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This old nut-Long interconnects or Long speaker cable.

Discussion in 'audio' started by Stilgoe1972, Nov 16, 2013.

  1. Stilgoe1972

    Stilgoe1972 pfm Member

    Due to a system equipment change around which involves an Audio research (ls27) & bryston 7bsst Im tossing up whether to go 11 metre fat as f.... speaker cables or 10m balanced leads from pre to power.
    Usually the balanced cables wouldn't be a problem.The output impedence of the ARC is 700ohm but may vary considerably and the input impedence of the bryston is 20kohm and may also vary considerably.Combined with 10 metres of vandamme quad core balanced cable could I be "damaging" the audio signal?
    I have contacted both AR and bryston about the variance in the input and output impedence over frequency but they haven't replied. I have found no measurements on the net either.
    On paper it fits the 10:1 ratio easily but in reality with the variances am I low pass filtering with the additional 1400fh of capacitance of these cables.
    This has led me to think, well just use big old fat as hell speaker cable (mogami 3104) and keep my interconnects all 1 metre.
    Any thoughts?
    Any body use 10m speaker lengths?
    Speakers are PMC IB2 with minimal impedence of 3.5ohm if that matters.
    Cheers for any advice:)
  2. Darth Vader

    Darth Vader From the Dark Side

    Keep the speaker leads short.


  3. Stilgoe1972

    Stilgoe1972 pfm Member

    Hi DV,

    Have you AB compared this scenario before?

    How's them amps. You changed to small ones yet?:)
  4. arthur

    arthur Banned

    Get those bad boys activated and solve the problem properly and make them sound as good as they should.
  5. demotivated

    demotivated pfm Member

    I doubt if any modern amp varies it's input impedance much. Speaker impedance does vary a lot so you get a slight dip where its low. Since this is just above the bass, it just means a bouncier bass. 2nd order bass xovers behave better with a bit of series resistance in the wire. Why not get some thin bell wire and try it on your speakers in their present position to show the effect of a long cable?
  6. Stilgoe1972

    Stilgoe1972 pfm Member

    Thanks Arthur, I think going active would cost beyond the speaker cable or interconnect budget:) cheers a way.
    Demotivated- cheers,but It's not so much the speaker impedence that I'm concerned about, its the possible impedence mismatch with the varying impedence of the pre and power causing problems with each other especially with that additional 10m of quad core van damme cable involved.
    The pmc IB2 speaker minimum impedence is 3.5ohm, so an easy load for 7bsst even with 10m of speaker cable.
  7. davidsrsb

    davidsrsb pfm Member

    Will you have 10 power cables as well, so that the power amplifiers are on the same spur?
  8. Stilgoe1972

    Stilgoe1972 pfm Member

    Errrr no. 2 power amps.
  9. davidsrsb

    davidsrsb pfm Member

    Missing "m". I am asking if the power amps would be effectively plugged into the same outlet(s) spur. Plugging into outlets on different spurs/rings causes noise in the interconnects (see the Biil Whitlock papers)
  10. mikemusic

    mikemusic pfm Member

    I bit the bullet a few years ago and put everything on the same wall.
    Would still prefer the kit next to me as was, but any leads now would be incredibly long
  11. Stilgoe1972

    Stilgoe1972 pfm Member

    Yes, they will be plugged into the same ring, which isn't a 'spur' . I'm not suffering from any noise in the interconnects as they are.

    Bottom line, has anybody noticed changes going from 3 metre speaker cables to lots more - ie 11 or so in a normal system with non fancy speaker cables?

  12. Michael J

    Michael J pfm Member

    My regular "short, thin" speaker cables are about 6m/19ft, generic 70-something stranded stuff. My "long, thicker" ones are over 12m/40ft, about 100 strand, and I don't have any problems using either - or noticed much if any difference in sound.
  13. dtd

    dtd pfm Member

    I noticed quite a difference going from 3m (2.5mm thickness) per amp to 0.5m (4mm thickness) per amp. Most noticeable in the bass region, less interaction with the room / cleaner bass due to better control of the speaker cones I'd guess. Though those amps do have some crazy damping factor of 11000 according to its literature (Hypex NC400). Night and day in this case, but would ofcourse depend on your amp and whether its damping factor is having a significant effect on your speakers?
  14. Norman Green

    Norman Green pfm Member

    Signals travelling a longer distance must surely slow the music down (signal and listener and reader fatigue factor).

    I can’t be serious.
  15. Darth Vader

    Darth Vader From the Dark Side

    In the early days speakers were 3 Ohms and were used with amps inside the case. Then there came the need for speakers remote to the amps like for example stage work/bands. A more expensive 15 Ohms speaker was developed to allow for this. Of course you could still drive a 3 Ohm over long cables but to do so required the use of line transformers at each end of the cable.

    There are a number of reasons why its better if you can use short cables to the speakers maybe less so important today with solid state amps. You can research this on the web. So if you ask a generic Q should I use long speaker cables or long balanced connects then I would go with the latter. But there are special cases no? Like old Naim amps that were unstable if the speaker cable was too short! Talk about good amplifier design.

    BTW I still have the 84Kg of amps as I'd have to spend £10K or so and I am informed for no gain in quality over what I already have. Seems a shocking waste of money.


  16. Stilgoe1972

    Stilgoe1972 pfm Member

    Good for you DV, stick with them:)

    On the cables front, it's more the impedance (pre & power) mismatch that's a bother which has led to even think about going single end.....YUk, as the impedences would match better.
  17. Darth Vader

    Darth Vader From the Dark Side

    I wouldn't call that a mismatch low (700) into high (20k) is good. Even the spec for the pre-amp says a minimum of 20K. I wouldn't worry about it. I believe it is the standard way of connecting pro equipment although I think 600 ohm output is the norm and maybe why its suggested 20K as the minimum load.



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