Setting Limiter on a DBX PX

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y2kindyz
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Setting Limiter on a DBX PX

#1 Post by y2kindyz »

Ok I can't seem to wrap my head around how set the limiter on my DBX PX.

On another post I was told to set my mixer to full volume with a 60hz sine wave from my phone. My EP2500 was set to max input and I measured over 50V. I backed off the dial to get 35V and I thought all is good.

Next, I ran the wizard on the PX and it asked me to place the input at 50%. Then it asked me to increase the volume on the PX to desired performance. (would this be the time to check voltage?) I set it to 5. Then it went thru a process and balanced out the speakers. It asked to reduce one side to 45%. Then it finished up the process. So now my input dials on my amp are set to 50 and 45%, where before they were about 80%. It is obvious that the PX increases the signal going to the amp, but now how do I use the limiter on the PX?
As per manual it has 10 levels of over easy limiting and a threshold of -40db - +20db.

How do I use the Limiter on the PX? Do I run the same 60hz sine from my phone to mixer and them limit the threshold to get the limited 35V?

Thanks in advance and I hope this makes sense,

Oscar

byacey
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Re: Setting Limiter on a DBX PX

#2 Post by byacey »

I haven't used the PX, but I don't think there is any place in the wizard that sets the limiter threshold; the wizard usually is just for auto EQ and FB setup. Setting the limiter is a manual function. General instructions are numerous in this forum.

You want the hardest limiting you can get; if you can shut off the soft knee function, do so.
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Bruce Weldy
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Re: Setting Limiter on a DBX PX

#3 Post by Bruce Weldy »

Do NOT use the setup wizard.

Use the EQ wizard only.

You did everything right. The setup wizard is a PITA and as far as I can tell does nothing whatsoever that's good. I guess it's fine if you are using off the shelf stuff where you put in all the model numbers, etc......but, that ain't the case here.

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y2kindyz
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Re: Setting Limiter on a DBX PX

#4 Post by y2kindyz »

So does the PX limiter serve any purpose? Has anyone used the limiter or understand how it is used?

Thanks,

Oscar

Bruce Weldy
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Re: Setting Limiter on a DBX PX

#5 Post by Bruce Weldy »

y2kindyz wrote:So does the PX limiter serve any purpose? Has anyone used the limiter or understand how it is used?

Thanks,

Oscar

Yes, of course it does....that's how you keep from blowing up your subs.

It works just like all the other driverack models. I set up a PX for a band a month or so ago. They aren't using BFM, but wanted to protect their investment...(pretty mature thinking for a bunch of 21 yr olds).

What exactly do you need help with doing and/or understanding?

6 - T39 3012LF
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"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

y2kindyz
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Location: MISSION, TX

Re: Setting Limiter on a DBX PX

#6 Post by y2kindyz »

Bruce Weldy wrote:
y2kindyz wrote:So does the PX limiter serve any purpose? Has anyone used the limiter or understand how it is used?

Thanks,

Oscar

Yes, of course it does....that's how you keep from blowing up your subs.

It works just like all the other driverack models. I set up a PX for a band a month or so ago. They aren't using BFM, but wanted to protect their investment...(pretty mature thinking for a bunch of 21 yr olds).

What exactly do you need help with doing and/or understanding?
Thanks Bruce

How do I get the limiter to limit voltage? At what point can I put the volt meter on the amp and limit output?

I was thinking of putting the volt meter on the amp during the setup process, when it asks to turn up to performance level, but I was not sure if the pink noise would give a constant output.

If I don't go thru the setup process what preset should I use?


Thanks in advance,

Oscar

Bruce Weldy
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Re: Setting Limiter on a DBX PX

#7 Post by Bruce Weldy »

y2kindyz wrote: How do I get the limiter to limit voltage? At what point can I put the volt meter on the amp and limit output?
Setting the voltage limit is done before you ever leave your house. You do it once and leave it. If it's done right, you don't need to do it again.


I was thinking of putting the volt meter on the amp during the setup process, when it asks to turn up to performance level, but I was not sure if the pink noise would give a constant output.
Ok, I think I see where your problem is.....you don't use the pink noise from the driverack to set your limiter. That noise is strictly for the auto-EQ.
If I don't go thru the setup process what preset should I use?
It's called custom. Dial it up, then set your own crossover points and limiter.

I'm short of time right now, but if you need instructions on the steps to set the limiter, let me know and I'll answer a little later today.

6 - T39 3012LF
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y2kindyz
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Location: MISSION, TX

Re: Setting Limiter on a DBX PX

#8 Post by y2kindyz »

Bruce Weldy wrote:
Setting the voltage limit is done before you ever leave your house. You do it once and leave it. If it's done right, you don't need to do it again.
Ok so if I send a 60hz sine wave thru my mixer into my PX, then the PX send signal to amp and then I dial back the input on the amp to 35V I am good? If so where is the PX going to limit the signal going to the amp?


Ok, I think I see where your problem is.....you don't use the pink noise from the driverack to set your limiter. That noise is strictly for the auto-EQ.
Ok I get it - Pink noise is for EQ. check

It's called custom. Dial it up, then set your own crossover points and limiter.
I have set the crossover, that was easy. took me a while to figure out the next page vs pushing the dial, but I got it.
I'm short of time right now, but if you need instructions on the steps to set the limiter, let me know and I'll answer a little later today.


Yes Bruce please, I need instructions and steps to set the overeasy and threshold on the limiter.

Thank you so much,

Oscar

Bruce Weldy
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Re: Setting Limiter on a DBX PX

#9 Post by Bruce Weldy »

Ok, here we go.

Use an iPad, iPhone, PC, or whatever to generate a 50 or 60hz tone. Run that into your board - I usually use a tape in, but it doesn't really matter as long as the signal gets to the main output.

Run your main output until you push the lights just past the green. I do this so that when I get to the first yellow light, I know I'm hitting the limiter.

Now, turn your amp all the way up and leave it.

Put your voltmeter across the + and - of the power amp. (no speakers plugged in)

You should see voltage. If it's the right amplifier for your rig, it should show more voltage than you need.

On the driverack, go to the limiter section. Turn the limiter on. Turn overeasy off. Now, while watching the volt meter turn the threshold until the voltage on the meter starts going down. When you get to your voltage limit - stop.

Now, while it's still hovering there at your voltage limit - push the master fader on your board all the way up into the red as far as it will go. You should see no change in the voltage. It should remain constant at your limit even though you've slammed it.

If that worked, then you are done and have speaker protection.


Your amps will always be at full gain. Except when powering up and down. Spin 'em down before turning on the system, then raise 'em up. Then when shutting it down - spin 'em down and turn off the amps. Remember - amps are last on and first off any time you fire up the system. Do that, and you won't have pops or blow anything up.

6 - T39 3012LF
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"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

y2kindyz
Posts: 378
Joined: Mon Jan 05, 2009 10:54 am
Location: MISSION, TX

Re: Setting Limiter on a DBX PX

#10 Post by y2kindyz »

Bruce Weldy wrote:Ok, here we go.

On the driverack, go to the limiter section. Turn the limiter on. Turn overeasy off. Now, while watching the volt meter turn the threshold until the voltage on the meter starts going down. When you get to your voltage limit - stop.

Now, while it's still hovering there at your voltage limit - push the master fader on your board all the way up into the red as far as it will go. You should see no change in the voltage. It should remain constant at your limit even though you've slammed it.

If that worked, then you are done and have speaker protection.
Thank you Bruce

That explains it perfectly.

I am running an EP2500 for subs (Tuba 30's 24" wide with delta 12lfa loaded) and XTI1002 for mains (until i build 12" OTops, I will be using Behringer EuroLive B2015 rated at 200 Watts).

Do you think the mains will keep up with the T30's? Or, will I have to back down the EP2500 a bit to raise the input on the XTI1002?

Bruce Weldy
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Re: Setting Limiter on a DBX PX

#11 Post by Bruce Weldy »

y2kindyz wrote:
Bruce Weldy wrote:Ok, here we go.

On the driverack, go to the limiter section. Turn the limiter on. Turn overeasy off. Now, while watching the volt meter turn the threshold until the voltage on the meter starts going down. When you get to your voltage limit - stop.

Now, while it's still hovering there at your voltage limit - push the master fader on your board all the way up into the red as far as it will go. You should see no change in the voltage. It should remain constant at your limit even though you've slammed it.

If that worked, then you are done and have speaker protection.
Thank you Bruce

That explains it perfectly.

I am running an EP2500 for subs (Tuba 30's 24" wide with delta 12lfa loaded) and XTI1002 for mains (until i build 12" OTops, I will be using Behringer EuroLive B2015 rated at 200 Watts).

Do you think the mains will keep up with the T30's? Or, will I have to back down the EP2500 a bit to raise the input on the XTI1002?

That will all depend on type of music, taste, etc. But, don't make those adjustments at the amp. Do it in the crossover section of the driverack. That way, once you get it like you like it - it's always there.

I wouldn't stack the Behringer and the Crown amp next to each other. They have opposite air flow - they will be sucking in the hot air from each other. Separate them by a foot or so....or put 'em in different racks.

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y2kindyz
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Re: Setting Limiter on a DBX PX

#12 Post by y2kindyz »

Ok cool so in the crossover section I can increase the mains and subs separately?

When making changes in the crossover section, are they immediate?

Bruce Weldy
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Re: Setting Limiter on a DBX PX

#13 Post by Bruce Weldy »

y2kindyz wrote:Ok cool so in the crossover section I can increase the mains and subs separately?

When making changes in the crossover section, are they immediate?

Yep and Yep.

6 - T39 3012LF
4 - OT12 2512
1 - T24
1 - SLA Pro
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"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

y2kindyz
Posts: 378
Joined: Mon Jan 05, 2009 10:54 am
Location: MISSION, TX

Re: Setting Limiter on a DBX PX

#14 Post by y2kindyz »

Thank you Bruce,

Love this forum

Bruce Weldy
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Re: Setting Limiter on a DBX PX

#15 Post by Bruce Weldy »

y2kindyz wrote:Thank you Bruce,

Love this forum

Did you just put in your location? I didn't notice before that you were in the Valley.

6 - T39 3012LF
4 - OT12 2512
1 - T24
1 - SLA Pro
2 - XF210


"A system with a few knobs set up by someone who knows what they are doing is always better than one with a lot of knobs set up by someone who doesn't."

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