Long inter-connects or speaker cable?

Steve.EX

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Given that i use 3 power amps, 1 for front pair, 1 for center and and 1 for rear/back in conjuction with a processor, rack mounted this entails a long co-ax from the non-local dvd player, shortish (.75m) inter-connects and lots of speaker cable : 4 x 7m for fronts (bi-amped), 3 x 6m for center (tri-amped) and 4 x 4m for rear and backs, co-ax is approx 6m but "reputedly" very high quality (read expense!!!).

As per usual the camp seems split as to having the power amps adjacent to the speakers (long inter-connects) or adjacent to source (long speaker runs).
Given a presumed standard for quality in both inter-connects and speaker cable does anyone have any defining discoveries on this matter, i feel given that i am using mains conditioning (isolating transformers etc) and high and low level stuff in close proximity is kept to an absolute minimum the method i am using offers the chance for induced problems etc (given maximum possible csa's of conductors etc)
Your opinions please, practicality should not be considered an issue.


Steve.
 
I know Nic has just suggested long interconnects, presumably as they would be better shielded??

What about using interconnect cable instead of speaker cable?? Just a thought! Would it work?:confused:
 
Yes, i am disposed to the realisation that perhaps "i have got it wrong" (yet again).
If i were to select the opinions of those i feel know or at least have experimented "a bit" almost to a man longer inter-connects seem the prefered option.



Steve.

(As the years roll on it seems that hifi now also to incorperate A/V theories have their own "circle of life").
 
i have used long speaker cables for some time, but i am in the process of changing the ste up to minimise speaker cable lengths. Since Nic has given that the thumbs up, obviously its a good plan!

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Originally posted by Jase
I know Nic has just suggested long interconnects, presumably as they would be better shielded??

What about using interconnect cable instead of speaker cable?? Just a thought! Would it work?:confused:

I don't think interconnect cable would work very well as speaker cable, after all they have been designed for each job specifically.

Speaker cable has true + and - sides, whereas interconnect has signal and earth.

For long interconnect runs use balanced cables (XLR) if it is an option. They will suffer from very little interference.
 
Originally posted by ReTrO
Speaker cable has true + and - sides, whereas interconnect has signal and earth.

erm.......yeah, and you can reverse the cable and have the same results!
 
Originally posted by mjn


erm.......yeah, and you can reverse the cable and have the same results!

Should have explained better.

Signal cables can all share a common earth, whereas speaker cables need their own + and - sides or BOOM!
 
thats better..!
 
Originally posted by ReTrO


Should have explained better.

Signal cables can all share a common earth, whereas speaker cables need their own + and - sides or BOOM!

So thats the technical term for it!
 
No one has yet explained why the long interconnects????? The interconnect carries a small signal therefore is very sensitive to any noise that is induced, whereas the same noise induced into a speaker cable will be insignificant because it carries a much greater signal........ or am i totally wrong?

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Signal cables, if they are decent, will have good shielding which stops the signal being interfered with. Balanced signal cables should 'theoretically' have no interference due to their design.

Speaker cables on the other hand are excellent at picking up interference, because they have no shielding. I used to use a bit of speaker cable as an FM aerial for my tuner, and it worked quite well.
 
ah..... i think that makes sense..... larger signal through speaker cable means it picks up interference more easily........ makes sense.

But...... surely any crap the interconnect picks up will then be amplified and then the signal will proceed to pick up more via the speaker cables?

Why dont you keep the signal as clean as possible prior to the amp, then you wont be amplifying the noise? Or is it siply a matter that a well shielded interconnect picks up negligible noise even when that noise is amplified?

I had a conversation this morning that made me consider this. High frequency signals..... interconnecting cable was kept minimal to avoid the raw signal picking up noise which would then be amplified.......

I believe long interconnects to be correct, and i see why for balanced, but i cant do that!

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I have now placed all power-amps local to their respective speakers (in the process losing LOTS of meters of cabling) and am happier with performance this way.

Steve.
 
I agree that the result seems to be bestter, but im trying to understand exactly why. In that way i can possibly work out something even better! :D

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I'm glad I haven't started cabling my new HT yet. It would actually be easier for me to site a power amp close to each Bi-Amped front speaker.

The problem I can see is running 2 X 20M long interconnects to the power amps is going to be quite expensive.

Can anyone recommend a good "bang for bucks" solution? I'm not after the cheapest interconnects but I do need a cost effective solution.

Mark
 
Hold that thought mark..... im making some of my own interconnects over the next short while....... the piano cable from tnt. at £2 a meter plus termination, it isnt too expensive.

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I don't think there is a simple answer to this (as always!) as I think it depends on the electrical properties of your processor/pre/power amp combination, plus the electrical load of the speakers as 'seen' by the amp. I have a Musical Fidelity Pre/Power driving a pair of Kef Speakers.
To quote from MF's literature.
" MF reccomends that long pre to power interconnects are used to allow the loudspeaker cables to be as short as possible.
The MF pre-amp has a very low output impedance and the power amp has a very high input impedance. This allows long interconnects to be used easily. This in turn allows the ideal of short loudspeaker cables to be achieved"

I suspect the differences between best case/worst case scenario's to be quite minor. I think the practicalities of cable layout and cost would influence me more!

Yummy Fur
 
Originally posted by buns
No one has yet explained why the long interconnects?????

Well it seems there is more interest in this topic than the two word answer by Nic so I will try and explain why.

It is based on the physical fact that the output impedance of a good preamplifier is low, the input impedance of a good amplifier is high, and hence the current is minimal. With the current being minimal, and the frequency limited to the audio band, we simply need a well screened analog interconnect. See the recent cable threads for more info on this

The situation is different with a power amplifer to loudspeaker connection. Here we have a very small output impedance of the amplifer and a veritable complex load of a loudspeaker (some much worse than others). The current is high and most amplifiers use feedback to improve their output quality. This requires a cable of low resistance, low capacitance and low inductance as well. This makes cable cooper hungry and (almost) impossible to screen. The lack of screen might affect the feedback circuitry. This combination of L, C and R is why Kimber cables are popular to remove all possible chance of any interactions (rare).

Ideally all speaker lengths should be the same. In practice they never are but I would give some thought to short L, C and R all having speaker cables the same length and short, with the rears allowed to be longer if amps are all in one place. The difference between 1m and 3m is really pretty small especially with good honest well-designed, non-tweako cables.

For really long interconnects there ‘may’ be benefit for balanced (XLR) connections but that is likely to be rare for our domestic installations.

A well designed amp, say a Tag will have no problem driving 10s of m of interconnect cables. Power amps, even top Brystons etc will not be able to do that with speaker cables without ‘problems’. Long interconnects, short speaker cables all the time. Now why do most people do it the other way round? This one is a no brainer.


Good 'bang for the buck' interconnect, look to co-ax cable like a quality RG6, 59 (50P - £4m)
 
I think im short of knowledge on the hardware side which leads to my not totally understanding. I understand what you say, but of course can think of counter arguements! :D

I'll trust you! I just got some IBM type 6 cable yesterday and am heading to maplin for plugs very shortly! so they are my interconnects very soon!

FYI, my amp is zero feedback......whether that makes a difference, i know not!

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