What size twin and earth cable?

graham.tompson · 03-03-2005, 12:30

having read various threads, twin and earth cable has been mentioned as very good to use with home cinema systems.

my question is what size cable should i be using, bigger the better?. as i was recently in b+q i notice they do 10mm thick.

any help would be appreciated

thanks

graham

asdigi · 03-03-2005, 12:34

sorry to sound a bit thick

but do you mean twin and earth flex as in what is used for extension leads etc or whats used inside house walls for mains wiring?

clockworks999 · 03-03-2005, 12:38

Quote:

Originally Posted by asdigi

sorry to sound a bit thick

but do you mean twin and earth flex as in what is used for extension leads etc or whats used inside house walls for mains wiring?

Solid core cable, as used for fixed wiring.
The stuff used for extension leads is 3-core flex.

clockworks999 · 03-03-2005, 12:44

Quote:

Originally Posted by graham.tompson

having read various threads, twin and earth cable has been mentioned as very good to use with home cinema systems.

my question is what size cable should i be using, bigger the better?. as i was recently in b+q i notice they do 10mm thick.

any help would be appreciated

thanks

graham

1.5mm lighting cable is fine for surround speakers or low powered stereos. Use 2.5mm for the front and centre speakers on higher output amps.

Note that the sizes (1.5mm, 2.5mm) refer to the cross-sectional area of each conductor, not the size of the external plastic sheath. IIRC, the biggest size used for domestic wiring is 6mm, for electric cookers.
Lighting circuits use either 1mm or 1.5mm, ring mains use 2.5mm.

Jim Rae · 03-03-2005, 12:45

Get twin by all means but you don't want an earth wire - or do you?

Thicker is usually better in most cases, although he HiFi folk will tell you all sots of things about being oxygen free etc etc...

clockworks999 · 03-03-2005, 13:51

Quote:

Originally Posted by Jim Rae

Get twin by all means but you don't want an earth wire - or do you?

Thicker is usually better in most cases, although he HiFi folk will tell you all sots of things about being oxygen free etc etc...

No, you don't need the earth wire, but the idea is to use solid-core cable. AFAIK, you can't buy twin solid-core, so the choice is between twin & earth solid, or twin flex.
Solid really does sound better than stranded/flex.

While "thicker is better" is normally true for stranded cable, it's not necessarily true for solid. IIRC, it's something to do with "skin effect", where the charge flows at a different rate on the surface of the conductor, to the centre of the conductor.
If you are using solid-core, it is best to use the smallest cable that can handle the peak current. Thicker cable will give a slight roll-off to high frequencies.

I am no expert (A-level physics, 30 years ago!), but I have experimented with cables, and I am convinced about these effects....

gerbilly · 03-03-2005, 23:31

It was me who started the twin and earth threads on here.

The 2.5mm one is what I got for my two front speakers and my centre. I have left QED original for the rears.

I used this to replace QED Silver Anniversary (5.99 per metre) and it sounds better to my ears.
Watched Hero yesterday and the scene with the arrows at the Caligraphy school sounded amazing.

gerbilly · 03-03-2005, 23:33

One other one try CAT5 cable if you are wanting cheap cable for your Hifi.

diablo · 04-03-2005, 05:51

I find the fashion for using CAT5 networking cable somewhat bizarre. This is a high impedance 24AWG cable which must be poor at carrying signals even when double or treble wired. If you need a hobby then braiding long lengths of CAT5 will keep you occupied for hours though.

As a contrast, mains type twin and earth has good electrical properties. Bigger the better to get the resistance low. Depends a lot on length of the cable as to how thick it should be. This type of cable is made from standard grade copper, which by dint of the manufacturing process is about 99.9% oxygen free. The 99.9999% oxygen free copper used in audiophile cables makes little difference - just adds slightly to the resistance.

'Skin effect' does make a very slight difference. It can change the effective resistance of the cable to high frequency audio signals. It may mean that a 20kHz tone is down by 5% in worst cases. This is not normally noticable - especially for people over the age of 15, whose ears cannot hear such a high pitch anyway.

I use Shark 12AWG cable from Maplins. It is reasonably priced at £15 per 10 metre drum. More expensive than twin and earth but looks a lot better and much less of a pig to handle than T+E.

gerbilly · 04-03-2005, 18:40

Diablo I will give it a try and get this from Maplins.

What colour is it and is it more flexible than the t and e.

I have also made the CAT5 cable and it is fine but it is a pig to make.

diablo · 05-03-2005, 01:40

The Shark cable has transparent PVC insulation, so its copper coloured. Very flexible stuff.

Another thing which I get from Maplins is their heatshrink tubing (F-70 type), which can be used to make connections to banana plugs, etc. airtight. This should prevent the copper oxidising and turning green.

Regards,
diablo

gerbilly · 05-03-2005, 21:52

Quote:

Originally Posted by diablo

The Shark cable has transparent PVC insulation, so its copper coloured. Very flexible stuff.

Another thing which I get from Maplins is their heatshrink tubing (F-70 type), which can be used to make connections to banana plugs, etc. airtight. This should prevent the copper oxidising and turning green.

Regards,
diablo

Diablo how do you do the heatsink bit still havent a clue what is for and how you get it to fit on the cable.

diablo · 05-03-2005, 22:35

Quote:

Originally Posted by gerbilly

Diablo how do you do the heatsink bit still havent a clue what is for and how you get it to fit on the cable.

It's just to keep the join between the cable and the plug airtight.
Copper is wonderful stuff for connections but if it is exposed to the air then it will go green and manky after a while. I suspect that it causes problems with the sound before the effect is really noticable visually.
Cable company QED make a big thing of this, and I suspect that they may actually be right. See their blurb here.
I use the heatshrink stuff to do much the same thing.

I get banana plugs with push-on flexible red/black 'covers'. The cover bit is put onto the lead followed by an inch and a half of F-70 heatshrink sleeving, then the actual banana plug is fixed to the wire. The heatshrink can then be pushed over the body of the plug and shrunk by heating with a hairdryer or something. After which the cover can be pushed over the top of that. Gives an airtight seal to prevent corrosion.

A lot of connections between amps and speakers just use bare wires. If this is the case then it's a good idea to leave a few inches spare at each end so that you can chop off the exposed part and strip back a new section of wire every few months.

I'm convinced that part of the reason that people say that new speaker cables sound better than the old ones is that the old ones are suffering oxidation / corrosion. They might hear the same improvement if the old ones were cleaned up.

I'll stop typing now as I'm starting to ramble.

diablo

03-03-2005, 12:30	#1
graham.tompson Forum Member Join Date: Jan 2004 Posts: 114	What size twin and earth cable? having read various threads, twin and earth cable has been mentioned as very good to use with home cinema systems. my question is what size cable should i be using, bigger the better?. as i was recently in b+q i notice they do 10mm thick. any help would be appreciated thanks graham

03-03-2005, 12:34	#2
asdigi Forum Member Join Date: May 2003 Posts: 2,914	sorry to sound a bit thick but do you mean twin and earth flex as in what is used for extension leads etc or whats used inside house walls for mains wiring?

03-03-2005, 12:38	#3
clockworks999 Forum Member Join Date: Aug 2003 Location: Cornwall, UK Posts: 2,014	Quote: Originally Posted by asdigi sorry to sound a bit thick but do you mean twin and earth flex as in what is used for extension leads etc or whats used inside house walls for mains wiring? Solid core cable, as used for fixed wiring. The stuff used for extension leads is 3-core flex.

03-03-2005, 12:44	#4
clockworks999 Forum Member Join Date: Aug 2003 Location: Cornwall, UK Posts: 2,014	Quote: Originally Posted by graham.tompson having read various threads, twin and earth cable has been mentioned as very good to use with home cinema systems. my question is what size cable should i be using, bigger the better?. as i was recently in b+q i notice they do 10mm thick. any help would be appreciated thanks graham 1.5mm lighting cable is fine for surround speakers or low powered stereos. Use 2.5mm for the front and centre speakers on higher output amps. Note that the sizes (1.5mm, 2.5mm) refer to the cross-sectional area of each conductor, not the size of the external plastic sheath. IIRC, the biggest size used for domestic wiring is 6mm, for electric cookers. Lighting circuits use either 1mm or 1.5mm, ring mains use 2.5mm.

03-03-2005, 12:45	#5
Jim Rae Forum Member Join Date: Mar 2002 Location: Ayrshire Posts: 4,125	Get twin by all means but you don't want an earth wire - or do you? Thicker is usually better in most cases, although he HiFi folk will tell you all sots of things about being oxygen free etc etc...

03-03-2005, 13:51	#6
clockworks999 Forum Member Join Date: Aug 2003 Location: Cornwall, UK Posts: 2,014	Quote: Originally Posted by Jim Rae Get twin by all means but you don't want an earth wire - or do you? Thicker is usually better in most cases, although he HiFi folk will tell you all sots of things about being oxygen free etc etc... No, you don't need the earth wire, but the idea is to use solid-core cable. AFAIK, you can't buy twin solid-core, so the choice is between twin & earth solid, or twin flex. Solid really does sound better than stranded/flex. While "thicker is better" is normally true for stranded cable, it's not necessarily true for solid. IIRC, it's something to do with "skin effect", where the charge flows at a different rate on the surface of the conductor, to the centre of the conductor. If you are using solid-core, it is best to use the smallest cable that can handle the peak current. Thicker cable will give a slight roll-off to high frequencies. I am no expert (A-level physics, 30 years ago!), but I have experimented with cables, and I am convinced about these effects....

03-03-2005, 23:31	#7
gerbilly Forum Member Join Date: Nov 2004 Posts: 842	It was me who started the twin and earth threads on here. The 2.5mm one is what I got for my two front speakers and my centre. I have left QED original for the rears. I used this to replace QED Silver Anniversary (5.99 per metre) and it sounds better to my ears. Watched Hero yesterday and the scene with the arrows at the Caligraphy school sounded amazing.

03-03-2005, 23:33	#8
gerbilly Forum Member Join Date: Nov 2004 Posts: 842	One other one try CAT5 cable if you are wanting cheap cable for your Hifi.

04-03-2005, 05:51	#9
diablo Forum Member Join Date: Jul 2003 Location: Fylde Coast Posts: 8,103	I find the fashion for using CAT5 networking cable somewhat bizarre. This is a high impedance 24AWG cable which must be poor at carrying signals even when double or treble wired. If you need a hobby then braiding long lengths of CAT5 will keep you occupied for hours though. As a contrast, mains type twin and earth has good electrical properties. Bigger the better to get the resistance low. Depends a lot on length of the cable as to how thick it should be. This type of cable is made from standard grade copper, which by dint of the manufacturing process is about 99.9% oxygen free. The 99.9999% oxygen free copper used in audiophile cables makes little difference - just adds slightly to the resistance. 'Skin effect' does make a very slight difference. It can change the effective resistance of the cable to high frequency audio signals. It may mean that a 20kHz tone is down by 5% in worst cases. This is not normally noticable - especially for people over the age of 15, whose ears cannot hear such a high pitch anyway. I use Shark 12AWG cable from Maplins. It is reasonably priced at £15 per 10 metre drum. More expensive than twin and earth but looks a lot better and much less of a pig to handle than T+E.

04-03-2005, 18:40	#10
gerbilly Forum Member Join Date: Nov 2004 Posts: 842	Diablo I will give it a try and get this from Maplins. What colour is it and is it more flexible than the t and e. I have also made the CAT5 cable and it is fine but it is a pig to make.

05-03-2005, 01:40	#11
diablo Forum Member Join Date: Jul 2003 Location: Fylde Coast Posts: 8,103	The Shark cable has transparent PVC insulation, so its copper coloured. Very flexible stuff. Another thing which I get from Maplins is their heatshrink tubing (F-70 type), which can be used to make connections to banana plugs, etc. airtight. This should prevent the copper oxidising and turning green. Regards, diablo

05-03-2005, 21:52	#12
gerbilly Forum Member Join Date: Nov 2004 Posts: 842	Quote: Originally Posted by diablo The Shark cable has transparent PVC insulation, so its copper coloured. Very flexible stuff. Another thing which I get from Maplins is their heatshrink tubing (F-70 type), which can be used to make connections to banana plugs, etc. airtight. This should prevent the copper oxidising and turning green. Regards, diablo Diablo how do you do the heatsink bit still havent a clue what is for and how you get it to fit on the cable.

05-03-2005, 22:35	#13
diablo Forum Member Join Date: Jul 2003 Location: Fylde Coast Posts: 8,103	Quote: Originally Posted by gerbilly Diablo how do you do the heatsink bit still havent a clue what is for and how you get it to fit on the cable. It's just to keep the join between the cable and the plug airtight. Copper is wonderful stuff for connections but if it is exposed to the air then it will go green and manky after a while. I suspect that it causes problems with the sound before the effect is really noticable visually. Cable company QED make a big thing of this, and I suspect that they may actually be right. See their blurb here. I use the heatshrink stuff to do much the same thing. I get banana plugs with push-on flexible red/black 'covers'. The cover bit is put onto the lead followed by an inch and a half of F-70 heatshrink sleeving, then the actual banana plug is fixed to the wire. The heatshrink can then be pushed over the body of the plug and shrunk by heating with a hairdryer or something. After which the cover can be pushed over the top of that. Gives an airtight seal to prevent corrosion. A lot of connections between amps and speakers just use bare wires. If this is the case then it's a good idea to leave a few inches spare at each end so that you can chop off the exposed part and strip back a new section of wire every few months. I'm convinced that part of the reason that people say that new speaker cables sound better than the old ones is that the old ones are suffering oxidation / corrosion. They might hear the same improvement if the old ones were cleaned up. I'll stop typing now as I'm starting to ramble. diablo

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What size twin and earth cable?