With no music playing and the sub active, am I supposed to hear a quiet but still audible powered hum? I seem to recall other subwoofers I owned in the past (it’s been awhile) doing something similar. Would prefer if that hum was not there. I have my cable plugged into the LFE port and the dial set to 3 as instructed. I’m still within my retailer’s easy-peazy return window if you think I’ve got a bum sub?
After listening to Darko’s review comment about a 4ms delay on lip sync for movies/tv when using the KW1 wireless controller, I paired mine via a the basic Best Buy cable (is this a potential hum culprit?) to my non-control panel LS50W2. But I have a KW1 that I could test with before returning if that could help the above or be useful for other reasons?
I have mine positioned on top of a sheepskin rug. I played around with it being off the rug and set closer to the corner on a hardwood floor, but couldn’t really tell much of a difference.
It’s positioned horizontally in-line with my LS50W2s in a corner directly behind a chair (and I have “corner” selected on the back panel).
Woofers are pointing perpendicular to both the chair and my primary seating position on a couch about 9’ from the sub. There is ~2’ space to the wall from each woofer and ~3’ from the back panel to the corner of the room.
I know placement is highly subjective, but would be curious if anyone had any thoughts/points about this setup? I know Darko preferred to have his centered between the two speakers, with a woofer pointing directly at the primary seating position, but for WAF reasons that’s not possible in my case.
I haven’t changed the default settings. Sounds great as-is but curious if I’m missing out by not experimenting more? It doesn’t need to be any louder (again, WAF).
Are there any released or potential firmware updates for this sub, and if yes how would those be administered?
Thanks for your feedback.
Other than the hum, overall this is such a killer product I feel like LS50W2 owners should really try to add it if at all possible.
In my experience hum is not normal, if it instantly goes away when you pull the cable it “could” be a ground loop? Make sure you have a proper ground from mains plug? Also might try a better/different cable (in case the one you have is defective)?
I would try the wireless and see what happens (see if the hum is gone after unplugging LFE).
As far as placement, have you done the subwoofer crawl? Place the sub in your primary listening position, play some bass heavy tracks, crawl around the room with your head at the height the sub will be and find the “sweets” spots (where ever the bass sounds the best). That is the spot in the room that is "best’ placement for the sub for that listening position. There may be more than one spot with varying degrees of bass.
I would definitely recommend playing around with the settings to get the crossover etc optimized.
look here for a discussion:
I would look at KEF site to see if there is an updated firmware for your sub and speakers.
I’m using it with LSX II and in my case it sounded best between the stereo speakers with the woofers facing towards the left and right, slightly farther back from the listening position than the LSX II.
I suspect this is because my room is rectangular and the left and right walls are closer than from to front to back.
It’s about 6 feet from the front wall.
I’m using the KC62 preset in the KEF app.
Hum is still present when I turn off LS50W2 and remove the Best Buy mono sub cable, so I presume that eliminates the cable as the issue.
Hum is also still present when I unplug from power strip and plug directly into either of the mains outlet. So presume that eliminates the power strip.
Hum also still present when I plug it into other outlets.
Ticking “Sub polarity” in the Connect app didn’t change anything.
Toggling “GND Lift” adds a new, different frequency hum on top of the existing hum.
And no hum from my LS50W2s or any of my other speakers plugged throughout my house.
Seems only thing that eliminates the hum is when sub is in standby mode (orange light) or is powered completely down. As soon as it is active/wakes up it’s back.
Don’t see how adding KW1 will help so guessing it’s a grounding or sub issue. Any suggestions on how to easily troubleshoot grounding?
Have you tried plugging it into the same mains outlet as the LS50?
I’ve had ground loop issues in my systems if components are plugged into different mains outlets.
If you’re running an extension cord and/or you have appliances (like a fridge or fan) on the same mains this can cause hum too.
Although it’s not applicable with the KC62, I’ve had components that hum when there is no input cable. So perhaps running yours with no cable as a means of testing might not rule out your sub cable as the culprit.
Also my audioquest sub cable has a separate terminal for grounding.
I’ve never needed to use it but its presence suggests sub hum could be a thing in some setups - if that helps at all.
Also, my house was built in the 40s when outlets weren’t grounded and they just had 2 prong plugs.
When the power was updated they did a poor job and a few of the outlets despite now having 3 prong outlets aren’t actually grounded.
As a last resort you could purchase an outlet tester for about $15 and verify your outlets are properly grounded.
I couldn’t say if it’s defective.
Assuming it’s a ground loop, they can be tricky to diagnose/solve.
In the past when I suspected I had one and couldn’t resolve it we set the equipment up at my dealer and there was no hum which confirmed it was in fact a ground loop or in some way related to my house electric.
Perhaps you could do something similar?
I have the LS50 W2’s and 2 x KC62’s, they hum when using LFE if they are active and no music playing, ie they are not in standby with the orange light.
Using them in manual mode and they don’t hum on standby. There’s no hum when music is playing and I absolutely love them and what they bring to the listening experience.
I listen to music only, maybe once or twice a day using this setup, At the end of the session I put the speakers into standby and flick the switch at the rear of the sub woofers, it’s no hardship for me and I’d do that if they didn’t hum.
As for positioning, it took 6 months for me to be happy with my sub placement, gain and app settings. It’s now what it’d consider to be set and forget, everything sounds great, some recordings sound incredible.
Best advice I can give with sub placement is do the subwoofer crawl, with it set as the factory setting, then adjust the gain and see what you think.
Ps there’s been a lot of internet chat about these subs starting to hum after the music stops, KEF must know I’d have thought. No it’s not ideal, but it’s no issue for me as they are switched off. I’d not swap this set up now, I’m v happy with it.
Ugh. Replacement KC62 has just started to experience some kind of popping sounds, along with some “crunching” sounds. Happens when both the TV mode on the LS50W2s or music mode is selected. When playing or not playing. Reported to KEF.
