| Author |
Message |
Al Dykes
Guest
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 Posted:
Tue Aug 30, 2005 4:20 pm Post subject:
Re: Coaxial vs CAT 5 |
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In article <Sj_Qe.32$ZL4.25@newssvr12.news.prodigy.com>,
Robert Redelmeier <redelm@ev1.net.invalid> wrote:
| Quote: | James Knott <james.knott@rogers.com> wrote:
As for those "Golden Ears" types, don't you know that their ears are
so good, that they can hear things that are physically impossible
to hear? A few years ago, there was a columnist (Larry Klien IIRC)
in Radio Electronics magazine, who'd occasionally take aim at those
Golden Ear types. Seems some of them can listen to two different
audio systems, in different environments at different times and tell
which one sounds best, but they also reject A-B tests as invalid.
Well, for them hearing has passed from a sensory experience into
a psychological experience. Perhaps a religious experience.
In a free country, we really should respect other religions,
even if we don't much believe them.
They're also the idiots who tend to buy stuff such as
Monster cables and other such junk.
Monster cables are not junk. They're usually fairly decent
midrange cables but sold at outrageous prices with the most
appalling pseudoscience flim-flam.
|
Agreed. The speaker cables are vastly overpriced. OTOH I find the
price for a Monster "patch cord" pair, well made, with heavy gold
plated RCA plugs (4 of them) for $20 or so not unreasonable. It's
been years since I needed to buy any.
I use their gold plated spade lugs and bannana plugs for the same reason.
--
a d y k e s @ p a n i x . c o m
Don't blame me. I voted for Gore. |
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Robert Redelmeier
Guest
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| Posted:
Tue Aug 30, 2005 4:20 pm Post subject:
Re: Coaxial vs CAT 5 |
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James Knott <james.knott@rogers.com> wrote:
| Quote: | As for those "Golden Ears" types, don't you know that their ears are
so good, that they can hear things that are physically impossible
to hear? A few years ago, there was a columnist (Larry Klien IIRC)
in Radio Electronics magazine, who'd occasionally take aim at those
Golden Ear types. Seems some of them can listen to two different
audio systems, in different environments at different times and tell
which one sounds best, but they also reject A-B tests as invalid.
|
Well, for them hearing has passed from a sensory experience into
a psychological experience. Perhaps a religious experience.
In a free country, we really should respect other religions,
even if we don't much believe them.
| Quote: | They're also the idiots who tend to buy stuff such as
Monster cables and other such junk.
|
Monster cables are not junk. They're usually fairly decent
midrange cables but sold at outrageous prices with the most
appalling pseudoscience flim-flam.
-- Robert |
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James Knott
Guest
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| Posted:
Tue Aug 30, 2005 4:20 pm Post subject:
Re: Coaxial vs CAT 5 |
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glen herrmannsfeldt wrote:
| Quote: | Robert Redelmeier wrote:
Al Dykes <adykes@panix.com> wrote:
isn't anyone concerned with high-end rolloff for
audio on UTP due to the capacitance ?
LOL! Do you think we have Golden Ears? Odd "capacitance"
that doesn't affect 100 MHz would somehow disturb 10kHz.
If you drive it with a 100 ohm source, then yes, but most line
outputs are 1000 ohms or so. 15pF/ft and 300ft is 4500pf.
4500pF*1000ohms is 4.5us, f=1/(2pi*4.5us)=100kHz, will have
some rolloff at 20kHz.
Telephone wiring uses 600 ohm source impedance and longer
wires. The parallel capacitance is balanced by series inductors
spaced out along the cable.
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Actually, telephone cable has appreciable rolloff within the voice
frequencies, which is why loading coils are used when going significant
distances. The coils flatten the attenuation within the desired bandwidth,
at the expense of higher frequencies. However I doubt that roll off would
be significant at the distances used in a home.
As for those "Golden Ears" types, don't you know that their ears are so
good, that they can hear things that are physically impossible to hear? A
few years ago, there was a columnist (Larry Klien IIRC) in Radio
Electronics magazine, who'd occasionally take aim at those Golden Ear
types. Seems some of them can listen to two different audio systems, in
different environments at different times and tell which one sounds best,
but they also reject A-B tests as invalid. They're also the idiots who
tend to buy stuff such as Monster cables and other such junk. |
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James Knott
Guest
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| Posted:
Tue Aug 30, 2005 9:22 pm Post subject:
Re: Coaxial vs CAT 5 |
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Al Dykes wrote:
| Quote: | Jeeesh, this thread came back from the dead. When people ask about
using telco wire for HiFi speakers (amps into a low impedance) is
making a mistake and it's possible to show rolloff, IMO. (I use 12 ga
stranded power tool extension cord wire cut to length. It comes in
pretty colors and handles nicely and is cheap.)
|
One thing pointed out by Larry Klien, was that for most purposes, ordinary
lamp cord was fine for connecting speakers. Anything else is a waste of
money. However I'd suspect using telephone cable or CAT 5 might have
resistance loss issues, when handling low impedance loads, over significant
distances. |
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James Knott
Guest
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| Posted:
Tue Aug 30, 2005 9:24 pm Post subject:
Re: Coaxial vs CAT 5 |
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Robert Redelmeier wrote:
| Quote: | Monster cables are not junk. They're usually fairly decent
midrange cables but sold at outrageous prices with the most
appalling pseudoscience flim-flam.
|
When defining "junk" I guess it's best to consider cost/value. The higher
the ratio, the more likely it's junk. ;-)
Bottom line, are you getting value for money? |
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James Knott
Guest
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| Posted:
Tue Aug 30, 2005 9:27 pm Post subject:
Re: Coaxial vs CAT 5 |
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Al Dykes wrote:
| Quote: | Agreed. The speaker cables are vastly overpriced. OTOH I find the
price for a Monster "patch cord" pair, well made, with heavy gold
plated RCA plugs (4 of them) for $20 or so not unreasonable. It's
been years since I needed to buy any.
I use their gold plated spade lugs and bannana plugs for the same reason.
|
That gold plating is another issue. If gold is so good (yes, I know it
doesn't tarnish) why are low noise instrumentation connectors made with
silver plating? Does the gold actually improve anything, other than
vendors profit? |
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Robert Redelmeier
Guest
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| Posted:
Tue Aug 30, 2005 10:53 pm Post subject:
Re: Coaxial vs CAT 5 |
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James Knott <james.knott@rogers.com> wrote:
| Quote: | When defining "junk" I guess it's best to consider cost/value.
The higher the ratio, the more likely it's junk. ;-)
Bottom line, are you getting value for money?
|
I don't think "junk" has any element of cost/value.
It seem to more equate to "garbage" -- low absolute value.
High-end sports cars definitely are not "junk",
but often have high cost per unit value.
-- Robert
> |
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Robert Redelmeier
Guest
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| Posted:
Tue Aug 30, 2005 11:02 pm Post subject:
Re: Coaxial vs CAT 5 |
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James Knott <james.knott@rogers.com> wrote:
| Quote: | One thing pointed out by Larry Klien, was that for most
purposes, ordinary lamp cord was fine for connecting speakers.
Anything else is a waste of money.
|
It is. My slight concern with lampcord is it can pick up 60 Hz
hum from any nearby powerfeeds (even in wall). So it should be
kept away from power, cross at right angles or be lazy-twisted.
| Quote: | However I'd suspect using telephone cable or CAT 5 might
have resistance loss issues, when handling low impedance
loads, over significant distances.
|
It does. Do not use Cat5 for low-ohm speakers if you want
decent volume.
-- Robert |
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Robert Redelmeier
Guest
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| Posted:
Wed Aug 31, 2005 12:44 am Post subject:
Re: Coaxial vs CAT 5 |
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James Knott <james.knott@rogers.com> wrote:
| Quote: | That gold plating is another issue. If gold is so good (yes,
I know it doesn't tarnish) why are low noise instrumentation
connectors made with silver plating?
|
The silver might be cheaper, or better for high currents.
I don't see silver often.
| Quote: | Does the gold actually improve anything, other than vendors
profit?
|
Yes. Why are RJ IDC teeth and contacts gold? Why are CPU
pins gold? Why are RAM module and PCI/AGP sockets gold?
Because they don't tarnish (form non-conductive oxides)
and form reliable connections.
Once upon a time, all of these internal PC connectors were
tin. Specially designed to penetrate the oxide layers.
Gold is cheaper, particularly considering reliability.
-- Robert |
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Al Dykes
Guest
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| Posted:
Wed Aug 31, 2005 12:58 am Post subject:
Re: Coaxial vs CAT 5 |
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In article <cG2Re.124$ZL4.80@newssvr12.news.prodigy.com>,
Robert Redelmeier <redelm@ev1.net.invalid> wrote:
| Quote: | James Knott <james.knott@rogers.com> wrote:
That gold plating is another issue. If gold is so good (yes,
I know it doesn't tarnish) why are low noise instrumentation
connectors made with silver plating?
The silver might be cheaper, or better for high currents.
I don't see silver often.
Does the gold actually improve anything, other than vendors
profit?
Yes. Why are RJ IDC teeth and contacts gold? Why are CPU
pins gold? Why are RAM module and PCI/AGP sockets gold?
Because they don't tarnish (form non-conductive oxides)
and form reliable connections.
Once upon a time, all of these internal PC connectors were
tin. Specially designed to penetrate the oxide layers.
Gold is cheaper, particularly considering reliability.
-- Robert
|
One of my pet peeves has been the quality of connections on the
speaker circuit. People spend $x,000 bucks on a 200w amp and speakers
and they find that they have cheapo 5-way bannana jacks that *can't*
be torqued enough to break the oxide layer IMO, and gold doesn't have
that problem.
I once measured the voltage drop across all 8 commections in a stereo
setup with a millivolt DMV and found it was *very* hard to get a low
resistance connection. Add 4 crappy connections in series with too
much 18ga wire connected to a 4ohm speaker and you're not getting your
money's worth. I think the worst connection I saw was .5 ohm and with
dynamic music i guess you've got spikes in the amps range. I was
measuring voltage drop with a .5 amp 400 Hz tone. (*loud*)
The gold spade lugs are nice but the area pressure on a bannana jack
is not enough to bake a really goot connection, IMO. At least on the
equipment I've had.
/end of rant/
--
a d y k e s @ p a n i x . c o m
Don't blame me. I voted for Gore. |
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James Knott
Guest
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| Posted:
Wed Aug 31, 2005 2:11 am Post subject:
Re: Coaxial vs CAT 5 |
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Robert Redelmeier wrote:
| Quote: | James Knott <james.knott@rogers.com> wrote:
That gold plating is another issue. If gold is so good (yes,
I know it doesn't tarnish) why are low noise instrumentation
connectors made with silver plating?
The silver might be cheaper, or better for high currents.
I don't see silver often.
|
Silver is the best conductor and makes good contact in connectors.
| Quote: |
Does the gold actually improve anything, other than vendors
profit?
Yes. Why are RJ IDC teeth and contacts gold? Why are CPU
pins gold? Why are RAM module and PCI/AGP sockets gold?
Because they don't tarnish (form non-conductive oxides)
and form reliable connections.
|
When I asked that question, I was referring to audio cables etc., as per the
discussion. Computer chips have their own issues, low noise isn't one of
them.
| Quote: |
Once upon a time, all of these internal PC connectors were
tin. Specially designed to penetrate the oxide layers.
Gold is cheaper, particularly considering reliability.
-- Robert |
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James Knott
Guest
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| Posted:
Wed Aug 31, 2005 2:14 am Post subject:
Re: Coaxial vs CAT 5 |
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Robert Redelmeier wrote:
| Quote: | When defining "junk" I guess it's best to consider cost/value.
The higher the ratio, the more likely it's junk. ;-)
Bottom line, are you getting value for money?
I don't think "junk" has any element of cost/value.
It seem to more equate to "garbage" -- low absolute value.
High-end sports cars definitely are not "junk",
but often have high cost per unit value.
|
Well, you could at one time spend a few thousand dollars on a Yugo... ;-)
One thing I often see, are people with spoilers etc., on the back end of a
Honda or Nissan. I wonder how much "value" they bring. ;-) |
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Robert Redelmeier
Guest
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| Posted:
Wed Aug 31, 2005 2:36 am Post subject:
Re: Coaxial vs CAT 5 |
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James Knott <james.knott@rogers.com> wrote:
| Quote: | Silver is the best conductor and makes good contact in
connectors.
|
Yes, it is the best conductor on a volumetric basis. Copper is
close, and aluminum is best on a weight basis. But Copper,
Silver and Aluminum easily form oxides which may outweigh their
conductivity advantage, particularly in thin layers. Gold has
only 40% more vol.resist than silver. But silver is much more
solderable.
| Quote: | When I asked that question, I was referring to audio cables
etc., as per the discussion. Computer chips have their
own issues, low noise isn't one of them.
|
Well, "noise" is hardly a precise term. Impedence discontinuities
affect all circuits, particularly high frequencies. I would think
audio requires good current capabilities, while computer circuitry
needs clean transmission of extremely high frequencies.
-- Robert |
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David Ross
Guest
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| Posted:
Wed Aug 31, 2005 8:20 am Post subject:
Re: Coaxial vs CAT 5 |
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James Knott wrote:
| Quote: | That gold plating is another issue. If gold is so good (yes, I know it
doesn't tarnish) why are low noise instrumentation connectors made with
silver plating? Does the gold actually improve anything, other than
vendors profit?
|
You can put down a gold plating about 4 molecules thick. I'm guessing
connectors do it a bit thicker but that uses very little gold. I wonder
if silver can be done that thin.
This could all change. Here's what I was told by someone who should
know. I recently learned that Kodak plans to stop making B&W film. And
that accounts for about 1/2 of the world's use of silver. And silver
prices have been dropping. A LOT. Plus a non trivial amount of the
world's gold comes as a by product of silver mining. Some think the
price of gold will rise. Who knows?
I just looked and silver is under $7. Do the Hunt brothers still own a lot? |
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Tomi Holger Engdahl
Guest
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| Posted:
Wed Aug 31, 2005 3:43 pm Post subject:
Re: Coaxial vs CAT 5 |
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Robert Redelmeier <redelm@ev1.net.invalid> writes:
| Quote: | James Knott <james.knott@rogers.com> wrote:
One thing pointed out by Larry Klien, was that for most
purposes, ordinary lamp cord was fine for connecting speakers.
Anything else is a waste of money.
It is.
|
You are right on this.
| Quote: | My slight concern with lampcord is it can pick up 60 Hz
hum from any nearby powerfeeds (even in wall). So it should be
kept away from power, cross at right angles or be lazy-twisted.
|
You shoud no concern much on this.
Even a normal lamp cord used as speaker cord is very resistant
to nearby powerfeed interference. The reason for this is
that the speaker circuit is very low impedance circuit
(amplifier sub ohm impedance, speaker 4-8 ohms). This kind
of low impedance circuit is very resitant to outside interference
pickup when wired with cable where the wires are quite near
to each other (does not need to be twisted pair, just wire pair).
The noise picked up by this kind of wire from external sources
(electric and magnetic fields) becomes mainly common mode
noise, which gets canceled by the floatign speaker load
(speaker reacts only to differential signal between speaker wires).
And the last thing is quite lof efficiencly of speakers
quarantee that even if some microwatts gets coupled to
the wire, those low power cannot generate audible amount of noise.
This is the normal case.
Generally unless you put the speaker wires to the same bundle
with the high current carrying power wires, you don't have
to worry about interference problems, at least on 60 Hz interference.
And generally even if you have the amplifier power and speaker
wires as one wire bundle, you generally do not get any problems.
If you have something to worry with speaker wire noise
pickup, that problem is most often RFI. The speaker wires
can pick up RF interferences. It is very rare that the
amoput of RF picked up by the speaker wire itself could
make much noise to the speakers. The bigger problem is
that the RFI can get through the speaker wires to inside
amplifier, near noise sensitive parts. There the RFI
can cause all kinds of cross modulation products,
can get demodulated and amplified etc.. The results
of those problems when amplified by the amplifier
electronics can sometimes be heard. The problem
can be seen when you are near radio transitter and
the amplifier you use is not well shielded against
interference. Typical problems that canbe heard are noise
humming/buzzing noise when using GMS cellular phone near
speaker wiring or "click" noise when pressing "talk" button
on walkie-talkie radio near stereo equipment.
| Quote: | However I'd suspect using telephone cable or CAT 5 might
have resistance loss issues, when handling low impedance
loads, over significant distances.
It does. Do not use Cat5 for low-ohm speakers if you want
decent volume.
|
You are right on this.
--
Tomi Engdahl (http://www.iki.fi/then/)
Take a look at my electronics web links and documents at
http://www.epanorama.net/ |
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