Grounding boxes?

[anthonyTD]

Fair point, However; would you also consider that its possible that connecting an Antena to the 0V of one's system, could actualy give these stray high frequency voltages a path of least resistance to escape the equipment its connected to, now don't get me wrong, this is not something i have given much thought to until now, but i assume that its probably one theory thats been hinted at. Again, your thoughts are very welcome.

I've posted a bit, but please ask any questions.

My basic premise is that if you like them use them, just don't try to fight the facts about what they are.

In audio why is everyone so obsessed with validating their hearing preference? Why isn't ok to just say, "I like it" ?

[Barry]

That does raise the question of why studios don't seem to even observe such problems or 'solutions', and they often have many exposed leads on patch bays.

Perhaps due their use of balanced-line interconnections. Anything that allows earth currents and noise on the mains safety earth to mix with the 0V or signal return is going to be a possible problem.

[Folsom]

Fair point, However; would you also consider that its possible that connecting an Antena to the 0V of one's system, could actualy give these stray high frequency voltages a path of least resistance to escape the equipment its connected to, now don't get me wrong, this is not something i have given much thought to until now, but i assume that its probably one theory thats been hinted at. Again, your thoughts are very welcome.

No, I would not. That would require a fundamental change in the fabric of our reality to be possible. Literally atoms themselves could not function that way as we know them today. There is nothing to consider unless you're writing fiction.

What is the objection to accepting the very engineering that makes your stereo possible, being applied to this subject? Why is it that all documentation ever written is insufficient? Do you believe all the huge text books on electronics are simply wrong? Are all the PHD's on planet earth insufficient? I guess I'm asking what would it take for you to accept fact?

The most basic concept of electricity is you need a complete circuit. How is a box completed if it isn't in part of a loop? Just for reference the impedance of air is 1.3*10^16 to 3.3* 10^16 ohm so you expect that to be the path that noise would follow? Because in order for a complete circuit to be made it would have to pass through the air and back to something that's part of the electrical system.

[The Black Adder]

As a believer of my friends opinion, I'm finding this subject to be very interesting. He has an amazing system which he loves.

Okay, plenty of mystique surrounds the technical side and it's certainly debatable. But in my research of this subject it comes down to the end user. People who try these things say they work, not all but a good majority say they do.

It's okay to be sceptical but until you try it first hand I'd like this one to be kept open to intelligent debate.

[Barry]

The concept of an electrical circuit becomes a bit nebulous at radio frequencies and above, so the fact that air has a resistivity of around 2.10¹⁶ Ωm is largely irrelevant. What is more important, from the point of view of an antenna, is that the impedance of free space is 377Ω.

In fact it the purpose of the antenna to match the impedance of free space to that of the receiver. This means antennae are band limited in their response. However that does not mean an inefficient antenna (i.e. one that does not offer a good impedance match at a specific frequency) cannot pick up RFI: it has been suggested that unshielded speaker cables of modest length can act as very inefficient antennae to AM broadcast transmissions (especially if the transmitter has a large ERP and is close by) and these can ‘feed back’ into the amplifier, become demodulated and ‘beat’ with the audio signal.

So whilst I think that a folded copper plate immersed in “kitty litter” (yes I know the stuff is a mixture of perovskite and piezoelectric minerals) might make an inefficient antenna to RF, in connecting it to earth via the safety earth of the audio components the, admittedly small, currents do have a chance to mix with the wanted audio signal current, if the signal return and safety earth are one and the same.

[Folsom]

The concept of an electrical circuit becomes a bit nebulous at radio frequencies and above, so the fact that air has a resistivity of around 2.10¹⁶ Ωm is largely irrelevant. What is more important, from the point of view of an antenna, is that the impedance of free space is 377Ω.

In fact it the purpose of the antenna to match the impedance of free space to that of the receiver. This means antennae are band limited in their response. However that does not mean an inefficient antenna (i.e. one that does not offer a good impedance match at a specific frequency) cannot pick up RFI: it has been suggested that unshielded speaker cables of modest length can act as very inefficient antennae to AM broadcast transmissions (especially if the transmitter has a large ERP and is close by) and these can ‘feed back’ into the amplifier, become demodulated and ‘beat’ with the audio signal.

So whilst I think that a folded copper plate immersed in “kitty litter” (yes I know the stuff is a mixture of perovskite and piezoelectric minerals) might make an inefficient antenna to RF, in connecting it to earth via the safety earth of the audio components the, admittedly small, currents do have a chance to mix with the wanted audio signal current, if the signal return and safety earth are one and the same.

To be clear the ground box dangles in the wind, it isn't connected by safety ground (which earth is connected to) to form a loop, the only path to that ground is through the equipment (if there is one depending on the box's recommended connection and the component). And complete circuits still exist in RF, they're just much more complex. Where you could draw say 10 elements prior in a circuit, with RF frequencies you may need to introduce another 10+ for things occurring that aren't represented properly by simple parts in the schematic (example inductance of leads, inductance of tracing, parasitics, etc).

[anthonyTD]

Again, thanks for your input, and as stated this theory is not one of mine, but its one that some have eluded to!

No, I would not. That would require a fundamental change in the fabric of our reality to be possible. Literally atoms themselves could not function that way as we know them today. There is nothing to consider unless you're writing fiction.

What is the objection to accepting the very engineering that makes your stereo possible, being applied to this subject? Why is it that all documentation ever written is insufficient? Do you believe all the huge text books on electronics are simply wrong? Are all the PHD's on planet earth insufficient? I guess I'm asking what would it take for you to accept fact?

The most basic concept of electricity is you need a complete circuit. How is a box completed if it isn't in part of a loop? Just for reference the impedance of air is 1.3*10^16 to 3.3* 10^16 ohm so you expect that to be the path that noise would follow? Because in order for a complete circuit to be made it would have to pass through the air and back to something that's part of the electrical system.

[Barry]

The metal plate in the grounding box is connected to something - whether to the mains safety earth or to the signal 'ground' of the equipment, the current of the RFI picked up goes somewhere, as do those of an antenna.

I didn't say complete circuits don't exist at RF, they do, but they are far less straightforward and clear cut, hence my term "nebulous". A better term would have been "vague", or "not simple".

Draw the circuit for a waveguide - in fact define the impedance of a waveguide, or even a coaxial cable at high frequency. Things become complicated at RF due to the distributed nature of physical electrical properties such as capacitance and inductance. At very high frequencies it is easier to think in terms of the distributed electric and magnetic field strengths than of voltage and current.

[Jac Hawk]

I've read this thread with interest and looked at the cost of these boxes, they aren't cheap, my feeling for what it's worth is even if it works there's not going to be a night and day difference if there was then there would be no debate and it would be an accepted necessary piece of kit, I'd like to see the results of a blind test and i think people who have bought them want to hear a difference to justify the outlay, i mean if you have just spent upwards of £400 on a wooden box of gravel you're going to want to tell yourself there's a difference and you haven't just wasted a load of cash on a very expensive box of dirt, so for me at the moment these things sit in the "Snake Oil" category.

[Barry]

Yes, but presumably people who have bought them have already heard the difference they make (to their ears at least, and hopefully in their own system), before they parted with their money.

I don't think many people fork out £400 without thought, so 'expectation bias' ought not come into it.