Speaker gauge for long run: 16 gauge installed, need 10? - AVS Forum | Home Theater Discussions And Reviews
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post #1 of 53 Old 03-12-2018, 10:30 AM - Thread Starter
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Speaker gauge for long run: 16 gauge installed, need 10?

Hi All,

So I finally got my home theater set-up and am pretty happy with the overall set-up except one thing is keeping me up at night. I have a 5.1.4 set-up with Martin Logan speakers (Motion 50 and 60 XT with in-ceiling surrounds) and Polk V60 atmos in-ceiling speakers. I have been doing more and more research and with my ML 4 ohm speakers (and Polk 5 ohm speakers), and my run distance (varies from 70 to 105 ft - with 105 ft being my front/center speakers), I should have used 10 gauge wire. However my installer used 16 AWG.

I feel like the sound is pretty good but I did notice that the center channel sounded maybe a bit dull and somewhat hit-or-miss depending on the movie scene. I am not sure exactly how to describe it but it is fairly subtle to my untrained ears. For two of the cables, he used 16/ 4 conductor cable and on one of the cables left two of the four conductors unused. So I paired two 16 gauge wires for my center channel (effective 13 gauge). I also played around with doing this for my front right comparing it to the front left using a 16 gauge speaker. I did note a difference although subtle again.

My question is since now everything is set-up, should I re-run everything with 10 gauge? It would involve some time since all cable is run throughout my ceiling and through a wall. I think I could just tie the new 10 gauge cable to the 16 gauge cable and use that as a pull/guide. Am I crazy for thinking about re-running all new 10 gauge wire? Another thought was doing 14/4 and doubling up for an effective gauge of 11 AWG. However all literature I have read only refers to 10 AWG at 100 ft. Would my gains going to a 10 gauge speaker wire be notable? Any thoughts/advice is appreciated before I pull the trigger (will cost ~$600 for 750 ft of 10 gauge cable, probably a lot cheaper for 14/4 - $375 for 1,000 ft). Has anyone doubled 12 gauge speaker wire? At that stage, I would think fitting the cables would be too difficult - I have never heard of anyone doubling 12 gauge speaker wire.

Thanks,

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post #2 of 53 Old 03-12-2018, 10:45 AM
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I’m not going to comment on your 14 vs 10 debate but I would like to point out that the center channel performance may be hit or miss due to differences in content mixes. My center, L and R are short runs of 12ga (~10 feet each) and there is a great difference in center audio quality from movie to movie. Maybe that is what you are experiencing more than signal loss in you Long cable runs?
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post #3 of 53 Old 03-12-2018, 11:15 AM - Thread Starter
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I’m not going to comment on your 14 vs 10 debate but I would like to point out that the center channel performance may be hit or miss due to differences in content mixes. My center, L and R are short runs of 12ga (~10 feet each) and there is a great difference in center audio quality from movie to movie. Maybe that is what you are experiencing more than signal loss in you Long cable runs?
It definitely could be. I can try to experiment more but did notice that I had a bit more clarity and loudness in the front left speaker (using paired 16/4) versus the front right speaker using just 16 gauge speaker wire (this was within the same movie/song. I held my head close to each speaker and there was a notable (but admittedly subtle) difference.
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post #4 of 53 Old 03-12-2018, 11:17 AM
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Originally Posted by JohnsonBig View Post
Hi All,

So I finally got my home theater set-up and am pretty happy with the overall set-up except one thing is keeping me up at night. I have a 5.1.4 set-up with Martin Logan speakers (Motion 50 and 60 XT with in-ceiling surrounds) and Polk V60 atmos in-ceiling speakers. I have been doing more and more research and with my ML 4 ohm speakers (and Polk 5 ohm speakers), and my run distance (varies from 70 to 105 ft - with 105 ft being my front/center speakers), I should have used 10 gauge wire. However my installer used 16 AWG.

I feel like the sound is pretty good but I did notice that the center channel sounded maybe a bit dull and somewhat hit-or-miss depending on the movie scene. I am not sure exactly how to describe it but it is fairly subtle to my untrained ears. For two of the cables, he used 16/ 4 conductor cable and on one of the cables left two of the four conductors unused. So I paired two 16 gauge wires for my center channel (effective 13 gauge). I also played around with doing this for my front right comparing it to the front left using a 16 gauge speaker. I did note a difference although subtle again.

My question is since now everything is set-up, should I re-run everything with 10 gauge? It would involve some time since all cable is run throughout my ceiling and through a wall. I think I could just tie the new 10 gauge cable to the 16 gauge cable and use that as a pull/guide. Am I crazy for thinking about re-running all new 10 gauge wire? Another thought was doing 14/4 and doubling up for an effective gauge of 11 AWG. However all literature I have read only refers to 10 AWG at 100 ft. Would my gains going to a 10 gauge speaker wire be notable? Any thoughts/advice is appreciated before I pull the trigger (will cost ~$600 for 750 ft of 10 gauge cable, probably a lot cheaper for 14/4 - $375 for 1,000 ft). Has anyone doubled 12 gauge speaker wire? At that stage, I would think fitting the cables would be too difficult - I have never heard of anyone doubling 12 gauge speaker wire.

Thanks,
Buy 10 ft of 10 ga wire, cut to size at Home Depot, take two front speakers down and run 5 ft 10 gauge runs; see if there is an improvement in YOUR perception. If so and WORTH it, do the work and spend the money!
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post #5 of 53 Old 03-12-2018, 11:36 AM - Thread Starter
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Originally Posted by schreib77 View Post
Buy 10 ft of 10 ga wire, cut to size at Home Depot, take two front speakers down and run 5 ft 10 gauge runs; see if there is an improvement in YOUR perception. If so and WORTH it, do the work and spend the money!
I thought about doing this - essentially moving my AVR to the HT (it is now in a closet 75 ft away) and running even 16 gauge speaker wire the short distance. I may try this and if a noticeable difference with 16 gauge, move up to 10 gauge.
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post #6 of 53 Old 03-12-2018, 12:21 PM
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For the most part, having too low a gauge wire for the run will do two, audible, things:

1) Lower the overall level of the speaker (you can get this back by adding channel gain)
2) Reduce the high frequency content (to some extent, you can get this back by adding EQ)

It can do other things, too, but whether they are audible is debatable.

However, the worst thing incorrectly sized wire does is make speakers harder to drive. So, in your case, having 4ohm speakers, IMO, you really need lower gauge wire if you expect to push them. Having them present a more difficult load to your amps through high gauge wire can result in overheating and/or shut-down/failure as you approach higher output levels. You may never experience this, though, depending on your listening habits (and amplification equipment, which I didn't see listed).
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post #7 of 53 Old 03-12-2018, 01:18 PM - Thread Starter
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Originally Posted by DreamWarrior View Post
For the most part, having too low a gauge wire for the run will do two, audible, things:

1) Lower the overall level of the speaker (you can get this back by adding channel gain)
2) Reduce the high frequency content (to some extent, you can get this back by adding EQ)

It can do other things, too, but whether they are audible is debatable.

However, the worst thing incorrectly sized wire does is make speakers harder to drive. So, in your case, having 4ohm speakers, IMO, you really need lower gauge wire if you expect to push them. Having them present a more difficult load to your amps through high gauge wire can result in overheating and/or shut-down/failure as you approach higher output levels. You may never experience this, though, depending on your listening habits (and amplification equipment, which I didn't see listed).
This is good to know. I am using an Onkyo RX920 which has 135 watts per channel. I don't like to listen super loud but at or just below movie theater levels (I have been increasing volume to 65 which I know is relative but do not like to go much beyond this). I hate to sacrifice if in fact I am giving up perceived differences, especially given the financial outlay to date. To me, the extra money is not too big of a deal, however re-running everything myself and the time investment is a little daunting. THe installer left it pretty easy for me though by including conduit the length of the attic. I am pretty OCD and a scientist by profession, so I am likely going to experiment. To me, just doing the 16 vs 10 gauge test may be worth it.
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post #8 of 53 Old 03-12-2018, 01:29 PM - Thread Starter
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Originally Posted by DreamWarrior View Post
For the most part, having too low a gauge wire for the run will do two, audible, things:

1) Lower the overall level of the speaker (you can get this back by adding channel gain)

I actually did increase the center channel gain by ~2 dB after EQing and it did help some. The center channel is the speaker I doubled up the 16 gauge speaker wire. THis did make a noticeable difference and I can hear the dialog much better and more clearly.

2) Reduce the high frequency content (to some extent, you can get this back by adding EQ)

I did EQ but how can I be sure everything was added back without testing? Do I need to get a USB mic and run software? I thought about this and would like to experiment how gauge impacts frequency, dBs in my HT set-up.

It can do other things, too, but whether they are audible is debatable.

However, the worst thing incorrectly sized wire does is make speakers harder to drive. So, in your case, having 4ohm speakers, IMO, you really need lower gauge wire if you expect to push them. Having them present a more difficult load to your amps through high gauge wire can result in overheating and/or shut-down/failure as you approach higher output levels. You may never experience this, though, depending on your listening habits (and amplification equipment, which I didn't see listed).

I have not experienced shut-downs to date but have only had everything set-up for a few days. I am running an Onkyo RZ920 with 135 watts/channel (3 channels driven). Not sure what this equates to with 9 channels driven.
see above
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post #9 of 53 Old 03-12-2018, 02:49 PM
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Originally Posted by JohnsonBig View Post
see above
Increasing the center volume probably helps regardless the wire gauge, not sure 2db is lost through the insufficient gauge alone. So, some (maybe most) of the effect is likely room related.

If you get a mic to test, you may see high frequency roll-off on the channels that you may not see to the same degree with larger wire. But, again, how much you notice this may not be worth the extra expense and pain of running new wire.

As for the receiver power -- I guess time will tell. At the end of the day, running 10 gauge is a better safe than sorry thing, since you don't have it, I wouldn't worry unless you start seeing issues.

All-in-all, I'd still want 10 ga for those runs, but I probably wouldn't go through the effort to redo it all unless I noticed problems.

As for your testing -- unless you run a parallel 10ga wire against the 16ga, I'm not sure how much it will tell you. If you run a 5' 16ga against a 5' 10ga you probably won't notice anything because the 16ga isn't under-spec'd at that length. If you run 5' 10ga against your 100' 16ga and don't notice a difference, that doesn't prove the 16ga wire isn't underspeced and causing undue load to your receiver (it likely is, especially if your speakers are 4ohm as advertised). It does prove you can't hear a difference, but your receiver may still "feel" a difference (if that makes sense).

How much? Looking at an impedance graph for the Motion 60, it dips below 4ohms from 80hz through about 3khz . That may be an issue if you drive your speakers hard. Especially so because your receiver isn't really 4ohm rated to begin with so far as I can tell. So, the long, inadequately-spec'd, wire will make that 4ohm dip appear even lower and harder to drive. Compounded with your boosting the levels to compensate, you may find yourself running out of steam (current) and taxing the amplifier.

Again, if you don't ask for high power levels, you may never have an issue. If you don't play demanding material, you may never have an issue. But, that's not to say that putting these speakers on 16ga 100' wire is a good idea, especially not with a receiver that's hardly rated to drive them to begin with.
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Originally Posted by DreamWarrior View Post
For the most part, having too low a gauge wire for the run will do two, audible, things:

1) Lower the overall level of the speaker (you can get this back by adding channel gain)
2) Reduce the high frequency content (to some extent, you can get this back by adding EQ)
Lower gauge is thicker so your assessment 1) is incorrect. Such thing will happen if the gauge is too high (thinner). Your assessment 2) is irrelevant in audio application. It's also called skin-effect but it's so minuscule in audio frequency that there's no need to worry about it.
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post #11 of 53 Old 03-12-2018, 03:29 PM
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Originally Posted by LFEer View Post
Lower gauge is thicker so your assessment 1) is incorrect. Such thing will happen if the gauge is too high (thinner). Your assessment 2) is irrelevant in audio application. It's also called skin-effect but it's so minuscule in audio frequency that there's no need to worry about it.
Sorry, I know lower the gauge is thicker wire -- brain fart / lack of proof-reading. I corrected myself later in the post, but recognize my inconsistency doesn't inspire confidence, lol.

As for #2 -- I'm not going to argue with you.

Either way, I'd prefer not to increase the load and add inductance by using long skinny wires if I can avoid it. Regardless of whether it is audible, it can cause hardships for the amplifier driving the speaker, especially if the speaker is a hard load to begin with (as it appears his may be).
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Originally Posted by DreamWarrior View Post
I'd prefer not to increase the load and add inductance by using long skinny wires if I can avoid it. Regardless of whether it is audible, it can cause hardships for the amplifier driving the speaker, especially if the speaker is a hard load to begin with (as it appears his may be).
That's right, it's better to have thicker speaker wire than thinner and there is no audible degradation by going thicker.
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post #13 of 53 Old 03-12-2018, 04:11 PM - Thread Starter
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Increasing the center volume probably helps regardless the wire gauge, not sure 2db is lost through the insufficient gauge alone. So, some (maybe most) of the effect is likely room related.

If you get a mic to test, you may see high frequency roll-off on the channels that you may not see to the same degree with larger wire. But, again, how much you notice this may not be worth the extra expense and pain of running new wire.

As for the receiver power -- I guess time will tell. At the end of the day, running 10 gauge is a better safe than sorry thing, since you don't have it, I wouldn't worry unless you start seeing issues.

All-in-all, I'd still want 10 ga for those runs, but I probably wouldn't go through the effort to redo it all unless I noticed problems.

As for your testing -- unless you run a parallel 10ga wire against the 16ga, I'm not sure how much it will tell you. If you run a 5' 16ga against a 5' 10ga you probably won't notice anything because the 16ga isn't under-spec'd at that length. If you run 5' 10ga against your 100' 16ga and don't notice a difference, that doesn't prove the 16ga wire isn't underspeced and causing undue load to your receiver (it likely is, especially if your speakers are 4ohm as advertised). It does prove you can't hear a difference, but your receiver may still "feel" a difference (if that makes sense).

How much? Looking at an impedance graph for the Motion 60, it dips below 4ohms from 80hz through about 3khz . That may be an issue if you drive your speakers hard. Especially so because your receiver isn't really 4ohm rated to begin with so far as I can tell. So, the long, inadequately-spec'd, wire will make that 4ohm dip appear even lower and harder to drive. Compounded with your boosting the levels to compensate, you may find yourself running out of steam (current) and taxing the amplifier.

Again, if you don't ask for high power levels, you may never have an issue. If you don't play demanding material, you may never have an issue. But, that's not to say that putting these speakers on 16ga 100' wire is a good idea, especially not with a receiver that's hardly rated to drive them to begin with.

I think this is good advice and will sit on it for a while longer. I may test the 3 channel 16 gauge short wire versus the 16 gauge current (long run) set-up if I can splurge for the usb mic. However I wonder if my money is better spent just getting the cable and replacing it on the weekend - not a bad project. In my field we often get into the weeds of theoreticals but I always try to relate it to the practical (clinical) aspects. In my reading on this topic, it is hard to come by practical differences of changes in wire gauge for example. This table from Belden (manufacturer of the 10 gauge cable I would buy) explains it pretty well graphically: https://www.belden.com/blog/broadcas...peaker-systems . This is why I appreciated your explanation of potential practical implications. I guess I can share my experience with what I find if in fact I go up to a 10 gauge wire. I pretty much went overkill on everything else (I also did a 1,000 ft Cat 6a cable run at the same time) so am kicking myself for this one!
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Your installer should replace the speaker wire for free. This was a totally bone-headed mistake.
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Originally Posted by LFEer View Post
Lower gauge is thicker so your assessment 1) is incorrect. Such thing will happen if the gauge is too high (thinner). Your assessment 2) is irrelevant in audio application. It's also called skin-effect but it's so minuscule in audio frequency that there's no need to worry about it.
Skin effect is indeed irrelevant, but with runs this long, I would think HF rolloff can occur without it.
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post #16 of 53 Old 03-12-2018, 07:51 PM - Thread Starter
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Your installer should replace the speaker wire for free. This was a totally bone-headed mistake.
Well, not sure about that but i did question him about it and at the time i was not as educated on the subject as i am now. I told him i did not mind spending more on cable, hdmi, etc since i wanted one and done. He assured me it was fine and that he had done 300 ft runs. I am not blaming him since he did a great job otherwise and things are running ok. I assume he does not do many installs with ppl as OCD as i am. I am willing to pay him to re-run the cable and texted him but have not heard back yet. We'll see. If not, i am fairly confident i will get it done, just will take a lot more time.
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Skin effect is indeed irrelevant, but with runs this long, I would think HF rolloff can occur without it.
I believe you are correct. There are other factors at play (capacitance of the wire?) when a long run is used that can impact the frequency response. I'm guessing @LFEer is reacting to the implication that wires can impact the HF, and snap-responding to declare skin-effect the audio-myth it is. But, I didn't make the statement with skin effect in mind.

For a long run like this I would want thicker conductors and a low capacitance per foot spec.
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Well, not sure about that but i did question him about it and at the time i was not as educated on the subject as i am now. I told him i did not mind spending more on cable, hdmi, etc since i wanted one and done. He assured me it was fine and that he had done 300 ft runs. I am not blaming him since he did a great job otherwise and things are running ok. I assume he does not do many installs with ppl as OCD as i am. I am willing to pay him to re-run the cable and texted him but have not heard back yet. We'll see. If not, i am fairly confident i will get it done, just will take a lot more time.
I believe 70v systems are better at handling longer wire runs. If that's what he's used to, maybe that's why he thought it mattered less for your system. Plus, if you're not overly concerned about the wire being transparent, it won't matter either. And, like I said above, just about everything the wire taketh, EQ/volume can restore. But, the additional load on your amp may or may not be an issue.

Again, I wouldn't worry about it unless you have issues with how it sounds and performs that you can't rectify by EQ/level adjustments alone.
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post #18 of 53 Old 03-12-2018, 09:20 PM
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Ya shuda located the AMP close to the L/C/R Speakers [do you have Pre-Outs that can drive a Remote Amp????]...esp. since it appears that you have "Golden Ears":
https://www.audioholics.com/audio-vi...er-cable-gauge[DAMPING FACTOR!!!!]
https://www.lifewire.com/speaker-cab...rences-3134603

More on this subject:
https://www.audioholics.com/audio-am...ystem-response[CRITICAL DAMPING FACTOR!!!!]
https://www.avsforum.com/forum/89-spe...l#post50516433
https://www.whathifi.com/forum/hi-fi/damping-factor-0

Unfortunately I have NOT seen similar analyses for Back-to-Back 70-volt Transformers [higher Impedance means Wire Inductance effect is more pronounced]....but they're fairly affordable if set L/C/R to "Small", so don't TRY to support S-W Freqs thru the Transformers....and back off from MAX AMP Output....so MIGHT be worth a try...but seems to be a Bad Band-Aide (esp. if they are "affordable") using known problematic Transformers...which we were happy see go when Solid-State Amps replaced Tube Amps:
https://www.belden.com/blog/broadcas...peaker-systems
https://www.google.com/url?sa=t&rct=...KSFirFkd2UBQv-

Does anyone have A/B Comparison Test and/or Analysis with and w/o 70-V Application for CRITICAL MUSIC LISTENING....NOT just large Lo-Fi PA or High Distortion Stadium Sound Systems????

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post #19 of 53 Old 03-13-2018, 01:38 PM
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OK since you are not holding your installer's feet to the fire you are basically on your own unless you hire someone else to help you.

Don't use transformers. Please.

From what you posted so far it seems that you have maybe one problematic long tube serving the front L/C/R with two cables of 16/4 that is constructed in twisted pairs (hopefully), and the center channel has a spare twisted pair that you might already have paralleled up to fix that channel.

There is a possible remedy that you might not have considered. Use the existing wire in parallel twisted pairs for the L/R and run a separate external twisted pair of 10ga for the center speaker somewhere out of sight. This is probably your simplest, least expensive, and most productive solution.

Be sure you preserve the twisted pairs when you parallel them up. Don't short the pairs. That destroys their noise immunity and introduces inter-channel crosstalk.

Another option is to use wireless and put amp near the affected speaker. That might be cleaner and easier, or not. It does fix the signal integrity issue of the overly long wire completely, however it also costs more, introduces additional time delay to the signal path, and potentially adds additional A/D/A conversion steps that affect signal integrity.

Depending on the configuration of your system it might not add any additional conversions if you can tie into the existing digital path before that final D/A e.g. in your room correction EQ.

Assuming those options have already been considered and rejected...

Can you disclose (even if to no one but yourself) exactly
  • how many conductors you need in the tube(s)
    (one twisted pair per channel)
  • what length of tube
  • which size tubing
  • what material of tubing
  • how many bends
  • what radius on each bend
  • which clamping system is holding the tubing
  • how many points it is secured at and at what positions
  • any joints along the tubing
  • what type of connector at the joints?
I would not advise casually trying to pull a 50'-100' long bundle of several 2x10ga speaker wires through walls in a finished space that was designed and built with 16ga unless you have checked all the relevant facts and done this sort of thing before. That is a thick and stiff bundle to pull that far under best circumstances even if it's just the L/C/R and that might be the reason your installer did not use 10ga in the first place.

Using 4x14ga is probably even worse for pulling because that adds thickness and stiffness to the bundle from the doubling of insulation thickness that comes with twice as many individual conductors, each with its own insulation on it.

If the tubing is too small for speaker wire of the proper gauge, and/or the wire you are considering has a soft outer jacket that could bunch or shred while being pulled, you might consider using the same color-coded single conductor wire that electricians like to run through conduit because it will have less insulation thickness on it, the insulation is crush resistant, plus it has a thin transparent tough and slippery outer jacket that slides readily through steel tubing. It is fire/crush rated for power line voltage and current so it is probably going to cost more than your estimate of speaker wire, perhaps considerably more.

The disadvantage of individual conductors is you might induce more inter-channel crosstalk from the close proximity of other channels, especially compared to speaker wire that is constructed as twisted pair. Your installer did use twisted pair, right, I hope? If it is not twisted pair it probably doesn't do much better than single conductors at rejecting crosstalk.

You can address this by pre-twisting the wire into pairs, or using pre-made twisted pair of similar toughness/slipperiness for pulling through conduit if you can find it, but that will again increase the cross section of the bundle, especially if you manually twist the wire yourself to save cost.

I would recommend practicing 'the twist' until you can create a uniform and smooth pair and use an appropriate number of twists per unit length if you try that. You can just count the twists in your existing wire if you like. That should be close enough. You need an axle-mounted jig with two spools on it that you can spin the whole thing as a single assembly while you pull wire off the spools, and a third spool to wind up the twisted pair on as you go, and you need to keep track of the length of the twisted pair so you know that you have made enough of it before you cut the thing.

Also you might want to pay attention to the direction of the twist so that you don't unwind any twist there might be in the stranded conductors and cause bunching. Probably it does not matter and I am just being OCD but I thought I would mention it.

If you 'roll your own' or use unsheathed pair off the shelf you don't get the extra bulk in the tubing from a separate speaker wire jacket on each twisted pair. You could also just skin the outer jacket off twisted pair speaker wire but I don't know if that 'nekkid pair' will pull through tubing without shredding. I would feel safer using something with exposed insulation that is designed for pulling through conduit.

Perhaps soldering the new pairs onto the ends of the old pairs with twisted solder joints will help, but even solder pulls loose under tension if the overlap is too short and it gets too stiff to bend around corners if the overlap is too long. Staggering the joints linearly along the bundle to prevent overlap in the bends may help maintain flexibility.

Lubricant may help it slide freely. Graphite? Lithium? you need professional advice if you have any doubts about whether you can do this.

I wouldn't recommend insulating the soldered joints because that just increases the bulk, so if the cable gets stuck in the conduit while you are pulling on it you are going to want those exposed joints well separated from each other along the length of the bundle to avoid shorts. Remember that those joints are going to migrate relative toward each other some as you pull so give them plenty of space.

This trick of staggering the joints to avoid shorts only works if the tubing is non-conductive so if you've got metal tubing you might want to think of something else or just pray you can complete the pull without it getting stuck.

The best case is your installer used a single length of big tube that is well secured with few and gentle bends so you have no issues. You need to check. Maybe post a picture of what you've already got with some drawings if you have any doubt about whether you can pull this off (in?)

Disclaimer: I am not a pro anything where electrical wiring and home theater are concerned. I'm just trying to be helpful. Don't hang yourself with the line I am feeding you. Professional advice is what you need and I ain't it.
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This link is worth a repeat. http://www.roger-russell.com/wire/wire.htm
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This link is worth a repeat. http://www.roger-russell.com/wire/wire.htm
...and this agrees with everything I've said on this thread (sans my "typo"). So, unsure why (besides my obvious error) you decided to whine about my previous post.

It says:

Quote:
So for these two reasons this measurable high frequency wire loss in the 10 to 20kHz region is not audible for moderately long wires like 50 feet. Longer runs may still not be audible for some people, provided the wire resistance is kept low enough.
Nearly the same statement I made that you jumped on to rant about skin effect. There is HF loss measurable in the wire, the poster may not be able to hear it...pretty sure that's what I said, right? Maybe I should have said, "possibly audible things" and you'd have let me slide, lol. Though, I think I've been pretty clear subsequently that the original poster may/may not be able to hear any changes by swapping out his wire.

I still think for his receiver's health (it's already not rated to drive his 4ohm speakers) and peace of mind, it's probably a good idea (I'd do it). The table in that web site would agree. But, if it's a pain in his rump, he may as well see if issues crop up in his use before dealing with it; they may never (I think I've been clear here, too).

So...why'd you call me out, again?
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For perspective on your electrical situation you should check out this calculator that is also linked elsewhere on this forum:

http://www.bcae1.com/images/swfs/spe...rassistant.swf

This calculator checks the current density to make sure your wire will not overheat. You don't have that problem unless you are using huge amps, but you can certainly check for it anyway.

Note that this calculator assumes that less than 1dB of loss is inaudible. This is not strictly true in all cases but it is an approximation of what you hear when you change your volume control by 0.5dB, and you cannot really perceive a change (at least I cannot until I change it another 0.5dB). Some want less than 0.5dB of loss in their wire but 1dB is commonly spec'd also.

Audioholics chart:
https://www.audioholics.com/audio-vi...er-cable-gauge

Their criteria of <0.2dB of insertion loss and damping factor >50 limits a 4 ohm speaker cable to 50' in their table. I think this is probably 100% overkill and you should be OK with 10ga unless you are interested in maintaining perfect acoustic transparency in a system that is probably full of far more serious warts than the 100' of 10ga wire.

Electrovoice calculates the -3dB rolloff point at the speaker from the wire capacitance (rc loss through the wire not counting capacitive loading on the amp), if you have the pf/' specified for your particular wire:
https://www.electrovoice.com/cableloss.php

Here is some background on twisted pair:

https://en.wikipedia.org/wiki/Twisted_pair
https://www.eeweb.com/tools/twisted-pair

With this info you can estimate the capacitance per length of any twisted pair you create yourself. I doubt it matters. Let your EQ fix it. There typically is not much audio power at very high frequencies anyway so even doubling it to make up for a -3dB loss will not add a lot of extra load on the amp.

At least now you can check all the important parameters and consider more options with the advice of real experts (that would not include me) before leaping into another quagmire.

You should be able to find the capacitance spec per length on your wire if your installer got it from a reputable source, but you might have to contact the manufacturer to get it. You probably want that corner frequency well above 20KHz to prevent audible effects for someone with pristine hearing (that's my criterion but not my hearing nor budget -- I do things on the cheap here because there just isn't much return with the top octave burned out already).

-3dB is the half power point and significant loss. If you can still hear 20KHz I would put -3dB up near 24KHz to be sure there is no appreciable attenuation in the wire from the capacitance, but that's just me. I overdesign everything I do until I get blindsided by something I didn't consider and then I find out what a putz I really am.

Note that if you replace with single conductor wires jammed into a small conduit this calculation becomes more problematic. You don't know how close each wire is to its neighbors (nor do you even have a spec if you made the twisted pair yourself) but you know there is more capacitive coupling than there would be if there is a separate jacket keeping the pairs apart from each other.

Twisted pair rejects differential mode signal coupling between pairs best when the twist rate differs so the twists don't align between pairs. Probably you don't care for speaker wire and/or your home brew will have plenty of randomness to it. However...

The capacitive coupling from one conductor in your conduit to neighboring conductors spaced equally far apart is identical in all directions whether they are in that pair or not, with half of those neighbors being at ground potential off your amps and all of them being relatively low impedance paths to ground. Your amp is almost certainly driving only one of those conductors single-ended, not differentially, so the net load on the amp and the net loss along the conduit is going to be a more complex function that does not approximate well as twisted pair driven differentially.

Without separate jackets keeping those twisted pairs separated from each other per channel, the capacitive load on your amp might be somewhat higher and the actual capacitive loss in transmission to your speaker might be a little higher too. Again, you probably don't care and this effect is probably minimal. It's just more of my OCD.

If you do decide to gang up the existing wires you need to be sure you parallel up twisted pairs not create complex stranded wire with insulation buried in it. You want all the return current from your speaker doing a loop through a twisted pair, not running in linear parallel paths through what amounts to a larger stranded wire that you built by ganging individual conductors without thinking. It matters how you do the wiring.

If you cannot twist in pairs then don't sweat it. Just make sure you can pull that wire through.
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post #23 of 53 Old 03-13-2018, 02:53 PM
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The main effect you would note from your existing wiring is probably a slight drop in perceived output, but for a 100W signal your power loss of ~1.6dB is ~30W. That is enough change to make the difference in output power between e.g. a garden variety 80W receiver vs. a prosumer 130W receiver a factor just to maintain the same acoustic level with your underspecified wire.

A related effect is the additional frequency response ripple. You could measure that with REW and a microphone but why bother? You already know it's there and you don't want it, and you can address it with competent room EQ and not cause issues with the amp if the loss across frequency only changes by about 2dB and you don't mind losing that much headroom. It will make it more difficult for your room EQ to do its job (you want to minimize all the error sources you can before using EQ) but it's not a show-stopper.

The damping factor will affect how well transients are damped at the woofer once the transient terminates in the signal coming from the amp. The energy in the woofer motion is sucked out through the power supply of the amp and the wire is part of that load. Longer wire is a softer load for the moving woofer (essentially a generator) to drive, and the woofer resonates more/longer. EQ will not fix this issue.

This softer damping is probably the subtle effect you are noticing the most IMO (but I don't really know). If it is, then measuring acoustically with REW can detect it, but displaying it in a meaningful way for this discussion might be challenging, as would be distinguishing it from modal acoustic resonance from the room itself if the two mechanisms overlap in frequency. A waterfall plot is probably the way you would detect changes in damping with changes in wiring and it might be more revealing on a short sweep through a given frequency range than a prolonged one i.e. use the small data record and a full frequency sweep so the generator moves quickly across the bass region and leaves plenty of s/n for the microphone to distinguish the speaker ringing from the tone being driven.

I don't thing REW with a UMIK is going to enlighten you much here. The differences you are looking for are subtle compared to things like reflections and modal resonances, speaker ports and cabinet/driver resonances, etc. and best measured electrically to avoid confusion. If you had a way of sampling the amp at its output and again at the speaker without causing more confusion in the probe lengths that might do it but I advise against trying it. That is something an engineer would be best at.

There is one thing that REW could spot for you though. If your amp is having trouble driving the load you might be able to detect that in the output from the speaker. It could show up as strange distortion, ringing, response peaks/dips, or even oscillation that might be ultrasonic or sporadic.

Probably the only thing your amp is going to do if it has trouble driving the load though is lose some transient performance and maybe shut down from thermal overload if you turn it up too high. Again I don't really know. Not an expert.

Disclaimer: All I did was give you a non-expert data dump. There might be rotten inside.
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But, I didn't make the statement with skin effect in mind.
You didn't clarify it on post # 6.
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Originally Posted by DreamWarrior View Post
Nearly the same statement I made that you jumped on to rant about skin effect. There is HF loss measurable in the wire, the poster may not be able to hear it...pretty sure that's what I said, right? Maybe I should have said, "possibly audible things" and you'd have let me slide, lol. Though, I think I've been pretty clear subsequently that the original poster may/may not be able to hear any changes by swapping out his wire.
There is a portion in that link about when differences can be heard.
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post #26 of 53 Old 03-13-2018, 10:49 PM
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You didn't clarify it on post # 6.
I clarified it 20 minutes before you decided to post a nonsense response to something that your own link agrees with.

What was it? The typo where I clearly should have said higher gauge than lower (or lower diameter instead of lower gauge)? Or was it that you just thought I believed in skin effect (or was a wire zealot) and had to correct me? This despite that I don't (and am not), as my post 20 minutes before yours (and all subsequent, and many other posts I've made on this forum) should make clear.

In the end, I don't think I'd be OK with 100' of 16ga wire on speakers that dip below 4ohms throughout a crucial frequency band. But, I also tend to have more demanding listening sessions and would likely have issues with the original poster's receiver on those speakers even without having undersized wire. So...his experiences obviously are not mine and, therefore, I've posted several times he should see if any issues arise and address them if they do and try to dismiss the OCD -- what's done is done, he's not going to melt the wire and any audible issues can be corrected. Worse case, he upgrades to a higher power amp (and those speakers probably won't take enough power as to make the 16ga wire's current capacity an issue, so they'll tap out before the wire).
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Originally Posted by DreamWarrior View Post
I clarified it 20 minutes before you decided to post a nonsense response to something that your own link agrees with.

What was it? The typo where I clearly should have said higher gauge than lower (or lower diameter instead of lower gauge)? Or was it that you just thought I believed in skin effect (or was a wire zealot) and had to correct me? This despite that I don't (and am not), as my post 20 minutes before yours (and all subsequent, and many other posts I've made on this forum) should make clear.
All this after stating,
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As for #2 -- I'm not going to argue with you.
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post #28 of 53 Old 03-14-2018, 09:16 AM
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All this after stating,
LOL -- indeed. But, I don't really think we're arguing, somehow, I think we agree (at least, I agree with everything in the site you posted, and wasn't aware I've contradicted it). I may lean more on the "play it safe side", so some of my statements may come across stronger than the site you posted, but...overall, I'm just trying to figure out why you called me out when it appears we agree.
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In practice, for all my systems, if the run is over 30ft I use 12ga wire. I doubt I ever hit its limits. Going with 10ga to me is overkill. In his situation, I would change the wire. However, there is another consideration. Some speakers need a little power to come alive. I have a Legacy system with Focus fronts and Silver Screen center, both models are 4ohm. When I watch a movie or TV there's a point where increasing the volume a little more will substantially improve its sound quality. It's possible between the long runs and the resultant lower power, the speaker is not doing its best. The Motion 50 looks like a substantial speaker. I'd never try to run it with 16ga. Crank it a bit and see what happens, before making an expensive decision.
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Crank it a bit and see what happens, before making an expensive decision.
Indeed.

A 2 dB line loss, though noticeable, will not make the difference between satisfying and unsatisfying. Those distinctions lie elsewhere, most likely related to a restless OCD quest for something better*.


(*better = new).
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