1 Topic by White Falcon (edited by White Falcon 2010-02-13 23:34:12)

  • Registered: 2009-06-09
  • Posts: 9

Topic: It can't be this good?

My new (old) PC Midi mixing desk shows 89.5db RMS noise levels in Digicheck @+4 levels. Main mix out. All channels routed and master faders up, channel faders down. A new Mackie 1604 has 88.5db with the same settings it says in the manual.

So, obviously im reading it wrong, as this desk must be (is) noisier. How do they get the numbers they get regarding noise, and how can i measure my noise levels to get a comparable reading in Digicheck?

Best Regards,
WF.

  • isaac
  • isaac
  • S/Mux specialist
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  • From: Auckland New Zealand
  • Registered: 2007-05-01
  • Posts: 339

Re: It can't be this good?

White Falcon wrote:

My new (old) PC Midi mixing desk shows 89.5db RMS noise levels in Digicheck @+4 levels. Main mix out. All channels routed and master faders up, channel faders down. A new Mackie 1604 has 88.5db with the same settings it says in the manual.

So, obviously im reading it wrong, as this desk must be (is) noisier. How do they get the numbers they get regarding noise, and how can i measure my noise levels to get a comparable reading in Digicheck?

Best Regards,
WF.

Do you mean -89.5? What sort of RME kit? What inputs? Totalmix will give you readings for all inputs and outputs.

Isaac.

  • Registered: 2009-06-09
  • Posts: 9

Re: It can't be this good?

Yeah, sorry i was in a hurry when i posted the question.

Yes, -89.5db

This is the main mix (L & R) from the desk into my converter (Lynx Aurora) via a RayDAT. The converter is set to +4. If i drop it to -10 i still get too good readings in Digicheck. The signal is unbalanced but +4 level. I have the master faders @ unity (top of their travel). And i monitor the inputs in Totalyzer. On an ordinary level meter it should be about -55db mix bus noise (not very good) for this console. I would like to get the correct numbers before i start refurbishing the desk; i'd like to see how much difference there are after a good refurbishment.

These numbers are clearly not right as i can hear the noise and some hum. If i plug in a mini mixer i get like -107db on the mix bus, which i've never seen in any mixing desks specifications. It usually (for a decent and mid size desk) is about -75db mix bus noise.

So how can i measure signal-to-noise in Digicheck and get specifiactions that i can use when i compare my gear to specifications in manuals etc? Or, how do i convert specifications in manuals so they compare to readings in Digicheck?   :-)

Thanks!

4 Reply by MC

  • MC
  • MC
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  • From: Germany/Thailand
  • Registered: 2007-04-06
  • Posts: 24,866

Re: It can't be this good?

Your readings might be correct. Use 'Bit Stat & Noise' to see the most accurate readings. Then think about the headroom. A mix bus specified at 75 dB might be referenced to the max available level, which is about +24 dBu. The reference is often unclear or not mentioned at all in such products. The converter again has its own headroom, setting it to +4 (dBu) does have no direct meaning in this case, you will have to calculate all the numbers against each other to get a uselful result.

The old mixer and the new one can be compared if they provide the same output level when used at max level.

Regards
Matthias Carstens
RME

MC's Website

  • Registered: 2009-06-09
  • Posts: 9

Re: It can't be this good?

Thanks Matthias!

Ok, then i guess that there is no easy way to compare the figures i get to mixer manual specifications. Still, i really like Totalyzer and its ability to see in which specific freq. areas noise problem lies. I found a bad power cable like that, for example.

Buying an old in line desk with a ancient computer in it is like opening a can of worms. But damn, it sounds way better then all the (pretty nice) desks i've owned so far.

:-)