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XLR vs RCA cable length

ehabheikal

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I was told by my audiophile friends to always reduce the length of my audio cables to the minimum for better sound. Now when connecting a DAC to an amp or preamp to power amp, if both support XLR would that be a moot point? Would I like be able to have a 5 meter (15ft) xlr cable between DAC and amp without loosing quality?
 

SIY

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Some advice (which assumes that you have non-exotic and thus likely to be engineered components):

1. Get smarter friends.

2. If your setup is balanced, 15 feet of cable will make close to zero difference.

3. If your setup is unbalanced, 15 feet is probably OK, but you could possibly pick up some noise (hum or buzz). If you don't have hum or buzz, you're golden.
 
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ehabheikal

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Some advice (which assumes that you have non-exotic and thus likely to be engineered components):

1. Get smarter friends.

2. If your setup is balanced, 15 feet of cable will make close to zero difference.

3. If your setup is unbalanced, 15 feet is probably OK, but you could possibly pick up some noise (hum or buzz). If you don't have hum or buzz, you're golden.
Thanx
 

sergeauckland

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Exactly this ^. At line level, balanced cables matter when cable lengths are 10s or 100s of metres, such as on stage or in a studio installation. At home, any sensible length is fine unbalanced using half-decent screened cable. 10m is not long.

S
 

dms

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Exactly this ^. At line level, balanced cables matter when cable lengths are 10s or 100s of metres, such as on stage or in a studio installation. At home, any sensible length is fine unbalanced using half-decent screened cable. 10m is not long.

S

I don't know if this counts as a zombie thread, but the core question is the same as the top post.

I have a Yamaha RX-A3070 with RCA pre-outs connected to Neumann KH310 speakers (L/C/R) with 13m XLR cables on 1m RCA->XLR patch leads. Clearly this is an unbalanced system.

The XLR cables I ordered were: 13m Van Damme Mini Quad with 1m Van Damme unbalanced patch.
The XLR cables I got were 13m Van Damme Mini Quad x1 (Center) and what I suspect was 2x 13m Van Damme Classic StarQuad (L/R) because these two are thicker, probably 6mm diameter. In any case the 3 cables did go through my ducting (no space left for anything else up front which pleased the Mrs) and I didn't realise.

These cables were made up for me by a cable shop in London....

The Neuman KH 310 manual suggests not to use an RCA cable of more than 10m.

What is bothering me no end is that am I likely losing anything by having 14m connections on unbalanced rather than balanced?

The only person I know who I get objective advice from is my Uncle who is a electronics/hifi nut and his initial opinion was "it's probably fine" which has changed to "it's fine" once I reported I heard no distortion in music/films. Originally he recommended I buy a Funk Sam-1B (pro grade unbalanced->balanced convertor).

The only thing which strikes me as off is that when I turn the speakers on (and if they have their XLR cable plugged in) and the receiver is off then there is a lot of noise from the speakers, it's loud and uncomfortable. That vanishes when I turn on the receiver even if there is no audible output or the input selected is off.

The system also sounds great to me and the speakers are a clear audible upgrade from the 20 year old budget Mission 702e I had, just as the SVS SB3000 is lightyears ahead of the Yamaha YST-205 it replaced.

So....

Questions

1) Objectively am I fine with my unbalanced cables at 14m run total?

Bonus question
2) If I want to go balanced I'm tempted by a processor around the $3.5k tier (so Anthem AVM60 but I'm UK based and I've seen it normally retail £3.6k and sometimes £2.6k) to replace by receiver BUT I'm told the processors at this tier do not have particular good XLR outs and the Anthem AVM60 claim it has "True-Balanced" and by inference the competitors are rubbish is tosh, any opinion?
 

sergeauckland

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So....

Questions

1) Objectively am I fine with my unbalanced cables at 14m run total?

Bonus question
2) If I want to go balanced I'm tempted by a processor around the $3.5k tier (so Anthem AVM60 but I'm UK based and I've seen it normally retail £3.6k and sometimes £2.6k) to replace by receiver BUT I'm told the processors at this tier do not have particular good XLR outs and the Anthem AVM60 claim it has "True-Balanced" and by inference the competitors are rubbish is tosh, any opinion?

1) Yes, fine. 14m isn't long, and provided you don't hear hum or whistles or squeaks (unless that's what your music sound like....King Crimson perhaps?) then no problem.

2) Bonus Question:- Frankly, I've have no idea what an AVM60 is or does, as I'm strictly a 2 channel guy (or Quadraphonic when I can be bothered) and I wouldn't pay £3.6k for any piece of audio equipment. As for True-Balanced, what's the alternative, fake balanced?

S.
 
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dms

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1) Yes, fine. 14m isn't long, and provided you don't hear hum or whistles or squeaks (unless that's what your music sound like....King Crimson perhaps?) then no problem.

2) Bonus Question:- Frankly, I've have no idea what an AVM60 is or does, as I'm strictly a 2 channel guy (or Quadraphonic when I can be bothered) and I wouldn't pay £3.6k for any piece of audio equipment. As for True-Balanced, what's the alternative, fake balanced?

S.

Cheers. No hums, whistles, squeaks. I assumed interference would be more insidious than and less obvious.

I am starting to hear oddities in the soundtracks and glitches but they are also there when I listen carefully for them on completely difference equipment, so it's the sources. I guess I'm just paying more attention to soundtracks now-a-days.
 

dms

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I've found a few reasoned articles online which back up what my uncle told me (me of no faith which is a bit rude given he briefly made a name for himself in at least his home nation in the 70's iirc after assembling the electronics in some serious speaker kit) which have also put my mind at ease.

http://www.empiricalaudio.com/computer-audio/audio-faqs/short-versus-long-cables
http://www.tonestack.net/articles/speaker-building/audio-interconnect-cables.html

The first one is very conservative coming up with an explanation with figures and them halving the output of their calculation. The second one is more cavalier. I've no idea of the authority of either.

Given how many posts or "articles" online I've seen about the need for XLR for "long" cable lengths (ok for electrical interference and truly long runs they clearly are better) and that long "RCA leads" cause problems I suppose it's a wake up call I haven't really seen decent objective or scientific explanations of why that's the case.
 

xaviescacs

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In this one, an inexpensive cable is 50 $ meter/pair, or 25 $ meter. Which means that a 5 meter pair costs 250 $!. Furthermore, they have choose an "inexpensive" RCA cable with high capacitance of 200pF/m on purpose. For instance, the basic Cordial unbalanced cable, the CFU, has a specification of 80pF/m:

https://www.cordial-cables.com/en/products/cfu-cc

and can be found at 19 € the pair of 6 m:

https://www.thomann.de/intl/cordial_cfu_6_cc.htm
 

DonH56

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Typical RCA cables use RG-6 or similar coax at around 25~30 pF/ft or 82~98 pF/m (I thought @xaviescacs CFU number was high then realized he was using meters and my memory is in feet -- units matter!)

Extremely long single-ended runs are used in the RF world all the time, though we match both ends to maximize power transfer, and use durn good shielding. At audio frequencies and impedances matching does not really matter and a 100 m RCA cable will work fine in most cases. Balanced (XLR) connections are typically needed when you have high noise, which is often the case in a commercial setting, or have a ground loop and XLR cables make it easier to "lift" the ground at one end and break the ground loop. The latter is probably the most likely scenario for home use, when the component at the other end of a long RCA cable is probably on a different circuit and thus more likely to introduce a ground loop (buzz, hum). However, there are a lot of noise sources in the average home, so I would not rule out the noise rejection benefits.

If I was putting cable in walls, I would spend the little extra and run XLR cables just in case they are needed. You can always run them single-ended and terminate in RCAs if that is sufficient (likely) but have the option of going balanced if need be. In the room, I have a couple of very cheap 50' RCA cables I use now and then. The introduced ground-loop hum connected to my rear subs so I use XLR to them, but in other situations they have worked without problem.

I (and many others) have run the numbers but I don't think I have a thread in the reference library on cable lengths (should probably do that someday). IIRC, 100 m RCA cables are no problem for typical preamp outputs, as far as bandwidth is concerned. IME, if anything, noise coupling and ground loops are much bigger problems than bandwidth for single-ended runs. And of course ground loops can happen even with short runs.

FWIWFM - Don
 
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