Outdoor speaker wire in raceway.

Status
Not open for further replies.

iwirehouses

Senior Member
Drill through the hatch? That sounds like a pretty good idea. Then just fill the hole with caulking. Is this commonly done for grounding electrode conductors's and such?
 

dbuckley

Senior Member
iwire said:
I have hooked up the show power for dozens of shows and been backstage at quite a few other large shows, I can not recall seeing speaker wiring larger than 14 AWG and I bet the size had more to do with long term durability for the repeated set up and break down.

Concert speaker systems are now frequently wired using Socapex cables. These cables used to just be used by the lampies then the riggers discovered them, and now noize have joined the party. Socas are usually #12. Socas for audio are usually wired as "power comes out of pins" to try and stop the speakers being plugged into the dimmers. Socas use a 19 pin connector with 18 core cable.

Speaker cable CSA has been going up anyway as amplifier power goes up; the big I-Techs are 7KW bridged into 4 ohm, Lab FP13000 is 6.5KW at 2 ohm, you just don't put this power level down cables of small CSA as you don't want to lose half the power in cable heat.

Too long or too thin speaker cables causes excessive power drop, as the cable impedance is not dissimilar to that of the speaker, and also reduces damping factor, giving the amplifier less good control of the cones. I would imagine a 500 foot spool of #14 would demonstrate this immediately in an a/b comparison.

Dont skimp of conductor size for speakers. And if you need to go large distances and you can sacrifice quality then 70V or 100V line will alow use of wire of smaller CSA.

(My speaker cables as 2.5mm, which is about equivalent to #13, but I only run an 'icle 1KW theatre rig)
 

iwire

Moderator
Staff member
Location
Massachusetts
dbuckley said:
you just don't put this power level down cables of small CSA as you don't want to lose half the power in cable heat.

That makes sense.

but....

I thought this thread was about an outdoor speaker at a residential property?

I would imagine a 500 foot spool of #14 would demonstrate this immediately in an a/b comparison.

Where?

In a typical residential system or in a concert system?

Dont skimp of conductor size for speakers.

Beyond the loss of volume that small cables may introduce (is that a real problem in a home system?) what do you see as the benefit to larger cables?

I will remain in doubt unless someone can show me that the current of a speaker requires a large cable.

I guess my home system will never measure up.
 

mdshunk

Senior Member
Location
Right here.
iwire said:
I guess my home system will never measure up.
I don't know. Looks like a pretty nice system to me, Bob.

ghetto_blaster_051216035418598_wideweb__300x375.jpg
 

dbuckley

Senior Member
iwire said:
In a typical residential system or in a concert system?

Residential. Well, you would notice in a concert system as well, I guess, but that is a tad off topic :)

Low powers over low distances you can use weedy wire for speakers without grief, but as the distance goes up, the the numbers of speakers being fed goes up, and the quality expectations go up the case for decent cable (and I'm talking pure CSA here, not oxygenated purple con-artist cable) becomes stronger. My outdoor speakers are all fed using weedy wire (1mm, about #17), but they are (a) not great speakers, (b) either have short cable runs or (c) use 100V line so cable length becomes effectively irrelevant.

And Marc - I love that photo!
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
dbuckley said:
My outdoor speakers are all fed using weedy wire (1mm, about #17), but they are (a) not great speakers, (b) either have short cable runs or (c) use 100V line so cable length becomes effectively irrelevant.
On the other hand, in my HT system, I use bi-wired #14 runs to the main speakers, supplied from a 300w/ch stereo amp, and #12 runs to the center, sides, and rears, from a 200w/ch 5-channel amp.

The two 15" subs, built into the main speakers, each contain 300w amps. That's a total of 2200w. I ran a 50a, 240/120v 4-space, 8-circuit panel to the equipment stack.
 

mdshunk

Senior Member
Location
Right here.
LarryFine said:
On the other hand, in my HT system, I use bi-wired #14 runs to the main speakers, supplied from a 300w/ch stereo amp, and #12 runs to the center, sides, and rears, from a 200w/ch 5-channel amp.

The two 15" subs, built into the main speakers, each contain 300w amps. That's a total of 2200w. I ran a 50a, 240/120v 4-space, 8-circuit panel to the equipment stack.
I think my 1984 model Curtis-Mathis console television has one 4" built-in speaker.
 

dbuckley

Senior Member
LarryFine said:
On the other hand, in my HT system, I use bi-wired #14 runs to the main speakers, supplied from a 300w/ch stereo amp, and #12 runs to the center, sides, and rears, from a 200w/ch 5-channel amp.

What - you mean you aren't using any of that funny coloured, funny named, really expensive horsesh*t that has a minimum bend radius measured in whole miles? :)
 

GeorgeB

ElectroHydraulics engineer (retired)
Location
Greenville SC
Occupation
Retired
iwire said:
Beyond the loss of volume that small cables may introduce (is that a real problem in a home system?) what do you see as the benefit to larger cables?

I will remain in doubt unless someone can show me that the current of a speaker requires a large cable.
Bob, he mentioned "damping factor" which is influenced by cable resistance. There are all sort of numbers bantered around, but most modern solid state amps will have an output impedance (Z) below 0.05 ohm (think of it as an equivalent series resistance with an ideal voltage source). Ideally, the source Z driving the speaker will be less than 1/100 of the speaker Z, so an 8 ohm speaker would follow the commands of the signal better with a source Z including cable of 0.1 ohm. That leaves about 0.05 for the cable. What happens if it is 0.8, or even 8 ohms? First there is power loss in the cable, but with just reasonable wire, that isn't significant. However, with small wire, the speaker is told to move BACK by signal going to zero ... the cone flaps in the wind if the amp can't control it.

He didn't mention one other issue that I've seen and which is often overlooked. The sound signal is AC. We've discussed skin effect before, that characteristic where more current flows in the outside of a conductor than inside, not uniformly distributed. This skin thins linearly with frequency, and is significant at 10kHz when the conductor is large. 8 insulated #24 conductors, paralleled in groups of 4, give effectively 18-2, and are a much better speaker cable than the 18-2 zip cord, especially as the lengths go up. Before you ask where in the world anyone would come up with that at a reasonable price .... GREAT medium power speaker cables can be made from a cat5 cable. 2 cat5 cables give you effectively 15-2 ... really good at reasonable lengths up to around 100W.

Can _I_ hear it; no. Can some real people; yes. Can it be measured with things like a signal generator and a fluke ... yes.

YMMV.

George
 

Jim W in Tampa

Senior Member
Location
Tampa Florida
Audio is still an AC system with varying frequency.Ohms law still applies and voltage drop is still an issue.Yes voltage may be increased with volume knob but i still like to keep losses to under 5%.Most people will not notice or care about best quaility.Its your dollars and your ears.
 

iwire

Moderator
Staff member
Location
Massachusetts
Jim W in Tampa said:
Audio is still an AC system with varying frequency.Ohms law still applies and voltage drop is still an issue.

Yes that is correct, have you attempted a VD calculation?

The current is so low you will not find much voltage drop.

But if you feel better using the 'Tim Allen' approach that more is always better knock yourself out. :smile:
 

stickboy1375

Senior Member
Location
Litchfield, CT
I used to help a stereo contractor for my boss, I don't think I ran anything bigger than 14 AWG... Usually ran 14-4 to the volume control the 16-2 to the speaker...
 

Jim W in Tampa

Senior Member
Location
Tampa Florida
iwire said:
Yes that is correct, have you attempted a VD calculation?

The current is so low you will not find much voltage drop.

But if you feel better using the 'Tim Allen' approach that more is always better knock yourself out. :smile:
At my club my longest run is about 100 feet.The lost from voltage drop is almost nothing.I do agree that i could have used #18 and a increase in volume would offset it's loss.When we raise volume (voltage) we increase distortion as well.How much of a concern this is would be up to the end user.I want the best i can afford.I just happened to have plenty of 12-2 stranded available for free.Now if i was going to need to buy it then i might think of going smaller.When i find the time i will do a test at about 20 cycles and another at 20,000.Will find some number 18 to see if it was worth it.
 

iwirehouses

Senior Member
Back to the original question, I called the wiremold company and they said UV rays will break down the wiremold. This guy had absolutly no idea what I could use and niether did any supply houses. Now I am trying to find a white cable that is water and UV proof to run speakers with. I white landscape lighting cable would be perfect but nonexistant as fast as I know. Hmmm..
 
Status
Not open for further replies.
Top