1/4" Speaker Cable Gauge Guidance

[Brian Patterson]

How heavy a gauge speaker cable is needed for a 100-watt amplifer?
At what gauge weight do instrument cables pose a threat?
Any specs or general guidance available on this subject?

 

[abarson]

18-16 gauge is more than enough.
I don’t understand the “threat” question. Can you pose the question more clearly?

 

[Brian Patterson]

18-16 gauge is more than enough.
I don’t understand the “threat” question. Can you pose the question more clearly?

Assuming the speaker(s) are within the wattage rating of the amp's output, whatever would compromise the amp and cause damage.

Also, are there any cable construction features that should be considered?

 

[lowplaces]

At what gauge weight do instrument cables pose a threat?

Are you asking if instrument cables are ok to use instead of a speaker cable ?

 

[agedhorse]

16-18 gauge speaker cable is plenty stout.

 

[abarson]

Using an instrument cable instead of a speaker cable is never advisable, regardless of gauge, wattage, etc.

 

[Michedelic]

How heavy a gauge speaker cable is needed for a 100-watt amplifer?
At what gauge weight do instrument cables pose a threat?
Any specs or general guidance available on this subject?

Never use intrument/line cable for connecting an amplifier to a speaker cabinet. A speaker cable is two separate parallel strands of equal thickness, whereas instrument cable is a core strand with a woven sheild around that, rubber insulation inbetween, and not heavy enough.

 

[jsk]

2.5mm speaker cable good to 10 metres even at high wattage.

 

[eniac]

[...]
Also, are there any cable construction features that should be considered?

This is a good question. Some bargain cables with phone (aka 1/4") plugs at both ends use plain zip cord. From a purely electrical perspective that's fine. But I've seen some where the sharp-edged cable crimp had cut almost completely through the insulation because, under the shell, there was no protective sleeve installed between the crimp and the cable. In light of normal physical handling, that's a short circuit waiting to happen sooner or later. And the presence of heat shrink exiting the shell is no guarantee that type of "I don't give a ___ about the customer" construction method wasn't used. Heat shrink can hide many abominations. You'd have to unscrew the shells to check.

I'd also avoid cables with no-name plugs.

 

[Brian Patterson]

16-18 gauge speaker cable is plenty stout.

Cool - thanks agedhorse.
BTW, what gauge are most instrument cables being made with?
Is a stouter gauge or limited length advantageous for instrument cables?

 

[agedhorse]

Instrument cables are NOT speaker cables.

 

[WayneP]

Gauge isn’t a concern with instrument cables – I don’t think I’ve ever seen it advertised. But FYI, I expect most are on the order of 22-24 ga. That would be for the center conductor.

Regards,
Wayne A. Pflughaupt

Ecclesia: Unique Arrangements of Hymns, P&W Standards, and Original Tunes
Administrator, Official Pedulla Club #45
Administrator, Official Heartfield Club #36
Administrator, Official Tobias Club #133
Administrator, Official Pre-Gibson Tobias Owners Club
Fretless Club #943
Big Cabs Club #23
My Rig: Stage and FOH Friendly
My Basses

 

[GreyBeard]

I just buy Wirlwind brand speaker cables and don't give it another thought. The biggest problems I've had with cheap speaker cables have been with the connectors failing and that can cause big problems for tube bass heads. (just my humble opinion)

 

[JazznFunk]

Instrument cables are not and never should be used as speaker cables. Full stop.

I prefer 12 gauge speaker cables as a general rule for durability. I've never seen gauge mentioned as a factor in instrument cables.

 

[byacey]

12 gauge is a waste of copper, unless your speaker runs are hundreds of feet long.

 

[JazznFunk]

12 gauge is a waste of copper, unless your speaker runs are hundreds of feet long.

12 gauge on a 3' run is a 'waste of copper' I'm fine with if it lasts me decades, in a robust and well-constructed cable/connector package. I'll happily spend the money on it, considering all of the 12 gauge speaker cables I own are ones I've had for close to 2 decades now.... with the newer Speakon-jack ones being the exception. I've had smaller gauge cables/connectors fail before. YMMV.

 

[HolmeBass]

Cool - thanks agedhorse.
BTW, what gauge are most instrument cables being made with?
Is a stouter gauge or limited length advantageous for instrument cables?

I would say if the speaker cable is longer than 10 feet long shoot for 16 gauge, maybe even 14.

 

[agedhorse]

For that application, 16 gauge is plenty big with no benefit of going larger.

There is a significant drawback to 12 gauge cables and 1/4” plugs however… with the larger cable comes an increase in the diameter and length of the plug body and weight on the plug which increases the stress on the jacks. I have seen jacks damaged this way.

 

[basscooker]

My 3' speaker cable will actually make the front feet of my MB200 lift off the cab if I don't add some weight to the front of the amp. It's 16ga, but with pretty robust insulation. I can't imagine how much stress a 12ga cable with heavier insulation would put on the amp's connector. I'm not 100% confident my MB200 really likes the cable I'm using now.

 

[JazznFunk]

My 3' speaker cable will actually make the front feet of my MB200 lift off the cab if I don't add some weight to the front of the amp. It's 16ga, but with pretty robust insulation. I can't imagine how much stress a 12ga cable with heavier insulation would put on the amp's connector. I'm not 100% confident my MB200 really likes the cable I'm using now.

Never had any of those issues with the 12 gauge cables I've been using for decades, but maybe I've just had good luck. In fact, the only failure I've ever had with a speaker cable was with the plug end on the cable, not the jack on either the amp or cabinet. There was a flaw somewhere in the plug end that caused it to short out.... thankfully it was a cable with lifetime replacement and I got it tested, confirmed defective, and swapped with no fuss by a local shop. I could see it being an issue with super lightweight heads these days.