HELP! New Denon 1905 Speaker Hum when Subwoofer connected

[msherman]

HELP
I just installed a new Denon 1905 receiver, and installed inwall speakers from HTD (5.1), and all was well.
then, i installed my subwoofer using a shielded cable. the cable runs under the house, and as soon as i installed it, all of the speakers had a slight hum, that grows worse over time...
i have isolated the ac outlet for the receiver, checked all connections, etc...
when the subwoofer is off but still connected, the speakers hum
when the subwoofer is disconnected, the hum is gone.
i know very little about this, and am TOTALLY frustrated...i was so excited to finally get surround sound, but this is ruining my experience.
any help will be greatly appreciated :M

[jimmyp58]

What do you all have connected in your system (besides what you stated)?

Jim

[msherman]

connections for 1905

i have the following:
dvd player attached with RGB cables and a optical audio cable
satellite receiver attached with S-video and optical audio cable
both dvd and satellite attached to tv with RGB cable
record player attached to auxilliary port with standard rca cables
2 front speakers
2 rear speakers
center channel
subwoofer

[jimmyp58]

I am confused....you have your satellite receiver attached with S-Video cable AND Component cable (rgb) to TV? Is this for HDTV (component) and S-video for 'regular' broadcasts? What kind of TV do you have?

My hunch is that you have some sort of ground loop in your system. This could be caused by your satellite not being properly grounded. Even though your sub is off, many subs go into standby mode (waiting for a signal) so they really aren't "off" hence the reason for the hum (the sub has an amplifier built-in it). Does the plug from your sub have two prongs or three? Do this, leave your sub on and connected but disconnect the cable from your satellite. Do you still have a hum?

Let us know....

Jim

[msherman]

Progress on Denon 1905

Jim,
I hooked up the subwoofer with cords, power on, etc... and then removed the two satellite in cords (they look like cable cords), and, the humming stopped when the cords were away from the TIVO receiver, but if i moved them near the TIVO receiver, the humming began again...

so...what do i do?

i followed the instructions from the denon book...the s video connects the satellite to the receiver, then the one RGB composite cord takes the video images to the TV from both the dvd player and the satellite...

should i hook up the satellite directly to the tv? if i do that, can i still run the sound through the receiver?

you've already been a big help, and i thank you and anxiously await your reply.

Marcus

[msherman]

more info on denon 1905

Jim,
the plug has three prongs...i also have a surge protector that you can run the two satellite lines into then with two separate returns, though i thought that would degrade the image...we have a 36 inch Toshiba that is HDTV ready, but we haven't gotten an HDTV receiver yet, if that helps at all.
Marcus

[jimmyp58]

There's a few different ways of hooking up video from a satellite receiver to a HT receiver/TV. The Denon book says one way. Another way is to simply take your s-video from your satellite and go directly to your tv. Then take your component from your dvd and go to the tv with this too (taking all video off the 1905. You can still take the sound from your satellite and go to your 1905 with it --- no problem there (take an optical from the satellite receiver to the 1905 and also take an analog cable (red and white) and go from the satellite receiver to the tv with this.

But that probably won't eliminatwe the hum. You probably have a coax cable from your wall to the satellite receiver, correct? That is probably where the hum is being introduced. Try the setup I just explained then remove the coax cable to see if the hum stops --- please report accordingly.

Jim

[msherman]

will check system tomorrow

Jim,
I will do as you recommend tomorrow and keep you up to date then
thanks for the help
Marcus

[jimmyp58]

Anytime Marcus....

Jim

[msherman]

The humming has stopped...

Jim,
well, i ran the s-video and RGB cords directly to the tv, and low and behold, the humming has stopped!!!
Thanks so much for your help.
What a relief that I can now use my system fully and not have an annoying hum.
Marcus

[jimmyp58]

Anytime Marcus....that is one of the true beauties of this wonderful forum!

Continued best of luck....

Jim

[Clive]

Good job JIM! :T