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.
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.The shop is Maplin electronics.
www.maplin.co.uk
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.
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.The shop is Maplin electronics.
www.maplin.co.uk
*SIGH*
Some of you have OBVIOUSLY never had wires melt on you before, because you have to run x current through y length of z-sized cable and it just doesn't have the poop for it...
LEMME TELL YA, the owners of the venue do NOT like having to fix the floor after you've burned a hole in it with molten copper! The people attending the disco also don't particularly relish the smell of charred polymers! Best of all, the music coming to a sudden end, along with, potentially, your soundsystem, is no fun at all!
www.siriusone.com sells spools of 250' 8-guage OFC 2-conductor wire for $50, I think. That will definitely be enough, unless you're running the wire more than maybe 1/2 mile.
Some of you have OBVIOUSLY never had wires melt on you before, because you have to run x current through y length of z-sized cable and it just doesn't have the poop for it...
LEMME TELL YA, the owners of the venue do NOT like having to fix the floor after you've burned a hole in it with molten copper! The people attending the disco also don't particularly relish the smell of charred polymers! Best of all, the music coming to a sudden end, along with, potentially, your soundsystem, is no fun at all!
www.siriusone.com sells spools of 250' 8-guage OFC 2-conductor wire for $50, I think. That will definitely be enough, unless you're running the wire more than maybe 1/2 mile.
>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
>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
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
Here is a conversion chart for those who want a Metric to AWG chart for any occasion.
http://www.vandenhul.com/artpap/awg.htm
Cheap And Cheerful.
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.
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.
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