Speaker Cable

Beecher

Woot! My engl rackmount pre-amp and poweramp are in the post ( ), and im about to order a cab, but ive just found out you dont use instrument cables to go between the poweramp and the cab (ive always been more obsessed about getting a good guitar collection rather than getting good amplification, something im about to rectify). Is this the right cable to order?

feylya

Aye, that should be grand. And Neutrik jacks rock!

moonboy

yeah a lot of people dont realise that instrument cables only carry sound signals NOT power..
but the link from head to cab NEeDS to carry power to power the cab so you need a cable to handle that.

Kenny_D

Picked up a speaker cable in Musician Inc for my cab this week for €5.50

Eoin Madsen

moonboy wrote:

yeah a lot of people dont realise that instrument cables only carry sound signals NOT power..
but the link from head to cab NEeDS to carry power to power the cab so you need a cable to handle that.

Well, technically it's just a higher wattage sound signal. Speakers don't actually need to be "powered" as such.

Paladin

Eoin Madsen wrote:

Well, technically it's just a higher wattage sound signal. Speakers don't actually need to be "powered" as such.

And ESB cables just carry a high wattage 50Hz sound signal

Guitar cables can be used to power cabs fine when the power is not too high, as RMS power is generally very low. A 200Watt PA in a garage or small pub running at a loud volume wont be delivering much power on average over a night. Which means a negligible power dissapation in the cables. For large power then speakers cables would be recommended, but in a pinch guitar cables probably wont be a problem. They will burn out if used for massive power though. Be warned. Use speaker cables if possible.

As a point of note, speaker cables can never be used for a guitar - they are twisted pair cables and will pick up lots of noise which will be amplified by the amp (obviously).

Eoin Madsen

Paladin wrote:

And ESB cables just carry a high wattage 50Hz sound signal

Well, yes. But that 50hz wasn't created with a sound transducer or from amplifying a signal created with a sound transducer or by a device intended to synthesize audio signals. You have to make a distinction somewhere!

Guitar cables can be used to power cabs fine when the power is not too high, as RMS power is generally very low. A 200Watt PA in a garage or small pub running at a loud volume wont be delivering much power on average over a night. Which means a negligible power dissapation in the cables. For large power then speakers cables would be recommended, but in a pinch guitar cables probably wont be a problem. They will burn out if used for massive power though. Be warned. Use speaker cables if possible.

The problem is impedance moreso than power dissipation. Output transformers (especially for valve output stages) are quite sensitive to mismatched loads. At best, a guitar lead will reduce the sensitivity and frequency response of the speaker. At worst, it could conceivably damage the amp.

-=al=-

i got a speaker cable with my TSL, so i take it that ones a-ok!? is there a point in upgrading it at all?

Paladin

Eoin Madsen wrote:

The problem is impedance moreso than power dissipation. .

Thats a tough distinction to make, considering that power is directly proportional to (resistance) impedance (P=R*I*I), but I know what you mean, however as regards the impedance mismatch for power transmission there is really little point in worrying about it over instrument cables for audio frequencies.

Eoin Madsen wrote:

Output transformers (especially for valve output stages) are quite sensitive to mismatched loads.

This can be true(ish). Well firstly it can ONLY apply to valve output stages, there not existing a transformer in any other amplifier output. However most valve amps are surprisingly tough with regard to this relative to their solid-state counterparts. The difference is that to really break a SS you need to short circuit it, and even at that modern ones should have over-current limiters to save it.
With valve amps using a mismatched load what you will get is greater harmonic distortion. They are reasonable tough as regards breaking. Short circuit is not as big a problem with valve outputs (though not recommended) and open circuit is definately not recommended (though its perfectly harmless for SS amps).

In short, the transmission line impedance of a speaker cable Vs instrument cable over short distances at audio frequencies will have no audible effect on anything. The resistance and power handling will be different though.

Speaker cables do have a smaller resistance than instrument cables so they can handle more power. The co-axial setup of instrument cables gives better noise rejection.

In short I think we all agree, use instrument cables for instruments and speaker cables for speakers

Beecher

Got a speaker cable from Rodge in Musician Inc today for 3 squids, kinda concerned though that the cable does say 'instrument cable' on it, but it also says 'low capacity, low impendance' on it. Anyone any ideas if this is suitable?

feylya

Open it up and look at the soldering connections. If both the wires have a sheath on them, it so be ok. If one of the wires is bare, it's an instrument cable.

Eoin Madsen

Paladin wrote:

In short, the transmission line impedance of a speaker cable Vs instrument cable over short distances at audio frequencies will have no audible effect on anything. The resistance and power handling will be different though.

Different resistance has an audible effect, that's the whole problem.

Eoin Madsen

Paladin wrote:

open circuit is definately not recommended (though its perfectly harmless for SS amps).

I knew an ss poweramp that would strongly disagree with that, were it still alive today.

Paladin

Eoin Madsen wrote:

Different resistance has an audible effect, that's the whole problem.

Well, resistance and impedance are different things, as is transmission line impedance.

Dunno if I can explain this well. Will try my best but apologies if I fail

As an example, IPX cables have a 50ohm impedance regardless of length. Its not a 50ohm resistance, its the impedance a cable of infinite length apears to have to an input signal. However this only becomes relevant at either high frequencies or long distances, at which time impedances have to be matched to maximise power transfer and to avoid your signal bouncing back down the line and frying whatever sent it.

At low frequency or short distance a cable (or wire) is not treated as a transmission line, its simply an electrical connection with a certain resistance.
For audio a guitar cable, whilst having a different transmission line impedance to a speaker cable, it is basically just an electrical connection like the speaker cable, but with thinner wire in it, and therefore greater resistance, and therefore worse power handling capability. The resistance is small though. Maybe a tiny fraction of an ohm for a speaker cable, and maybe an ohm for long guitar cables? Never measured it. Is negligible as far as the impedance matching Vs audible difference is concerned anyway. Its the power handling thats important.

As an experiment, try using both types of cables to connect an amp to speakers (at low power) and see if you can hear any difference. I certainly cant.

Eoin Madsen

I understand that, didn't particularly want to get technical re impedance vs resistance etc.

I have done that by experiment, and I did find a difference.

Paladin

Then use speaker cables

My point is basically if you dont have one available an instrument cable will function just fine. My hearing doesnt notice any difference, and most audiences probably wont either.

Eoin Madsen

Paladin wrote:

My hearing doesnt notice any difference, and most audiences probably wont either.

Hmm, I didn't consider it a subtle difference, tbh.

Most curious. I'll do some further research into it. Cheers for the info.

Paladin

Just checked....

My bands bass player owns our PA and he apparantly is using one guitar cable with a bent jack and one speaker cable for the two speakers. He is a careless bastid tho
He played a bass amp that for the last 2 years had 2 out of the 3 bass,mid and treble knobs broken :cool:

Beecher

feylya wrote:

Open it up and look at the soldering connections. If both the wires have a sheath on them, it so be ok. If one of the wires is bare, it's an instrument cable.

Thanks for that, it wasnt a speaker cable which is gonna bother me as my setup arrived today and I could be playing with it if I didnt have to wait for a new cable !



aint she buuutiful! No reverb though but a g-major will sort that out nicely

feylya

Nice! How much did that set you back? What controller are you using?

Beecher

feylya wrote:

Nice! How much did that set you back? What controller are you using?

500 euro's (plus 45 shipping) off the ebay, including the 6U case Ive got a behringer fcb1010 lying around from my days when I thought the amplitube vsti was the best thing ever! Also have various footswitches lying around aswell which could also do the job

feylya

Sweet! What cab you using?

Beecher

feylya wrote:

Sweet! What cab you using?

Ive got a lend of a 1x12" off a mate, its in bits but should do the job till I can order either this or this along with a g-major on sunday!

feylya

Personally, I'd go for the Framus.

Beecher

feylya wrote:

Personally, I'd go for the Framus.

I like the look of the framus, and the fact its a 2 x 12" (which is all I really need), plus it has the same speaker as the engl, plus look at that price!!! Im only worried about the quality of the cab, marine ply doesnt sound that awesome.

SirLemonhead

Beecher wrote:

I like the look of the framus, and the fact its a 2 x 12" (which is all I really need), plus it has the same speaker as the engl, plus look at that price!!! Im only worried about the quality of the cab, marine ply doesnt sound that awesome.

What would you rather it was made of?

Beecher

MasterOfSolos wrote:

What would you rather it was made of?

Solid wood as opposed to plywood.

feylya

Rare that you get a solid wood cabinet tbh. Most of them are plywood, birch usually afaik. Only the stupidly expensive custom Mesa cabs are solid hard wood.