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4 conductor cabling on dual 18 subs
Caleb Dueck:
--- Quote from: Michael Mills on March 23, 2023, 01:07:54 AM ---Amps are Crown MA 2500 bridged, with 1 amp per box. Cables are 50'
4 sub boxes and 4 amps.
--- End quote ---
The main benefit to using 4 conductor cable, besides higher damping factor, is that you can use one amp channel per driver rather than one per sub. Especially if it's a 4 ohm sub (dual 8 ohm drivers), each amp channel will run at 8 ohms rather than 2 ohms. Even though the power to the sub looks lower on paper, look at amp output vs time graphs, as that along with higher damping will help it perform better overall.
I'd say go for it, as long as it addresses the amps as well.
Steve-White:
I'd be inclined to look at the numbers for 4x 14ga - not so sure you want to bridge those amps into a 4 ohm load. With one amp per pair of 18's I'd go dual channel to the drivers with independent runs to them from the amps.
Matt Vivlamore:
--- Quote from: Michael Mills on March 22, 2023, 06:20:03 AM ---Is it worth the expense and to go with 4 conductor cables to each sub box, example...jbl 828s in discrete vs a 2 wire in parallel?
--- End quote ---
The switch on the back of the SRX828S, isn't the same as the old SRX47## series. The switch allows you change from Pins 1 to Pins 2.
What can do is run NL4-4C into the 828 (switched to Pins2) and then Link up to your mains with jumper (Pins1). I did this when I had my SRX7## system and it worked out great.
Caleb Dueck:
--- Quote from: Matt Vivlamore on March 30, 2023, 11:05:35 AM ---The switch on the back of the SRX828S, isn't the same as the old SRX47## series. The switch allows you change from Pins 1 to Pins 2.
What can do is run NL4-4C into the 828 (switched to Pins2) and then Link up to your mains with jumper (Pins1). I did this when I had my SRX7## system and it worked out great.
--- End quote ---
It's a simple internal rewire to have pins 1 to one driver and pins 2 to the other.
Tim Weaver:
--- Quote from: Steve-White on March 23, 2023, 08:38:10 PM ---I'd be inclined to look at the numbers for 4x 14ga - not so sure you want to bridge those amps into a 4 ohm load. With one amp per pair of 18's I'd go dual channel to the drivers with independent runs to them from the amps.
--- End quote ---
This.
We have been running 4 conductors on subs for years so that each driver gets powered discretely. The benefit gets better when you have multiple dual 18's and you never know how many you are going to use that day. If you out out 3/side with the standard wiring you'll have a 2 ohm load and a 4 ohm load, but with the discrete wiring both loads would be 2.6 ohm. You'll get a balanced load on your amp (and distro, depending how its wired) by using the discrete wiring.
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