Dbx Driverack PA limiter settings help

R

Richard Stringer

Sophomore
Jan 13, 2011
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16
Boston, Lincolnshire, UK
Hey ya guys, I managed to get myself a Dbx Driverack PA for a cheap price, I need a bit of help with setting the limiters on it is possible. Do you think you could help me? I've got two Peavey UL215H mid/highs which are rated at 1,000 watts continuous average power and 2,000 watts program and they're 4 ohms. They're being powered by Yamaha P7000S amplifier, with one cab per channel in stereo. The Yamaha P7000S specs are here :

http://www.yamahaproaudio.com/global/en/products/poweramps/ps_series/specifications.jsp

Below are the limiter threshold settings i've got for the Driverack PA on the high frequency outputs of the unit based on using the limiter threshold calculator, can you tell me if the threshold value looks accurate?

http://www.poulpetersen.dk/Appn/gblimthc.html

And for the low frequency outputs i've got two JBL SRX728S subs which are rated at 1,600 watts continuous average power and 3,200 watts program, they're 4 ohms. Powering them i've got one JBL MPA750 bridged per sub. Here's the specs for the JBL MPA750 :

http://www.jblproservice.com/pdf/MPA Series/MPA750.pdf

Below are the settings for the threshold i've got using the same threshold calculator :

http://www.poulpetersen.dk/Appn/gblimthc.html

Does the threshold setting look correct on this one too? I've selected 2 ohms for nominal load of the amplifier because from what I know bridging an amplifier into 4 ohms is using the amplifier as dual 2 ohms right? Or should I select 4 ohms for nominal impedance of the amplifier because i'm bridging at 4 ohms?

Can you guys check these threshold settings are correct and if possible, give me your idea of what you think would be a good setting for the 'Over Easy' setting? Thanks guys, I apreciate your help.
 
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Re: Dbx Driverack PA limiter settings help

Well for one thing Silas, I never run my system into clipping, I always make sure that the red lights never flicker even, but this has only gotta last me until march when I get myself an XTA DP200 or a BSS FDS334T.
 
Re: Dbx Driverack PA limiter settings help

Richard Stringer said:
Well for one thing Silas, I never run my system into clipping, I always make sure that the red lights never flicker even, but this has only gotta last me until march when I get myself an XTA DP200 or a BSS FDS334T.
Click to expand...

That is good to hear. If you are truly the only one running your rig, and you keep it out of clip, I don't think you even need to bother with the Driverack PA limiters. The amps aren't large enough to do any damage when run within their limits. Of course, if you get the usual DJ on your rig, you might want to carefully monitor him, because most DJs can blow up a rig with even really good limiters...
 
Re: Dbx Driverack PA limiter settings help

Richard,

Seriously, don't set the limiters. They do not offer broad enough options to prevent overheating your drivers without paying an enormous performance penalty. As long as you run your rig reasonably you will be fine. I do not know about either of those other processors limiters, but regardless any settings you have in your DRPA will not transfer over.
 
Re: Dbx Driverack PA limiter settings help

From what I know, I mean read about in the manuals, both the Yamaha P7000S and MPA750 both have built in clip limiting anyway actually. The Yamaha amp's specs state :
'Limiter Comp : THD 0.5 %', that means a clip limiter right? Just not switchable like on a lot of amplifiers.

The MPA750 manual states :
'Clipping activates a “Clip-Limit” circuit. This permits the amp to reach the point of clipping without premature limiting, for exceptional headroom capability.
However, once clipping is reached (for any reason), input volume is then limited to
prevent gross clipping. This circuit limits distortion caused by clipping to about 1%
to10% (depending on degree of overdrive), which is audible but not severe.'
 
Re: Dbx Driverack PA limiter settings help

The limiters on the DRPA are useful. The indicators on the PA turn red when you hit the limiter, telling you to turn things down. No red lights = you're good to go.

Expecting them to actually protect gear though, is another matter altogether.
 
Re: Dbx Driverack PA limiter settings help

Brian jojade said:
The limiters on the DRPA are useful. The indicators on the PA turn red when you hit the limiter, telling you to turn things down. No red lights = you're good to go.

Expecting them to actually protect gear though, is another matter altogether.
Click to expand...

So if you can't see your amps, calibrate your limiter threshold to match the clip threshold. Perfect :lol:
 
Re: Dbx Driverack PA limiter settings help

Silas Pradetto said:
So if you can't see your amps, calibrate your limiter threshold to match the clip threshold. Perfect :lol:
Click to expand...
That's what I do.
Saves walking back to the racks.
I do set the limiters under clip for the HF to avoid instant burn if someone were to drop a mic in a monitor, but the HF limiters never come on in normal use.
 
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