Grounding Speakers


My Tannoy DC8Ti speakers have a ground connector.  Can someone give me a good idea as to why I should use it?  Full disclosure - I had them grounded to my pre amp before.  I just received, assembled, and reinstalled my gear on a new Butcher Block four shelf rack.  My other rack has 3 shelf, so I’m reconfiguring the layout.

My turntable is grounded to my phone pre Amp.  My power amp also has a ground connector.  Should I ground the speakers to the pre amp, power amp, or to a dedicated earth ground?  And is there any reason to use the power amp ground?
oldschool1948
Groundhog Day! Different details, same day. In the original script he relived it for millions of years. In the movie it wound up being thousands. Here its merely hundreds. It only seems like forever.

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I found a manual for the DC8T online, which includes the following statement that I assume is also applicable to the DC8Ti:

Connection of Earth or 'Ground' Lead:

Use of a shielded or screened loudspeaker cable will offer further performance advantages when used with the five-way terminal panel. The screening termination should be connected to the earth or ground (green) terminal on the loudspeaker and to the ground or earth connection on the amplifier. Alternatively if you are not using a screened loudspeaker cable but wish to utilise the earthing facility, run a single cable between the earth or 'ground' (green) terminal on the loudspeaker to the earth (ground) connection on the amplifier .

Regards,
-- Al

Thanks Al.  Your help as given me information to think about after I do some more research on my options.

Millercarbon
Groundhog Day! Different details, same day. In the original script he relived it for millions of years. In the movie it wound up being thousands. Here its merely hundreds. It only seems like forever.
Was unnecessary.  
@oldschool1948,

Tannoy owner here, I have not tried the earth connection on the amplifier as I am currently using Nordost Star Grounding scheme for my entire system. My Tannoy’s are currently grounded to Nordost QKORE6 ...this does provide enhanced mid-range clarity and quieter background. I believe the idea behind the ground connection on Tannoy’s is to reduce unwanted radio frequency interference.

I believe the idea behind the ground connection on Tannoy’s is to reduce unwanted radio frequency interference.
+1.  That's my belief as well.

Also, while it would seem unlikely that the speaker itself could respond to RF frequencies, at least in a way that would be audible, I suspect that the likeliest way in which RFI picked up by the speaker cables could affect sonics would be as a result of the RFI being injected into the feedback loop of the amplifier, assuming the amp has a feedback loop. If so, the benefit of this ground connection, if any, in addition to being dependent on the RFI environment at the particular location would be dependent on the design of the specific amplifier. Including the amount of feedback it utilizes, its output impedance, its bandwidth, and perhaps other design-dependent variables.

The bottom line being that the only way to know if there would be a benefit in a particular system is to try it in that system.

Best regards,
-- Al


@lalitk Thanks for the input.
Just one caution: If that earth connection on the speaker ties the common (negative terminal) to ground then it would damage an amplifier with active speaker terminal outputs if you ground the speaker.
I have the tannot legacy eatons and I use 12 gauge stranded green wire (could use solid copper, but a bit less flexibility), terminated to one gold plated 8 gauge #6 spade to the amp. On speaker end, stripped and silver solder tinned wire ends to the 5th ground speaker terminal. The ground wires from both left and right channels are terminated together into the one aforementioned spade connector (two 12 gauge wires equates to 9 gauge) and attach to one of the rear chassis screws of my Sugden A21se. Not certain if I can detect a difference....anyhow, I like the fact that the 5th terminal is provided and it probably can’t hurt...
I always like solid copper over stranded
It’s nothing more than marketing.

Every design is trying to offer something unique and whilst I know some Tannoys use autotransformers in their crossover, I’m pretty sure it’s nothing to do with that.
Yes supposedly over time, stranded can develop the so called skin effect distortion etc, at least that is what I've read. Stranded major advantage is flexibility. Solid is a bit more difficult to work with, but is better for a more wide open space, as stranded is better for tighter quarters due to its flexibility. However, it being only the ground wire and not a signal carrying wire, it probably will not have any audible influence whether it be solid or stranded wire. 
Skin effect distortion? I’m not sure that’s true since the signal is not frequency varying. Or is it? Hmmmmmmm...🤔
You can get 14 gauge twisted pair power cord with a shield  (third conductor) This is what Tannoy had in mind. If your cable is not shielded using the ground connector is useless. 
I have 12 gauge copper wire, which is a bit stiff, but I prefer a single strand.

After doing some on-line research and taking into consideration the comments here, I'm going back to what I had before I started this thread:  ground wires run from each speaker to my power amp to my pre amp to create a Star ground setup. 

All of my equipment is connected to a Furman power conditioner, which is connected to a dedicated line.  In essence, I'm following the advice found on the PS Audio site:   
https://www.psaudio.com/ps_how/how-to-practice-best-grounding/

On a side note, I started building my music room a little over a year ago.  I'm in the process of tweaking things, hence the new audio rack. Next steps are to replace my NAD M22v2 power amp, with a much better amp or mono blocks, and then work with GIK on room treatment.  

Setting up a dedicated listening room has been a learning process, and I truly appreciate all of the help and information that I've received and gleaned from this forum.  Many thanks to everyone who has chimed in.