volume on the sub down slightly and increase the signal from the source, room correction in my case went from - 3 to +3 db.

I found an album from a Roon search called BASS TEST. Playing that will definitely wake up the subs. I use it to verify everything is working properly.

Setting the sub to manual works fine – as outlined here:

Setting low pass to 250Hz on the LS50WII makes sure there’s ample signal going to the sub, which is limited to 45Hz in turn so the 70Hz high pass/ 45Hz low pass balance remains intact. The KC62 jumps into action immediately, regardless of the volume of the music playing.

Works absolutely fine in my system – and I can’t hear any difference compared to LFE/45Hz low pass via the LS50WII. I am rather conservative with volume (slightly over 12 o’clock). Makes for a nice foundation and a lovely clean, fast and deep bass.


Here’s what KEF recommends:

The following “workaround” can improve the switch-on behaviour even at lower levels:

  1. set the mode switch of the KC62 to "Manual
  2. select the KC62 as the connected subwoofer in the Connect app
  3. configure the High Pass Filter to 70 Hz in the App
  4. set the low pass filter for the sub to 250 Hz in the app.
  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 behaviour still causes 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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That’s pretty much what I posted above. :smiley:

Be careful with #6 though – I found 3 o’clock to be excessive.

Yes, the volume setting is wholly individual from room to room. 1 o’clock is sufficient for me at neutral (0dB) gain setting. Also experiment with the subs woofers firing either the length or the width of the room. I have them facing towards me same as the speakers.

Same here. :wink:

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I have heard reports that using the workaround makes the bass sound horrible. I do know it wakes the sub almost immediately.

I recently acquired a mic and some software to see what some audio analysis may show; however, I am a complete neophyte as far as this is concerned. Any suggestions?

KEF LS50W version 1 user here paired with a couple of B&W ASW608 subwoofers (small, white, cheap especially at the bargain price I got them for, and intended to be a stopgap purchase until I worked out what I really wanted but are now well into year 3 of their residence in my living room). I would have upgraded to a pair of LS50W v2 plus matching stands and a pair of KC62 over a year ago now had it not been for this staying-in-standby mode so, if anyone from KEF is still monitoring these forums, that’s over £5K of revenue sitting on the sidelines from me alone just because of this one issue.

I probably won’t bother making serious efforts to find an alternative right now, aesthetics are also a key consideration for my household so small and white are essential properties plus I know already that the KEF50W is good and I am confident that the KC62 can outperform my B&W ASW608s (at least when they switch themselves on!) so I’ll carry on watching and waiting but I’m certainly not going through the hassle of upgrading and then potentially returning the KC62s until this standby issue is sorted out.

Obviously from this thread I know that there is a workaround that some people are satisfied with (although some are not) but come on KEF - the LS50W and KC62 are supposed to be a match made in heaven but they can’t even coordinate power-on/off properly without a workaround?

I really hope that rumour of a firmware fix for the LS50W is true (and a fix on the LS50W side makes makes sense, someone in this thread actually suggested that quite a while ago). If such a fix really isn’t possible then I hope that a KC62 v2 can resolve the issue even if the resolution is as crude as having an extra 3-way switch on the back for on/off/auto which is what my B&Ws have. In fairness my B&Ws also sometimes drop into standby when my LS50Ws are still playing but at least I can set the switches to on rather than auto and that forces them to stay on (24/7 if I forget to turn them off).

I believe there are enough KC62 owners with this problem for a proper class action lawsuit. It is insane that KEF has not formally addressed this, the sub is useless in LFE for anything with silent or low volume passages such as jazz, classical and movies. I trusted KEF will do the correct thing and kept mine long enough that I can no longer return it. Needless to say, Im angry.

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I had no prior experience with KEF, but expected a much more satisfactory solution to this defect.

Honestly surprised the sub passed quality control checks.

I’m running it with my LS50WIIs and KEF Connect app sub selection of KC62 with a +10dB gain.

The sub now comes On at lower volumes, and I timed a better than 15 minute period from when I shut Off the speakers, until the sub went into Standby.

So, it is working better. Maybe due to the recent LS50WII firmware update to Ver 2.3.

I wanted to have the sub facing me, but got tired of going over to the side to see if the orange Standby LED indicator was lit. Lol.

Maybe after some audio analysis with REW, I will turn the sub towards me.

Should I add KC62 to WII? Thanks

That’s entirely up to you. :slight_smile:

For me, the KC62 has filled out the LS50WII with a nice foundation resulting in a full range sound and a controlled, deep and pleasantly dry (as in: non blooming) bass that integrates well with the speakers.

Setting the subwoofer to manual mode, I have no problems at all waking the sub from sleep, even when playing music with modest bass at low volumes. So yes – I’m very happy with the combo.

I found KF92 open box for $1600. Do you think KF92 to big for WII? Thanks

Weird. Something wrong. Plugged my kc62 in. Seconds later it was thumping away with clean tight bass. Used the Kef Connect default crossover settings.

Works flawlessly.

A big big win for me

Neil, did you buy your KC62 recently? Nice that it works w default settings. I need to raise the sub gain by 16 dB with the KEF app just to wake it up.

I would like to face the sub driver toward me, but I like to keep an eye on the orange LED on the side that shows the sub has gone back to Standby.

My sub is working better now than it used to.

A bit late on my response. I have the KF92 working with the Kef LS50 Meta. A great match. Definitely not too big.

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