Speakerplans.com Homepage
Forum Home Forum Home > General > Electro Frying Forum
  New Posts New Posts RSS Feed - Newbie set-up help
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Newbie set-up help

 Post Reply Post Reply
Author
Message
djgorey View Drop Down
Young Croc
Young Croc
Avatar

Joined: 29 December 2007
Location: S. Wales
Status: Offline
Points: 1306
Post Options Post Options   Thanks (0) Thanks(0)   Quote djgorey Quote  Post ReplyReply Direct Link To This Post Topic: Newbie set-up help
    Posted: 07 July 2019 at 9:22am
Hi all

Looking for some help in setting up my dcx. It’s a mobile disco rig so goes mixer -> dcx -> amps (1 bass, 1 mid-hi). 

My amps are quite a bit bigger than my speakers so I’ve set up the limiters to protect them. The limit lights on the dcx flash when the master out on my mixer is at about 75%. What I’d prefer is to have the master out on my mixer at 100%. The limit value is different for bass and tops. 

Is the way to do this to reduce the input gain on the dcx to get it most of the way and then use the output gains to fine tune?
Gaffa tape is like the force in Star Wars - there's a dark side and a light side and it holds the universe together
Back to Top
Conanski View Drop Down
Old Croc
Old Croc
Avatar

Joined: 26 January 2006
Location: Ottawa, Canada
Status: Offline
Points: 2515
Post Options Post Options   Thanks (0) Thanks(0)   Quote Conanski Quote  Post ReplyReply Direct Link To This Post Posted: 07 July 2019 at 8:39pm
Originally posted by djgorey djgorey wrote:

What I’d prefer is to have the master out on my mixer at 100%.
Why? Most mixers and consoles generate enough signal(+4dB) to drive most amps to full output at the 50% control position on the master and pushing the signal higher introduces distortion pretty quickly.

What is the typical master signal level at on your mixer with the control at 75%? If it is at +8dB or more you're already out of headroom on the mixer.
Back to Top
djgorey View Drop Down
Young Croc
Young Croc
Avatar

Joined: 29 December 2007
Location: S. Wales
Status: Offline
Points: 1306
Post Options Post Options   Thanks (0) Thanks(0)   Quote djgorey Quote  Post ReplyReply Direct Link To This Post Posted: 07 July 2019 at 8:51pm
It’s an Ecler Nuo 4.0 so there’s no output metering, just mix levels pre-master out. At 100% it’s 0dBV
Gaffa tape is like the force in Star Wars - there's a dark side and a light side and it holds the universe together
Back to Top
Conanski View Drop Down
Old Croc
Old Croc
Avatar

Joined: 26 January 2006
Location: Ottawa, Canada
Status: Offline
Points: 2515
Post Options Post Options   Thanks (0) Thanks(0)   Quote Conanski Quote  Post ReplyReply Direct Link To This Post Posted: 07 July 2019 at 9:34pm
Ok the mixer has relatively low output then, you're probably only getting the first 2-3 input LEDs lit up on the DCX now anyway? In that case your plan is good crank the main out to max and adjust the levels and limiting in the DCX, should work fine.
Back to Top
djgorey View Drop Down
Young Croc
Young Croc
Avatar

Joined: 29 December 2007
Location: S. Wales
Status: Offline
Points: 1306
Post Options Post Options   Thanks (0) Thanks(0)   Quote djgorey Quote  Post ReplyReply Direct Link To This Post Posted: 07 July 2019 at 9:54pm
Cool. Thanks and yes, I’m only just lighting up the input meters on the berry at the moment. 

Gaffa tape is like the force in Star Wars - there's a dark side and a light side and it holds the universe together
Back to Top
ceharden View Drop Down
The 10,000 Points Club
The 10,000 Points Club
Avatar

Joined: 05 June 2005
Location: Southampton
Status: Offline
Points: 11776
Post Options Post Options   Thanks (0) Thanks(0)   Quote ceharden Quote  Post ReplyReply Direct Link To This Post Posted: 08 July 2019 at 12:28am
It's pretty normal not to see much on the input metering on a DCX.  The meters are relative to full scale which is something like +22dBu (18dB above +4dBu nominal).

If you want to run your mixer and the input of the DCX hotter, just turn down the input gain control on the DCX to -6dB or less.
Back to Top
djgorey View Drop Down
Young Croc
Young Croc
Avatar

Joined: 29 December 2007
Location: S. Wales
Status: Offline
Points: 1306
Post Options Post Options   Thanks (0) Thanks(0)   Quote djgorey Quote  Post ReplyReply Direct Link To This Post Posted: 19 July 2019 at 11:10am
So I’ve set the gains and limiter as I would want them and now I can turn my mixer up full and the limit lights don’t flash so all good. 

However, I then tried turning the input gain up on the mixer channel to try to get the limiters to kick in - I want to see what happens so if it ever happens on a gig, I’m ready. I didn’t have my speakers connected. 

The limit lights on the berry came on as I would expect, but it didn’t seem to cut any signal to the amps; the amps were still flashing away. I’ve set a 4s release time so in my head, I’d expect the music to drop out for 4s once the limiter is hit? Have I misunderstood how it works or am I missing something in how I’ve set it up?
Gaffa tape is like the force in Star Wars - there's a dark side and a light side and it holds the universe together
Back to Top
JBK View Drop Down
Registered User
Registered User


Joined: 03 March 2016
Location: Besançon
Status: Offline
Points: 262
Post Options Post Options   Thanks (0) Thanks(0)   Quote JBK Quote  Post ReplyReply Direct Link To This Post Posted: 19 July 2019 at 2:38pm
A limiter do not cut the signal but rather stops it from increasing further when it's higher than the threshold, so when the limiter comes in action the signal still pass by but is reduced during the release time (4s in your example)
You got to know that the dcx only have a peak limiter which is not the best way to limit a system. To avoid speaker damage, you'll need a RMS limiter.
Peak limiting can do more bad than good if not controlled, ie if a daft DJ turns everything in the red, the dcx will be in constant limiting and the signal that will pass will look like a square wave (high RMS value but no peaks), not good at all for the amps and speaker, expect to cook some coils.
The dcx will limit the peaks but will not activate if the average power of the signal is too high (without peaks)
If I'm talking chinese I'll suggest more reading and learning on the subject till you feel confident. Look up for rms versus peak limiting, crest factor. This subject is complex, but already talked about dozens and dozens of times, here and on other forums.
Back to Top
djgorey View Drop Down
Young Croc
Young Croc
Avatar

Joined: 29 December 2007
Location: S. Wales
Status: Offline
Points: 1306
Post Options Post Options   Thanks (0) Thanks(0)   Quote djgorey Quote  Post ReplyReply Direct Link To This Post Posted: 19 July 2019 at 2:44pm
Brill. Thanks for the tip. 

After I posted it, I kind of worked it out. 

I’m the only person going to be using my rig so the limiters are for my benefit. If I see them flash, I turn down my mixer until they go away!
Gaffa tape is like the force in Star Wars - there's a dark side and a light side and it holds the universe together
Back to Top
 Post Reply Post Reply

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.06
Copyright ©2001-2023 Web Wiz Ltd.

This page was generated in 0.078 seconds.