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Using shielded Cat6 as speaker cable for ceiling speakers

Discussion in 'Audio Visual' started by pls1, 27 Mar 2019.

  1. pls1


    18 Apr 2007
    Thanks Received:
    United Kingdom
    I've seen a few threads on other forums talking about using Cat6 as speaker cable but recommendation is to braid it which sounds like a ball ache.

    My setup is a multi-room 6 channel LivingControl Roombox6 which I'm planning to use to drive ceiling speakers in several rooms.
    Some of these speakers have been previously wired in to some cheapo ebay car amps which works ok but they do suffer from crackling sometimes due to interference. Thoughts are both the cables in use (1mm twin & earth) and probably the amps causing it.

    The new wiring between the Roombox6 & ceiling speakers will be predominately under floors & ceiling voids so there is the potential to be near other mains cables and other Cat6 for WiFi APs etc. Maximum cable run lengths will be in the region of 10-15m.

    Is shielded cable the best option or just try and separate the cables as much as possible and ground the amp/speakers to minimise interference? Twin & Earth obviously has an earth core so that could be utilised.

    I'll spend the money on decent cable if necessary but its not a case of 'money is no object'! :rolleyes:
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  3. bernardgreen


    3 Nov 2006
    Thanks Received:
    United Kingdom
    Speaker cable is not critical other than having a low impedance. The low impedances of the amplifier output and matching speaker means that the cable is not going to be affected by signals or 50 Hz power capacitively coupled to the speaker cable. Twisted pair cable is more than adequate for eliminating interference. The impedance ( resistance ) of CAT 5 would be a minor problem ( loss of volume ) on a long run.

    The ultimate of best speaker cables can be found HERE and they are not screened. They are a bit expensive and intended fro people with more money than sense ( of hearing ).
  4. Lucid


    10 Sep 2013
    Thanks Received:
    United Kingdom
    Don't use CAT cable for long speaker runs. I know there's a whole community of beardy-weirdies who've convinced themselves they've found magical properties in multiple lengths of CAT cable plaited together for speaker wire. I think the preferred quantity is 9-ply. If they want to dick about with that stuff draped across the living room floor then fine. But as an alternative to decent thickness 100% copper braided cables for muliroom use it's really a waste of time, effort and money.

    I sell and install multi-room audio gear as part of my business. I have not encountered any interference on long speaker runs (50-70m typically) with decent amplification and good in-ceiling speakers.

    When I'm spec'ing an install, the thing I am most interested in considering is the voltage drop over distance for the current being carried. The reason is cost. It's much cheaper to conserve the power than it is to buy more powerful amplifiers. I can offset a large portion of the potential power losses by using an optimum thickness multi-strand speaker cable made from genuine 100% copper. This last bit is really crucial. There's a lot of cable on offer that is aluminium with a thin anodised layer of copper. It's crap. The worst offender is the stuff with hundreds of filaments.

    Standard thicknesses for speaker cable are 1.0mm, 1.5, 2.5, and 4.0mm. If we take a 50W amplifier rated for an 8 Ohm load, and match that with an 8 Ohm speaker of decent efficiency (87-90dB/W/m), then compare the power losses for a 30m cable run, and then for a 15m run, we get

    50W @ 30m
    1.0mm - 21% loss (to 39.5W)
    1.5mm - 14% loss (to 43.0W)
    2.5mm - 9% loss (to 45.5W)
    4.0mm - 6% loss (to 47.0W)

    50W @ 15m
    1.0mm - 11% loss (to 44.3W)
    1.5mm - 7% loss (to 46.3W)
    2.5mm - 5% loss (to 47.5W)
    4.0mm - 3% loss (to 48.5W)

    Once you start to see the effect of thickness versus distance then it's easier to work out what to spend on.

    At the longer distance, 1.00mm cable throws away a 1/5th of the amplifier power. Upgrading to a 2.5mm cable more than halves the losses. That's a worthwhile gain. A 4.0mm cable is overkill at this distance.

    Over the shorter distance, a 1.5mm cable offers the best cost/performance balance. There's minimal technical benefit from going for a 2.5mm cable. However, there may be a price break on offer from the retailer, so that could swing an advantage where an install had a mix of cable run distances.

    If this or any other reply was helpful to you, then do the decent thing and click the T-H-A-N-K-S button. It appears when you hover the mouse pointer near the Quote Multi-quote buttons. This is the proper way to show your thanks for the time and help someone gave you.
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    United Kingdom

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