Houston Wire 2-conductor with shield question...

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I went to my local electrical supplier today to try and get a 1000'
spool of 2 conductor+shield wire for headphone cue runs and also for
general short run balanced wiring...sometimes 30ft or less microphone
runs or balanced line level runs.

They said that they did not carry west penn wire, but they carried
Houston Wire. They had 2conductor+shield 18 gauge (#HW58730).

2 questions:

1) I was curious if the "shield" surrounded the 2 conductors, but it
didnt... it just ran parallel with the other 2 conductors. Is this
OK? Why is it called a "shield" if it doesnt shield, but just runs
parallel?

2) Is the quoted price of $144.50 too much? A friend of mine told me
to expect around $70 for a 1000' spool of westpenn wire.


thx,
frenchy

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Houston Wire 2-conductor with shield question...

Group: rec.audio.pro Date: Mon, Nov 22, 2004, 12:57pm From:
frenchy*NO*@*SPAM*houseofharmonystudios.com (they call me frenchy)
I went to my local electrical supplier today to try and get a 1000'
spool of 2 conductor+shield wire for headphone cue runs and also for
general short run balanced wiring...sometimes 30ft or less microphone
runs or balanced line level runs.
They said that they did not carry west penn wire, but they carried
Houston Wire. They had 2conductor+shield 18 gauge (#HW58730).
2 questions:

1) I was curious if the "shield" surrounded the 2 conductors, but it
didnt... it just ran parallel with the other 2 conductors. Is this OK?
Why is it called a "shield" if it doesnt shield, but just runs parallel?
2) Is the quoted price of $144.50 too much? A friend of mine told me to
expect around $70 for a 1000' spool of westpenn wire.
thx,
frenchy<<<<<<<<<<<<<<<<<

18ga is kind of heavy for your purposes. What he showed you is 2
conductor with a ground wire and maybe a foil cover over everything.

That type of construction is ok for permenent installs but not for
cables that are going to be flexed a lot.

Look for proper 2 conductor shielded microphone cable. Try
www.markertek.com.

Eric

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On 22 Nov 2004 13:54:36 -0500, kludge@panix.com (Scott Dorsey) wrote:

>>They said that they did not carry west penn wire, but they carried
>>Houston Wire. They had 2conductor+shield 18 gauge (#HW58730).
>
>That's probably a little better-made than the West Penn stuff.

So youve heard of Houston Wire? Do you know that it is better made
than WestPenn or is that speculation? The other local electrical
supplier stocks Genesis cable and quoted me $98.08 for a 1000' spool
(P/N:1214).

Doing a deja search doesnt turn up anything with regards to these
brands, let alone a meaningful quality comparison. I guess I am just
skeptical of buying these unknown brands as opposed to standard Belden
or WestPenn....but on the other side of the coin, could headphone cues
really sound that much different when in the end it is still 18AWG
2-conductor with shield? Should I be asking for spec sheets of some
kind?

attempting to be an informed installer who supports local electrical
suppliers,
frenchy

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they call me frenchy <frenchy*NO*@*SPAM*houseofharmonystudios.com> wrote:
>On 22 Nov 2004 13:54:36 -0500, kludge@panix.com (Scott Dorsey) wrote:
>
>>>They said that they did not carry west penn wire, but they carried
>>>Houston Wire. They had 2conductor+shield 18 gauge (#HW58730).
>>
>>That's probably a little better-made than the West Penn stuff.
>
>So youve heard of Houston Wire? Do you know that it is better made
>than WestPenn or is that speculation? The other local electrical
>supplier stocks Genesis cable and quoted me $98.08 for a 1000' spool
>(P/N:1214).

I have used the Houston stuff, and it's nothing to write home about,
but it's more flexible than the West Penn stuff. Note that the shield
will not carry much current; it's a shield and not a current-carrying
member. You don't want to use this for headphones where the ground
impedance needs to be low.

I have never used the Genesis cable.

>Doing a deja search doesnt turn up anything with regards to these
>brands, let alone a meaningful quality comparison. I guess I am just
>skeptical of buying these unknown brands as opposed to standard Belden
>or WestPenn....but on the other side of the coin, could headphone cues
>really sound that much different when in the end it is still 18AWG
>2-conductor with shield? Should I be asking for spec sheets of some
>kind?

No, you should be asking how flexible it is. Buy the cable that is
most flexible. Buy unshielded 18/3 or 18/4.

>attempting to be an informed installer who supports local electrical
>suppliers,

You might try Graybar if you have a local one.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

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In article <vqn4q05ih8ph9ceseounhfn9b8kjeod96n@4ax.com> frenchy*NO*@*SPAM*houseofharmonystudios.com writes:

> Doing a deja search doesnt turn up anything with regards to these
> brands, let alone a meaningful quality comparison. I guess I am just
> skeptical of buying these unknown brands as opposed to standard Belden
> or WestPenn....but on the other side of the coin, could headphone cues
> really sound that much different when in the end it is still 18AWG
> 2-conductor with shield?

Is this a line level signal (to a headphone amplifier) or the
headphone level signal (from a headphone amplifier through 50 feet to
the headphones)? Either way, 22 gage should do fine. Headphones aren't
like speakers and only need a couple of hundred milliwatts, maybe
50 mA for your average 100 ohm headphones.

I can see that you're tempted to use two conductor shielded cable for
headphones because it has the right number of conductors if you
count the shield, but a shield isn't really intended to carry current, and
it's carrying the current of both phones. I doubt that you'd have a disaster
if you used it in this application - I have run headphones through a 150
foot mic snake and theyv'e sounded just fine for musicians' cues, but
there are some technical reasons to use something else.

If this isn't for a portable setup you might consider using Cat5 Ethernet
cable. That's as cheap as dirt and it's four pairs of #24 wire. Use a pair
for each phone and two pairs for the common and you should be able
to melt eardrums.


--
I'm really Mike Rivers (mrivers@d-and-d.com)
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

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On Mon, 22 Nov 2004 17:48:44 -0500, Audioetc@webtv.net (Eric Toline)
wrote:

>How loud is loud and what guage cable comes attached to your headphones?
>Bet it's a lot thinner than 18 ga.

Standard loudness for a drummer or bass player to have his headphones
cranking while tracking. Sure headphone internal wiring is small, but
they are not running 50ft nor even 50inches.

>
>
>Microphones don't really care but depending on what connectors you're
>using the heavier guage could be a problem. All of my mic cables are 20
>or 22 gauge Canare star quad.
>
>Eric

Is it true that the 18awg has a higher capacitance per foot and
therefore is less suited for microphone applications? I'll probably
just use 22awg and be done with it. The headphones wont really
care...its the mics which are the most critical link anyway.

thx,
frenchy

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On 22 Nov 2004 21:06:54 -0500, mrivers@d-and-d.com (Mike Rivers)
wrote:

>Is this a line level signal (to a headphone amplifier) or the
>headphone level signal (from a headphone amplifier through 50 feet to
>the headphones)?
It is the signal from the headphone amp to the headphones. I have my
headphone amp located in my recording rack and I control everyones cue
level from my magic seat.


>Either way, 22 gage should do fine. Headphones aren't
>like speakers and only need a couple of hundred milliwatts, maybe
>50 mA for your average 100 ohm headphones.
>
>I can see that you're tempted to use two conductor shielded cable for
>headphones because it has the right number of conductors if you
>count the shield, but a shield isn't really intended to carry current, and
>it's carrying the current of both phones.

I am noticing that there is something funny going on with what these
cables are called vs what is really inside them. Above you call them
"two conductor shielded", but inside of them is 2conductors, the foil
shield AND a drain wire which does have the ability to carry current.

For microphones, the drain wire is connected to pin1. Not sure how
the shield foil gets grounded, because you certainly dont solder the
shield foil on either end, so the uninsulated drain wire must just
make electrical contact with the foil shield during some parts of the
cable run. In this application no current flows in the shield foil
nor the drain wire except for ground loops, right?

For headphones, the foil shield is not necessary, nor can it carry
current, which was your above point, BUT the drain wire absolutely is
necessary and CAN carry current back from the headphone drivers. But
as scott pointed out, it must carry the current for both the L and R
drivers, but it is only as thick as the others...which is a
limitation....thus your cat5 idea below.

> I doubt that you'd have a disaster
>if you used it in this application - I have run headphones through a 150
>foot mic snake and theyv'e sounded just fine for musicians' cues, but
>there are some technical reasons to use something else.
>
>If this isn't for a portable setup you might consider using Cat5 Ethernet
>cable. That's as cheap as dirt and it's four pairs of #24 wire. Use a pair
>for each phone and two pairs for the common and you should be able
>to melt eardrums.

Now that is an excellent idea because I will be buying a spool of it
anyway. Lets take a look at this further. You say 4 pairs of 24awg
wire....

Pair1a Headphone1 L+
Pair1b Headphone1 R+
Pair2a Headphone2 L+
Pair2b Headphone2 R+
Pair3a Headphone1 COM
Pair3b Headphone1 COM
Pair4a Headphone2 COM
Pair4b Headphone2 COM

So now the current load is split equally amongst the available wires.
All send paths have an equally "wide" return path. the only negative
that I see is that now each wire is only 24awg...but I guess this is
better than trying to jam two returns thru one 22AWG or 18AWG wire.

I knew I came here for a reason. I was trying to be a thrifty shopper
and use a 1000' spool for 2 different reasons. Looks like I will be
using Cat5 cable for 2 different reasons....and just get the best
microhpone cable for mic sends and balanced line level sends.

Thx for your help. Last thought...can I use cat5 for gigabit
ethernet...or is it limited to 100Mbps ethernet?

thx,
frenchy

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In article <1117q0tmbec9a8sgmodgoj7nvvr9v71re5@4ax.com> frenchy*NO*@*SPAM*houseofharmonystudios.com writes:

> I am noticing that there is something funny going on with what these
> cables are called vs what is really inside them. Above you call them
> "two conductor shielded", but inside of them is 2conductors, the foil
> shield AND a drain wire which does have the ability to carry current.

That's what we call two-conductor shielded cable. Sure, the shield and
drain wire can carry current but they aren't supposed to. The shield
is supposed to be just that - a shield. The reason for the drain wire
is so that you can connect the shield to the box (through the
connector) so you have a continuous shield - one box, another box, and
the shield of the wire connecting them. That's what keeps goblins out.

> For microphones, the drain wire is connected to pin1. Not sure how
> the shield foil gets grounded, because you certainly dont solder the
> shield foil on either end

The shield is in physical contact with the drain wire so they're also
electrically connected. The reason for the drain wire is because you
can't solder to the foil shield. Wire with a braided shield may or may
not have a drain wire. If it doesn't, you just unbraid the shield a
bit at the end and solder to that. Or you use crimp connections on the
shield.

> In this application no current flows in the shield foil
> nor the drain wire except for ground loops, right?

That's correct (and of course you shouldn't have a ground loop). This
is why the shield or drain isn't designed to any particular current
carrying specification.

> For headphones, the foil shield is not necessary, nor can it carry
> current, which was your above point, BUT the drain wire absolutely is
> necessary and CAN carry current back from the headphone drivers.

Well it doesn't matter which you consider to be the current carrier,
and in fact the shield and drain are electrically in parallel, so they
both carry some current.

> Now that is an excellent idea because I will be buying a spool of it
> anyway. Lets take a look at this further. You say 4 pairs of 24awg
> wire....
>
> Pair1a Headphone1 L+
> Pair1b Headphone1 R+
> Pair2a Headphone2 L+
> Pair2b Headphone2 R+
> Pair3a Headphone1 COM
> Pair3b Headphone1 COM
> Pair4a Headphone2 COM
> Pair4b Headphone2 COM

Well, I was thinking more along the lines of
Pair 1A - Headphone L
Pair 1B - Headphone Common
Pair 2A - Headphone R
Pair 2B - Headphone Common

etc.

That way, you'll maintain pairs and if you're going to run two sets of
headphones through the cable, you might get a little less crosstalk by
using a pair per headphone (headphone and common) rather than using a
pair for right and left, and another pair doubled up for the common.
Twisted pairs tend to work that way, but it might not be significant.

> I knew I came here for a reason. I was trying to be a thrifty shopper
> and use a 1000' spool for 2 different reasons. Looks like I will be
> using Cat5 cable for 2 different reasons....and just get the best
> microhpone cable for mic sends and balanced line level sends.

According to Steve Lampen of Belden, their Cat5e or Cat6 cable makes
great balanced line level cable if you can live without the shield
(which you should be able to do at line levels if your inputs and
outputs are balanced). In fact, Steve's talking to a manufacturer
about making adapters with a DB25 on one side and two RJ45s on the
other, for connecting DB25-based 8-channel devices using two pieces of
Ethernet cable with standard RJ45 connectors.

> Thx for your help. Last thought...can I use cat5 for gigabit
> ethernet...or is it limited to 100Mbps ethernet?

I'm not a networ person, but I know that as the speed goes up, so do
the numbers. I'd use Cat6 for gigabit, but I imagine someone with
network smarts knows for sure.

--
I'm really Mike Rivers (mrivers@d-and-d.com)
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

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>> For microphones, the drain wire is connected to pin1. Not sure how
>> the shield foil gets grounded, because you certainly dont solder the
>> shield foil on either end
>
>The shield is in physical contact with the drain wire so they're also
>electrically connected. The reason for the drain wire is because you
>can't solder to the foil shield. Wire with a braided shield may or may
>not have a drain wire. If it doesn't, you just unbraid the shield a
>bit at the end and solder to that. Or you use crimp connections on the
>shield.
>
>> In this application no current flows in the shield foil
>> nor the drain wire except for ground loops, right?
>
>That's correct (and of course you shouldn't have a ground loop). This
>is why the shield or drain isn't designed to any particular current
>carrying specification.

Can I play devil's advocate regarding the ground loop when connecting
two different pieces of line level gear using balanced mic cable...

I am testing my understanding, lemme know if my logic is flawed...

By definition you create a ground loop because the gear on each side
is each connected to ground through the AC safety ground which should
never be lifted....then the gear is connectected together by the drain
wire that we have been speaking about (pin1)...so by definition we
have created an intentional ground loop....intentionally violating the
rule that I have heard Scott Dorsey say before that each peice of gear
should have one and only one path to ground.

....So now that we have intentionally created this ground loop...the
problem will or will not be noticed depending on whether current flows
in this ground loop. If the gear is each on the same AC circuit, then
there is no reason for current to flow because the grounds are at the
same potential. If the gear is on separate circuits (which they very
well could be in a medium sized studio with different rooms and lots
of gear), then the two different circuits must each go directly to the
same electrical distribution box and share the same Low impedance path
to earth from there...in which case no ground current flows and no
problem exists...even though we have intentionally soldered a ground
loop together. An audible problem exists when the two different
circuits do not share the same low impedance path to earth. This
discussion doesnt even account for the fact that some gear throws
nasty stuff onto the ground lines and causes audible noise even if the
wiring is proper.

Is this correct?
I am re-wiring my studio all the time and as I learn more, I do it
different each time. I keep adding more gear and more rooms, so I
cant run everything on the same circuit anymore like I used to.

thank you very much,
frenchy

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In article <bci9q0pej05hqd3nchpd0bhu5v9qbd7uhd@4ax.com> frenchy*NO*@*SPAM*houseofharmonystudios.com writes:

> Can I play devil's advocate regarding the ground loop when connecting
> two different pieces of line level gear using balanced mic cable...
>
> I am testing my understanding, lemme know if my logic is flawed...

Oh, you can always screw up a good thing, but if the two pieces are
properly designed, there won't be a ground loop.

> By definition you create a ground loop because the gear on each side
> is each connected to ground through the AC safety ground which should
> never be lifted....then the gear is connectected together by the drain
> wire that we have been speaking about (pin1)...so by definition we
> have created an intentional ground loop....intentionally violating the
> rule that I have heard Scott Dorsey say before that each peice of gear
> should have one and only one path to ground.

This is where the "properly designed" comes in. The safety ground and
the shield should be tied together at a single point inside the box.
If the shield is connected to pin 1, which goes through a meandering
circuit board trace, eventually finding its way to the ground
(reference) point on the power supply, and if the safety ground wire
is just attached to a convenient screw inside the chassis, then you
have what's known as "The Pin 1 Problem." This can be fixed.

You get to make the assumption that two power cords plugged into
adjacent outlets have the safety ground at the same potential. And
if the shield is connected to the same point, it's at the same
potential, hence no ground loop current. It's not perfect, but it's a
lot closer than random or haphazard ground connections in equipment as
was prevalent in the early "semi pro" days.



--
I'm really Mike Rivers (mrivers@d-and-d.com)
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

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: So, since Cat5 cable is 24awg, is this wire big
enough for a
: send/return for a headphone channel? Per your above,
you would have
: 24AWG sending Headphone #1 L and 24AWG returning
Headphone #1 L.

This rather delux headphone system hooks with cat5
http://www.musiciansfriend.com/srs [...] id/241501/

Phil Abbate
:

Archived from groups: rec.audio.pro (More info?)

<< So, since Cat5 cable is 24awg, is this wire big
enough for a
: send/return for a headphone channel? Per your above,
you would have
: 24AWG sending Headphone #1 L and 24AWG returning
Headphone #1 L.>

<This rather delux headphone system hooks with cat5 <snip link to Furman HDS6
system>

The Furman HDS6 does not send amplified headphone levels down the Cat5 cables.
The master unit sends line level audio & DC voltage to the remote submixer
units which amplify the signal.

Scott Fraser

Archived from groups: rec.audio.pro (More info?)

In article <1102600140.616003.55000@f14g2000cwb.googlegroups.com> tymish@hotmail.com writes:

> Aye but you can get sheilded CAT5.

I've seen it with an overall shield (not sure what this is called) but
not with individually shielded pairs.

Does overally shielding make any difference in the performance of the
cable for audio?

--
I'm really Mike Rivers (mrivers@d-and-d.com)
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

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Mike Rivers wrote:
> In article <1102600140.616003.55000@f14g2000cwb.googlegroups.com> tymish@hotmail.com writes:
>
>
>> Aye but you can get sheilded CAT5.
>
>
> I've seen it with an overall shield (not sure what this is called)

CAT5 STP


> not with individually shielded pairs.

Dunno if AES benefits the way T-1 does from combining all the TX and RX in separate shielded bundles.




> Does overally shielding make any difference in the performance of the
> cable for audio?

Depends on the kind of interference you have about (but you know this.)