With polarity Off, I hear a small difference when I slide the sub out low pass frequency from 40 to 250Hz.
With polarity On, the difference becomes huge and I hear more bass
Does that mean the “good setting” is polarity Off for my sub?
Are you all happy with the 250Hz workaround? I find it annoying that it sounds different when I slide to 250Hz.
Do I hear a difference because of my room / room placement and there is still a phase difference?
another question, I find the sound not great to listen to people talking on TV, would like a more forward sound for that, any suggestion?
Hi pfa50
I think you may have answered your own question:
Either your sub is in phase with the main speakers or it is the opposite, which means part [rather a lot?] of the sub’s output is lost when combined with the bass output of the Kef LS50 IIs.
Personally, I’m very happy with the 250Hz workaround - using it I find that only the most ‘bass-light’ of music fails to trigger the KC62 to turn on - which for me was the big problem I had from inception.
I can’t answer you on your room placement. My experience - in my lounge, when I owned a Velodyne DD10, which was sold over a year ago, along with all the rest of my ‘generation 2’ kit - is that subwoofer placement does make a difference to the sound, for sure, in that a room’s natural resonance can be triggered by a badly placed subwoofer. You just have to experiment with positioning, to find that sweet spot where things just sound better.
In my case, I don’t have many options on where to place the KC62 because it is used in my study, which is much, much smaller and so it lives under my iMac desk on a set of Orea Bronze support (which really tightens the sound, if you are interested).
Sorry, but I have no ideas about how to boost your ‘presence’ frequencies for a better TV sound in respect of voices. That sounds like you’d need to ask Kef to engineer a set of ‘tone controls’ into their Kef Connect app - which might be of value to many folks?
Hope all that helps. Happy listening!
cheers
Terry 
Isn’t it the opposite? When I set polarity to On I hear a huge difference with low pas 250Hz because it’s not in phase with the main speaker?
I think that either my Kef LS50 WII OR the KC-62 has had it’s output / input wired incorrectly. I can’t be certain of that, but it’s the only explanation that makes sense.
What matters is that in one position of the polarity switch you will find the strongest bass response (and very little in the opposite position) so that’s what you should choose. 
I recently got a kc62, it has the same LFE wakeup problems with WIIs. It needs 33/34 to kick in.
And while suggested workarounds do help with the volume needed to wake it up they make it sound worse than the default settings.
I wasn’t able to replicate the same bass response in manual mode. Setting the same LPF on the sub doesn’t match the sound I get with the defaults. I played around with LPF/gain/volume and there’s no way to make it sound even similar.
In general manual mode makes the sub sound slower and and boomier with much less dynamic. It’s a huge audible and even visible difference. The system in default LFE 45/70 with 0 gain sounds awesome the sub totally disappears and works for any type of music you throw at it. It feels like in LFE mode kc62 DSP works much better. While everything I tried in manual sounds okay at best, but then you play another song, change volume etc and it sounds like a generic cheap subwoofer. So to me kc62 worth the price tag only when it works with the settings proposed by KEF, any deviation kills the magic.
That’s what my dealer wrote to me "It is true that KEF will lower the trigger level through an update next year, at that time the sub may function completely as you would expect."
But then to other people KEF replied that they need to send it to fix the problem. Either my dealer knows something or they don’t want me to return it while I can 
It’s pretty unbelievable that people are still receiving KC62 models with auto-wake sensitivity issues. It doesn’t speak well on KEF, nor does all this need for workarounds to a problem they themselves created for customers, and especially the lack of clear communication.
I can’t say for sure how much your dealer knows, but many of us have heard directly from KEF that a fix was already rolled out (circa mid-summer), and that a repair for existing subs is out there and available either at a KEF in-house repair center or at an authorized service center. Not anything about a fix becoming available in 2022.
However, complicating things, in the case of @ROB_BREWER , KEF tells him his serial number indicates he is unaffected by the problem but yet he’s still having problems. Makes me wonder if they accurately told me the status of my sub, too.
The whole thing is such a bummer considering the price that KEF is demanding on this.
Yes KEF told me I am unaffected by the issue because it was too recent but the issue is very real. They suggested a different workaround (LFE + LPF at 70Hz, +5db gain). It sounds so bad that I have serious doubt they are taking this seriously.
Ridiculous stuff for a product with that price tag. I also found that all of the “workarounds” make the sub perform much worse the louder you get. Different workarounds create totally different dynamics and the response in general. it’s either too boomy or too quiet or it doesn’t blend that well. Influence on the sound stage is huge as well. And any workaround with manual sounds the worst for me.
Although, I experimented and that’s the closest I could get it with the sub waking up around 20-25 volume.
So I connected both speakers and used stereo mode in the app. Also the crossover know has some impact on the sound, so it’s position is not random. Although it’s not supposed to in LFE mode. And I had to flip the phase both on the sub and in the app.
I don’t have any technical base or logic behind that setup. It just sounds the closet to the recommended settings to my ears.
Anyway I still can return it, so I think that’s what I’m gonna do.
What is the minimum sound level for the sub to kick in on average? From my tests it’s about volume 40 (around 70db). Does that sound acceptable that at 65Db, the £1400 sub stays off?
you may want to check the video of the KC 62 at darko.audio where he extensively describes how he figured out how to get the device sonically integrated in his environment.
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 comply with the EU directives on energy saving.
With the following “workaround”, the switch-on behavior can be improved even at lower levels:
Urs, I agree with the posts before. If you manipulate the system by setting 250 Hz as LTF I explore crappy Bass Sound. This was mentioned several times by several people.
I m extremely disappointed that the Sub is only activated by extremely high sound level. Would expect a technical solution such as sending a ping every x minutes to the sub by the LS 50 at maybe 12-14 Hz which we as humans can not hear anyway. This can be initiated at a certain output level ie 15 or 20 or so. Can’t be so difficult and possibly integrated into the app (with possibility to activate in the Menue to comply with EU derective) and speaker firmware update if needed.
I used your settings but left the Sub gain in original KC62 setting with 0. The second cable definitely helps to wake the KC62 up at lower volume. But still not at a reasonable level. I think the + 8 gives the extra while reducing the out power of the sub. It is a bit tricky to balance this out depending on the room. Thanks for the input. The issue has to be solved by KEF itself.
Do similar problems exist with the KF92? Thanks.
It’s really hard to manage to get replies from them. At the moment they are just telling me I can return it to get a refund, they don’t seem to be willing to communicate anything about the issue.
Does anybody know if the KC62 uses DSP when in manual mode.
Or does it use an internal analog crossover then?
This is just super disappointing so far. This problem has existed for so long and no official statement from KEF. Especially given the price point. I’ve had mine from new with the LS50WII’s. Tried the manual “fix” but agree with others that it sounds way worse than LFE. Trying +10dB in app with volume at 9 o’clock at the moment.
Hoping for at firmware fix but don’t know if this is technically possible. Some word from KEF on this would be nice.
Also completely useless with movies with long stretches of dialogue followed by a sudden burst/explosion. It’s way to fast to go into sleep mode considering it takes 6 seconds to wake up (explosion long gone).
Hello All - as of yesterday LS50W II landed and today is day-2 on it. So far its really good compared to previous gen.
Sub: SV Micro 3000
I want help in reviewing my settings and this is what worked for me. Understood most on this thread are on KC62 or KEF subs.
Desk Mode, Wall Mode → OFF
Treble trime, Balance control → 0db, Center
Phase correction → ON
Sub Out:
How many → One
Channel → Mono
HPF → ON @70Hz
Sub Out LPG → 250Hz (actually it does not matter upto about 80-90Hz)
Sub gain → 10dB (It does not work for me if I keep it at 0dB like other cases described above)
Sub polarity → OFF
KW-1 → Don’t care (OFF)
Low Pass Filter → ON (LFE Disabled)
LP Freq → 65hz
Slope → 24dB
Volume → -12dB
Please feel free to let me know if I m in right/wrong path especially with “Sub gain”. Because with 0dB, there is nothing on my Sub.
Anyone using SVS subs have similar config or something different, do let me know. Appreciate for inputs/review in advance.
