Harmony Central Forums
Announcement
Collapse
No announcement yet.

Speaker cable gauge question

Collapse



X
  • Time
  • Show
Clear All
new posts

  • 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/FMIC/JAM Industries 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 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


            • #7
              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


              • #8
                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/FMIC/JAM Industries Company, continuing factory level product support and service for Genz Benz

                Currently product development engineer: Mesa Boogie

                Comment


                • #9
                  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


                  • #10
                    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


                    • #11
                      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


                      • #12
                        Wire ampacity varies depending on the thermal rating of it's insulation, and the cooling effects of the materials surrounding the wire, including ambient temperature. Material also matters... aluminum wire has a lower ampacity due to lower "per unit" conductivity. Duty cycle also affects the ampacity. Ampacity is independant of applied voltage which is why a piece of 12 gauge wire may carry up to 100kVA (similar to 100,000 watts) of power to a load without a problem under high voltage conditions.

                        12 gauge (copper) wire can have an ampacity of between 10 amps and 30 amps depending on the application.

                        Nothing is quite as easy or simple as it seems.
                        -------------------------------------------------------------------------------------------------------------------------------------------------------------------
                        Former product development engineer: Genz Benz, a KMC Music/FMIC/JAM Industries Company, continuing factory level product support and service for Genz Benz

                        Currently product development engineer: Mesa Boogie

                        Comment


                        • #13
                          No, you can keep increasing the current but the losses in the wire will increase by the square of the current till the wire melts.

                          Actually, it becomes even more non-linear as the temperature increases the wire's resistance increases too but only as the wire gets really hot.

                          For example, in free air, 0-2000 volts, uninsulated copper wire is code-legal to 78 amps for type PFAH ot TFE (teflon) at an opertaing temperature of 482 degrees F, and nickel coated copper conductor. For copper only, 68 amps.

                          This is all provided the voltage drop is acceptable for the application.
                          -------------------------------------------------------------------------------------------------------------------------------------------------------------------
                          Former product development engineer: Genz Benz, a KMC Music/FMIC/JAM Industries Company, continuing factory level product support and service for Genz Benz

                          Currently product development engineer: Mesa Boogie

                          Comment


                          • #14
                            You are hinting at the thermal non-linear portion of the curve... like the yield point on structural materials.
                            -------------------------------------------------------------------------------------------------------------------------------------------------------------------
                            Former product development engineer: Genz Benz, a KMC Music/FMIC/JAM Industries Company, continuing factory level product support and service for Genz Benz

                            Currently product development engineer: Mesa Boogie

                            Comment


                            • #15
                              Seems pretty silly for a bucks worth of wire to even debate it, since larger wire isn't going to hurt anything.

                              Comment













                              Working...
                              X