Help! Onkyo 898 - Sub Hummmmmm

[bochadley]

Hello,

I have a Onkyo 898 with Speakercraft Aim Series and an Innovative Audio Sub table. The system has worked great until recently.

I'm getting a low frequency "hum" from the Sub. When I disconnect the input cable from the reciever the "hum" quits. I've replaced the cable and still have the "hum".

Not sure if the problem is with the Sub or the Reciever but I'm hoping someone out ther can steer me in the right direction....

Thoughts,

Chad Jordan :lol:

[Burke Strickland]

Did you recently add or change a connection from cable TV to your receiver (or anywhere else in the system the receiver and sub are part of)? That is often a culprit in causing hum, because of the ground differential that can introduce to the system.

[bochadley]

Burke,

Nothing has changed in my system.

[Azeke]

Trying plugging the sub into a different electrical outlet.

Ensure that power cords are separated from audio cables.

My quick thoughts,

Azeke

[rsteve11@roches]

Sounds like grounding

Maybe try a different outlet.

[bochadley]

All,


Tried different cables. Tried different outlet. No change.

[Clive]

Although not highly recommended, but have you also tried just disconnecting the RCA cable from the sub, leave it plugged into AC and power it up? Just to see if it's AC? Can you borrow another Sub from a friend or family to try-out to see if it's the receievr?

[joostenjohn60]

What you may have to look at is whether or not the sub is earthed and the receiver is not or vice versa in my experience with both pro audio and domestic these problems are always earth related ( potential differences).

[Burke Strickland]

earthed = grounded
earth = ground

Whichever term you use, ground potential diffenrences or earth potential
differences continue to be one of the most common causes of hum in audio systems.