Can wrong cable gauge damage an amp?

[Aillo]

Hello,

First of all, I am sorry if my thread isn't in the right place. I couldn't find any section about cables so I am posting my question here.

I am a musician and phd musicologist. Like most people who record music, I have a first setup in a studio where I do all the music recording, mixing, mastering and serious listening stuff. In my living room, I have a second setup, a Marantz 1070 amp connected to two Alesis M1 Passive MKII speakers. I also own two JBL Control Ones that I would like to put in the kitchen.

I don't want to use a different amplifier. So I am planning to connect those JBLs to the same amp. The cable distance will be around 20m (65f). I really don't care about the sound quality in the kitchen so I want to go for standart cables which are 2 X 0.75mm2 in my country of residence. We don't use the American wire gauge system but it is a little bit thinner than the 18 AWG. The reason I do this is the cables will go through many visible places and if I use thicker stuff, my wife may try to kill me... Also it is much cheaper...

So the question is: can cable resistence possibly damage an amplifier such as my Marantz 1070? Or do you see any other problem in my setup excepting the sound quality?

PS: JBLs will be connected to the 2nd (Remote) output of the amp.

Thanks in advance for all your answers,

 

[ConradH]

I'm going to say no, the cable can't damage the amp.

 

[DaveVoorhis]

So the question is: can cable resistence possibly damage an amplifier such as my Marantz 1070? Or do you see any other problem in my setup excepting the sound quality?

No, (slightly) higher resistance won't cause damage to the amplifier.

 

[the skipper]

No, thinner cable increases resistance. Lower resistance is an issue. Higher is not.

But, you might want to consider the rated impedance of your four speakers. If you play them at the same time, the impedance (resistance) your amp sees is decreased and THAT may be an issue, ..not the thin wire..

 

[62caddy]

High capacitance cable is another story however...

 

[Aillo]

Ok. Thx for all the super quick answers!

No, thinner cable increases resistance. Lower resistance is an issue. Higher is not.

But, you might want to consider the rated impedance of your four speakers. If you play them at the same time, the impedance (resistance) your amp sees is decreased and THAT may be an issue, ..not the thin wire..

That is a good point. My Alesis speakers are 4 ohms and the JBLs should be 8 ohms. So you do not recommend using both at the same time, am I right? Could you explain why?

 

[the skipper]

I would not run them both simultaneously. Disregarding the wire, the impedance presented to the amp is about 2.7 ohms. That's dangerously low and can fry many amps.



The formula for calculating the impedance is (r1 X r2/r1 + r2), or (8 X 4/8 + 4), or (32/12), or 2.66 ohms.

 

[WaynerN]

It should be the equivalent of 16awg.

 

[musichal]

There are some outboard speaker selector switches with separate attenuators (volume controls) that will allow you to run both sets off your amp without fear of too low an impedance. Used to be Niles was our go-to, but others can post some examples of current models that will do this for you. And it also gives you control of the levels of each speaker pair separately, which you may find is needed.

 

[Aillo]

I would not run them both simultaneously. Disregarding the wire, the impedance presented to the amp is about 2.7 ohms. That's dangerously low and can fry many amps.

View attachment 1387499

The formula for calculating the impedance is (r1 X r2/r1 + r2), or (8 X 4/8 + 4), or (32/12), or 2.66 ohms.

That is valuable info. Thx a lot. I guess I have done that mistake in the past. Will never do again. But amp sounds ok. I have also checked the operation manual, it says that basicly if a pair of 4 ohms plugged in, I shouldn't use anything else with it.

There are some outboard speaker selector switches with separate attenuators (volume controls) that will allow you to run both sets off your amp without fear of too low an impedance. Used to be Niles was our go-to, but others can post some examples of current models that will do this for you. And it also gives you control of the levels of each speaker pair separately, which you may find is needed.

Thx for the info musichal. I guess for now I am ok because there is a switch on my amp and luckly (or weirdly) the amount of volume is pretty much the same. That kind of stuff should be very useful though in a more complicated setup.

 

[musichal]

That is valuable info. Thx a lot. I guess I have done that mistake in the past. Will never do again. But amp sounds ok. I have also checked the operation manual, it says that basicly if a pair of 4 ohms plugged in, I shouldn't use anything else with it.



Thx for the info musichal. I guess for now I am ok because there is a switch on my amp and luckly (or weirdly) the amount of volume is pretty much the same. That kind of stuff should be very useful though in a more complicated setup.

As long as you don't run both pair simultaneously, you should be okay.

 

[dondoucette]

This is what Brian Gary Wachner of BGW Systems has to say about speaker wire.




Just FYI

 

[Gibsonian]

No damage but I would opt for smaller gage wire than that for 65 ft unless I'm broke. I don't run that small of wire period. You are adding more than an ohm of resistance to you circuit with current plan.

 

[Bodyblue]

16awg should be fine maybe 14 if it is not too visible. The 1070 in good condition can easily deal with 4ohm loads but nothing lower than.

The wire terminals on the back probably cant take anything bigger than 14awg anyway.

 

[toxcrusadr]

If you DO want to run both sets simultaneously, you can get a speaker selector box that has impedance compensation. It will present an 8 ohm load to the amp with both sets playing. If you're not going to play both, might as well not have it in the signal path.

 

[twiiii]

Same chart Crown used with their DC series amplifiers. But it assumes you know the damping factor of your amp. As long as the internal resistance as a sum of the two conductors doesn't amount to 5% of the impedance of the speaker you should be OK. So you don.t want the internal resistance to be more than 8 X o.o5= 0.4 ohms. or about 14 awg wire for your distance. Remember wire with in walls has to be CL2 rated to prevent pollution of off gases during a fire. . $$. Wrong wire your insurance company may not pay..

 

[Aillo]

Thx everyone for all the additional information. I studied it and found it very valuable for general hifi knowledge. But I have the impression that we are slightly getting off track here. So, I would like to sum up a little:

As I mentionned, I have a studio at my place where I can do all the audiophile stuff. I also have a second setup, much more modest one that I use for daily listening. To that setup, I want to add two more speakers. First of all, I know now that I should definitly not use simultanously a pair of 8 ohms with a pair 4 ohm speakers with my Marantz amp, thanks to your recommendations. But I would like to remind the first question: can wrong cable gauge damage an amp such as my Marantz 1070 or not?

Again, as I mentionned, I really really really do not care about the sound quality of those remote speakers (it is for the kitchen, so I can listen to music while cooking and washing the dishes). All the data that has been shared at the late posts doesn't say anything about damaging, it mostly points out problems regarding sound fidelity. Also, many people told me in the begining that it wouldn't damage but now I start to hear comments such as:

As long as the internal resistance as a sum of the two conductors doesn't amount to 5% of the impedance of the speaker you should be OK. So you don.t want the internal resistance to be more than 8 X o.o5= 0.4 ohms. or about 14 awg wire for your distance.

OR

16awg should be fine maybe 14 if it is not too visible.

Without giving a direct answer to the question, these kind of remarks scare me a little. So please tell me why "16 awg should be fine" or "why I don't want the internal resistance to be more than..."

BECAUSE it can possibly damage the amp (or not)? That is really what matters to me. If yes, please share your experience of thin cable damaging an amp.

Thanks in advance for your further answers and your understanding.

 

[the skipper]

But I would like to remind the first question: can wrong cable gauge damage an amp such as my Marantz 1070 or not?

No. This was answered quite plainly in the first responses you received. What more do you want?

 

[DaveVoorhis]

But I would like to remind the first question: can wrong cable gauge damage an amp such as my Marantz 1070 or not?

There is no cable gauge you can use that would damage your Marantz 1070.

 

[Aillo]

No. This was answered quite plainly in the first responses you received. What more do you want?

My message wasn't to you the skipper. I just don't understand why people keep recommending thicker cables. We already know about that stuff. Yes, it is much better. I got it. We all got it I guess.