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  • Speaker cable gauge question

    i'm currently using 4mm conductor thickness cable for connecting my amps to subs in about 50ft lengths,

    my question is -
    If my amp rack has speaker patch leads going from the amp binding post to a rack patch panel, and these patch leads are made up of 1mm thickness conductor and a lenght of about 1 foot will the small gauge patch leads have a detrimental effect on the system?


    cheers, john
    VHT pittbull CL100
    marshall 1992 plexi superbass 1969
    marshall 1992 superbass 1980
    marshall jcm800 2203 1984
    marshall jcm800 2203 zakk wylde
    marshall 2555 jubilee
    marshall TSL 601 combo
    marshall jcm600 2x12 combo
    Trace elliot Bonneville 100watt head
    peavey 5150
    peavey bravo 1x12 valve combo
    custom made marshall 2203 copy
    mesa boogie 395 power amp
    marshall jmp-1 pre amp
    marshall 9001 valve preamp


    gibson zakk wylde les paul
    gibson les paul studio 1995
    gibson sg 62 reissue 1991
    esp ltd ec-1000 stbc
    Edwards Les Paul Custom
    fender floyd rose strat
    squire super sonic
    epiphone les paul std
    epiphone Wayne static Flying V

  • #2
    Short answer: At low power, no. At high power, yes.

    We just finished having a 4-page debate (er... shouting match) about cable thickness. You can read it here.

    Comment


    • #3
      Why such small hook up wire? 1mm is roughly 20 awg.

      I'd use at least 2mm wire inside the rack (14 awg). Typically the cabinets themselves will have 16 awg hookup wire inside ... and it quickly gets smaller once it hits the speaker.
      Don Boomer

      Comment


      • #4
        All depends on how much power AND the minimum load impedance you operate at. For some applications it may be fine (like acoustic music wher ethe sub may be a small 100 watt 8 ohm box) but, I would look at either 16 or 14 gauge in as much as the cost is insignificant and the mechanical integrity is better. No benefit in going beyond 14ga for such a short run on any reasonable system configuration.
        -------------------------------------------------------------------------------------------------------------------------------------------------------------------
        Former product development engineer: Genz Benz, a KMC Music/Fender Musical Instruments Company, continuing factory level product support and service for Genz Benz

        Currently product development engineer: Mesa Boogie

        Comment


        • #5
          Originally posted by nobrainer440
          Short answer: At low power, no. At high power, yes.

          We just finished having a 4-page debate (er... shouting match) about cable thickness. You can read it here.


          yeah i did read that thread, it go quite scary in there!! lol

          ok i'm sending about upto 1.5Kwatt down 5 inches of 20 awg cable, I know 20awg is far to small but let me stress it's only 5 inches the 50foot run is down 4mm cable (whatevet the awg for that is!!)




          john
          VHT pittbull CL100
          marshall 1992 plexi superbass 1969
          marshall 1992 superbass 1980
          marshall jcm800 2203 1984
          marshall jcm800 2203 zakk wylde
          marshall 2555 jubilee
          marshall TSL 601 combo
          marshall jcm600 2x12 combo
          Trace elliot Bonneville 100watt head
          peavey 5150
          peavey bravo 1x12 valve combo
          custom made marshall 2203 copy
          mesa boogie 395 power amp
          marshall jmp-1 pre amp
          marshall 9001 valve preamp


          gibson zakk wylde les paul
          gibson les paul studio 1995
          gibson sg 62 reissue 1991
          esp ltd ec-1000 stbc
          Edwards Les Paul Custom
          fender floyd rose strat
          squire super sonic
          epiphone les paul std
          epiphone Wayne static Flying V

          Comment


          • #6
            Originally posted by dboomer
            Why such small hook up wire? 1mm is roughly 20 awg.

            I'd use at least 2mm wire inside the rack (14 awg). Typically the cabinets themselves will have 16 awg hookup wire inside ... and it quickly gets smaller once it hits the speaker.

            ?

            I think kobe means 4sq. mm, which I believe is about 1/2 way between 10 and 11 ga.

            4sq. mm is pretty fat stuff.

            I believe 4sq. mm is the fattest conductor that will fit in NL4FC and NL4FX cord ends.

            oh wait a minute... now I see the 1mm stuff (my eyes are just crap, and I never seem to have reading glasses close at-hand... and who's idea is black on a blue background typing field... don't those computer wiz-kids know most of us are varying degrees of colorblind? Psstt: Black on a white background is the highest resolution possible... ok? You know? Like all the boarder stuff which I can clearly read... even at arms length, or even slightly less. Crap... I hate getting old). Yup... that's pretty thin stuff. Yup, you're probably choking your chicken with that doing speaker cable duty... no matter how short it is. I suspose it would be fine for a few 10's of watts, but I doubt that's the application. I'd be kind of concerned about the possibility of spring loaded or screw banana posts cutting right through 1mm wire. I guess feel back there when your system's running hard and see if the conductors are getting warm. If they're getting at-all noticably warm, you're throwing away some potential.

            Comment


            • #7
              Originally posted by Audiopile
              ?

              I think kobe means 4sq. mm, which I believe is about 1/2 way between 10 and 11 ga.

              4sq. mm is pretty fat stuff.

              I believe 4sq. mm is the fattest conductor that will fit in NL4FC and NL4FX cord ends.

              oh... now I see the 1mm stuff. Yup... that's pretty thin stuff. Yup, you'd be choking your chicken with that doing speaker cable duty.


              choking the chicken...ha ha thats a great phrase!!

              remember than 1mm stuff is only a very short run.

              john
              VHT pittbull CL100
              marshall 1992 plexi superbass 1969
              marshall 1992 superbass 1980
              marshall jcm800 2203 1984
              marshall jcm800 2203 zakk wylde
              marshall 2555 jubilee
              marshall TSL 601 combo
              marshall jcm600 2x12 combo
              Trace elliot Bonneville 100watt head
              peavey 5150
              peavey bravo 1x12 valve combo
              custom made marshall 2203 copy
              mesa boogie 395 power amp
              marshall jmp-1 pre amp
              marshall 9001 valve preamp


              gibson zakk wylde les paul
              gibson les paul studio 1995
              gibson sg 62 reissue 1991
              esp ltd ec-1000 stbc
              Edwards Les Paul Custom
              fender floyd rose strat
              squire super sonic
              epiphone les paul std
              epiphone Wayne static Flying V

              Comment


              • #8
                Originally posted by kobe
                choking the chicken...ha ha thats a great phrase!!

                remember than 1mm stuff is only a very short run.

                john

                Like Andy sez: It's a combination of wattage, load impedance, and length of the run. Admittedly your run is real short, but I suspect the wattage is high enough and the load impedance is low enough that you could benefit from a larger cable size regardless of how short you make it. With that short of runs, the cost difference is minimal, and the PITA factor of dealing with 16ga. or even 14ga. is probably minimal.

                FWIW:
                AWG = sq. mm
                10 = 5.26
                11 = 4.17
                12 = 3.31
                13 = 2.62
                14 = 2.08
                15 = 1.65
                16 = 1.31
                17 = 1.04
                18 = 0.823
                19 = 0.653
                20 = 0.518

                Comment


                • #9
                  Originally posted by kobe
                  choking the chicken...ha ha thats a great phrase!!

                  I believe that reference has a notably different meaning here on the other side of the pond... but it seemed descriptive in the context of the subject matter. I guess the end result is about the same... possibly lots of activity, but a fairly single ended result regardless of the context.

                  Comment


                  • #10
                    Electricity is much like plumbing.

                    If you feed a 2" copper pipe with a 1/2" copper pipe, you'll never have more water in the 2" pipe than the 1/2" pipe can deliver.
                    Thanks,
                    Bill Cronheim
                    Entertainment Systems Corporation
                    Back stage since 1965
                    Equipment specialist since 1973

                    Comment


                    • #11
                      Yes, electricity has analogies to plumbing but applying the analogies appropriately can cause some misunderstandings.

                      Provided the power loss in the 6" piece of wire does not endanger the wire's insulation due to temperature rise, the wire's contribution over a 50' length of cable is only 1% of the total voltage drop. The only thing the speaker cares about is the total voltage drop to the speaker. If you look inside the amplifier, you may be surprised at the wire gauge feeding the output jacks, and the PCB traces feeding the speaker outputs. It's all calculated on voltage drop and I**R heating effects.

                      There is a point where the voltage drop will cause an unsafe rise in conductor temperature, so this is the second factor that must be considered. 17 gauge equiv. of 1 sq mm is a bit light IMO for your application, but not catastrophicly so. I would look at 16 gauge equiv. as a minimum and 14 as "ideal".
                      -------------------------------------------------------------------------------------------------------------------------------------------------------------------
                      Former product development engineer: Genz Benz, a KMC Music/Fender Musical Instruments Company, continuing factory level product support and service for Genz Benz

                      Currently product development engineer: Mesa Boogie

                      Comment


                      • #12
                        Originally posted by agedhorse
                        Provided the power loss in the 6" piece of wire does not endanger the wire's insulation due to temperature rise


                        Seems to me the minute one runs a continous load greater than the ampacity of the cables conductor, voltage drop in inevitable and failure just around the corner.
                        Thanks,
                        Bill Cronheim
                        Entertainment Systems Corporation
                        Back stage since 1965
                        Equipment specialist since 1973

                        Comment


                        • #13
                          Originally posted by agedhorse
                          Yes, electricity has analogies to plumbing but applying the analogies appropriately can cause some misunderstandings.

                          Provided the power loss in the 6" piece of wire does not endanger the wire's insulation due to temperature rise, the wire's contribution over a 50' length of cable is only 1% of the total voltage drop. The only thing the speaker cares about is the total voltage drop to the speaker. If you look inside the amplifier, you may be surprised at the wire gauge feeding the output jacks, and the PCB traces feeding the speaker outputs. It's all calculated on voltage drop and I**R heating effects.

                          There is a point where the voltage drop will cause an unsafe rise in conductor temperature, so this is the second factor that must be considered. 17 gauge equiv. of 1 sq mm is a bit light IMO for your application, but not catastrophicly so. I would look at 16 gauge equiv. as a minimum and 14 as "ideal".


                          This is exactly right. Since the run is short, it wont affect the overall voltage drop all that much, BUT since the diameter is so small, overheating is a very real risk.

                          Comment


                          • #14
                            Originally posted by nobrainer440
                            This is exactly right. Since the run is short, it wont affect the overall voltage drop all that much, BUT since the diameter is so small, overheating is a very real risk.


                            In The automotive industry they call that a "fusable link"
                            J.R. Previously jrble

                            See my Dog Of The Hair studio at: http://www.dogoth.com/studio/

                            Quote from someone: Flat response? Get out the jack and change the tire.
                            If you think "power is knowledge", you have it backwards.

                            Comment


                            • #15
                              Originally posted by BillESC
                              Seems to me the minute one runs a continous load greater than the ampacity of the cables conductor, voltage drop in inevitable and failure just around the corner.

                              It's been awhile since I've thought about it... but as I understand it, amps (coulombs of electrons) per unit of time is the limiting factor in wire. Yes, the voltage can be raised so those electrons are at a higher state of energy... but you can still only shove so-many electrons down a given gauge of wire per unit of time... as opposed to the water and waterpipe anology... where the same 1/2 dia. of pipe can carry wildly varying quantities of molecules of water depending on the pressure pushing them along. There isn't necessarily an upper limit of how many water molecules a 1/2" dia. pipe can carry per unit of time... the quantity just keeps increasing the more the pressure is cranked up... although admittedly, the wall thickness might have to be increased to handle the pressure... but it's still a 1/2" pipe... as opposed to wire, where the electron quantity capacity can't be increased in a given guage wire... by adding more insulation... or something... maybe by cooling it?

                              Comment



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