Genelec Community Forum has been archived

Thank you for all the years of Community discussions and activity!

The time has come for us to retire the community forums, but we will keep everything available for reading. There is a lot of valuable content written over the years, and you'll be able to access all of that. However, no new posts can be written, or old posts modified.

If you have questions, we recommend you use the Support function on the bottom right corner to contact our Customer Support directly.

Alternatively, if you wish to engage in a community discussion with other people, there are many active forums available. There is also an active, fan managed GENELEC COMMUNITY in Facebook, and many Genelec employees are active in the discussions there.

We are sorry for any possible inconvenience this may cause you, but we hope to hear from you through the other channels mentioned above.

Genelec Support

Message Boards

7070A hum in the HT + Audio usage

kosta88, modified 5 Years ago.

7070A hum in the HT + Audio usage

Youngling Posts: 1 Join Date: 8/12/16 Recent Posts
Hello,

I am trying to use only one subwoofer in the following combo-setup:
- Active system (usually for computer use, sound production, gaming, etc)
- Home-Theater setup

As an Active System there are two 1031A, connected as usual to front IN L/R. Always worked fine.
Soundcard is a Focusrite Forte.

HT-Setup is a Marantz SR7009, which, up until now, had a 2nd subwoofer.
I connected that sub to SUM/LFE-IN, and that worked out fine. I have a good sound, no hum, nothing from the HT-Setup.

Now the two systems are in the same room, and I would like to use only one subwoofer - my 7070A.

Connecting both systems to the sub causes the sub to hum - BUT: not when computer is "idle".
Usually only when I open a game, only then, there is a hum.
The hum is also not present if either speakers or home-theater is not connected.
And: it is independable from the mute/volume setting on the Forte.

The cable connecting the HT and the sub is a high-quality cinch cable, and on the subwoofer-side there's an adapter from Amazon... however, I also have a "self-made" cable, which I soldered, setting pin 2 to signal (inner cinch) and pin 1/3 to ground (outer ring on cinch) - same hum, nothing different.

So to shorten it:
If both genelecs and HT are connected there is a hum - only when some (3D) game is running.
If I disconnect (or power down) Forte, there is no hum.

I am quite at the end of my wits, as this is no ordinary 50Hz hum.

Ideas, suggestions, where to start troubleshooting?

Best regards,
Kosta

EDIT:
After some searching, I found out I might try using a DI-Box. However, I do question this approach. Because, why does the noise happen when I use a game, and doesn't happen when I don't... what do you think?
ilkka-rissanen, modified 5 Years ago.

Re: 7070A hum in the HT + Audio usage

Yoda Posts: 2564 Join Date: 3/23/09 Recent Posts
Hi,

In general it is not advisable to connect multiple sources to same subwoofer, this can cause ground loop problems and noise.

I am not sure if I understand this sentence: "I connected that sub to SUM/LFE-IN, and that worked out fine." Can you explain more?

Unfortunately I don't have any idea why the hum is only present during games.