ProSoundWeb Community

Please login or register.

Login with username, password and session length
Advanced search  

Pages: [1]   Go Down

Author Topic: limiting and gain output help  (Read 536 times)

Shaun Hughes

  • Newbie
  • *
  • Offline Offline
  • Posts: 1
limiting and gain output help
« on: March 21, 2014, 10:50:46 am »

Hello all,

Need a little bit of help is anyone can help or guide me in the correct direction, basically, I am changing the settings of my soundsystem and also getting more equipment for the system,

Im wondering is it possible to use a DCX2496 to set gains & limit amplifiers to a curtain output (Power Watts) which will then allow me to just use the dcx as the control of amplifiers instead of adjusting the amplifers dials, hopefully that makes sense,

I have a AVC 2 which will be the system limiter which will go inbetween the mixing desk and the DCX 2496,

heres the amplifers, their specs and what i need from each amplifer in relation to power for the drivers RMS

Processor is a DCX 2496
amplifiers are 
x4 pxm 1450........... 2400w pc @ 4 ohm
x2 cmark mr3000.... 1600w pc @ 4 ohm
x1 t.amp 2400........  1200w pc @ 4 ohms
x1 t.amp 2400........  650w pc @ 8 ohms
x1 qsc rmx 850....... 280w pc @ 4 ohms
x1 qsc rmx 850....... 180w pc @ 8 ohms
 

what the settings need to be at,
x4 pxm 1450........... 2000w pc @ 4 ohm..... input sensitivity 0.775v
x2 cmark mr3000.... 1400w pc @ 4 ohm..... input sensitivity 0.775v
x1 t.amp 2400........  1000w pc @ 4 ohms..... input sensitivity 0.775v
x1 t.amp 2400........  500w pc @ 8 ohms..... input sensitivity 0.775v
x1 qsc rmx 850....... 200w pc @ 4 ohms......input sensitivity 1.15v
x1 qsc rmx 850....... 100w pc @ 8 ohms......input sensitivity 1.15v

trying to work out both the output gain and the limit level for the dcx

Thanks in advance :)

Shaun
« Last Edit: March 21, 2014, 11:02:30 am by kyriptus »
Logged

Tim Perry

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1205
  • Utica-Rome NY
Re: limiting and gain output help
« Reply #1 on: March 29, 2014, 09:58:28 am »

Shaun, I wonder why you feel you need to use the limiters. You are already limited by the max Power (and voltage) output of each amplifier.

To answer your question directly we will need more info including them make/model of each speaker and the associated amplifier. Even then the answer will be largely a matter of the philosophy of the individual based assumptions  of the operating conditions.

I'd guess that all of us never want to lose any equipment to abuse, misuse, or accidents, but the first line of defense has got to be the operator.
Logged

Brad Weber

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 2215
  • Marietta, GA
Re: limiting and gain output help
« Reply #2 on: March 29, 2014, 10:50:37 am »

Im wondering is it possible to use a DCX2496 to set gains & limit amplifiers to a curtain output (Power Watts) which will then allow me to just use the dcx as the control of amplifiers instead of adjusting the amplifers dials, hopefully that makes sense,
Shaun, neither the DCX2496 nor the front panel controls of your amplifiers are going to limit the amplifiers' potential outputs.  They can affect the signal level to the amplifiers, and thus the amplifier output for a given input level, but the amplifiers themselves will always be capable of their full rated output.

Adding to the issue, some of the amp ratings you list are at 20-20kHz and 0.1% THD, others at 1% THD and some unidentified frequency and others I have no idea, but the point is they are not 'apples to apples' and some of them may not be directly indicative of the actual output for subwoofer or full range use.  Similarly, the 8 Ohm or 4 Ohm impedances likely noted for your speakers are probably nominal values, the actual impedance is going to vary greatly with frequency with the minimum impedance likely being lower than the nominal impedance.  The point is that the power ratings you noted may not be as precise as you think in terms of what you'll get in actual use.

To quantify Paul's point, the difference between 2400W and 2000W is -0.8dB and the difference between 1600W and 1400W is -0.6dB, so in most cases you are talking about fraction of a dB differences.

FWIW, 0.775V is 0dBu and 1.15V is +3.4dBu.
« Last Edit: March 29, 2014, 02:29:44 pm by Brad Weber »
Logged

Paul G. OBrien

  • Sr. Member
  • ****
  • Offline Offline
  • Posts: 430
Re: limiting and gain output help
« Reply #3 on: March 29, 2014, 12:25:43 pm »

You have a couple complicating factors here.. most of your amps use the consumer(-10dBu) input sensitivity while the lowest the DCX limiters can be set is -1dBu, so you're gonna have to run the inputs pretty hot to have any useful range in the limiters.
Secondly the power levels you want to limit to are only fractions of a dB below clipping and the DCX limiters aren't a true brick wall so you will find they will have to be tweaked from theoretical anyway, so your best course of action is to just setup the system with one each of the -10dB and +4dB amps without speakers connected and experiment with the various input and limiter settings until you get something that works acceptably well.
Logged
Pages: [1]   Go Up
 


Page created in 0.102 seconds with 22 queries.