Setting limiters

rec

I have a new DRPA+
When setting the limiters, do I just go thru the different levels of overeasy or am I missing some other setting?
Do we have guidelines for the Threshold?
Direct me to existing if I need to do some reading
Thanks

Gadget

Try these FAQ's
http://www.dbxpro.com/FAQs/process.php?cat=5
or my thread in our FAQ's
viewtopic.php?f=60&t=1488
Compression depends on a lot of variables, and is a personal thing...
G

rec

So I am still reading and punching buttons
When setting my gain structure the only way that I can get my amps to clip is the set the +4/10 db switch on the back to -10.
When it is set to +4 I can turn the amp attenuators all the way up and get no clip light on the amp
Same for both amps qsc GX5 & 1850HD
Is that acceptable?

Next question
My threshold lights seem to stay red when setting the limiters unless I set the threshold to a large negative number ex: -20
What am I doing wrong?

Dra

Are you getting the mixer (we don't know what it is) to peak (or all red LED's lit)? If not, where are your master faders? Something tells me you are missing a step (or 2).
The 260 wizard likes the 1850 at only 35%(10 o'clock). We don't use the wizard's recommendation much around here, but they are usually in the ball park.

DRA

rec

Here is the DJ mixer that I am using
http://www.ureidj.com/product_1601S.aspx

I have the red led's just barley flickering on the mixer (channel gain, and master volume)
Do I need to have them on steady?

Dra

OK.
DPRA+ set to +4db.
The mixer has a max output of +20dbu.
The output meters register +5 (whatever that means).
The mixer has a non-defeatable "Output Protection Limiter" when the unit clips.
This is what I would try.
Speakers on but turned down the amps to 1/10th output (or less maybe).
Play the Pink noise source CD.
Bring up the masters until you hear the "OPL" kick in. Then dial back a tad until you hear it disengage.
The meters will register what the mixer does just before clipping.
Unplug the speakers.
Now you should be able to get the amps to clip.
Set the gain structure as described.
Set the limiters as described.
This should protect the speakers beyond the mixers protection circuit. (double protection)

DRA

rec

excellent, I will give this a try and report back
Thanks
R

rec

I tried your advice and for the life of me I cannot hear any sort of cut back with the UREI mixer
Maybe it is too subtle to hear, or I dont know what I am listening for
I have another cheaper DJ mixer (numark ), that I am going to hook up and
see what sort of results I get with it. My tops sound great I am just not comfortable that I am
getting the limiters set right so I am afraid to crank them up too much.

Dra

Maybe you need to increase the channel input gain to get it to clip. If the mixer has "peak stop" protection then it just won't get louder, as apposed to "cutting back".

DRA

rec

Dra,

The mixer has a max output of +20dbu.

Here is the output for my mixer spec page
AUDIO OUTPUTS (LEVEL/IMPEDANCE)
Master (Balanced) +2dBu/600 Ohms

You said that is was +20dbu, but that looks like +2dbu
I am a noob so its possible I am not looking in the right place
here is the link
http://www.ureidj.com/product_1601S_spec.aspx
Thanks for your on going help

Gadget

no... +2 is the "sensitivity standard" the MAX output of the mixer is +20... Dra looked it up..

Maybe you need to increase the channel input gain to get it to clip. If the mixer has "peak stop" protection then it just won't get louder, as apposed to "cutting back".

What he wants you to try is to INCREASE the INPUT gain on the channel till you get clipping... (Level or Trim controls per channel in your case) if you CANNOT get sufficient gain to clip the mixer your source material/players need to be looked at.
Gadget

rec

Great, I was not doubting Dra's info. Just trying to get my head around all this and make sure that I understand everything.
I can get a clip light when I crank up the channel gain/trim
Should the channel clip light be lit up steady when setting my gain structure or just flickering

Dra

Different manufactureres have different approaches.
Some may use the "clip" light as a "you only have 3db of headroom left".
Some use the light as "you are now clipping".
Unless you call their tech support, you are better off just using the occassional lighting (for structure processes, not for real world usage).

DRA

rec

Ok, so I have my gain structure and limiters figured out.
Now when I take my system to a gig and RTA the room do I need to
reset my limiters, or are they uneffected?
Have to admit I am a little nervous about getting there and botching up my limiters and having
to start over under the gun.

Gadget

If you take NOTHING more form this discussion remember this...Limiters will not save your speakers from damage! They can actually CAUSE the damage if misused...I would recommend keeping a pretty close eye on that... because on my system if I see activity on the limiters my headroom is about gone... Furthermore, the DRPA limiters are NOT brick wall... so overshoot is inevitable if you start hitting the limiters...your far better off to use the meters and gain structure to keep yourself safe, and let the limiters be there for that accidental mic thump or droppage...

But to the limiters when set shouldn't require a whole lot of attention. Especially if your watching your master meters on the board you'll know exactly how much headroom you have left...THAT is the way to protect your system.
Gadget

rec

I am still unsureabout reading the LED indicators on the front of the drive rack.
When you talk about seeing activity of your limiters are you talking about the color LED's or the actual limiter
indicators when you hit the utility button.

Gadget

Both...

So did you completely MISS my last post? :roll:

rec

Gadget, Not at all. I have never used any sort of sound processing equipment before and I am
just making sure that I understand completely what is going on. You actually just made a profound statement that clears things up even more for me even more.

the DRPA limiters are NOT brick wall... so overshoot is inevitable if you start hitting the limiters...your far better off to use the meters and gain structure to keep yourself safe

Us noob's dont have a point of reference when using this type of equipment for the first time, so we are naturally unsure, even when the pros tell us how to do it. Thanks a bunch for your knowledge and keep it coming. I like the straight forward answers, I am the same way.
Cheers

rec

if you cannot get the amps to clip, or your amp sensitivity is perceived to be too high... then adjust the crossover gains...

If I increase the crossover gain on my subs do I need to reset my limiters?
The reason is that I can barley get my sub amp to clip when setting the gain structure
Is there any rule of thumb when setting the crossover gain? or is it trial and error

Gadget

Please depend on the GAIN STRUCTURE to tell you when the amps are about to clip and NOT depend on the limiters to protect your system...

That said, yes increase your crossover gain for the subs.. this is normal since most non horn loaded subs are less efficient than the tops... generally by more then 3-5 db to the mids and more like 10-12 db to the horns...

Then if it makes you feel better reset the limiters...
Gadget

rec

Thats what I am doing, per the instructions in the start here section.
Thanks
R