Conference hips::uk_audioo

    What is Bi-wireing ?

    If you have a speaker with two drive units (bass and tweeter), the
    crossover divides the signal between these two drive units.
    
    The crossover may be arranged in such a way as to separate the two
    halves of the crossover electrically.  The connections for the
    speaker are then made with a pair of wires for the tweeter and another
    pair for the bass unit.  This will often give benefits in the area
    of imaging and perhaps cleaner bass etc.

    re .0......
    
    I don't know a lot about bi-wiring in your configuration, but my
    guess is it would be a mistake to use different cable for each drive
    unit. All frequencies should arrive at the drive units in the same
    relationship as they start out from the amp's 4mm sockets, and with
    the same relative amplitudes. You will hear a difference, of course,
    but would it be better? You've nothing to lose by trying, but I
    wouldn't spend a lot 'till I knew - try using solid mains wire first.
    I would guess you'd get the most enjoyable (not necessarily analytic)
    results using identical lengths of the cable you already have.
    
    There are better cables, of course, but that's another can of worms
    altogether.
    
    Dave

    Hi,
    
    Could some one help me with this question. 
    
    I have a pioneer a-400 and Cyrus 780 speakers. These speakers can be
    bi-wired. Would I get an improvement in performance by connecting each
    drive unit via seperate cable ? The poineer only has one set of speaker
    outputs. 
    
    Could someone explain why bi-wiring in general improves quality.
    
    Regards,
    Jonathan
    
    
    
    

    
    You can bi-wire by having two wires starting at the amplifier end each
    terminating in one of the sets of terminals at the speaker end.
    
    
    rough diagram, one channel only shown
    
    
    
    ------                                          |        |
    |    |{-----------------------------------------| HF unit|
    | A  |{------------------------------ red \  /--|        |
    | M  |                                     \/   |        |
    | P  |{-------------------------------black/ \--|        |
    |    |{-----------------------------------------| LF unit|
    ------                                          |        |
    
    Hope that makes some sort of sense.
    
    As to *WHY* is sounds better, there are probably as many answers as
    there are speaker reviewiers. The only this to do is to try it and see,
    after all unless you're using �100 per metre cable, its only going to
    cost a few quid

    Thanks.
    
    I'll certainly give it a try. I was just trying to understand a
    technical reason why the sound could be improved. I guess it's down to
    the old lugoles again.
    
    Regards,
    Jonathan
    
    

    A technical reason that has recently been given in What Hi-Fi is that
    when the LF half of the speaker is working hard voltage fluctuations
    can occur in the speakers earth plane (it becomes something other than
    0).  This can effect the performance of the HF half.  Bi-wireing ties
    both halves of the speaker down to a comman earth (ie. that of the
    amplifier).  
    
    Being non-technical I find it difficult to understand why linking both
    halves of the speaker together at the amp should make any difference
    over linking them at the speaker.  I also find it difficult to
    understand why speaker manufacturers haven't designed the 'problem' out
    - Rega for example do not provide terminals for bi-wiring claiming that
    this would not improve the performance of their speakers.  The Rega
    Kyte has recently received rave reviews.
    
    Has anybody who has experimented with bi-wiring noticed any real
    (rather than percieved) improvement ?
    
    Nigel
    
    
    

Surely a perceived improvement is a real improvement?  Use your ears.

    My Kabers are Tri-wired and it did make a small but significant
    difference.

    Re -2    My apologies, what I really meant was is any difference such
    that there is no possibility that it could have been imagined.
    I think it is implicit in my question that I haven't done a comparison.
    If I had I would of course have used my ears and fully expect
    respondents to have followed your advice. If this is not the case
    please would you let me know what organ was used in making the
    comparison (and how).
    
    Re -1    
    
    How do you hide the cables ?
    
    How small does a difference have to be for it to be insignificant ?
    
    Can you describe the effect and is it worth the bother  ?
    
    Regards
    
    Nigel
         

    I can easily hide the cables because my speakers are either side of the
    cabinate with the Hi-Fi in.
    
    As for the difference, it may be small relative to say a LK-1 .v. Kairn
    but it is certainly much cheaper :-) having done it I wouldn't go back.
    
    		Rik

    It's a mechanism by which the HiFi manufacturers conspire to make you
    buy twice as much massively over priced speaker cable than you would
    normally, IMHO ;-)

    Re -1
    
    Oh, does that mean that bell wire from B&Q is a no no.

>>    Oh, does that mean that bell wire from B&Q is a no no.

	not at all - that's doing a very good job for the speakers
	in the kitchen :)
	
	jack 

RE: 81.7

Dredging back to my days in electronics I can probably elaborate a bit;

Passive systems require the high & low frequency split to take place after the
signal has been amplified via the use of a passive crossover (usually situated
inside the speaker). In electronic terms this is a high power signal which
causes a headache when trying to design the crossover. If a high power signal
is placed in close proximity to the ground line it can induce a current within
the ground line. This ground line will be common to all parts of the circuit &
hence this distruption of the reference point can have quite adverse affects on
the parts of the circuit which are dealing with small signal levels
(predominantly the HI frequency part of the circuit). 

The theoretical advantage of BI-wiring is that it allows the HI & LO frequency
part of the circuit to be physically separated - the two earth lines only
joining at the amplifier terminal. This allows the crossover designers more
scope for keeping the earth line away from the high signal line (thereby
reducing the current induction effect). 

There is another advantage too if you consider that there is always some
voltage difference within an earth line. BI-wiring reduces the harmfull effect
of this by allowing the difference in voltage on the ground line the be less to
the HI frequency (where it has the most damaging effect) than the difference
between ground & the LO frequency signal (where the effect is less damaging).

How much of an improvement (if any) BI-wiring makes depends on both the
complexity & design competence of the crossover. For a speaker with a complex
crossover such as the Linn Sara 9 (beast of a crossover if ever I saw one) then
the advantages of BI-wiring were easy to hear. However better speaker driver
design has meant that these complex designs have fallen out of favour & some
crossovers these days consist of only one component (eg EPOS range) - in these
cases the advantages for BI-wiring are largely academic. In an interview the
designer of the EPOS range of speakers admitted that a BI-wiring option had
been included for marketing reasons rather than the pursuit of better sound
quality.

As always only your ears can decide but be careful about invalidating certain
manufacturers warranty cover - BI-wiring Naim amplifiers for instance will
jepordise your warranty.

Jeff

    I've just bought some Mission 760i SE's and they're wired up as per
    normal at the mo. I will bi-wire them next week and tell you of any
    difference, though I doubt I'll notice anything I play 'em so loud I'm
    as deaf as a post anyway!
    
    Dan
    ;-)

    Well, after years of being a sceptic and scoffing at things like
    freezing disks, green lines on disks, gold mains plugs, cables having
    a direction, parking your car away from the house, having books with an
    odd number of pages(!), etc etc I bi-wired my speakers last weekend
    fully expecting to have another jolly old wheeze at all those hi-fi 
    anoraks (you know the type, $10000 system but only a couple of LPs, 
    usually Genesis)
    
    Anyway, lordy, lordy whats this ? The difference was easy to hear !
    Or was it that I was just listening more ? So, I bi-wired one speaker
    only and tried again, it was true ! Much cleaner treble, it was so easy
    to hear the difference, I got my girlfriend to listen in too and she
    agreed straight away, so I'm not dreaming.
    
    So there we are, bi-wiring my speakers did make a difference and a big
    one at that - I've heard much less aural differences between mid and 
    very high priced CD players.
    
    Really, I'm gobsmacked, where do you get the green pens ?
    Dave WOOD (Mission Cyrus 752's by the way)