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Old 13th February 2012, 01:55 PM   #1
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Default best arrangement to cut down cable lengths

i've read it here a while back that when possible the interconnect cable should be the longest to cut down on other connectors' length- is this true?

meaning the best result is to be had by having the longest cable from the line stage to the amp with the shortest wires to the speakers, provided that the line stage is active.

could i get an explanation behind this?

and what about the signal length from the source to the line stage? does the same rule still apply?
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Old 13th February 2012, 02:07 PM   #2
DF96 is offline DF96  England
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Unless your line stage has low output impedance it is the interconnects which need to be short. ICs and speaker cables have vaguely similar (to within an order of magnitude) capacitance, yet the difference in source impedance can be three or four orders of magnitude. That means that any effect of capacitance, such as dielectric non-linearity, is likely to be worse for an IC than a speaker cable. Now I am not saying that there is an effect, I don't know, but if there is then ICs should be short even if that means longer speaker cables.

You need to be aware that this is the opposite of the advice which most people will give you.
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Old 14th February 2012, 12:10 PM   #3
marce is offline marce  United Kingdom
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I agree, low level signals short cables (IC's), higher level signals longer cable (speaker cable).
If for no other reason than noise pick up.
Or use balanced system.
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Old 14th February 2012, 12:39 PM   #4
AndrewT is offline AndrewT  Scotland
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I am one of those opposite Members.
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Old 14th February 2012, 04:30 PM   #5
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At 1W 8 ohms I can hear 25' of 16 ga zip cord sounds worse than 10' of AWG 10 extra flexible. AWG10 3SO cord is $4 a foot or more, so you can't afford a lot of that. Op amps line drivers are not so worried about series resistance, whereas the high currents on high resistance connections from an amp to a speaker mess up damping etc. The distortion I hear on zip cord is on top octave Steinway grand piano, so it is not just damping that is messed up, that is a bass response number.
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Old 14th February 2012, 04:37 PM   #6
4642a is offline 4642a  United States
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Quote:
Originally Posted by indianajo View Post
At 1W 8 ohms I can hear 25' of 16 ga zip cord sounds worse than 10' of AWG 10 extra flexible
I thought that the larger diameter cabling should ideally be used with the longer length run... it seems that this example is not following that rule...

could that be part of the reason the longer cable 'sounds worse'?
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Old 14th February 2012, 04:48 PM   #7
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If you are European or Asian, 10 AWG is a lot fatter than 16 AWG zip cord. Much more copper.
Longer cable more resistance. The feedback circuit of the amp stops at the speaker terminal. The feedback circuit is what controls distortion. So what happens out there at the speaker is uncontrolled by the amplifier. Op amp line drivers run low currents, 10-30 ma, so the resistance of 100' of snake cable is not significant. The capacitance of the twisted pair is more of a factor, and the 60 hz pickup is way more of a problem at 100'. Power amps run currents of 5-22 amps, so V-I*R, the voltage of speaker wire can become a measurable quantity over 6'. Look at pro stage sound setups before radio mikes and mixers. The mixer was in the audience because that is where the sound must be balanced. Condenser mikes made that possible because they have a built in line driver. They ran snakes out to the mixer board from the condenser mikes and back to the power amps on stage. The power amps were always up there next to the speaker, because of the current causing voltage drop problem.
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Last edited by indianajo; 14th February 2012 at 04:52 PM.
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Old 14th February 2012, 04:52 PM   #8
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Quote:
Originally Posted by PreSapian View Post
i've read it here a while back that when possible the interconnect cable should be the longest to cut down on other connectors' length- is this true?

meaning the best result is to be had by having the longest cable from the line stage to the amp with the shortest wires to the speakers, provided that the line stage is active.

could i get an explanation behind this?

and what about the signal length from the source to the line stage? does the same rule still apply?
If the connection was balanced and the cable was shielded twisted pair then yeah, that'd be great.
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Old 14th February 2012, 05:04 PM   #9
data is offline data  Australia
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Quote:
Originally Posted by indianajo View Post
At 1W 8 ohms I can hear 25' of 16 ga zip cord sounds worse than 10' of AWG 10 extra flexible. AWG10 3SO cord is $4 a foot or more, so you can't afford a lot of that. Op amps line drivers are not so worried about series resistance, whereas the high currents on high resistance connections from an amp to a speaker mess up damping etc. The distortion I hear on zip cord is on top octave Steinway grand piano, so it is not just damping that is messed up, that is a bass response number.
Hang on!


Let me look at this, you are comparing two different cables, that are different length, different gauge and different construction or different dialectic structure or thickness?

So what is contributing to the sound difference?

One of these factors, or two, or all?

I go for low capacitance, and low inductance in both uses, as best I can. But that's just me, and I'm pretty new to all this....relatively, so just my novice view. For both I go for solid core copper, 20awg for speaker cable and 24awg for ICs.

Edit: Easier to show how I construct ICs, rather than explain it, see here http://diyaudioprojects.com/Power/diySilver/ not my page, just that it is the same way.

Last edited by data; 14th February 2012 at 05:30 PM.
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Old 16th February 2012, 02:23 AM   #10
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Quote:
Originally Posted by data View Post
Hang on!

Let me look at this, you are comparing two different cables, that are different length, different gauge and different construction or different dialectic structure or thickness?

So what is contributing to the sound difference?

One of these factors, or two, or all?
Yeah, the cables are different. I picked up the extra flexible 4SO10 cord out of the dumpster, knowing that fatter is better. I've used it for years, even on my ST70 tube amp that only puts out 2 amps into 8 ohms. Then I wanted to carry my speakers out the door on the 4th of July and blow 1812 overture all over the yard so I cut up some old yard light zip cord into two 25' pieces and tried them out. Then, later, inside, I did a listening test on the zip cord before putting the 10 ga cable back on. It sounds worse on my test record, top octave solo Steinway piano (Peter Nero, Young & Warm & Wonderful, Secret Love track). A sound engineer was just saying on another thread, that studios use piano tracks to test their setups. I have never had speakers that sounded anywhere close to even my Sohmer piano, until I bought the Peavey SP2-XT's. But they sound closer to real with the 8' 10 ga cable instead of the 25' of 16 ga seven strand zip cord. The amp that day was the CS800s Peavey, but the dynakit ST120 with djoffe bias mod and modern NTE60 output transistors sounds exactly the same in my opinion, at the 1W I use in the living room.
Theory? I don't know. I have seen discussions of damping factor being related to cable impedance, which makes for tighter bass. Damping factor is not an element of top octave Steinway piano source material, that is more messed up by intermodulation distortion. So I don't know why it messes up the sound, but it does. The 4SO10 has rubber insulation and about 1 twist per foot. The 16 ga zip cord has PVC insulation and parallel runs. For calibration source, I have the real Steinway piano setting between the speakers. The bass of Mr Nero's 11' studio grand is better than the bass on my 40" console piano, but the treble sounds are pretty close to the same.
And I don't know anybody that hooks up speakers with anything thinner than 18 ga zip cord. Monster cable has gotten rich selling fat cable for speakers, but the 4SO10 extra flexible industrial cable for 440 VAC 3 phase mining equipment is excellent, in my opinion. If you can afford it.
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Last edited by indianajo; 16th February 2012 at 02:40 AM.
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