I also have the issue of the KC62 not turning on with my LS50 Wireless II speakers. I have the KC62 connected via the wireless connection (KW1). If I disconnect the power to the KW1 and then plug it back in the sub would then be connected. If I just turned the music up, it would not always turn on.
Very frustrating situation for a premium product.
Is KEF coming out with a firmware upgrade to solve this issue?
Anyone knows or @Ben_Hagens comment on output voltage spec on the “RCA Subwoofer output” ? I could not locate this spec ?
I am now hearing a white noise, very noticeable, on the KC62 when no music is playing, any idea what the issue could be? Tried to ask KEF but they are not responsive
I’m thinking of getting a KEF LS50 Wireless II with a KEF Kube subwoofer. Do these problems still exist in 2022? I like my subwoofer to try to help, even at low volumes.
Greetings from Australia , Just found this forum after searching for issues with the sub turning on from STBY and noise feedback when the sub its in LFE . I have had my KEF LS50 ii wireless for about a year now and love them . After seeing details and specs and sizes etc of the Kc62 invested in one of these to go along with my system . Picked it up this month (March 2022) from an authorize Australian retailer (But believe the stock may have been from last year ) I’m running the Kc62 with the KEF KW1 Wireless Subwoofer Adapter .
I noticed that in LFE input: it’s much noisier than on the manual and has a constant hum / static noise even when no music is playing . Tried a whole bunch of different power points etc and makes no difference to the noise when in LFE . When I switch it to manual mode the noise completely disappears . As such I have been running it in manual mode since .
Also noticed there is issues with the sub going into STBY mode while music is playing or not turning on from STBY mode when starting music . I listen to a lot of classical / jazz and acoustic music even though there is not a lot of deep bass in some of these types there is still some low end musical instrument sounds in the track Generally around the 35 to 40 volume range in the evening . I assume that the sub only switches out of STBY mode when frequency’s hit a certain range on the tracks ? When I play more modern bass heavy songs it seems to have no issues coming out of STBY mode.
Hi Terry got the details settings for the KEF connect app , what settings are needed on the back of the sub ?
Hi Kirt
Awfully sorry, but I can’t help you now as I have recently traded in the lovely KC-62 sub (and the Kef LS50 Wireless II speakers) to upgrade my main Grimm/Kii Three system.
I think (hope) that I’ve discussed the settings elsewhere in postings I’ve made previously, so if you search then you should find them.
Hope that helps
Cheers 
Terry
Hi Kirt, played a lot with the settings and it is difficult. Best result with waking up the KC62 on low level on my LS 50 MKII was to have two cable from each Speaker to the Sub and use the following settings (sorry all in german). Sub setting will follow:
Let me ask a stupid question, and I’m asking it as someone with KEF LS50WIIs in my living room, KEF LSXs in my bedroom, and a full KEF R-level home theater/audio setup in my family room:
With all the available subwoofers out there, why is everyone tying themselves in knots trying to get this unit to work the way they want to? I bought the KC62, was unimpressed/disappointed, and returned it.
Is there something about the quality of this unit that you’ve found worth the time and trouble and tweaking necessary to get it to work well?
Does using 2 cables in stereo mode actually make any real-world difference (with the 1 KC62 sub)?
Over at AV Forums/KC62 Owners Thread, Klopek says,
Not been following the thread, but just in case this isn’t known:
(From KEF support)
“We are working on a fix to ensure there is a constant signal passing into the KC62 to ensure it’s operating at lower listening levels. This will come by way of a FW update for the LS50W2 (as this will be the signal generator) - so please ensure you have auto-updates set on your main control device for as and when this update is released.”
I asked KEF support, twice, to confirm this… but, shockingly, no answer.
Rob
I tried a cable from each LS50W2 to a Y- adapter into my KC62. I have heard reports that will help turn the sub On quicker. It did not help me.
I believe I did it in Mono mode, not stereo, so I don’t think I helped you, Kim.
Edit:
I thought there had been an improvement in turning On, and staying On, but no, the update has not helped.
Unfortunately, this is not the case for me. Unfortunately, the update to 2.3 has not improved anything for me.
I don’t think so. If so it would be enough to just turn on the Wireless II’s and the sub would wake up after a short while. Isn’t happening here.
I was considering buying a KC62 but having read this thread now I’m having second thoughts.
Just to make sure I understand the problem people are having … is it that sometimes, e.g. at low volumes, the KC62 won’t play sound at all? Or is it more of a “turning on” problem, where the KC62 won’t power up from sleep/standby unless it receives a high signal… in which case, can you walk over to it and manually (using a button/switch?) power it up?
Thanks trying to understand what’s up
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.
