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Crazy or True?

#24
Showdown said:
The Planet Waves cables I use are the same way, for the same reason. I don't know if it really makes any difference, but I like the cables so I use them.
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Actually, Planet Waves does the opposite. They only shield ground to the amp. The idea being you only want one ground. Much like some people use star grounding in a guitar.

Planet Waves' solution sounds more reasonable than Monster's to me. If you do have a noise problem, it would be interesting to try plugging the cable in the wrong way around.

But people have been using normal cables for decades with no problems. I think the directional cables may have some theory to back them up, but in practice it probably doesn't make any difference.

So, IMHO, it is marketing snake oil.... but they aren't actually lying.
 
#27
seanm said:
Actually, Planet Waves does the opposite. They only shield ground to the amp. The idea being you only want one ground. Much like some people use star grounding in a guitar.

Planet Waves' solution sounds more reasonable than Monster's to me. If you do have a noise problem, it would be interesting to try plugging the cable in the wrong way around.

But people have been using normal cables for decades with no problems. I think the directional cables may have some theory to back them up, but in practice it probably doesn't make any difference.

So, IMHO, it is marketing snake oil.... but they aren't actually lying.
Click to expand...

Yea, that isn't the reason I use Planet Waves. About 6 years ago I bought three PW cables. Since that time I've used them extensively on countless gigs, rehearsals, etc. They are all as good as new. They are very reliable, they work well, and I don't have to worry about them failing. And they aren't as expensive as some other premium brands.
 
#28
The noise issue these cables are most likely to solve is ground loops - so both Monster and PW are going to fix that regardless of which way you plug them in.

Any other noise source (common mode) is probably going to be very low level - this is when us engineer types start looking in detail at the noise contributed by the ground and not just assuming ground is ground! When we do start splitting those hairs, it's generally accepted in the literature I've read that grounding at the source is the way to go.
 
#29
niftydog said:
The noise issue these cables are most likely to solve is ground loops - so both Monster and PW are going to fix that regardless of which way you plug them in.

Any other noise source (common mode) is probably going to be very low level - this is when us engineer types start looking in detail at the noise contributed by the ground and not just assuming ground is ground! When we do start splitting those hairs, it's generally accepted in the literature I've read that grounding at the source is the way to go.
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Could be. But a "normal" audio system has an active source and active sink, both of which are grounded. Since a bass is basically a floating ground, I think it would be better to ground at the amp, since the amp hopefully has a proper ground.

It's fun to talk about, but I don't think it would matter much either way.
 
#30
It makes sense to me if there are 2 signal conductors surrounded by a shield. Connect the 2 signal conductors the same at both ends but just connect the shield at one end. Then plug the shield's end into something that shunts to ground any noise picked up by the shield.

Good God!! Does this mean I now partly approve of Monster?!?!?
 
#31
That is one of the biggest things that is tough for me to wrap my head around with my understanding of electronics vs. line electricity. I can't accept that a conductor out doesn't have a way to get the current back to source. I see how the pedal or amp has power in/power out, but the bass seems to only be getting its power out with an incomplete circuit back. Open circuit:confused:. No matter how much explaining I get it still feels like an open circuit, and yet there it is.... working.
 
#32
seanm said:
It's fun to talk about, but I don't think it would matter much either way.
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Hmm, don't know about fun! The guys I know that find this interesting think that 5 parts per million is an enormous number!

cheapbasslovin said:
That is one of the biggest things that is tough for me to wrap my head around with my understanding of electronics vs. line electricity. I can't accept that a conductor out doesn't have a way to get the current back to source.
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As long as the current is flowing to/from somewhere it doesn't matter if it doesn't get back to the source.

Your pickup generates an AC voltage which causes an AC current to flow back and forth: Allow that current to flow in/out of the input of an op amp and it will be amplified. If the ground references are offset by a DC voltage it doesn't matter, the AC signal just gets superimposed on top of the DC. After all, what we call "ground" is really just an arbitrary voltage reference point. Making both reference voltages the same doesn't change the way the AC current flows.

Code: 
   xVDC   < AC current >    xVDC      aVDC    < AC current >     aVDC
    o------------------------o         o--------------------------o
    |                        |         |                          |
    |                       .-.        |                         .-.
    C|                      | |        C|                        | |
    C|                      | |        C|                        | |
    C|                      '-'        C|                        '-'
    |                        |         |                          |
    o------------------------o         |                          |
   yVDC                     yVDC      bVDC                       cVDC

Calling any one of the DC voltages "ground" in either diagram doesn't change anything.
 
#34
Thank you, Nifty.

I had to sit and look at what you had written for about 10 minutes and beat my head against some things for a while..... but I think I've got it. Way back in the recesses of my brain I found some basics that applied here, that had gotten lost in my daily use of complete closed loop circuits found in ladder logic and line voltage wiring.

Thanks again.
 
#35
plug in this cable. play for a minute.

unplug it and turn it around.

it still works? sounds the same?

that cant be, otherwise the makers of these obviosuly superior and obviously overpriced cables would by lying to all of their customers buying the "most expencive, therefore the best" product.
 
#36
Maybe not quite the same thing, but I have a short speakon cable for my head and cab that only works one way round. It's thrown me a few times when I've got everything plugged in and no sound. The packaging doesn't mention anything, but I assume it's directional. So I've put an 'amp' label one end and 'cab' the other.
 
#39
#40
JustDavid said:
Weird.

Does a standard cable work also?
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Speakon cables are not always wired the same at both ends. The most common arrangement has two wires in the cable, but four connectors inside the plug, which may need to be wired in any arrangement of those four to meet the design of a given amp or cab.

So he answered that a "regular 1/4" speaker cable" would work fine both ways, but it is entirely normal that the Speakon cable would not work both ways. Depends on the specific amp and cab.
 

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