Subwoofer hum with no grounds?

Loth wrote:

You were right, I plugged it into the tape output and it started
playing music. So the sub outs are just bad - it's so strange to me
that both of them went bad together.

I guess we'll just have to save up and get a new receiver to use the
subwoofer. Not the best news, but something we were probably going to
do someday anyway.

By the way, I love your sig. I've always liked that quote.


Hi Loth.

The sub outs are in parallel, so whatever happens [or doesn't] in
one happens in the other.

I wouldn't be so quick to condemn the receiver however.
It's entirely possible the subwoofer outs are disabled or level set to
zero in the menu.

I downloaded the user manual from Onkyo, but it's a lot easier if
you have the unit in front of you at the same time. Sit down with the
manual and go over every setting that has anything to do with the
subwoofer and/or LFE channel. Don't be afraid to simply play with it.

I just gave it a quick scan, but it looked like the system setup
menu gives the option of setting the subwoofer parameter to 'NO'.
I don't recall you mentioning how high you had the gain control on
the sub when you heard the hum, but if it was maxed, that may well be
normal if there's no signal present.

I stole that sig from another Usenet poster close to twenty years
ago. It's my alltime favorite. :-)

--
-Gandalf

Never meddle in the affairs of a dragon for you are crunchy and taste
good with ketchup!

Bill wrote:

If your receiver has pre-amp outputs, you can use one of them for the
sub. The mid and high frequencies will be filtered and ignored by the
sub, but the bass will be passed along to the sub. It usually won't
really matter if you use left or right main because both will have the
same bass frequencies in most tracks, but to be sure you can buy a $5
Y-cable and blend the left/right signals into the sub.

It looks like the Onkyo only has pre-out/main-in.
Not only would that make wiring weird, it would likely combine the front
left and right speakers into mono as well.

Aside from that, there would be no LFE channel at all, although I
suppose *any* sound from the sub would be better than none.

Afterall, isn't that the whole concept behind Bose? ;-)

--
-Gandalf

Never meddle in the affairs of a dragon for you are crunchy and taste
good with ketchup!

"Gandalf" wrote in message
.. .
Bill wrote:

If your receiver has pre-amp outputs, you can use one of them for the
sub. The mid and high frequencies will be filtered and ignored by the
sub, but the bass will be passed along to the sub. It usually won't
really matter if you use left or right main because both will have
the same bass frequencies in most tracks, but to be sure you can buy
a $5 Y-cable and blend the left/right signals into the sub.

It looks like the Onkyo only has pre-out/main-in.
Not only would that make wiring weird, it would likely combine the
front left and right speakers into mono as well.

If the sub has left/right low level in/out then it would work perfectly,
shunting the bass to the sub and higher frequencies to the main
speakers.

Aside from that, there would be no LFE channel at all, although I
suppose *any* sound from the sub would be better than none.

Doesn't the receiver have bass management? If so, the LFE can usually be
directed to the main speaker lines, and the pre-out/main-in lines would
shunt all of the bass including the LFE channel sounds to the sub.

I don't use a sub anymore, but my receiver is setup to direct all bass
to the front main speakers and that includes the bass from the LFE
channel.

Afterall, isn't that the whole concept behind Bose? ;-)

No. Bose uses similar principles, but lies about the results.

:-)

On Jan 11, 9:57 pm, Gandalf wrote:

The sub outs are in parallel, so whatever happens [or doesn't] in
one happens in the other.

I wouldn't be so quick to condemn the receiver however.
It's entirely possible the subwoofer outs are disabled or level set to
zero in the menu.

I've messed with the menu a lot. Currently the subwoofer is set to
'off', but that's so we can get bass from the regular speakers. I
played with the settings while it was on, and there was no response
from the woofer.

The hum goes up & down with the gain, it's something you hear even when
it's only on a little.

Most of this is over my head, but if you tell me what I should plug in
where I'd be happy to try it.

"Loth" wrote in message
oups.com...
Most of this is over my head, but if you tell me what I should plug in
where I'd be happy to try it.

We can't tell you exactly which cable and where because we don't know
the source yet. But try reading this for info:

http://forum.ecoustics.com/bbs/messa...79/180767.html

wrote:
As a christmas present for ourselves, my husband and I bought a new set
of speakers - nothing fancy, but nicer than our stereo setup. We got
the yamaha NS-SP5700 5.1 surround sound system from Best Buy and hooked
it up to our hand-me-down Onkyo TX-DS939 receiver.

All the speakers work fine, but the subwoofer produced a humming noise
and no other sound. We returned it, but the new one has the same
problem, so we're assuming now that it's something other than the
woofer.

Here's what I know so far: the humming goes up and down when I turn the
volume knob on the subwoofer, stops when I unplug it from the back of
the receiver, but doesn't when the receiver is turned off. It's a
louder buzzing than the buzzing that happens when I touch the wire with
my finger. I tried using a different cable for the subwoofer but it
still buzzed. There's only one input on the back of the subwoofer, and
the receiver is capable of handling 2 subwoofers but switching the cord
from one to the other made no difference.

Neither the subwoofer nor the receiver have a grounded plug, and the
outlets in our house aren't grounded(except for the computer room).
The rest of our setup includes a TV, VCR, Tivo with cable, PS2 and
Gamecube. Everything but the subwoofer is plugged into a power strip,
the woofer is plugged into a different outlet but plugging it into the
power strip didn't fix it. The room has dimmer lights, but I'm not
sure exactly why that's a problem except that a few troubleshooting
guides mentioned that that might make a difference.

All the guides I've seen for people with my problem say that it's
almost positively a grounding feedback thing, but since nothing in this
setup has grounded plugs I'm at a loss. The only option that sounds
feasible is that maybe my cable connection is doing something, but how
would I test for that or fix it? I tried moving all my speaker cables
and power cords away from the cable but it still buzzed.

We'd really like to use the .1 of our new system, so if anybody has any
ideas we're all ears.

told you i would help you solve this
if you e mail
the hecklers here are a pain.

this is a real pain in the ass
you keep editing the letters out
of my e mail address
mykey mykey 01 @ yahoo.com
you have done so in my profile too.
why dont you let us communicate?

wrote in message
ps.com...
this is a real pain in the ass
you keep editing the letters out
of my e mail address
mykey mykey 01 @ yahoo.com
you have done so in my profile too.
why dont you let us communicate?


Eh? Just who do you think is editing this out, and who in the hell are you
talking to? Are you so completely clueless that you don't know that blank
spaces are not allowed in a lot of web/net based and other computer
applications? You must be if you chose an e-mail address with spaces in it
to start with. Just because Mac or Windows allows you to name files with
spaces doesn't mean that the underlying infrastructure of the net, developed
on Unix and carried forward from the Dark Ages of computerdom, will perform
the same way. Some databases and applications won't even let you use a "-"
instead of a "_" in an email address.

I guess it's all a conspiracy against you. But hey, if you still can't
figure out how to use a caps key, what should we expect of you.