The No.1 Website for Pro Audio
 All  This Thread  Reviews  Gear Database  Gear for sale     Latest  Trending
Digital out genelec 8351
Old 5th April 2019
  #31
Quote:
Originally Posted by Ulrich View Post
B is recommended. The "bottleneck" is the 24 bit fixed point AES transmission between RME and Genelec. Here it is recommended not to attenuate (= loosing resolution), but to attenuate later in the DSP speaker itself.
That makes sense, but it seems there is more to the story.

I dug further into this on the RME support page. .

According to the RME manual:

RME: Support

Signal Quality

Besides, the signal quality is of course very important when making gain changes. The source signal should ideally not be changed, no matter how strong the level may be changed. This is only possible within limits though. For decreasing levels, the lowest components of the signal get lost automatically because of the limited resolution at the ports. In this case, we speak about 24-Bit, meaning levels below -144 dBFS.

As can be seen in the figure below, with 24-Bit it is well possible to create and display levels below -144 dBFS. The 2nd harmonic of the test signal e. g. is at -160 dBFS. By attenuation by 10 dB it can be shown without effort that TotalMix leaves the original signal unaltered (no visible distortions, no change of the level relations.) Even the 2nd harmonic shows cleanly at -170 dBFS.



Attenuating by 30 dB lets the signal dive under the measurement limit of the FFT, i. e. the noisefloor. This noisefloor - in reality quantization distortions - is generated by truncation at 24-Bit, in this case caused by outputting the test signal via an ADAT port.

In conclusion, or 'Summing up', we can say: TotalMix causes practically no signal degradation thanks to simple fixed point arithmetic. Signal-to-noise ratio (SNR) and total harmonic distortion (THD) of the original signal are left practically unchanged.


So in order to not accidentally blow my speakers, and to still use my current setup, I find the -40db and -50db attenuation toggles to be useful within the GLM window.

Then I just adjust level with ARC USB within a few db for listening. As far as I can tell from both reading the manual and listening I'm not losing any fidelity.

Thanks again!
Old 5th April 2019
  #32
Lives for gear
 
elambo's Avatar
Quote:
Originally Posted by Louie1 View Post
So in order to not accidentally blow my speakers, and to still use my current setup, I find the -40db and -50db attenuation toggles to be useful within the GLM window.

Then I just adjust level with ARC USB within a few db for listening. As far as I can tell from both reading the manual and listening I'm not losing any fidelity.

Thanks again!
I don't know that that's the "perfect" scenario, but I know that it doesn't need to be perfect and your method will be fine. Don't overthink it. Again, anything so short of technically ideal won't likely show up in your monitors or in your ears.
Old 5th April 2019
  #33
Agreed. And as it turns out setting the AES send in Total Mix at 0db combined with either the -40db or -50db attenuation toggle in GML (depending how "hot" the source material is) work out to about the "recommended" SPL in the room (to minimize Fletcher-Munson curve effect). I'm guessing it is not a coincidence that Genelec chose these values.
Old 6th April 2019
  #34
Gear Maniac
 

Quote:
Originally Posted by Louie1 View Post
So in order to not accidentally blow my speakers, and to still use my current setup, I find the -40db and -50db attenuation toggles to be useful within the GLM window.

Then I just adjust level with ARC USB within a few db for listening. As far as I can tell from both reading the manual and listening I'm not losing any fidelity.
Yes, and definitely better than doing all the attenuation in Totalmix.
Post Reply

Welcome to the Gearslutz Pro Audio Community!

Registration benefits include:
  • The ability to reply to and create new discussions
  • Access to members-only giveaways & competitions
  • Interact with VIP industry experts in our guest Q&As
  • Access to members-only sub forum discussions
  • Access to members-only Chat Room
  • Get INSTANT ACCESS to the world's best private pro audio Classifieds for only USD $20/year
  • Promote your eBay auctions and Reverb.com listings for free
  • Remove this message!
You need an account to post a reply. Create a username and password below and an account will be created and your post entered.


 
 
Slide to join now Processing…
Thread Tools
Search this Thread
Search this Thread:

Advanced Search
Forum Jump
Forum Jump