Speaker Wire Question

[alatraveler50]

So I've read all about speaker wire and learned about impedance, damping factors, etc. What kind of effect can you expect running, say, #14 wire to it's max length and then hooking it up to a speaker that is prewired with #22?

I have some older small 8ohm speakers that came with an inexpensive HT system that I want to use with a new system for my Back Surrounds. They are prewired but I have wired for better speakers in the future.

I know I shouldn't have a problem but I've never seen anything about this type situation and I'm curious.

Thanks

 

[Adam]

Welcome to the forum!

I don't know what you mean by "max length" for the 14-gauge wires, but it's doubtful that you'd notice any effect at all from that. If you wanted to calculate the effect, it's a function of how long your 14-gauge wires are, how long the 22-gauge wires are, and how well you've made the connections between wires.

I sure wouldn't worry about it, though.

Adam

EDIT: You can always trim the existing 22-gauge wires to make them shorter if you want. The shorter those wires, the less resistance there will be in the wire chain between your amp and those speakers. Again, though, I wouldn't worry about it.

 

[Midcow2]

Welcome to the forum!

I don't know what you mean by "max length" for the 14-gauge wires, but it's doubtful that you'd notice any effect at all from that. If you wanted to calculate the effect, it's a function of how long your 14-gauge wires are, how long the 22-gauge wires are, and how well you've made the connections between wires.

I sure wouldn't worry about it, though.

Adam

EDIT: You can always trim the existing 22-gauge wires to make them shorter if you want. The shorter those wires, the less resistance there will be in the wire chain between your amp and those speakers. Again, though, I wouldn't worry about it.

Adam is correct you probbly won't see much difference.Here is layman's answer, bascially you take your speaker nominal impedance and add the wire impedance ( based on the length)

speaker mpedance/ (speaker impedance + wire impedance) = percent of power going to your speaker.

If the percent is 90% or higher you probalby won't notice any difference. This means the impedance of your wire can be up to .89 ohms for 8 ohm speakers

gauge ohm/ft. ft @.89 ohms
12........0.00187......476ft.
14........0.00297......300ft
16........0.00473......188ft
18........0.00751......118ft
20........0.0119.........74ft
22........0.0302.........29ft

You can argue a different percent than 90% ,but you can still see how absurd it is to get bigger wire

 

[j_garcia]

It sounds like what you are saying is the speakers are already installed and have 22AWG wiring already in place. If that is the case, how much of the 22 will be in use? That 22AWG will create an issue if it is a long distance; if it is a few feet, it probably won't be an issue.

 

[E-A-G-L-E-S]

Adam is correct you probbly won't see much difference.Here is layman's answer, bascially you take your speaker nominal impedance and add the wire impedance ( based on the length)

speaker mpedance/ (speaker impedance + wire impedance) = percent of power going to your speaker.

If the percent is 90% or higher you probalby won't notice any difference. This means the impedance of your wire can be up to .89 ohms for 8 ohm speakers

gauge ohm/ft. ft @.89 ohms
12........0.00187......476ft.
14........0.00297......300ft
16........0.00473......188ft
18........0.00751......118ft
20........0.0119.........74ft
22........0.0302.........29ft

You can argue a different percent than 90% ,but you can still see how absurd it is to get bigger wire

So for say a 30' run from an EP2500 to a sub, all I need is 20guage?

 

[Midcow2]

So for say a 30' run from an EP2500 to a sub, all I need is 20guage?

I was showing by example the limits wiring can go. Normally ,you don't run at limits and maybe you want 95% or more of power going to your speakers.

I think you are being fictious, but I will answer as if a real conern/question.

Subs are usually powered so a Berhingher EP2500 is a completed overkill. And if it is a passive sub you probably need a new sub.

However 300W/channel into a pair of MartinLogan Summit 4 ohm speakers you might want 12 gauge, That is one monster speaker power

For almost all speaker runs, 14 gauge works fine. I would not use 22 gauge normally, but it will probably work and if there are 4 wires, OP can double up and effectively get 20 gauge. That will work with minimal degradation in speaker sound.

 

[Adam]

And if it is a passive sub you probably need a new sub.

Midcow, I agree with a lot of what you say...but not this. So his sub doesn't have a built-in amp, no big deal. Some people prefer that.

 

[Midcow2]

Adam is right! THERE ARE SOME GOOD PASSIVE SUBS

Midcow, I agree with a lot of what you say...but not this. So his sub doesn't have a built-in amp, no big deal. Some people prefer that.

Okay, I'll take this back. You are correct there are some great passive subs.
Mea Culpa. It is just that a lot of the ones you see are powered and a lot are normally connected to LFE (pre-out level) or sub pre-out.

 

[alatraveler50]

I was thinking of Roger Russell's "Wire Chart" when I said "Max Length". This is something I was curious about and had not seen anything on it. Figured it would not be a problem but ... if you don't ask, you will never know.

Thanks

 

[Adam]

I was thinking of Roger Russell's "Wire Chart" when I said "Max Length".

Gotcha. Those lengths are based upon having the speaker wire not exceed 5% of the rated impedance of the system. If you run that length and then add some more wire, then you'll go above 5%. The audible effects of that? I don't know, but I'm guessing it'll be minor - especially for rear speakers that get relatively low amounts of power sent their way.

if you don't ask, you will never know.

Very true! Glad that you stopped by. Hopefully you'll find other stuff here that you like and stick around!

 

[alatraveler50]

I only wish speakers and 22awg were installed!!! I'd used it, lol. After three years and an $65,000 addition/renovation, it hit me about 2 months ago that I needed to pull speaker wire before I closed up the wall that I left open for HT/CATV/CAT 5/Sat Ant, etc. I've been working the last two weekends in the attic (over 100deg) pulling cables. Still itching from insulation. Wife wants to put ceiling speakers in all the new bedrooms, so I have to mess with more insulation down the road. (Stuff doesn't bother her). Now I have to cut up all my sheetrock and have insulation drop down on me.

 

[alatraveler50]

Thanks again, Adam. Plan on sticking around. Even though I'm not all that technical, you can never stop learning. That's what makes life exciting.

 

[E-A-G-L-E-S]

I was showing by example the limits wiring can go. Normally ,you don't run at limits and maybe you want 95% or more of power going to your speakers.

I think you are being fictious, but I will answer as if a real conern/question.

Subs are usually powered so a Berhingher EP2500 is a completed overkill. And if it is a passive sub you probably need a new sub.

However 300W/channel into a pair of MartinLogan Summit 4 ohm speakers you might want 12 gauge, That is one monster speaker power

For almost all speaker runs, 14 gauge works fine. I would not use 22 gauge normally, but it will probably work and if there are 4 wires, OP can double up and effectively get 20 gauge. That will work with minimal degradation in speaker sound.

Actually, I am being sincere...didn't think it came across anyother way. About to order 50' of 12 guage and was hoping I could save a little money and be able to tuck away a smaller guage more easily.
EP2500 is too much? I need a new passive sub?
Well let's see....my Tempest-X arrives tomorrow(first of two) and people use alot more than a single EP2500 for DIY projects.
I'm sure those M.L.'s sound really good, but I'm saving a boatload of money and will be able to go lower and louder.
I am not a fan of plate amps, I like the idea of having headroom.
To each their own, no?

Oh and my set-up will be connected to my AVR's Sub/LFE out....not sure why you think it wouldn't?


Also, I'd like to hear why you think a exteranlly amp driven sub would be 'any different at all' than the identical set-up with a plate amp on the back panel?

 

[Adam]

Glad that you'll be sticking around. This site might give you a nice break from inhaling insulation.

 

[ParadigmDawg]

You guys have it all wrong. Your speaker cable has to be the size of jumper cables or you just are not a good audioholic.

BTW, I dont believe in big speaker cable or bi-wire, I just like the way it looks. My cheap Home Depot wire is used for everything except the mains (the wire you can see) and it does the same thing as my fancy pants cable!

 

[E-A-G-L-E-S]

All of my speakers are currently connected with 14guage from good 'ole Home Depot. I was told there wouldn't be any diference so I went for the least expensive.

 

[Adam]

...my fancy pants cable!

We should start calling you Duke Henry the Red.

[Someone is bound to get that one.]

 

[ParadigmDawg]

I dont get it!

We should start calling you Duke Henry the Red.

[Someone is bound to get that one.]

 

[jamie2112]

We should start calling you Duke Henry the Red.

[Someone is bound to get that one.]

I don't get it either Greg. Adam stop calling people names....

 

[Adam]

I dont get it!

"Well, Hello Mr. Fancy Pants..."

From Army of Darkness.