PA 4ohm linkage

[la bam]

That's what it looks like, but then linking them gives 2ohms. Linking the other side gives 2ohms. So a total of 1 ohm which isnt safe.

Weird.

I've used some systems in the past that keep the load spread - ie stays at 4ohm, or halves - linking 2 gives 8ohm. That's why I'm a bit stuck with this design.

[Bill Fitzmaurice]

2 hours ago, la bam said:

Just weird that they build in the links to connect the tops to the subs but that then makes this system 2 ohm per side per one input from the amp which is unusable for any amp (combined 1ohm).

They don't do that. Using the speakons there's no connection between the drivers of the subs and the drivers of the mains.

[Bill Fitzmaurice]

27 minutes ago, la bam said:

 

I've used some systems in the past that keep the load spread - ie stays at 4ohm, or halves - linking 2 gives 8ohm. That's why I'm a bit stuck with this design.

The design isn't unusual, you're just not used to dealing with passive subs/mains that require bi-amping. I recommend this exact 4 pole speakon wiring in all my passive subs and mains. It's also the most commonly used arrangement in high end commercial passive PA.

[la bam]

Ok Bill, sorry, I'm getting confused again

if I send the amp to the tops then the link to the subs, they all work.

so what is the ohmage there?

How would you power this system with amps and connections?

Edited February 11, 2020 by la bam

[la bam]

Actually...... am I over thinking it?

Is 2 ohm one side L and 2 ohm the other side R - actually 2 ohm. Not the 1ohm i mentioned (i was thinking if it was bridged).

So I could use 1 amp that is 2 ohm stable like a qsc rmx2450 or plx2402?

Edited February 11, 2020 by la bam

[Bill Fitzmaurice]

2 hours ago, la bam said:

Ok Bill, sorry, I'm getting confused again

if I send the amp to the tops then the link to the subs, they all work.

so what is the ohmage there?

How would you power this system with amps and connections?

If that results in one amp channel powering both speakers don't do that. If you don't split the lows to the subs and the rest to the mains with an electronic crossover the system simply won't work as it should. All you're risking is blown drivers, as well as bad sound.

Ohmage is what you pay to Jack Bruce, Entwhistle, even Sir Paul. Speakers have impedance.

You must bi-amp, either using a single two channel amp with one channel for the subs and one for the mains, or using a pair of two channel amps, one amp for the subs, one for the mains.

Edited February 11, 2020 by Bill Fitzmaurice

[la bam]

Thanks for your patience Bill. I'll get there I promise:)

Ah, so the link mechanism is not to link subs to tops etc, it's to link tops to tops, and subs to subs?

[Bill Fitzmaurice]

The XLR are a means to send signal to the sub driver without using the speakons. They also could be used to link sub to sub, and main to main, assuming the mains panels look the same.

 

[la bam]

In all honesty I'm still no further on with this.

Do I need an amp that has 4 core connections? I cant get the subs to work on their own.

Which cabs to I link to each other?

I fully understand the conventional 1 amp into the 2 tops and 1 amp into the subs (using a crossover) but have no idea how to use this system I have. 

[Bill Fitzmaurice]

You need a break out panel. My assumption is that you don't know what that is. Go to my forum and ask there in the Pro Sound Setup  section. This wiring may be Greek to you but not to the PA gurus on my site. It's how most of them  run their rigs, because it is conventional with large touring systems.. 

Edited February 17, 2020 by Bill Fitzmaurice

[la bam]

Thanks bill. What is your forum?

[Bill Fitzmaurice]

https://billfitzmaurice.info/forum/

[Phil Starr]

14 hours ago, la bam said:

In all honesty I'm still no further on with this.

Do I need an amp that has 4 core connections? I cant get the subs to work on their own.

Which cabs to I link to each other?

I fully understand the conventional 1 amp into the 2 tops and 1 amp into the subs (using a crossover) but have no idea how to use this system I have. 

Everything Bill has said is right. If you are still struggling I'll try and see if I can make it simple. These speakers are designed to be used with two stereo PA amplifiers and a crossover. Anything else is a bodge. You could use it with a single amp if it was 2ohm stable but it would be less than good even though you could get sound out of all the speakers. To get the best out of these you need an extra amp and a crossover.

Some PA amps have the crossover built in.

The reason your speakers are wired to 2+ and 2- is to stop you damaging the speakers accidentally. You'd originally have had a lead with four wires running to the subs, you'd then have had the option of running a lead from the 1+and - of the second speakon socket to run the tops or running a longer lead all the way from the amp. If you had two identical leads then there is the possibility of accidentally plugging the bass frequencies into the tops and damaging the speakers at high power, Running the subs through 2+and - stops you muddling the feeds up. It's also possible the system may have run off a 4-way PA amp

To run the subs directly you can simply change the connections at one end of the speaker lead, wiring the +output from the amp to 2+ and the - to 2-, better mark the lead as sub to make sure you know which is the 'special' lead. Many speakons don't need soldering so it's an easy job but get someone else to make a lead up if you aren't sure.

Even so the point of subs isn't to get more bass, it's to improve the sound by making sure the tops only have to deal with tops and the subs to handle the bass. Just connecting up all four speakers to a single PA amp won't improve the sound it will make it unbalanced and too bassy as well as introducing other distortions.

Hope that makes sense