I have just ran a 14 gauge speaker wire for my subwoofer. I put 2
gold RCA plugs on either side of the cable. When I hook this into my
receiver's sub-out, then to the subwoofer, I get a low pitched hum
along with the sound from my receiver. The hum is very low in volume,
but still enough to be annoying. The cable run is about 35 feet from
the receiver and runs through my basement. There are other wires that
this sub line runs close to (but not right next to) like security
cables and 120Volt lines. Could this be causing it? What can I do to
get rid of this noise?

Thanks in advance!

Steve-o

In article LpRUb.107445$U%5.552904@attbi_s03,
Steve-o wrote:

I have just ran a 14 gauge speaker wire for my subwoofer. I put 2
gold RCA plugs on either side of the cable. When I hook this into my
receiver's sub-out, then to the subwoofer, I get a low pitched hum
along with the sound from my receiver. The hum is very low in volume,
but still enough to be annoying. The cable run is about 35 feet from
the receiver and runs through my basement. There are other wires that
this sub line runs close to (but not right next to) like security
cables and 120Volt lines. Could this be causing it? What can I do to
get rid of this noise?

I'm unclear as to whether your sub is a passive one (which gets all of
its drive power from the receiver), or an active one (which has its
own amp and power cord, and takes a low-level signal from the
receiver). The fact that you're mentioning RCA plugs suggests to me
that it's the latter, as these plugs are _not_ usually considered a
good choice for high-power audio connections.

If the subwoofer is an active one - you should really use a shielded
cable rather than 14-gauge speaker wire.

If it's a passive one, and is being driven by the amplifier - one
possibility is that the cable is picking up a _lot_ of hum from nearby
power wires. Separating the speaker and power wires as much as
possible (several feet) might help. This would, I think, be an
unusual situation.

Another possibility is that the hum is coming from the receiver
itself. Try this experiment: temporarily move the subwoofer to near
the receiver, and connect the two together with a short wire. If you
still hear hum in that situation, it's probably coming from the
receiver rather than via inductive pickup in the wiring.

A fairly common source of hum in A/V systems is a ground loop, caused
by a direct or indirect connection of a cable TV feed to the A/V
system. Quite often, cable-TV installations are not properly
grounded, and a voltage difference can develop between your A/V
system's ground (which is tied back to your house ground via the power
wiring) and the cable (which is probably grounded out by the street,
on the power pole, etc.). The best fix for this is an RF-type
ground loop isolator or "ground breaker" - basically a small isolation
transformer, which will pass the RF signal through the cable but block
the ground current. They're available from people like Parts Express,
and [I think] from Radio Shack. Disconnect cable-TV feed from the TV
set or receiver, connect the feed cable to the ground breaker, connect
the ground breaker to the TV or receiver. The TV should work, and the
hum should be greatly reduced or eliminated.

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

Steve-o wrote:
I have just ran a 14 gauge speaker wire for my subwoofer. I put 2
gold RCA plugs on either side of the cable. When I hook this into my
receiver's sub-out, then to the subwoofer, I get a low pitched hum
along with the sound from my receiver. The hum is very low in volume,
but still enough to be annoying. The cable run is about 35 feet from
the receiver and runs through my basement. There are other wires that
this sub line runs close to (but not right next to) like security
cables and 120Volt lines. Could this be causing it? What can I do to
get rid of this noise?

Thanks in advance!

Steve-o

Not clear on your setup...are you talking about line-level connections
or speaker-level connections? The latter would use speaker wire
(but most likely not RCA connectors) while the former would use
shielded interconnect cable + RCA connectors.

--

-S.

"They've got God on their side. All we've got is science and reason."
-- Dawn Hulsey, Talent Director

Is this a powered sub? If so, do not use speaker wire (parallel
cord); use coaxial interconnect which is shielded.

Kal

On Fri, 06 Feb 2004 18:54:35 GMT, (Steve-o) wrote:

I have just ran a 14 gauge speaker wire for my subwoofer. I put 2
gold RCA plugs on either side of the cable. When I hook this into my
receiver's sub-out, then to the subwoofer, I get a low pitched hum
along with the sound from my receiver. The hum is very low in volume,
but still enough to be annoying. The cable run is about 35 feet from
the receiver and runs through my basement. There are other wires that
this sub line runs close to (but not right next to) like security
cables and 120Volt lines. Could this be causing it? What can I do to
get rid of this noise?

Thanks in advance!

Steve-o

In article LpRUb.107445$U%5.552904@attbi_s03,
Steve-o wrote:
I have just ran a 14 gauge speaker wire for my subwoofer. I put 2
gold RCA plugs on either side of the cable. When I hook this into my
receiver's sub-out, then to the subwoofer, I get a low pitched hum
along with the sound from my receiver.

As expected. Most speaker wire is unshielded and there are weak magnetic
fields arround your 120V lines.

Use a more suitable cable like RG6. Or microphone wire, with the shield
connected only at the receiver end.

--
a href="http://www.poohsticks.org/drew/"Home Page/a
Life is a terminal sexually transmitted disease.