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Posted By: pmulvey is it bad to tie cables together - 08/28/07 01:59 AM
I have misjudged the length of cable required for wiring my new qs8s. Is it a very bad thing to tie the lengths together to get the right length? The cable is not fancy but is decent gauge and quality.
Peter
Posted By: HomeDad Re: is it bad to tie cables together - 08/28/07 02:08 AM
I did the same thing, I can't tell if there is a difference in sound quality. So I would guess if tied well you should have no problems.
Posted By: Mojo Re: is it bad to tie cables together - 08/28/07 02:09 AM
Some people out there may tell you that they can hear the difference splices make. I for one can only hear the electrons panting as they cross the splice when my room is very quiet and I put my ear really close to the cable .

Seriously, it's only bad if it's visible and you don't make it look nice and neat.
Posted By: pmulvey Re: is it bad to tie cables together - 08/28/07 02:17 AM
guys - thanks for the quick show of reassurance - wires, bits of loose plaster and plastic conduit lying all over the place - really want to get this job over today!!
thanks again for posting
Posted By: SirQuack Re: is it bad to tie cables together - 08/28/07 02:49 AM
Most likely it won't make a difference as long as you splice them togethor well with connectors or sheathing. If they are going to be hidden in the ceiling permately, something tells me that I would feel much better if it was done correctly with a solid length from end to end, but that is just me. Wire is not that expensive.

jmo

Randy
Posted By: Bill3508 Re: is it bad to tie cables together - 08/28/07 03:00 AM
I wouldn't think it would be a good thing to do and while if done properly you might not notice a difference I would be driven crazy by the idea that there could be a flaw in my system.

Bill3508
Posted By: JohnK Re: is it bad to tie cables together - 08/28/07 03:09 AM
Bill, as long as there isn't a complete break in the connection there's no possible problem and no special care is necessary. The electromagnetic wave traveling along the outside of the wire can't notice splices.
Posted By: Mojo Re: is it bad to tie cables together - 08/28/07 03:15 AM
Quote:

...I would be driven crazy by the idea that there could be a flaw in my system.




Then you probably wouldn't want me to tell you the countless of flaws that exist within every conductor in your system. You may want to invest in a SQUID magnetometer to identify and remedy these flaws if they really bother you .
Posted By: SirQuack Re: is it bad to tie cables together - 08/28/07 03:18 AM
John,

So your saying if a person does a poor job at twisting the ends togethor there won't be any potential issues? I find this hard to believe. Back in the day when I was into installing car audio, I can't tell you how many times someone came to me with problems. Upon inspection, most people just twisted the wire ends a few times with their fingers and in many cases only half the strands were making contact. In addition, no electrical tape, or protective sheathing was used. After bouncing around for a few months, the connections would loosen.

Are you assuming everyone does a good job at splicing two wires togethor? I'm not saying Bill would do a poor job, but as you know we see a lot of people on here that don't even hook up the correct polarity, let along give attention to the connections.
Posted By: JohnK Re: is it bad to tie cables together - 08/28/07 03:24 AM
Sure Randy, as the long as the connection isn't broken. The "bouncing around" you mention in a car would break the connection, at least intermittantly.
Posted By: Murph Re: is it bad to tie cables together - 08/28/07 12:07 PM
I mentioned this before and it was disputed but I can say for certain that many a data circuit has been fixed by removing bad splice work. Because time is of essence, stripping, twisting and taping is too slow and if not tight and well taped can cause issues (looseness or corrosion.

We use splice connectors that don't require stripping and are gel filled to prevent corrosion. Yes, it's overkill for home audio and still a splice to the cable enthusiasts but another example of splices effecting transmittion came about when we started using b-wire connectors similar to these.


It was eventually discovered, after much frustration, that unless the techs crimped them with all of their might, the connection would eventually weaken and cause errors.

We went back to our original style, similar to these, and they remained reliable.



I'm a bit off track but what I was trying to say is that a solid connection is VERY important but a good, well taped twist should be more than sufficient if you can forget it's there.
Posted By: SirQuack Re: is it bad to tie cables together - 08/28/07 01:57 PM
Murph, thanks for clarifying the point I was trying to make.
Posted By: Mojo Re: is it bad to tie cables together - 08/28/07 02:24 PM
Murph & Randy,

Agreed that extra care has to be taken with data circuits as they are higher speed and more prone to reflections as a result of potential impedance mismatch at the joint.

I actually would never recommend that data circuits be crimped but rather soldered or even better, replaced. And they should be tested end-to-end with an SWR meter. The problem out there is that many technicians that serviced audio circuits such as POTS are now also servicing data lines with the same techniques as audio. I'm not insinuating anything about you, Murph. I am expressing a little frustration on my end because these same technicians have caused me and my teams endless frustration over the years even though we've published very detailed instructions about the processes they must use to install DCEs and DTEs.

Audio speaker cables, being lower frequencies, are not susceptible to reflection in a way that can be detected by human hearing. Some use heatshrink over audio cable splices because they are worried about oxidation. I think this too is over-kill but it sure makes the connection look nice and provides for some stress relief.
Posted By: Murph Re: is it bad to tie cables together - 08/28/07 03:55 PM
Don't worry about insulting me Mojo, I'm not actually the guy out doing the work but I'm involved from many other angles.

I am curious though, would you consider your above advice solid in the Telecom world for outdoor purposes? I can't imagine trying to solder effectively while hanging from a pole during the rain or snow in order to attach two wires together.

This would have been the area where I was referring to? I work for Bell-Aliant, an income trust Telco tied to Bell Canada. Together we cover over 50% of Canada and I know that soldering is not used anywhere to join loops, feeder, distribution pairs etc. in the outdoor environments. Indoors there are generally patch panels so it becomes less of an issue.

Certainly solder is better but I am curious if standards in your area are so much better than ours. Also by "data Circuits", I would be referring to old school technologies like frame relay, datapac, etc. Not really 'high speed" depending on your standards. However, we certainly don't solder our copper pairs outdoors for ADSL service up to 10MB either. Anything faster than that is fiber.

We also found our most sensitive circuits to poor crimps were ones where radio stations relayed their remote broadcasts to their transmitting stations via our copper data lines but using analogue (not really data, but using data groomed copper.) This is still not comparable to a home environment as it involves long distances and other factors.

I agree with everything you said from a technical standpoint. However, because you seemed to feel so strongly about it, I would really like to understand if our standards are that far behind that of your geography's. It's an efficiency vs. quality thing for sure.

Also since I mentioned my company name, none of my post, in any way, reflects the views of my company or is in any way, representative of my company. and what ever else goes into the usual disclaimer clause.....
Posted By: SirQuack Re: is it bad to tie cables together - 08/28/07 07:21 PM
I think what I was trying to say is being misunderstood. I never said that there would be any noticable quality difference in the sound.

The only point I was trying to make is in regards to the quality of work. If people like twisting 3 strands of speaker wire togethor half assed, so be it.

I would feel much better having a professional looking job from end to end, especially if it will be concealed in a finished ceiling or wall long term. Yes, you can extend your speaker lengths by adding additional wire with no negative sound results. I would just assume people would take care to make nice twists and cover with appropriate tape or wire ends.
Posted By: Mojo Re: is it bad to tie cables together - 08/29/07 08:24 PM
Our equipment gets installed on poles, electrical substations and head-end (office environments). Surprisingly, where we've had the majority of our splicing problems is in the office environment where soldering is easy to do. In the substation and pole-top environments, new cables are pulled most of the time. If they can't pull new cables, they will use ring or spade terminals with terminal blocks or male/female blades.
Posted By: Murph Re: is it bad to tie cables together - 08/30/07 07:01 PM
Hmm Interesting. Is your company a data only or telcomm as well.

Where we break off into buildings (loop), pairs are also generally placed on blocks at the tops of poles. However, directional changes from one direction to another (one cable count to another) are spliced due to necessity as they can be 500 or 1000 pair cables. We also solder in CO's where applicable.

Glad to see we were not that far off after all. I couldn't imagine a lineman up a pole trying to use an electric or butane soldering gun. I'm sure the safety implications themselves would prevent it.

Thanks for the conversation. Sorry for the hijack.
Posted By: haylo75 Re: is it bad to tie cables together - 08/30/07 09:56 PM
Nice to see some fellow telco folk on here. I work for AT&T (SBC) ((Southwestern Bell)). I'm an application developer supporting our Network Services department. A lot of the work I've been doing this year has revolved around the FTTP/FTTN product we're rolling out.
Posted By: Hutzal Re: is it bad to tie cables together - 08/30/07 10:23 PM
just to add to everyones comments, I think splicing to a surround speaker (such as the QS8) is perfectly fine, I would however, have second thoughts about doing that for my mains or my centre channel.

This is just my feeling, It wouldn't bother me TOO much to have a spliced wire to one of my QS8s...but I am a bit OCD since I got into this audio thing (just ask my wife, I drive her up the wall sometimes).
Posted By: Mojo Re: is it bad to tie cables together - 08/30/07 11:25 PM
Quote:

...I would however, have second thoughts about doing that for my mains or my centre channel.




Why?
Posted By: BBIBH Re: is it bad to tie cables together - 08/31/07 07:44 PM
Having spent 20 years engineering for telco, wireless, cable and datacom, standardization has brought a great deal of common elements to every company. Regionalities are less common today, and this builds better systems.

Infrastructure is evolving, with antiquated systems being replaced, although it takes a LONG time to replace everything that is sunstandard. I have seen many working example of wooden binding posts still in use, and developing nations sometimes don't have the benefit of technical expertise, or cash funding to impose new technology to ensure a solid infrastructure.

As for splicing, as long as it satisfies these 2 criteria, it should be fine : Electrical Stability (proper connection technique, isolation and insulation) and Physical Stability (numerous methods)
Posted By: Hutzal Re: is it bad to tie cables together - 08/31/07 07:52 PM
Quote:

Quote:

...I would however, have second thoughts about doing that for my mains or my centre channel.




Why?




I really do not know, I know it wouldn't make a difference, but I would just prefer a single audio cable with no splices for my mains and centre...just being OCD is all.
Posted By: Mojo Re: is it bad to tie cables together - 08/31/07 08:59 PM
Quote:

...I would just prefer a single audio cable with no splices for my mains and centre...




Me too.
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