Internal speaker cable for high power disco/pa cabs

[JOE DIRT®]

ok.peeps....can you please ALL read the original question?????..it was about internal wiring of some pa speakers....NOT external

DIRT®

[Nappylady]

Internal wiring? 12-guage, I'd say. It's a nice round number and there is a lot of it around.

[trwh]

Originally posted by Bill Fitzpatrick
Just use 16 guage zip cord. Save money. With 4 foot runs, even IF you can hear the difference between zip and some esoteric wire in a home environment it wouldn't show up in your application.

I second that

Originally posted by The Paulinator
Try the wire from a Sega Genesis controller. I have found it to sound much better than, say, a Playstation controller. If the piece is not long enough you can connect them end-to-end with some well-chewed bubble gum.

lol!

Personally, I'd just use the first ~2.5mm^2 cable that came to hand. It's really not critical. I would only splash out on Van Damme for external runs, where you need its robustness.

See ya,
Tim.

[mrfeedback]

Originally posted by MadMax
As long as there is more copper in lead than vc then vc will melt first.
I am with Mr feedback but I use cat five x3 briaded with colors for + and white & colors for - . thats 12 strands each way. Ive got 600w into sub and when the house shakes the cable stays cold.
Mark

12 Pair has plenty of copper, sounds very good and is a lot less mucking around than braiding Cat-5.
nowadays I don't bother to use anything else.

Eric.

[GM]

>I'm planning on making some 3 way disco/pa speakers which will be used in medium venues at high volume levels.

>I've got the plans,the construction guide and I know what drivers and crossovers to use,and I've got all the tools and the 18mm plywood.
Eminence Delta 15 [400w rms] for bass,Eminence Alpha 8 MR[125w rms] for midrange,Eminence APT150 compression horn and driver combination[85w rms] and a Eminence PXB3-5K[600w rms 3 way crossover].

>I'm going to be driving them with a 600w rms into 8 0hm per channel power amp.

>But nowhere is any indication of that size[gauge] internal wire you have to use.So I guess 10 gauge-14 gauge OFC cable for the bass driver,14 gauge-18 gauge for the mid driver,16 gauge-24 gauge for the tweeter.
====
The wire in the speaker to the woofer should have at least as much cross sectional area as its leads from the amp, which ideally will be sized based on minimal voltage drop over their length. The mids/HF are isolated by their respective XOs, and while their gauge should be based on the same voltage drop parameters, the distance from the speaker's terminals to the driver's will be so short that their gauge will be quite small.
====
>How can you tell when buying a certain thickness of loudspeaker wire how many amps and watts the cable can handle?

>Also the shop sells 22 gauge ofc ,high temperature wire,which has silicon insulation,and can handle 300 0c short time,180 0c long term and can handle 35amp,600v max.Is this cable suitable for loudspeaker cable,it seems weird that 22 gauge cable can handle 600v and 35 amp.
====
There are charts based on application, heat rise, insulation, etc., in the various UL/NEC/NFPA classes. A wire may have a number of different current ratings depending on the app. it's used in. Any wire is suitable if its gauge is sufficient to handle the required current over the desired distance without breaking down. It may not perform as you want it to for a variety of reasons, but technically, it's suitable.

FWIW, solid core silver plated copper has the lowest voltage drop over distance for a given guage, and what the following is based on, so if stranded or twisted pairs are used, the results should in theory be derated ~20%. I normally just go to the next larger size and use the conductors out of Romex for both speaker leads and woofer internal wiring, and armature winding wire for the other drivers. Anyway, here's an old post of mine about calculating wire runs:

Assuming you don't want the wire to act as a resistor to either flatten a
rising response or better match the impedance of a tube amp, then the size
is determined by how much voltage drop you consider acceptable.

Using the driver's Pe, Re (or total Pe, Re if multiple drivers are used),
then with the formula:

I = (Pe/Re)^0.5

you can calculate ~ max current draw capability. If this number is >the
amp's rating, then you may clip it on loud passages.

To determine wire size required:

Circular Mils (CM) = (2*L*I*10.8)/VD

Where:
L = length of wire in ft
I = max current of circuit
VD = voltage drop

Some rounded off CM values:

32ga = 64
30ga = 100
28ga = 159
26ga = 320
24ga = 404
22ga = 640
20ga = 1024
18ga = 1624
16ga = 2580
14ga = 4109
12ga = 6529
10ga = 10384
8ga = 16512

Example:

Pe or short term peak rating = 400W
Re = 3.4ohms
wire run (one way) = 20ft
VD = 1V (this is considered the max acceptable, I usually use 0.3-0.5V)

Sqrt 400/3.4 = 10.846A

(2 x 20 x 10.846 x 10.8)/1 = 4685.472CM, or 12ga.

As you can see, small wire/long distances can eat up amp headroom.
Conversely, if the amp is near/on the speaker, acceptable wire size becomes
tiny (or Vd vanishingly low if a large gauge is used).

At what point downsizing the wire becomes audible is of course dependent on
the individual and his system/room.

HTH,

GM

[kelticwizard]

2.5mm^2 is between 14 gauge and 13 gauge AWG, for Americans wanting follow Pinkmouse and trwh's advice. The runs inside a cabinet are so short that I am sure 14 gauge is being more than generous.

Here is a conversion chart for those who want a Metric to AWG chart for any occasion.

http://www.vandenhul.com/artpap/awg.htm

[JOE DIRT®]

yepp it is...I suggested what I use...because I like it...this thread has been taken out of hand but oh well

[OMNIFEX]

All you need is 16 gauge.

You are not runnig feet, or, miles of wire.

Only if your using two drivers on one wire, I
would recomend 12 gauge.

Esoteric wire is not needed. The speakers will
be used for boom boom music, not symphany
music.

[mrfeedback]

I made a pair of 12-pair telephone cable speaker wires for a professional guitarist friend that connect from his Marshall amp to his Marshall quad-boxes and he MUCH prefers them to the fig-8 cable that he was using.
You don't need to go overboard, but low inductance cable always sounds better than fig-8 cable in my experience.

Eric.