2 subs on a stereo amp

[marct10]

im trying to connect 2 BK XLS400 subs to a Naim NAP100 using high level inputs from the loudspeaker binding posts.
I can connect either one to either speaker and it works, when I connect both simultaneously they hum. Sounds like a ground loop. Should I just use one ground reference from one speaker for both subs ?
Thanks
Marc

 

[djftw]

In the first instance I would look at where everything is plugged in (to the mains), sometimes these things are something as simple as getting everything on the same circuit - or identifying a duff extension or socket and getting it fixed/replaced! One of these is useful for checking everything is in order...

https://www.toolstation.com/shop/El...al+Test+Equipment/sd3348/Socket+Tester/p82826

Plugging everything into a known "good" multiway can be a good way to see if this is the problem.

 

[mbu]

im trying to connect 2 BK XLS400 subs to a Naim NAP100 using high level inputs from the loudspeaker binding posts.
I can connect either one to either speaker and it works, when I connect both simultaneously they hum. Sounds like a ground loop. Should I just use one ground reference from one speaker for both subs ?
Thanks
Marc

Are you connecting both like this ? I think this should be correct but best you get in touch with BK. And previous post correct. Best you have all gear including subs on one mains circuit.

Neutric speakon lead. Right chan sub. Red wire to red speaker terminal , black to black speaker terminal - right speaker. White wire not used.

Neutric speakon lead. Left chan sub. White wire to red speaker terminal, black to black speaker terminal - left speaker. Red wire not used.

 

[marct10]

Thanks for the replies. Yes that is exactly how I have them wired, all mains connections to one good quality short extension lead. Individually both work as expected but as soon as I connect both Neutrik connectors simultaneously they start to hum.
I have mailed BK but they haven't got back to me yet. My only thought is that perhaps the two subs should share a single ground from one speaker, just as if I was only running one sub ?

 

[mbu]

Thanks for the replies. Yes that is exactly how I have them wired, all mains connections to one good quality short extension lead. Individually both work as expected but as soon as I connect both Neutrik connectors simultaneously they start to hum.
I have mailed BK but they haven't got back to me yet. My only thought is that perhaps the two subs should share a single ground from one speaker, just as if I was only running one sub ?

I think your correct. Connecting the 2 blacks together from both subs to just one -ve/black terminal of either speaker will clear the hum.