Jump to content


Wiring Crown CE4000 in Bridge Mono


  • Please log in to reply
12 replies to this topic

#1 k4ng1

k4ng1
  • Members
  • 9 posts

Posted 09 March 2006 - 04:23 PM

Hi,  

I was wondering if anyone can shed some light on the set up below.

DJ Sound System

What I run now

I run a pair of JBL SRX725's powered by Crown CE4000 amp at 4ohms dual. Each channel at this ohm rating pumps out 1200watts a side which on most occasions I never go near. The JBL cabs are 1200rms.

What I am going to do

For some bigger shows I am going to add the JBL SRX728s 18" dual subs. To get that true low end I crave for.

I am thinking of using another Crown CE4000 amp but this time 4ohms Bridge Mono mode giving me a total combined power of 2800watts so 1400 watts for each sub box. I will be running two sub boxes in total.


What I need some advice on...

I want to know...

1. The process of creating the 4ohm Bridge Mono setting on the amp and
2. The correct speaker to amp connection since only one channel will be used.

Also I be using the Driverack PA once I add the subs so expect to feed everything into the rack and out to my mixer so in the end...

I will have....

SRX725 pair running 1200watts @ 4ohm Dual.
SRX728s pair running total 2800watts @ 4ohm Bridge Mono

Into Driverack and to mixer.

Any advice would be most appreciated. Thanks!

#2 DGlass

DGlass

    .

  • Members
  • PipPipPipPipPip
  • 2,541 posts

Posted 10 March 2006 - 02:48 PM

I am attaching links below on our web site that will have the information you are looking for. For further information you may also want to check out other posting in this forum related to Bridge-Mono operation of amplifiers.

Page 10 of the CE4000 amplifier manual.
http://www.crownaudio.com/pdf/amps/125645.pdf

The “Crown Amplifier Application Guide”
http://www.crownaudio.com/pdf/133472.pdf

Page 3 of our “Guide to Neutrik Speakon NL4FC Connector Assembly”  http://www.crownaudio.com/pdf/amps/126986.pdf

I hope these help.

#3 Bud Bolf

Bud Bolf

    Power User

  • Members
  • PipPipPipPipPip
  • 201 posts

Posted 11 March 2006 - 04:31 AM

Hi k4ng1
There are a couple of problems with doing what you want to do.
A SRX728 cab is rated at 4 Ohms so two SRX728 cabs paralleled together will give you a 2 ohm load.
You can not run a CE4000 Bridged at 2 ohms!

The JBL SRX 728's are rated Continuous /RMS at 1600 watts.
With the 1.5x to 2x Power Amp to Continuous / RMS ratio the SRX728's should be powered with between 2400 to 3200 watts per cab.

Your two options are:

1) Run one CE4000 per channel and put one cab on each channel at 1200 watts at 4 ohms per cab.
Since these cabs should get between 2400 to 3200 watts, you can see that 1200 watts is very under powered.
You would need to properly set up your "Gain Structure" so you do not overload the Input on the CE4000 and send the amp into clip!
The last page of the DRPA Manual goes over setting up your Gain Structure!

2) Bridge one CE4000 to one SRX728 cab and then the cab will get 2800 watts.
Properly powered between 2400 and 3200 watts, these cabs rock!

I would advise you to try it both ways, per channel to both cabs and Bridged to one cab and see what you like!
Depends on the music and application that you are using these cabs for.

I have the CE4000 Bridged on my Subs and I also use the DriveRackPA. (DRPA)
Set up Mixer out to DriveRack in, out of the Highs on the DriveRack to your
top cabs power amp. Low out of DRPA to the CE4000 for your Sub(s).

For your 728 Sub CE4000 set your LPF and HPF filters per cab and for your 725's
CE4000 set your HPF filter and leave the LPF flat.
The DriveRack has the settings for the JBL Speakers and the CE4000.
For the CE4000's use the 1.4 volt Input setting on both amps.
If the DRPA does not have the Speaker Tunings installed go to the DBX website and you can get them there.
For great help with the DRPA go here:
DBX DriveRack Forum

QUOTE
What I need some advice on...

I want to know...

1. The process of creating the 4ohm Bridge Mono setting on the amp and
2. The correct speaker to amp connection since only one channel will be used.


There is a switch on the back of the CE4000 that puts the amp into Bridged mode.
As far as connecting the speakers to the amp you can use the Binding posts or Speakon at Channel 1
For the Binding posts Bridged, you use the 2 red posts 1+ for Positive and 2+ for Negative.
For the Speakon you would need to wire a Speakon to 1+ for Positive and 2+ for the negative, and then at the speaker end 1+ wire to 1+ and 2+ wire to 1-.
I use 12/2 speaker wire for my top cabs..
I use 12/4 for my Subs and wire each speaker independantly in the cab
1+/1- to one speaker and 2+/2- to the other Speaker, then combine 1+ and 2+ for the positive and 1- and 2- for the negative at the amp.

There are many different options available for wiring Amps to cabs.
You could use a 12/4 Speakon cable and run first to the Sub and then a short 12/2 to go from the Sub to the Top cab if using stacks.
Then you just have 2 speakon cables one left and one right rather than 4 with 2 left and 2 right or each stack where ever they are.

In my amp rack I use the Binding posts to a rack panel with NL4MP-UC chassis speakons.

Here is a link to a post at ProSoundWeb about wiring an amp rack.
Click here: Amp Rack

If you look around at PSW you will see lots of information on 728's and 725's.

Good Luck,
      Bud

#4 k4ng1

k4ng1
  • Members
  • 9 posts

Posted 15 March 2006 - 01:18 PM

Thanks Bud, makes sense. I guess there are different ways to make this work.

I have an additional question or another possible route to get these subs fired up...

Do you think it is possible to wire the pair of SRX728s cabs (in series) at 8 Ohms and then power them from a bridged CE4000 amp?

According to the CE4000 manual, I can get a total of 2400 watts if I go 8ohms Bridge Mono so this would give me 1400 watts a cab, which is underpowered but for what we are going to use them there is no way we can ever push them real hard.

Thoughts?



QUOTE(Bud Bolf @ Mar 11 2006, 01:31 AM)
Hi k4ng1
There are a couple of problems with doing what you want to do.
A SRX728 cab is rated at 4 Ohms so two SRX728 cabs paralleled together will give you a 2 ohm load.
You can not run a CE4000 Bridged at 2 ohms!

The JBL SRX 728's are rated Continuous /RMS at 1600 watts.
With the 1.5x to 2x Power Amp to Continuous / RMS ratio the SRX728's should be powered with between 2400 to 3200 watts per cab.

Your two options are:

1) Run one CE4000 per channel and put one cab on each channel at 1200 watts at 4 ohms per cab.
Since these cabs should get between 2400 to 3200 watts, you can see that 1200 watts is very under powered.
You would need to properly set up your "Gain Structure" so you do not overload the Input on the CE4000 and send the amp into clip!
The last page of the DRPA Manual goes over setting up your Gain Structure!

2) Bridge one CE4000 to one SRX728 cab and then the cab will get 2800 watts.
Properly powered between 2400 and 3200 watts, these cabs rock!

I would advise you to try it both ways, per channel to both cabs and Bridged to one cab and see what you like!
Depends on the music and application that you are using these cabs for.

I have the CE4000 Bridged on my Subs and I also use the DriveRackPA. (DRPA)
Set up Mixer out to DriveRack in, out of the Highs on the DriveRack to your
top cabs power amp. Low out of DRPA to the CE4000 for your Sub(s).

For your 728 Sub CE4000 set your LPF and HPF filters per cab and for your 725's
CE4000 set your HPF filter and leave the LPF flat.
The DriveRack has the settings for the JBL Speakers and the CE4000.
For the CE4000's use the 1.4 volt Input setting on both amps.
If the DRPA does not have the Speaker Tunings installed go to the DBX website and you can get them there.
For great help with the DRPA go here:
DBX DriveRack Forum

QUOTE
What I need some advice on...

I want to know...

1. The process of creating the 4ohm Bridge Mono setting on the amp and
2. The correct speaker to amp connection since only one channel will be used.


There is a switch on the back of the CE4000 that puts the amp into Bridged mode.
As far as connecting the speakers to the amp you can use the Binding posts or Speakon at Channel 1
For the Binding posts Bridged, you use the 2 red posts 1+ for Positive and 2+ for Negative.
For the Speakon you would need to wire a Speakon to 1+ for Positive and 2+ for the negative, and then at the speaker end 1+ wire to 1+ and 2+ wire to 1-.
I use 12/2 speaker wire for my top cabs..
I use 12/4 for my Subs and wire each speaker independantly in the cab
1+/1- to one speaker and 2+/2- to the other Speaker, then combine 1+ and 2+ for the positive and 1- and 2- for the negative at the amp.

There are many different options available for wiring Amps to cabs.
You could use a 12/4 Speakon cable and run first to the Sub and then a short 12/2 to go from the Sub to the Top cab if using stacks.
Then you just have 2 speakon cables one left and one right rather than 4 with 2 left and 2 right or each stack where ever they are.

In my amp rack I use the Binding posts to a rack panel with NL4MP-UC chassis speakons.

Here is a link to a post at ProSoundWeb about wiring an amp rack.
Click here: Amp Rack

If you look around at PSW you will see lots of information on 728's and 725's.

Good Luck,
      Bud


#5 Bud Bolf

Bud Bolf

    Power User

  • Members
  • PipPipPipPipPip
  • 201 posts

Posted 16 March 2006 - 06:12 AM

Howdy,
You asked:
QUOTE
Do you think it is possible to wire the pair of SRX728s cabs (in series) at 8 Ohms and then power them from a bridged CE4000 amp?


A couple of things on this,
1) Yes you could wire a 728 in Series and it would now be 16 ohms and then
Parallel two cabs together to get to 8 ohms.

2) From what I understand there is a way with the 728's that you can have 1+/1-
go to one speaker and 2+/2- go to the other, and each speaker is wired Independently as I have in my Dual 15's.
This would be easier and not void a Warranty by reconfiguring the wiring inside your Cab that JBL has done so well.
With a 12/4 speaker wire you would Series the speakers at the amp Rack.

Bottom Line there are problems with this:

1) In Series if one of the Speakers dies then the Cab would die, like Christmas lights on a tree, when 1 goes out they all go out.

2) You are only gaining 200 watts per cab running them this way rather than just connect them one cab Per Channel at 4 ohms and the CE4000 puts out 1200 watts per Cab!
That's 600 watts per speaker, the Series way nets you only 700 watts per speaker and it is a poor inneficeint way of doing things.
Series, though rarely done it is Frowned upon in Pro Audio when dealing with
large anounts of Power!
In the world of Pro Audio, 100 watts will net you really nothing extra, nothing that you would ever experience. It's very negligible.
You need to double the Power for a 6dB increase and you will hear the difference!
When you put 2800 to 3000 watts to these cabs you will know it!

I would wire each cab per Channel and use the 1200 watts per cab.
Set your Gain Structure from Mixer to Amp correctly so that at your loudest you do not see any Clip lights on your amps, mark this and DO NOT go over it!
I ran like this for awhile until I could purchase another amp, you can too!

No matter how excited the night becomes and you'd like that extra little bit of Ooomph, don't push that FADER and clip or your speakers or your speakers may not live to Oooomph again!
That's your money and equipment not a yelling crowds!
Tomorrow they won't care if your Reconing speakers!
I had an outdoor gig and a Greek dancing troup was performing to a CD,
They like it really loud and I was right at Max and watching my Clips lights flicker.
The Dancers manager asked me to turn it up, I looked right at him and said NO,
that's as much as they will get.
He looked pretty surprised but just turned and walked away and I did not see him again!
I know what the System will do and I will not compromise that for anyone,
unless he has lot's of CASH!

Good Luck,
       Bud

#6 k4ng1

k4ng1
  • Members
  • 9 posts

Posted 16 March 2006 - 02:24 PM

Thanks Bud, makes alot of sense and see why it would not be the best thing to wire in Series.

I have decided to get two CE4000 amps and bridge them so that I get the 2800watts per cab. I don't want to take chances since the events we do are high profiled and I need the best sound.

So, in total I will have 3 CE4000 amps that power the following:

x2 SRX725's - 4ohms dual (1200watts a side)
X2 SRX728s - 4ohms bridge mono (2800watts a cab)

For the subs, on the amp do I need to parallel the channels as show in the manual with jumper placements?

The only thing that jumps out at me is the my 725's are delivering 1200watts a side, where my subs are delivering a thundering 2800watts a side. This will probably sound stupid, but with this set up, are'nt my 725's at a disadvantage compared to the subs? Last thing I want it boom boom as opposed to a clear high, mid, low set up. I guess this is where the DBXPA kicks in right?

And one more question:

I am still going to use Speakon to Speakon and wanted to know the wiring...

According to what I read, it goes as follows:

At the speaker end: connect the load across the + terminals of the connector so CH1 is the positive and CH2 is the negative. Is this right for the speaker end? What is the connection for the amp end?

Thanks again!  smile.gif


QUOTE(Bud Bolf @ Mar 16 2006, 03:12 AM)
Howdy,
You asked:
QUOTE
Do you think it is possible to wire the pair of SRX728s cabs (in series) at 8 Ohms and then power them from a bridged CE4000 amp?


A couple of things on this,
1) Yes you could wire a 728 in Series and it would now be 16 ohms and then
Parallel two cabs together to get to 8 ohms.

2) From what I understand there is a way with the 728's that you can have 1+/1-
go to one speaker and 2+/2- go to the other, and each speaker is wired Independently as I have in my Dual 15's.
This would be easier and not void a Warranty by reconfiguring the wiring inside your Cab that JBL has done so well.
With a 12/4 speaker wire you would Series the speakers at the amp Rack.

Bottom Line there are problems with this:

1) In Series if one of the Speakers dies then the Cab would die, like Christmas lights on a tree, when 1 goes out they all go out.

2) You are only gaining 200 watts per cab running them this way rather than just connect them one cab Per Channel at 4 ohms and the CE4000 puts out 1200 watts per Cab!
That's 600 watts per speaker, the Series way nets you only 700 watts per speaker and it is a poor inneficeint way of doing things.
Series, though rarely done it is Frowned upon in Pro Audio when dealing with
large anounts of Power!
In the world of Pro Audio, 100 watts will net you really nothing extra, nothing that you would ever experience. It's very negligible.
You need to double the Power for a 6dB increase and you will hear the difference!
When you put 2800 to 3000 watts to these cabs you will know it!

I would wire each cab per Channel and use the 1200 watts per cab.
Set your Gain Structure from Mixer to Amp correctly so that at your loudest you do not see any Clip lights on your amps, mark this and DO NOT go over it!
I ran like this for awhile until I could purchase another amp, you can too!

No matter how excited the night becomes and you'd like that extra little bit of Ooomph, don't push that FADER and clip or your speakers or your speakers may not live to Oooomph again!
That's your money and equipment not a yelling crowds!
Tomorrow they won't care if your Reconing speakers!
I had an outdoor gig and a Greek dancing troup was performing to a CD,
They like it really loud and I was right at Max and watching my Clips lights flicker.
The Dancers manager asked me to turn it up, I looked right at him and said NO,
that's as much as they will get.
He looked pretty surprised but just turned and walked away and I did not see him again!
I know what the System will do and I will not compromise that for anyone,
unless he has lot's of CASH!

Good Luck,
       Bud


#7 DGlass

DGlass

    .

  • Members
  • PipPipPipPipPip
  • 2,541 posts

Posted 17 March 2006 - 11:16 AM

And one more question:

I am still going to use Speakon to Speakon and wanted to know the wiring...

According to what I read, it goes as follows:

At the speaker end: connect the load across the + terminals of the connector so CH1 is the positive and CH2 is the negative. Is this right for the speaker end? What is the connection for the amp end?


Here is a link to our SpeakOn Guide it will help explain things.

http://www.crownaudio.com/pdf/amps/126986.pdf

Keep the wiring at the speaker end the way the speaker needs it. Most full range boxes and subs will use 1+/1- but some boxes require 2+/2- when setup as a top box and sub in this case it would depend on the box you are connecting to. For this information you will need to check the speaker's manual or data sheet.
At the amp end for Bridge-Mono you will need to use the 1+/2+ on the SpeakOn connector as channel 1+ will be the positive speaker lead connection and channel 2+ will be the negative speaker lead connection. (Check out other posting in this form for description of Bridge-Mono operation) I would then mark this cable end as "Amp End" so it doesn't get mixed up and turned around. smile.gif

#8 Bud Bolf

Bud Bolf

    Power User

  • Members
  • PipPipPipPipPip
  • 201 posts

Posted 19 March 2006 - 11:20 AM

Hi K4ng1,
OK first things first.
I use the Binding posts on my CE4000 and run a short wire to a 1 space Rack panel that has Speakon NL4MP-UC chassis connectors mounted on it.

I use a spade connector (a Y crimp) at the Banana and run a wire from 1+ to 1+ at the NL4MP-UC then use 2+ (the Negative) to 1- at the NL4MP-UC.
You use the two RED Binding posts. If you do it this way you can then use regular Speakon to Speakon from the Amp to the Speakers.
If you go to Pro Sound Web's Lab Lounge there is a gentleman named Tom Reid
that has your Setup.
He is  thinking of using XS500's one per speaker Bridged to the 728's and I am not sure if he has done this yet but as I say he has been working with a SRX JBL rig for awhile!
For specific setup I would have you search him out!
I am going to give you a couple of Links for you to check out.
One is on Bridging Setups and the other is for Tom's SRX Post.
I'll be right back.
OK I'm back, try this link it is about the 725/728 combo, also do a search and
you will find more Info.
Click on Tom and ask him a question too.
Link here:SRX Post

Here is a link to re-wiring Amp racks, also a search will reap rewards and plenty of ideas for you.
When you Register at PSW remember that unlike here, you have to use your real name!
Link is here: Rewire Amp Rack
Good Luck,
    Bud
PS. Your on the right track.

#9 k4ng1

k4ng1
  • Members
  • 9 posts

Posted 28 March 2006 - 07:17 PM

Thanks for the wealth of information. I will check out more info, but can say that since posting my questions on this forum the little light above my head has come on and things are starting to click.

I just stepped back and looked at the logical path of what I wish to do and then reviewed possible routes thanks to the input I received from here  smile.gif

If I get confused, I know where to come!

Thanks.




QUOTE(Bud Bolf @ Mar 19 2006, 08:20 AM)
Hi K4ng1,
OK first things first.
I use the Binding posts on my CE4000 and run a short wire to a 1 space Rack panel that has Speakon NL4MP-UC chassis connectors mounted on it.

I use a spade connector (a Y crimp) at the Banana and run a wire from 1+ to 1+ at the NL4MP-UC then use 2+ (the Negative) to 1- at the NL4MP-UC.
You use the two RED Binding posts. If you do it this way you can then use regular Speakon to Speakon from the Amp to the Speakers.
If you go to Pro Sound Web's Lab Lounge there is a gentleman named Tom Reid
that has your Setup.
He is  thinking of using XS500's one per speaker Bridged to the 728's and I am not sure if he has done this yet but as I say he has been working with a SRX JBL rig for awhile!
For specific setup I would have you search him out!
I am going to give you a couple of Links for you to check out.
One is on Bridging Setups and the other is for Tom's SRX Post.
I'll be right back.
OK I'm back, try this link it is about the 725/728 combo, also do a search and
you will find more Info.
Click on Tom and ask him a question too.
Link here:SRX Post

Here is a link to re-wiring Amp racks, also a search will reap rewards and plenty of ideas for you.
When you Register at PSW remember that unlike here, you have to use your real name!
Link is here: Rewire Amp Rack
Good Luck,
    Bud
PS. Your on the right track.


#10 vsop

vsop
  • Members
  • 6 posts

Posted 04 April 2006 - 06:58 PM

Why not just get an I-tech amp in place of the 2 ce4000's.

You can run one unit in 8 ohm mono and blow the doors off the 2 CE4000's

An I-Tech4000 would do the job and an I-Tech6000 would really give you some power to thump with

#11 Bud Bolf

Bud Bolf

    Power User

  • Members
  • PipPipPipPipPip
  • 201 posts

Posted 04 April 2006 - 08:34 PM

QUOTE(vsop @ Apr 4 2006, 07:58 PM)
Why not just get an I-tech amp in place of the 2 ce4000's.

You can run one unit in 8 ohm mono and blow the doors off the 2 CE4000's

An I-Tech4000 would do the job and an I-Tech6000 would really give you some power to thump with


Hey yea,
Get an I-Tech 4000, they are only around $5000.00
Right now 2 CE4000's are about $1800.00
I just cannot rationalize the expenditure for the amps.
I can do a lot with $3200.00

If I could afford it, I would love to have I-Tech's!
Due to the cost of the I-Tech's and to pay for them via a working band or a DJ,
that's a lot of gigs!
Maybe with time, they will come down in price where the working (Weekend Warrior) gigger can afford it.
The I-tech's were really not designed for US, but if you have the money,
go for it!

Later,
   Bud

#12 vsop

vsop
  • Members
  • 6 posts

Posted 06 April 2006 - 08:25 PM

QUOTE(Bud Bolf @ Apr 4 2006, 09:34 PM)
QUOTE(vsop @ Apr 4 2006, 07:58 PM)
Why not just get an I-tech amp in place of the 2 ce4000's.

You can run one unit in 8 ohm mono and blow the doors off the 2 CE4000's

An I-Tech4000 would do the job and an I-Tech6000 would really give you some power to thump with


Hey yea,
Get an I-Tech 4000, they are only around $5000.00
Right now 2 CE4000's are about $1800.00
I just cannot rationalize the expenditure for the amps.
I can do a lot with $3200.00

If I could afford it, I would love to have I-Tech's!
Due to the cost of the I-Tech's and to pay for them via a working band or a DJ,
that's a lot of gigs!
Maybe with time, they will come down in price where the working (Weekend Warrior) gigger can afford it.
The I-tech's were really not designed for US, but if you have the money,
go for it!

Later,
   Bud



Opps.. I have not checked the price of the CE4000's in a while.. Had mine for a bit now..  I was still thinking that they were close to $2k each.. But at $900 each new, the CE4000 is a steal.  I might have to pickup another one and put my QSC RMX2450 to use as a booth or use it to power the highs in a tri-amp setup with the CE's so low in price now.

#13 k4ng1

k4ng1
  • Members
  • 9 posts

Posted 10 April 2006 - 06:39 PM

If I even attempted to drop an itech 4000 or 6000 into my amp rack, I may have awesome power, but the price I will probably pay is the wife leaving me!  

Bud, you said it right, it ain’t for us weekend warriors unless of course one has a FAT checkbook. I am waiting for my two CE4000’s to come in to take care of my SRX728s.

I read in another posting that the CE4000 is going to be discountinued – is this correct??? If so, why is Crown getting rid of this true workhorse and what is the replacement? I picked up two for a great price and am worried now. I assume that the 3 year no fault will still be applicable regardless?

I’ll be back soon, got some more questions.

Arvi  smile.gif


QUOTE(Bud Bolf @ Apr 4 2006, 05:34 PM)
QUOTE(vsop @ Apr 4 2006, 07:58 PM)
Why not just get an I-tech amp in place of the 2 ce4000's.

You can run one unit in 8 ohm mono and blow the doors off the 2 CE4000's

An I-Tech4000 would do the job and an I-Tech6000 would really give you some power to thump with


Hey yea,
Get an I-Tech 4000, they are only around $5000.00
Right now 2 CE4000's are about $1800.00
I just cannot rationalize the expenditure for the amps.
I can do a lot with $3200.00

If I could afford it, I would love to have I-Tech's!
Due to the cost of the I-Tech's and to pay for them via a working band or a DJ,
that's a lot of gigs!
Maybe with time, they will come down in price where the working (Weekend Warrior) gigger can afford it.
The I-tech's were really not designed for US, but if you have the money,
go for it!

Later,
   Bud