Earthing your loudspeakers

[The Black Adder]

Hello old things.

Right.. does anyone earth their loudspeakers? I've heard about it but never tried it.

Are we chasing after one of these 'I can't tell the difference' here? Or maybe even a 'wow' in sonics.

Be interesting to know what the science is behind this idea as Russ Andrews sell the idea... but hey, I love reading that comic... much better than the Beano.

Cheers
Joe

[MartinT]

What would you earth? My speaker cabinets are made of wood.

[Reid Malenfant]

Quite a few more modern Tannoy speakers can be earthed as they have the Earth terminal on the same panel as the speaker connectors. I have a feeling it Earths the speaker chassis, there may be a possibility that this is advantageous in certain circumstances.

However in just about ever circumstance (unless the power amp is bridged or balanced output) the negative terminal of the loudspeaker is at ground potential anyway. Though admittedly it's not connected to the speaker chassis so can't act as a screen...

Suck it & see is my opinion, if you can try it with no bother it might be worth seeing what the outcome is ;)

[Ali Tait]

Yes quite correct, it does indeed earth the speaker basket. No idea if it makes any difference.

[YNWaN]

This idea has been around for quite some time and, as stated earlier, it is about earthing the chassis/basket of the mid/bass driver (usually). Now I own a system in which one can easily mess about with a number of the earthing relationships between various components, In fact, just tonight, I was experimenting with the way the sub-woofer earth interacts with the other components ( and a quite obvious difference it makes too). However, whilst I think that apparently subtle earth difference make a difference, I have a problem with earthing the basket of a driver. That problem is that the basket is not part of the electric circuit - it is insulated from the parts that carry any signal.

[MartinT]

Thought so; I can't see any benefit and, in any case, few people are going to hack open their lovely speakers to bring an earth connection out.

[DSJR]

At around the same time as the speaker earthing, Tannoy also launched their expensive super-tweeters which, contrary to the claims, came in at quite audible frequencies (7 - 8kHz) and "only" went out to 28kHz as well - apparently...

Still, made for some interesting magazine articles and loads of publicity I seem to recall.

[YNWaN]

Thought so; I can't see any benefit and, in any case, few people are going to hack open their lovely speakers to bring an earth connection out.

I suppose, in theory, it may be possible for the basket to hold, or have generated within it, an electro-magnetic charge; it's even less likely with a cast aluminium basket though.

However, if one wanted to experiment it wouldn't be that hard with many speakers. If the drive unit fixing bolts are visible one could just trap a piece of wire under one of them (just for experimentation) and run that to earth (or the - post at the back of the speaker as some recommend).

[electric beach]

I think I saw it was about impedance matching with the amp and that soldering a connection from the negative terminal to the chassis basket can be difficult. Running a seperate third independant cable from the basket to the amp chassis was suggested as ideal. I can't find the discussion now.

Impressions of the efficacy were hazy... :rolleyes:

[HighFidelityGuy]

I doubt there would be any benefit to earthing the basket from a shielding point of view but I guess there may be some static build-up caused by cone movement which it could be beneficial to sink to earth. Definitely don't connect the basket to the negative speaker terminal though this could cause issues with bridged amps.

On a similar subject: I've recently being trying some Supra Ply 3.4/s speaker cable. This has a braided screen that connects to earth at the amp. The reviews I read looked favourable so I decided to give it a try. It's still burning in at the moment but I'll do some comparisons to other cables soon.

[Barry]

In earthing the speaker basket there is a partial screening of the voice coil, though this would be of negligable benefit: the speaker cables themselves are likely to pick up more RFI.

I cannot see how earthing the baskets will discharge any static build up, as what two parts are rubbing together to create the tribolelectric effect?

I think the provision of an earthing terminal is a fad and possibly Tannoy covering their back as regards CE compliance is concerned: all metal work forming part of equipment that is connected to the mains supply must be electrically bonded together. With the predeliction of owners running their speakers with the decorative grills removed, the speaker chassis fixing bolts, and sometimes the frames, are exposed.

My speakers are earthed, but being electrostatic, use a mains power supply and operate at high voltage, so this is a sensible if not essential precaution.

[YNWaN]

I think I saw it was about impedance matching with the amp..

Hmm..I can't honestly see how it could alter the impedance matching between the amp and the speaker.

[electric beach]

Hmm..I can't honestly see how it could alter the impedance matching between the amp and the speaker.

Yes, you're undoubtedly right, it was more likely the common earthing, I don't profess to understand these things, I just remembered reading some discussion and experimenting on the subject; I'll try to find where I saw it, a thread on DIY Audio probably.