Length of Speaker Cable?

Discussion in 'Cables & Switches' started by stuart2, Jan 17, 2008.

  1. stuart2

    stuart2
    Active Member

    Joined:
    Feb 24, 2006
    Messages:
    335
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    18
    Ratings:
    +14
    Just how long is too long? I know sound quality reduces with length of speaker cable. But at what point does this become significant with a reasonable cable from say QED, Chord, etc.? With HiFi speakers you would need maybe 4 metres. Hopefully sound quality would not have degraded with just 4 or 5 metres? With surround sound you would need significant lengths for the rear speakers.
     
  2. John Clark

    John Clark
    Active Member

    Joined:
    May 8, 2005
    Messages:
    120
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    18
    Ratings:
    +4
    http://www.roger-russell.com/wire/wire.htm

    you probalby have to find a conversion table for the guage but this will tell you what you need to know. Also try reading all, it opened my eyes somewhat to speaker cables.

    Regards

    John
     
  3. davepuma

    davepuma
    Distinguished Member

    Joined:
    Jun 24, 2004
    Messages:
    17,536
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    166
    Ratings:
    +3,506
    That's the link I was trying to find! I don't have it bookmarked on this pc.
     
  4. stuart2

    stuart2
    Active Member

    Joined:
    Feb 24, 2006
    Messages:
    335
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    18
    Ratings:
    +14
    Thanks very much John. :thumbsup:
     
  5. BlueWizard

    BlueWizard
    Distinguished Member

    Joined:
    Jun 19, 2007
    Messages:
    22,255
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    166
    Ratings:
    +4,195
    Here is a link to the AVForum's Cable forum which compares AWG/SWG/Euro wire gauges and also has a ohms per kilometer rating.

    Speaker Wire Gauge Conversion - Euro/UK/American
    http://www.avforums.com/forums/showthread.php?t=686328&highlight=wire

    In short,

    Euro Standard Wire -

    1x1.00mm2 ... 18.10ohm/km ... > 18 ga AWG
    1x1.50mm2 ... 12.10ohm/km ... > 16 ga AWG
    1x2.50mm2 .... 7.40ohm/km .... > 14 ga AWG
    1x4.00mm2 .... 4.61ohm.km .... > 12 ga AWG

    One Kilometer is about 3281 feet (3280.84).

    So,

    1.00mm2 = .0055 ohms per foot
    1.50mm2 = .0037 ohms per foot
    2.50mm2 = .0023 ohms per foot
    4.00mm2 = .0014 ohms per foot

    We could tolerate loses of 0.1 meaning an 8 ohms speaker could have 0.8 ohms of wire, but 0.01 would be more ideal, meaning an 8 ohm speaker could have .08 ohms of wire.

    Which means 14 feet of 1.00mm2 (18 AWG) with an 8 ohm load.
    (target_ohms_loss/ohm_per_foot = 0.08/.0055 = 14.54 feet).
    Or about 7.3 feet to a 4 ohm load. (11ft for 6 ohms)

    Again, that is ideal, from a practical perspective you can double that and not have any problems at all, and you will find that is consistent with the wire chart on the Roger-Russel page linked to below.

    There are wire gauge charts all over the Internet for every wire gauges standard in the world. If you can't find this thread, simply search wire gauge and you will find an ohms/foot chart somewhere. Keep the total resistance of the wire to about 1/50th of the speaker and you should be fine.

    Steve/bluewizard
     

Share This Page

Loading...