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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => LAB Lounge => Topic started by: Mark Wilkinson on February 09, 2015, 03:05:18 pm

Title: I-Nuke NU4-6000 not per website
Post by: Mark Wilkinson on February 09, 2015, 03:05:18 pm
Probably nobody cares much about this amp, but I saw Art's post on its decent power output in another thread, and thought I'd give it a try....

I have a pair of old yam sv-115IV tops and a pair of 118IV subs, that my son and his roommates  in VTech were begging to drag into their apt.
3-4 of them play instruments, but still....Last thing I want to do is put any $ into this :)

So I thought this amp with four channels and built in 100hz crossover might make a real easy cheap setup. One amp, disposable mixer, no x-over.....let the beer fly

On the Behringer site, the quickstart guide (that is, the manual? ugh) shows a 3 position crossover slider ..... LF-Full Range-HF, per pair of linked channels. (A&B, C&D)
My idea was to use one pair of linked channels for LF, and one pair for HF. That would even allow level control to balance the mains to subs with nothing else needed.
 
The quickstart quide shows what it calls horizontal biamping, and other than some funky speakon connections, that looked like it would work for what i had in mind.
I was hoping to maybe even bridge the linked pair to the subs.

But the actual unit delivered is different.  Each pair of channels has a crossover slider with only 2 positions.....  Full-Range - Split.  Which means A is high, B is Low, etc for C&D).
This works somewhat, but since gain on both A & B is controlled by the A pot only, there is no relative level adjustment between mains and subs.
And it's not clear how, or if it's even possible to use both bridge and crossover....

Bottom line, the unit is much less flexible in routing than as shown on the web...
Again, sorry if zero interest, but just in case....
 
Title: Re: I-Nuke NU4-6000 not per website
Post by: Mike Pyle on February 09, 2015, 05:30:06 pm
Which model did you get?
Title: Re: I-Nuke NU4-6000 not per website
Post by: Luke Geis on February 09, 2015, 06:18:15 pm
Well you can't use bridge if it's going to be run in split mode. However a picture is worth a thousand words. Show us what you have. The picture on the Behringer website shows what you describe in your earlier paragraph. The later paragraph would seem to make sense why things are messy, but show us.
Title: Re: I-Nuke NU4-6000 not per website
Post by: Mark Wilkinson on February 09, 2015, 07:55:27 pm
Well you can't use bridge if it's going to be run in split mode. However a picture is worth a thousand words. Show us what you have. The picture on the Behringer website shows what you describe in your earlier paragraph. The later paragraph would seem to make sense why things are messy, but show us.

Model NU4-6000.
Here's the back input panel as delivered and then as per web.....
Title: Re: I-Nuke NU4-6000 not per website
Post by: Jens Droessler on February 09, 2015, 08:53:08 pm
What happens if you set the crossover switch to crossover as in your picture, but set the input switch to stereo?
Title: Re: I-Nuke NU4-6000 not per website
Post by: Mark Wilkinson on February 09, 2015, 09:40:22 pm
What happens if you set the crossover switch to crossover as in your picture, but set the input switch to stereo?

Then crossover has no effect, both channels (A&B) are full range.
The only time crossover has an effect is in Mono.....afraid to see what happens in bridge with xover on haha..

On the web layout, I was hoping crossover came first, applying to both linked channels.  And that you could then mono, stereo, or bridge the channels as desired.
Don't even get to find out because of the switcharoo  :(
Title: Re: I-Nuke NU4-6000 not per website
Post by: Tim Weaver on February 09, 2015, 11:02:32 pm
Then crossover has no effect, both channels (A&B) are full range.
The only time crossover has an effect is in Mono.....afraid to see what happens in bridge with xover on haha..

On the web layout, I was hoping crossover came first, applying to both linked channels.  And that you could then mono, stereo, or bridge the channels as desired.
Don't even get to find out because of the switcharoo  :(

Well that blows!

Buy him 2 more subs to balance out the system!  :P
Title: Re: I-Nuke NU4-6000 not per website
Post by: Lyle Williams on February 10, 2015, 03:17:27 am
What happens if you set the crossover switch to crossover as in your picture, but set the input switch to stereo?

+1
Title: Re: I-Nuke NU4-6000 not per website
Post by: Greg Martin on February 10, 2015, 09:22:46 am
I'm curious to see what the configuration on mine is.   I only use it to power up four floor monitors, and haven't ever compared the input switching to what the web images have.    I'll check it out this afternoon at home and post up what I find.   (not that it's THAT helpful for you...)
Title: Re: I-Nuke NU4-6000 not per website
Post by: Mike Pyle on February 10, 2015, 10:30:01 am
Model NU4-6000.
Here's the back input panel as delivered and then as per web.....

If it were me I'd send it back. That is a major change in the application of the amplifier, and a poor design choice. Hard to believe they would do that without at least documenting it.

FWIW, QSC has the same funky crossover scheme on their GX amplifiers, which is one reason I've never been enthusiastic about them.
Title: Re: I-Nuke NU4-6000 not per website
Post by: Art Welter on February 10, 2015, 11:24:16 am
Probably nobody cares much about this amp, but I saw Art's post on its decent power output in another thread, and thought I'd give it a try....

So I thought this amp with four channels and built in 100hz crossover might make a real easy cheap setup. One amp, disposable mixer, no x-over.....let the beer fly

1)My idea was to use one pair of linked channels for LF, and one pair for HF. That would even allow level control to balance the mains to subs with nothing else needed.
 
But the actual unit delivered is different.  Each pair of channels has a crossover slider with only 2 positions.....  Full-Range - Split. 
2) Which means A is high, B is Low, etc for C&D).
This works somewhat, but since gain on both A & B is controlled by the A pot only, there is no relative level adjustment between mains and subs.
3)And it's not clear how, or if it's even possible to use both bridge and crossover....
Mark,
1) You can't use the crossover and bridged mode at the same time, you can have a stereo pair of A/B and C/D each with the 100 Hz crossover.
2) The gain controls only work independently when set to stereo.
3) Clearly not ;^(.

Coming from the era of 5 way binding posts on virtually all amps the most confusing thing for me was dealing with the Speakon connectors, I had to make up a dozen Speakon to banana "normal" and 3 "bridge" Speakons to be able to use the three amps in all the usual configurations I anticipate with the various speakers I own.

It was a lot of work, and 14 adapters that would not have been needed if there were 5 way binding posts, but for the average user saves time. At $350 a pop hard to complain about the little details,  the performance of the amp is spectacular for the price.

Art
Title: Re: I-Nuke NU4-6000 not per website
Post by: Tim Weaver on February 10, 2015, 12:19:26 pm
Mark,
1) You can't use the crossover and bridged mode at the same time, you can have a stereo pair of A/B and C/D each with the 100 Hz crossover.
2) The gain controls only work independently when set to stereo.
3) Clearly not ;^(.

Coming from the era of 5 way binding posts on virtually all amps the most confusing thing for me was dealing with the Speakon connectors, I had to make up a dozen Speakon to banana "normal" and 3 "bridge" Speakons to be able to use the three amps in all the usual configurations I anticipate with the various speakers I own.

It was a lot of work, and 14 adapters that would not have been needed if there were 5 way binding posts, but for the average user saves time. At $350 a pop hard to complain about the little details,  the performance of the amp is spectacular for the price.

Art




Does that mean the OP could fix this with a couple of XLR Wyes? Split signal going into A&B, turn on crossovers, enjoy gain control via front panel?
Title: Re: I-Nuke NU4-6000 not per website
Post by: Lyle Williams on February 10, 2015, 02:29:44 pm



Does that mean the OP could fix this with a couple of XLR Wyes? Split signal going into A&B, turn on crossovers, enjoy gain control via front panel?

I think it will work just fine with L connected to Input-A and R to Input-C, with both mode switches set to stereo and both crossover switches set to split.
Title: Re: I-Nuke NU4-6000 not per website
Post by: Mark Wilkinson on February 10, 2015, 03:45:29 pm
I think it will work just fine with L connected to Input-A and R to Input-C, with both mode switches set to stereo and both crossover switches set to split.

Hi,  when mode is set to stereo the crossover has no effect, either on or off.
So you simply get 4 independent full-range channels with both mode switches set to stereo.


Title: Re: I-Nuke NU4-6000 not per website
Post by: Tim Weaver on February 10, 2015, 03:54:17 pm
Hi,  when mode is set to stereo the crossover has no effect, either on or off.
So you simply get 4 independent full-range channels with both mode switches set to stereo.


Well then. Back to buying another pair of subs for +6dB of gain matching!  8)
Title: Re: I-Nuke NU4-6000 not per website
Post by: Mark Wilkinson on February 10, 2015, 03:54:34 pm
Mark,
1) You can't use the crossover and bridged mode at the same time, you can have a stereo pair of A/B and C/D each with the 100 Hz crossover.
2) The gain controls only work independently when set to stereo.
3) Clearly not ;^(.

Coming from the era of 5 way binding posts on virtually all amps the most confusing thing for me was dealing with the Speakon connectors, I had to make up a dozen Speakon to banana "normal" and 3 "bridge" Speakons to be able to use the three amps in all the usual configurations I anticipate with the various speakers I own.

It was a lot of work, and 14 adapters that would not have been needed if there were 5 way binding posts, but for the average user saves time. At $350 a pop hard to complain about the little details,  the performance of the amp is spectacular for the price.

Art

Art, yep, it is what it is.....I was just hoping from the depiction of the 3 position x-over switches on the web that the x-over settings might come before the mode switch...like what I could do with a real x-over haha.
Oh well, I need to either get 2 more subs like Tim said, or just let main/sub balance fall to eq .....or put a frigging x-over in ;D
But you're right, it is a great value....
mark
Title: Re: I-Nuke NU4-6000 not per website
Post by: Luke Geis on February 10, 2015, 07:47:35 pm
Possible solution......

You could run the tops on channel A & B in full range and then link the subs together on channel D with the crossover on. This will allow you to at least control level and you could send the sub signal via an aux?
Title: Re: I-Nuke NU4-6000 not per website
Post by: Scott Holtzman on February 11, 2015, 02:30:52 am
I'm curious to see what the configuration on mine is.   I only use it to power up four floor monitors, and haven't ever compared the input switching to what the web images have.    I'll check it out this afternoon at home and post up what I find.   (not that it's THAT helpful for you...)

Hi Greg, how is the NU4 holding up for monitors.  I have about a dozen decent 12" monitor wedges and I was thinking of picking up one of these amps and rack it up with an x32 rack.  Send it out with a pair of kw181's and 122's on top for a decent 'b" system that with a proper connection panel in the front of the rack will be easier to setup than the powered monitors.

The construction is cheap but it looks like it would hold up for local rentals.

A report would be appreciated.

Title: Re: I-Nuke NU4-6000 not per website
Post by: Greg Martin on February 11, 2015, 11:31:21 am
Quite well, frankly.   It's been rack mounted it's whole life (about a year now) and is used for my band and for me running sound for others.  Plenty of volume for rock stages, and durable enough to live in a mobile-only system.  The faceplate is a bit cheesy looking and plasticy, but there's nothing in the build of the actual chassis that makes me worry about loading the rack in and out of places.   Sure, it's my own equipment so there's an extra ounce of prevention, but I wouldn't expect rampant damage if rented out.   The fact that it weighs 11 pounds makes moving a rack so much easier that there's probably less chance of someone botching something; less force upon impact, too...
Title: Re: I-Nuke NU4-6000 not per website
Post by: Mark Wilkinson on February 11, 2015, 11:36:32 am
Possible solution......

You could run the tops on channel A & B in full range and then link the subs together on channel D with the crossover on. This will allow you to at least control level and you could send the sub signal via an aux?

Thx Luke, yep, but I guess that would leave the subs pretty under powered..

I've decided to just give in and use an old x-over.... x-over HP to stereo  A & B mains, x-over LP to C&D in either mono or bridge...

Disappointing not to have an all-in-one solution as potentially available from online documentation....but the dang amp still represents the cheapest way I can find to power the old boxes...
Title: Re: I-Nuke NU4-6000 not per website
Post by: Mark Wilkinson on February 11, 2015, 11:37:31 am
I'm curious to see what the configuration on mine is.   I only use it to power up four floor monitors, and haven't ever compared the input switching to what the web images have.    I'll check it out this afternoon at home and post up what I find.   (not that it's THAT helpful for you...)

Hi Greg, yes thx...I'd be curious...
Title: Re: I-Nuke NU4-6000 not per website
Post by: John Roberts {JR} on February 11, 2015, 11:48:55 am
FWIW the generic crossovers built into value amps are rarely above average, but it does suck that they changed the feature after publishing it.

A 3-pos switch is more expensive than 2 position so somebody managing that product may have been caught in a cost squeeze and decided  to protect the profit margin by taking a cheaper approach on that feature, instead of raising the price or missing the profit target. Sometimes it is difficult to support even modest cost increase. On paper it looks like the same feature set to casual customers, while in use it clearly isn't. 

It could be even cheaper without the crossover, but that is perceived as a valuable feature at POS well in excess of it's BOM cost.

JR
Title: Re: I-Nuke NU4-6000 not per website
Post by: Lyle Williams on February 11, 2015, 12:31:25 pm
Then crossover has no effect, both channels (A&B) are full range.
The only time crossover has an effect is in Mono.....afraid to see what happens in bridge with xover on haha..

On the web layout, I was hoping crossover came first, applying to both linked channels.  And that you could then mono, stereo, or bridge the channels as desired.
Don't even get to find out because of the switcharoo  :(

Not having a proper manual is a bit of a sin on Behringer's part.  The way I look at it this is just two amps in the one box.  EPQ/EPX manuals seem to say Stereo+Crossed is the right setting.  I (cough) have four EPQ amps and this is how they work (but not how I use them.)

The general NU6000 manual says Mono+Crossed is the correct setting, but then says:

Run a 4-pole speaker cable with professional twist-locking connectors from OUTPUTS CH A to the subwoofer.
(The subwoofer receives its low-frequency signal from Channel B using poles 2+ and 2-, while the middle and upper frequency ranges use Channel A via poles 1+ and 1-.).
Title: Re: I-Nuke NU4-6000 not per website
Post by: Jens Droessler on February 11, 2015, 12:34:25 pm
It's not necessarily the switch only, but the added circuitry to give the additonal options as well. But yes, that's probably what happened.

And yes, most of those crossovers aren't very useful. Many combinations of speakers won't perform that well with a fixed crossover. You can't change the frequencies, you can't leave a gap if needed, you can't address phase response issues... but not even being able to change the bass level independently from the top level? If that's the truth, the crossover is indeed completely useless.

Run a 4-pole speaker cable with professional twist-locking connectors from OUTPUTS CH A to the subwoofer.
(The subwoofer receives its low-frequency signal from Channel B using poles 2+ and 2-, while the middle and upper frequency ranges use Channel A via poles 1+ and 1-.).

This doesn't contradict what was said here. The correct setting for this could still be mono.
Title: Re: I-Nuke NU4-6000 not per website
Post by: Lyle Williams on February 11, 2015, 12:43:33 pm
Absolutely the correct setting on the NU6000 is mono.  The NU4-6000 is highly likely to be just two of the NUx000 circuit designs  in the one box.
Title: Re: I-Nuke NU4-6000 not per website
Post by: Keith Broughton on February 11, 2015, 01:07:07 pm
It's unfortunate that this amp doest come in the DSP version.
I have used other iNuke DSP amps and the setup was easy and more flexible.
The price list shows a $50 difference to go from a regular amp to a DSP version...still very cost effective.
Title: Re: I-Nuke NU4-6000 not per website
Post by: Scott Holtzman on February 11, 2015, 01:58:26 pm
Quite well, frankly.   It's been rack mounted it's whole life (about a year now) and is used for my band and for me running sound for others.  Plenty of volume for rock stages, and durable enough to live in a mobile-only system.  The faceplate is a bit cheesy looking and plasticy, but there's nothing in the build of the actual chassis that makes me worry about loading the rack in and out of places.   Sure, it's my own equipment so there's an extra ounce of prevention, but I wouldn't expect rampant damage if rented out.   The fact that it weighs 11 pounds makes moving a rack so much easier that there's probably less chance of someone botching something; less force upon impact, too...

That's great to hear.  The construction inside the iNuke is minimalistic so I was concerned.  Compared to a Crown XTI, a light weight amplifier it's pretty baron inside those Nuke's

It should pair nice with an x32 rack.  If it does or doesn't I will share results as always....Thanks
Title: Re: I-Nuke NU4-6000 not per website
Post by: Mark Wilkinson on February 11, 2015, 02:01:32 pm
Not having a proper manual is a bit of a sin on Behringer's part.  The way I look at it this is just two amps in the one box.  EPQ/EPX manuals seem to say Stereo+Crossed is the right setting.  I (cough) have four EPQ amps and this is how they work (but not how I use them.)

The general NU6000 manual says Mono+Crossed is the correct setting, but then says:

Run a 4-pole speaker cable with professional twist-locking connectors from OUTPUTS CH A to the subwoofer.
(The subwoofer receives its low-frequency signal from Channel B using poles 2+ and 2-, while the middle and upper frequency ranges use Channel A via poles 1+ and 1-.).


Yes, the manual I received says, in Mono mode with crossover engaged, to use Channel B's 2+ and 2- poles for LF.
BUT, I have yet to find a signal there.....it's on B's 1+ and 1-
Hey, at least it's LF  :)
Title: Re: I-Nuke NU4-6000 not per website
Post by: Mark Wilkinson on February 11, 2015, 02:10:14 pm
It's not necessarily the switch only, but the added circuitry to give the additonal options as well. But yes, that's probably what happened.

And yes, most of those crossovers aren't very useful. Many combinations of speakers won't perform that well with a fixed crossover. You can't change the frequencies, you can't leave a gap if needed, you can't address phase response issues... but not even being able to change the bass level independently from the top level? If that's the truth, the crossover is indeed completely useless.


Hi John, Jens,

Yes, I knew the imbedded x-over would be pretty worthless.  The specs for the old carpet covered yamis recommend 90hz, which was close enough to the NU4's 100hz for me.....in this application for sure  ;D
Title: Re: I-Nuke NU4-6000 not per website
Post by: Tim McCulloch on February 11, 2015, 02:39:35 pm
That's great to hear.  The construction inside the iNuke is minimalistic so I was concerned.  Compared to a Crown XTI, a light weight amplifier it's pretty Baron inside those Nuke's

It should pair nice with an x32 rack.  If it does or doesn't I will share results as always....Thanks

That would make it a Beechcraft, not a Behringer...
Title: Re: I-Nuke NU4-6000 not per website
Post by: Jens Droessler on February 11, 2015, 05:52:11 pm
Yes, the manual I received says, in Mono mode with crossover engaged, to use Channel B's 2+ and 2- poles for LF.
BUT, I have yet to find a signal there.....it's on B's 1+ and 1-
Hey, at least it's LF  :)
I think you missunderstood what they meant. The output signal from channel B will be on 2+/- of the speakon output of channel A. They could have formulated that better. It means you can put a 4wire speakon cable to channel A or C and have ch A/C on 1+/- and ch B/D on 2+/-.
Title: Re: I-Nuke NU4-6000 not per website
Post by: Luke Geis on February 11, 2015, 07:57:22 pm
Thx Luke, yep, but I guess that would leave the subs pretty under powered..

I've decided to just give in and use an old x-over.... x-over HP to stereo  A & B mains, x-over LP to C&D in either mono or bridge...

Disappointing not to have an all-in-one solution as potentially available from online documentation....but the dang amp still represents the cheapest way I can find to power the old boxes...


Well if the tops are what I think they are in ohms, the subs will actually pair up well. In theory there will almost twice the wattage for the subs which should be at 4 ohm's.  Also running it that way you have the ability now to turn the tops down a little to match the subs if need be. It's an option that in theory should provide better results than the basic method currently used.
Title: Re: I-Nuke NU4-6000 not per website
Post by: Mark Wilkinson on February 11, 2015, 09:00:02 pm
I think you missunderstood what they meant. The output signal from channel B will be on 2+/- of the speakon output of channel A. They could have formulated that better. It means you can put a 4wire speakon cable to channel A or C and have ch A/C on 1+/- and ch B/D on 2+/-.

Jens, yes, you are correct as stated. Thanks, I did miss what they meant.
 
As you say, the output from Channel B is on speakon 2+/- of output channel A if you want to 4-wire it.   
And as I found, it is also on output B 1+/-
So either way, I guess nothing changes from the available output combinations, other than being able to run 4 wire speakons, or 2 wire ones.
Title: Re: I-Nuke NU4-6000 not per website
Post by: Mark Wilkinson on February 11, 2015, 09:21:27 pm
Well if the tops are what I think they are in ohms, the subs will actually pair up well. In theory there will almost twice the wattage for the subs which should be at 4 ohm's.  Also running it that way you have the ability now to turn the tops down a little to match the subs if need be. It's an option that in theory should provide better results than the basic method currently used.

The S115IV tops, and SW118IV subs (2), are all 8 ohm boxes.  Tops and subs have same wattage specs; noise 250, program 500, max 1000.  Tops are 99db 1w, subs 96.
So I'm thinking that level power to all leaves me at least 3 db short on the subs...and probably more like 6-9db short, given the usual sub boost bias...

It's why I thought this amp would be perfect if I could high pass two channels in stereo, and low pass two channels bridged into parallel subs. (with maybe a little cut to the subs)

I'm still going this route I guess, but with an external x-over.......unless I'm missing something????
Thx again. Mark
Title: Re: I-Nuke NU4-6000 not per website
Post by: Scott Holtzman on February 12, 2015, 02:49:27 am
That would make it a Beechcraft, not a Behringer...

Tim, you are tough man.  Indeed I am used to typing the aircraft type rather than the proper word barren.  Rather than try and use big words I should have just said that the construction sucks and the stuff that's now wave soldered looks like they used the solder blob/bomb method.  Honestly I think the Kenwood Class D amp I have in my truck is beefier that the inside of the iNuke's.  Compared to the brick shit house EP series from Behringer it was a shock.  Say what you will but the EP's are very usable but heavy amplifiers.  Used within limits they get the job done.  With the iNuke stuff it just looks like a fan failure or an undetected fault would cause the amp to meltdown.

One of the things I learned in the last year, especially from listening to the big iron drivers like yourself Tim is you have to count on your gear.  When I would role a Behringer EP amp in I always would have a spare in the truck and a reluctance to use them to capability that they just could not take it.  With the Crown XTI, QSC, B&M drivers and Sennheiser Wireless I use today I have confidence.  Sure things can still break but I haven't been let down yet. 

The difference between flying a Baron or a Cherokee!

Title: Re: I-Nuke NU4-6000 not per website
Post by: Lyle Williams on February 12, 2015, 03:17:07 am
So you need to be bridged into the subs?  Stereo left into input A, stereo right into input C, switches to mono+crossed.

Output A gives you left tops, output B gives you left sub, output C gives you right tops, output D gives you right sub.

Uses all of your speakers, is stereo, relative sub/tops level is controllable, and it will be way louder than you can run in the appartment.
Title: Re: I-Nuke NU4-6000 not per website
Post by: Mike Caldwell on February 12, 2015, 09:09:30 am
That would make it a Beechcraft, not a Behringer...

Don't worry I got your joke and laughed! Things will really be scary if Behringer starts up an aircraft division.
Title: Re: I-Nuke NU4-6000 not per website
Post by: Mark Wilkinson on February 12, 2015, 09:59:59 am
So you need to be bridged into the subs?  Stereo left into input A, stereo right into input C, switches to mono+crossed.

Output A gives you left tops, output B gives you left sub, output C gives you right tops, output D gives you right sub.

Uses all of your speakers, is stereo, relative sub/tops level is controllable, and it will be way louder than you can run in the appartment.

Thanks Lyle.  How does this give control of relative sub/tops level?  In mono mode, level for A & B is controlled solely by A pot,  C & D by C pot.

This is the config I'd decided to try first, hoping relative balance is close enough for low shelving eq to suit to taste.

And sure, for apt use I get about anything works .... but I have told my son he is welcome to play with the rig here and there, outside included. So looking for all the available sub there is....
Title: Re: I-Nuke NU4-6000 not per website
Post by: Lyle Williams on February 12, 2015, 10:50:14 am
Ok, I see the problem now.  Yep, that seems to be a dumbass design decision.

Especially as they had this sorted out properly in their earlier amp designs.
Title: Re: I-Nuke NU4-6000 not per website
Post by: Luke Geis on February 12, 2015, 04:40:19 pm
The S115IV tops, and SW118IV subs (2), are all 8 ohm boxes.  Tops and subs have same wattage specs; noise 250, program 500, max 1000.  Tops are 99db 1w, subs 96.
So I'm thinking that level power to all leaves me at least 3 db short on the subs...and probably more like 6-9db short, given the usual sub boost bias...

It's why I thought this amp would be perfect if I could high pass two channels in stereo, and low pass two channels bridged into parallel subs. (with maybe a little cut to the subs)

I'm still going this route I guess, but with an external x-over.......unless I'm missing something????
Thx again. Mark

Well sort of...... The general rule is 2x the power to the subs as to the tops. If you run the tops at 8 ohms you would have X watts. Now the subs would be ran in parallel, which is a 4 ohm load. This should nearly double the watts supplied to them. Now you could bridge mono the last two channels which would give you about 5x the power. However I do not think you could utilize the X over with the last 2 channels in bridge mode? The literature seems to present that it can? Based on what you say it will not.

Here goes:

1. Run channel A & B as a basic stereo setup. No there will not be a low pass, but there could be worse things, plus you really could use one anyway.

2. Run channel C & D in mono with the crossover engaged and run the subs out of the appropriate output. This will yield nearly twice the power or about a 3db boost. Not as much boost as many would like, but you can turn the tops down 3db to acquire a 6db difference.

3. Test and see if in bridge mode for C & D that the X-over function still works? If it does this will yield 5X the power to the subs.

4. get a X-over that will allow 3 inputs ( L, R, and mono/subs ) then set it up for your speaker config of L & R with mono subs. Now set the amp up to run A & B in stereo and C & D in bridge mono. Left and Right to A & B and subs to the appropriate +/- output terminals on the C & D outputs. This is the best option and will yield the best results all around.
Title: Re: I-Nuke NU4-6000 not per website
Post by: Jens Droessler on February 12, 2015, 05:52:50 pm
No, it won't. Why keep people recommending sending the subs separately from the mixer? Just give a stereo signal to the DSP and use a stereo setup. Setup levels correctly (NO boost on the subs, same SPL!), setup phase correctly (if you can't measure it, use one of the tricks to get a good approximation) and do anything like bass boost to taste either in the input section of the DSP,  the output EQ of your mixer or even better, the EQ in the input channel. That's how it's done if you care about the physics involved.
Title: Re: I-Nuke NU4-6000 not per website
Post by: Mark Wilkinson on February 12, 2015, 07:53:57 pm

Here goes:

1. Run channel A & B as a basic stereo setup. No there will not be a low pass, but there could be worse things, plus you really could use one anyway.

2. Run channel C & D in mono with the crossover engaged and run the subs out of the appropriate output. This will yield nearly twice the power or about a 3db boost. Not as much boost as many would like, but you can turn the tops down 3db to acquire a 6db difference.

3. Test and see if in bridge mode for C & D that the X-over function still works? If it does this will yield 5X the power to the subs.

4. get a X-over that will allow 3 inputs ( L, R, and mono/subs ) then set it up for your speaker config of L & R with mono subs. Now set the amp up to run A & B in stereo and C & D in bridge mono. Left and Right to A & B and subs to the appropriate +/- output terminals on the C & D outputs. This is the best option and will yield the best results all around.

Thank Luke,

1. yep

2. C & D, in mono, with crossover engaged, only outputs LF to D.  C is HF.  So only one channel is available to drive subs.

3. Tested. Crossover does not work in bridge mode.

4. External x-over seems best to me too.
 I'm thinking to simply send L, R, to the external x-over and let it do the work with three sends to the amp....
....... L high pass and R high pass, to amp A & B in stereo mode. Mono summed Low pass to amp C & D in bridge mono, or just plain mono C&D if bridge is too much power.
Title: Re: I-Nuke NU4-6000 not per website
Post by: Scott Holtzman on February 12, 2015, 10:51:34 pm
No, it won't. Why keep people recommending sending the subs separately from the mixer? Just give a stereo signal to the DSP and use a stereo setup. Setup levels correctly (NO boost on the subs, same SPL!), setup phase correctly (if you can't measure it, use one of the tricks to get a good approximation) and do anything like bass boost to taste either in the input section of the DSP,  the output EQ of your mixer or even better, the EQ in the input channel. That's how it's done if you care about the physics involved.

There are many reasons to run aux fed subs and I suggest you take a look at some of extensive discussions about them before you dismiss the tool out of hand.

Title: Re: I-Nuke NU4-6000 not per website
Post by: Tom Bourke on February 13, 2015, 12:28:11 am
No, it won't. Why keep people recommending sending the subs separately from the mixer? Just give a stereo signal to the DSP and use a stereo setup. Setup levels correctly (NO boost on the subs, same SPL!), setup phase correctly (if you can't measure it, use one of the tricks to get a good approximation) and do anything like bass boost to taste either in the input section of the DSP,  the output EQ of your mixer or even better, the EQ in the input channel. That's how it's done if you care about the physics involved.
We recommend it because it works.  Running sound is about compromise.  Sub off aux solves some big problems while only creating some small ones if done right.  It is not that hard to create a good crossover for the signals that are using subs.  Some may choose to use it as an effect.  That's OK too, if it sounds good, it is good.

Title: Re: I-Nuke NU4-6000 not per website
Post by: Jens Droessler on February 13, 2015, 09:37:23 pm
Please do not misunderstand what I'm writing here. English is not my native language, so some words might not be the best fit for what I intended to express, and some of the written might be considered as written in anger. It is all written by me while being fully rational. So please read it with a rational head voice. Words in bold are just to emphasize.

We recommend it because it works.  Running sound is about compromise.  Sub off aux solves some big problems while only creating some small ones if done right.  It is not that hard to create a good crossover for tshe signals that are using subs.  Some may choose to use it as an effect.  That's OK too, if it sounds good, it is good.
It only solves problems you cause yourself by what I consider improper use. You compromise where no compromise is needed. And why? Not because it is good, but because you are used to it. I'll try to explain later.

There are many reasons to run aux fed subs and I suggest you take a look at some of extensive discussions about them before you dismiss the tool out of hand.
I read them all at some point. I discussed, thought about them, simulated and tried them many times. There is no good reason for doing it in the modern sound biz, as there is always the better solution. It is as much a tool as a rock is to hammer a nail: You might see it as a tool, but it's not actually the right tool for the job, it's a workaround. Do your homework correctly on the actual physics involved, treat any job no matter the size the same, bring the right tools, and you won't need such crude workarounds. Yes, subs off aux can be done right, but it offers no benefit at all with modern technology. To use another analogy: If you can build a house to stand on its own, why would you build a weak house and use external bracing to make it stand?

A try to explain: The subs off aux method stems from a time when most affordable mixing desks had some aux sends, but compared to nowadays limited EQ possibilities and in most cases not even a locut/highpass per channel. A solution was to highpass the whole main output, put the bass cabs on a post fader aux send and turn them up only for instruments needing them. It was necessary because there were no proper tools to control this situation. It is a workaround.
But now we have all that. We have tuneable locuts and we have four fully parametric EQs per input channel, and that is enough and much better than having ONE fixed frequency highpass (or in some cases none at all, because some peole drive their tops fullrange, only giving the subs a lowpass) for everything. Now you'll say 'No, it's not enough. I still have mud from other channels and even deep vocals coming out of the subs.' And you're right about that. But why is that? It is because you insist of having the boost (to taste) in the bass range only needed for say bassdrum and bass guitar in a rock band on the whole mixed signal (in the DSP controller, the active crossover or simply the level control of the amp or powered sub) instead of those channels' input EQs. Every single bit of signal the subs get will be 6 to 10dB louder than what comes out of the tops from it. It is easy to see why the subs sound mudded up, and also why a 12dB slope locut literally 'won't cut it':  With 6dB boost on the subs, a 12dB locut won't actually work on the frequency you set it to, but a lot higher. It might even leave a bump in the response if tuned lower than the acoustic crossover to the subs or might work down to the crossover freq as expected and then go up in response again if tuned higher than the crossover.
Try it. Spend some work at home into getting your system flat, no boost on the subs. If a -20dBu sine signal at 150Hz will lead to 100dB out of your tops, it should lead at 80Hz to 100dB out of your subs too. Get the phase in the crossover region straight. You only need to do this one time if done correctly, so save or remember those settings. If the room does need corrections because of ring modes and such, do these corrections on the mains EQ, not in the outputs of the DSP or the levels controls on the amps/powered speakers. Leave them alone! And everything having to do with taste (like a 6 to 20dB boost on a bassdrum) should be done in the input channel or a sub group. Now the locuts in the input channels work like they are supposed to do and they should be set as needed.

I know, most won't try it. Many won't even try to understand what I've written, because 'it always worked the way I do it now and I can't think of it getting any better' or whatever. Some of them trying it won't perceive a difference (not having the means to set the PA up correctly for this to work, PA not on a quality level allowing for a clearly notable difference or simply ears that aren't trained enough to hear a difference) and will go back to their old ways. So be it. Anybody can work the way he/she wants. Still the fact remains: This is the physically correct way to do it and you can choose to work with the physics or around them, by trying to bypass them. I take pride in being a sound technician, so I chose the technically correct way.

For those trying and having problems: Write a personal message to me, i'll try to help in detail.
Title: Re: I-Nuke NU4-6000 not per website
Post by: Scott Holtzman on February 13, 2015, 11:24:31 pm
Please do not misunderstand what I'm writing here. English is not my native language, so some words might not be the best fit for what I intended to express, and some of the written might be considered as written in anger. It is all written by me while being fully rational. So please read it with a rational head voice. Words in bold are just to emphasize.
It only solves problems you cause yourself by what I consider improper use. You compromise where no compromise is needed. And why? Not because it is good, but because you are used to it. I'll try to explain later.
I read them all at some point. I discussed, thought about them, simulated and tried them many times. There is no good reason for doing it in the modern sound biz, as there is always the better solution. It is as much a tool as a rock is to hammer a nail: You might see it as a tool, but it's not actually the right tool for the job, it's a workaround. Do your homework correctly on the actual physics involved, treat any job no matter the size the same, bring the right tools, and you won't need such crude workarounds. Yes, subs off aux can be done right, but it offers no benefit at all with modern technology. To use another analogy: If you can build a house to stand on its own, why would you build a weak house and use external bracing to make it stand?

A try to explain: The subs off aux method stems from a time when most affordable mixing desks had some aux sends, but compared to nowadays limited EQ possibilities and in most cases not even a locut/highpass per channel. A solution was to highpass the whole main output, put the bass cabs on a post fader aux send and turn them up only for instruments needing them. It was necessary because there were no proper tools to control this situation. It is a workaround.
But now we have all that. We have tuneable locuts and we have four fully parametric EQs per input channel, and that is enough and much better than having ONE fixed frequency highpass (or in some cases none at all, because some peole drive their tops fullrange, only giving the subs a lowpass) for everything. Now you'll say 'No, it's not enough. I still have mud from other channels and even deep vocals coming out of the subs.' And you're right about that. But why is that? It is because you insist of having the boost (to taste) in the bass range only needed for say bassdrum and bass guitar in a rock band on the whole mixed signal (in the DSP controller, the active crossover or simply the level control of the amp or powered sub) instead of those channels' input EQs. Every single bit of signal the subs get will be 6 to 10dB louder than what comes out of the tops from it. It is easy to see why the subs sound mudded up, and also why a 12dB slope locut literally 'won't cut it':  With 6dB boost on the subs, a 12dB locut won't actually work on the frequency you set it to, but a lot higher. It might even leave a bump in the response if tuned lower than the acoustic crossover to the subs or might work down to the crossover freq as expected and then go up in response again if tuned higher than the crossover.
Try it. Spend some work at home into getting your system flat, no boost on the subs. If a -20dBu sine signal at 150Hz will lead to 100dB out of your tops, it should lead at 80Hz to 100dB out of your subs too. Get the phase in the crossover region straight. You only need to do this one time if done correctly, so save or remember those settings. If the room does need corrections because of ring modes and such, do these corrections on the mains EQ, not in the outputs of the DSP or the levels controls on the amps/powered speakers. Leave them alone! And everything having to do with taste (like a 6 to 20dB boost on a bassdrum) should be done in the input channel or a sub group. Now the locuts in the input channels work like they are supposed to do and they should be set as needed.

I know, most won't try it. Many won't even try to understand what I've written, because 'it always worked the way I do it now and I can't think of it getting any better' or whatever. Some of them trying it won't perceive a difference (not having the means to set the PA up correctly for this to work, PA not on a quality level allowing for a clearly notable difference or simply ears that aren't trained enough to hear a difference) and will go back to their old ways. So be it. Anybody can work the way he/she wants. Still the fact remains: This is the physically correct way to do it and you can choose to work with the physics or around them, by trying to bypass them. I take pride in being a sound technician, so I chose the technically correct way.

For those trying and having problems: Write a personal message to me, i'll try to help in detail.

Yes, sometimes non-native English does read as combative and people get aggressive (like me), I need to keep that in mind.  Sorry

We just are going to have to agree to disagree on this one.  If I want to only put a couple of instruments to the subs the tool is an aux fed sub.  I have found it tightens up the low end considerably.  Sure I could go in and tune the low cut on every channel, on every gig but that's going to get old if I am doing 4 bands in one night.

As far as private discussions, heck no.  Put them out in public where the world can benefit.  For every person that contributes I bet 1000 or more read it.  We are contributing to a global brain trust.

By the time I am dead anything relevant I need to share (and many things I am sure most would prefer I kept to my self) will be enshrined on some server somewhere in the digital ether.

Title: Re: I-Nuke NU4-6000 not per website
Post by: John L Nobile on February 13, 2015, 11:55:49 pm
I've tried aux fed subs years ago for a few months and it doesn't work for my mix. I've had a few guys use my system last year that wanted that and I told them that I wasn't going to rewire my system for them. They thought I didn't know much about sound cause that's the way to do it these days. They also thought I was crazy to not get a 2 box "line array"  After hearing their mix I thought the same about them lol.
Whatever works for you is great but you should be able to do both. I feel that aux fed subs leads to a bass heavy mix but that is what a lot of modern music is. Seems like kick is the most important thing in some people's mixes. I lean towards vocals as #1 but that's what the show I do is all about.
Last few acts I've seen have been heavy in kick and bass with shrill vocals that didn't sound good and hard to hear. Which
I found weird cause the crowd paid to see the singer not the drummer.
Jens, as Scott said, I'd like to hear more about your reasons and methods. I'm always interested in trying something different. I do a house gig and like to change things up so that I don't get bored or stale.
Title: Re: I-Nuke NU4-6000 not per website
Post by: Scott Holtzman on February 14, 2015, 12:02:46 am
. They also thought I was crazy to not get a 2 box "line array"  After hearing their mix I thought the same about them lol.


Wow, I would hate to think using aux fed subs puts me in the same class as line array box numb nuts that just like pretty shiny things. 

Title: Re: I-Nuke NU4-6000 not per website
Post by: Luke Geis on February 14, 2015, 12:35:44 am
Jens,

    Almost all truly professionally ran PA's are more than likely ran as subs on AUX. There is more than several reasons for this. With today's modern DSP it is much easier to tune a PA than it was 15-20 years ago. Sending the PA a simple 2 channel mix only truly works well with pre recorded media. However with an un-mastered non studio mix being created live, there is a little less sonic control that is available. Proximity effect, mic movement and room characteristics play a huge part in making a live show sound just that. This is why even well done live recordings sound nothing like their studio counterparts. This is only the surface, so lets go deeper.

Just because the mixers these days have 4 band fully parametric EQ with low cuts and every other trick doesn't mean you want/need to use it. Every time a filter is engaged you introduce phase shift ( be it minimal or not ) and are of course at the mercy of the filter design which may introduce other artifacts to the sound when used. The physics of the filter designs mean that phase shift is inevitable if they are used. Doing this to every single channel may start to destroy the entirety of the mix? Perhaps not though, as the phase shift may be negligible? The idea is to get the sound you want from the source, not at the channel strips with aggressive EQ use. Boosts are generally frowned upon and extreme cuts reduce level too much sometimes.

The ultimate goal in system design and optimization is linearity. That is, " what goes in, is what comes out " as a general rule. A well designed and tuned system will not be entirely flat, but will have a very predictable and appealing sonic response in that space. In theory a downward slope from the lows to the highs is favored at around 3db per octave tapering off more after about 10-12khz. No matter how you desire to tune the PA, Linear simply means an even response from one extreme to the other devoid of large humps or cuts in the audio spectrum. It should be smooth and linear, simply put.

This goal can be achieved using either a full range setup or with subs on an aux. No matter what what goes in, the PA reproduces it in the predictable way that it was tuned. So now we are back to the start again where the mixing desk and engineers are what makes or breaks the show. In the case of a simple full range setup the engineer will have to employ more low cuts and perhaps use his EQ filters to tame more of the mics proximity effect. He may even have to employ the Compressor to also tend more to plosives or in the case of heavy shelf or low cut use, he may have an uneven compression sound that does not fit the sonic character of the instrument as much as without the filters in use? If the system is tuned to have less than normal bass ( ideally 3-6db over the mids and highs ) they may have to use filters to add bass, which is somewhat considered taboo. The more you can set a system up to reduce the use of EQ filters the better. Too much of a good thing is still too much.

Now in the case of an Aux fed system, there is no rule that says you can't put everything in the subs still. If both ways of deployment sound the exact same utilizing the same X-over settings and EQ, the only difference being that you can control what goes into each part of the PA, then you have added that much more control to the mix. Now that you can control what goes into the subs entirely, you may not need to employ as many low cut filters or shelves? You may find that you need to use less EQ filters to control content that builds up from Proximity effect on the mics? You may also find that Compression sounds more natural now that you can actually compress the sound more as it is heard? You may also not need to add bass to channels that are lacking because now you can simply dial more up in the subs if needed.

From a Physics standpoint the two ways of deployment only differ in that the Aux fed sub can be used as a separate mix. Between the two deployments, neither is more TECHNICALLY correct than the other. Each one works exactly the same way with physics. Each deployment method has a workaround that must be considered. One requires an extra AUX send and the user to create a mix in that AUX. The other requires you to be more aggressive with EQ filter deployment for sonic control. Tit for Tat if both systems are setup in there respective ways to acquire the exact same sonic response, those two differences will be the only considerations.

Now getting back on track for the OP, the goal was to be able to control the subs output. We offered a way to achieve that with what he already has on hand. His other consideration was having more sub power than tops. We were able to address that as well. From an objective standpoint the suggestion of subs on an aux was the easiest way to get him from point A to B. The only downside being that he won't have a X-over for the tops. That is not the end of the world. In the end the realization is that he will want to have an external X-over to achieve the ultimate results with what he currently has. Whether he runs the system as full range or Subs on AUX is up to him. Being able to do it either way is not a bad goal from a design standpoint. It leaves him with options. The fact of the matter is, subs on Aux takes nothing away from the systems ability. Technically you have twice the amount of control and you don't even have to walk to the amp rack to do it.

The only real complaint I have heard about subs on Aux mixing is that there is a separation from the subs to the tops from the instruments. I think it's just laziness? All you have to do is add what you want into the subs, separation anxiety resolved....... I think it could also be bad system tuning. The PA should sound as one. Remember that content below about 80hz has little to no directionality. That means that you can't really localize where anything below 80hz is coming from. The big point being that if you need something in the subs, with subs on aux, you can put it there; or not.
Title: Re: I-Nuke NU4-6000 not per website
Post by: John L Nobile on February 14, 2015, 02:13:42 am
Wow, I would hate to think using aux fed subs puts me in the same class as line array box numb nuts that just like pretty shiny things.

Didn't mean it that way. Just trying to give you a idea where their headspace was. It's new so it must be better.
Title: Re: I-Nuke NU4-6000 not per website
Post by: Tom Bourke on February 14, 2015, 04:19:32 am
It only solves problems you cause yourself by what I consider improper use. You compromise where no compromise is needed. And why? Not because it is good, but because you are used to it. I'll try to explain later.
I agree with Scott.  It is about control.  Also keep in mind that there are many kinds of gigs.  These days I don't do any bar band audio.  I am mostly corporate.  I may have 1 podium or Lav, a dozen lavs, or a rock band the CEO wants to party with after the general session.  A typical system for me has some combination of main LR, front fills, subs, over heads, and delays.  I control them with a combination of Aux and Matrix, depending on the needs of the gig and the equipment provided/available.

Given all that, what physics involved dictate that I need to have any part of the signal from the lav's routed to the subs to be technically correct?  90% of the time the subs are just to make the marketing video have a little thump.
Title: Re: I-Nuke NU4-6000 not per website
Post by: Scott Holtzman on February 14, 2015, 04:38:00 am
I agree with Scott.  It is about control.  Also keep in mind that there are many kinds of gigs.  These days I don't do any bar band audio.  I am mostly corporate.  I may have 1 podium or Lav, a dozen lavs, or a rock band the CEO wants to party with after the general session.  A typical system for me has some combination of main LR, front fills, subs, over heads, and delays.  I control them with a combination of Aux and Matrix, depending on the needs of the gig and the equipment provided/available.

Given all that, what physics involved dictate that I need to have any part of the signal from the lav's routed to the subs to be technically correct?  90% of the time the subs are just to make the marketing video have a little thump.

(http://www.shipulski.com/wp-content/uploads/2011/10/thomastankcrash.jpg)

A few posts ago I mentioned that "we are contributing to a global brain trust" then I looked at the title of this thread.  To say many technical people go off on tangents is an understatement.  Pity the person who searches for information on the NU4-6000, reads a few posts about the internal filter configuration changing, the obligatory Behringer bashing and then a 5 page debate over aux fed subs.  Even my dog comes back when I call him from chasing a critter in the back yard!
Title: Re: I-Nuke NU4-6000 not per website
Post by: Stu McDoniel on February 14, 2015, 09:28:49 am
(http://www.shipulski.com/wp-content/uploads/2011/10/thomastankcrash.jpg)

A few posts ago I mentioned that "we are contributing to a global brain trust" then I looked at the title of this thread.  To say many technical people go off on tangents is an understatement.  Pity the person who searches for information on the NU4-6000, reads a few posts about the internal filter configuration changing, the obligatory Behringer bashing and then a 5 page debate over aux fed subs.  Even my dog comes back when I call him from chasing a critter in the back yard!
This could lead to the dreaded "Thread Lock"!
Title: Re: I-Nuke NU4-6000 not per website
Post by: John Roberts {JR} on February 14, 2015, 11:31:48 am
(http://www.shipulski.com/wp-content/uploads/2011/10/thomastankcrash.jpg)

A few posts ago I mentioned that "we are contributing to a global brain trust" then I looked at the title of this thread.  To say many technical people go off on tangents is an understatement.  Pity the person who searches for information on the NU4-6000, reads a few posts about the internal filter configuration changing, the obligatory Behringer bashing and then a 5 page debate over aux fed subs.  Even my dog comes back when I call him from chasing a critter in the back yard!

Life is too short and boring to stay on topic or only answer questions once.

JR