Output Voltage?

[Scott Fahy]

Since the install of the Venue we have been having problems with the board running in the red more then we would like. After doing some investigating last night it turns out the DSP's were set at 18V sensitivity, which worked with the old analog board and kept everyone happy with the SN but does not allow enough SPL from the Venue. We want to match the output level of the Venue to the DSP and I need to know the voltage output of the Venue at 0 db on the meters (RMS ballastics).
Scott

[Sheldon Radford]

Hi Scott,

0 dB on VENUE meters = +4 dBu (referenced to 0.775 V)
Similarly, max output on VENUE is +20 dB = +24 dBu

Sheldon

[Scott Fahy]

Thanks Sheldon,

We lowered the input sensitivity on the DSP to 9V, we'll see how it works this weekend.

Scott

[Sheldon Radford]

Cool - let us know how it works out.

9 V may be a bit low, though. If the sensitivity rating indicates the rms voltage required to drive the DSP unit to full scale then a value around 12 V might work better.

To put some actual voltage numbers to the dBu values:
0 dB VENUE meter = +4 dBu = 1.228 V rms = 3.472 V p-p

This gives 20 dB of headroom for peaks, so for max output:
+20 dB VENUE meter = +24 dBu = 12.277 V rms = 34.723 V p-p

Here's a handy dB-to-voltage conversion website.

Sheldon

[Scott Fahy]

Sheldon,

The DSP doesn't have a 12 volt setting but it looks like the 9V worked well this weekend. The FOH engineer had plenty of headroom and was driving the board to a nice level and the DSP inputs were quite happy. I'm mixing next week and should get a first hand feel for how things are running. I'll let you know after the rehearsal on Tuesday night. The true test will be with our other FOH engineer, he drives the system a bit hotter.

I may try putting an Impact on the main outs and see what happens.

Scott

[Sheldon Radford]

Glad to hear it's working for you. Out of curiosity, which DSP is being used?

Sheldon

[Scott Fahy]

Sheldon,

We're using QSC Basis 922az and two 904's for added outputs. The 922 is an 8 in 8 out and the 904's are 16 out each.
http://www.qscaudio.com/products/net...asis_922az.php


At some point we want to make the switch to digital outs from the Venue to the Basis. I really should go look at the specs on the Basis stuff and see if they have AES/EBU inputs.

Scott