1 Topic by anttipi (edited by anttipi 2010-10-08 23:23:23)

  • Registered: 2010-02-18
  • Posts: 51

Topic: Digital gain reduction quality in HDSP 9632

I own the HDSP 9632 soundcard and I'm about to hook up a pair of active monitors to it. My plan is to set the monitor volume controls to the highest volume I'll need with the HDSP mixer set at ~0 dB. I'll then control volume straight from the HDSP mixer panel. But my question is, how about the quality of the digital gain reduction in the 9632 compared to an external analog controller (not taking into account the impracticality of using a mouse)? 

What I've read on the internet: reducing gain in the digital domain (as opposed to on external analog controller) can cause bit depth loss. Someone said however that it's an "audiophile myth" because the bit loss is beyond the hearing capability of humans. And thirdly, I've read the amount of bit loss depends on how well the gain reduction is implemented in the digital interface (sounds logical).

I was considering a passive volume control to put in between but all of the better ones are too pricey (and I only need one volume with no other gimmicks) - plus there have been reports of uneven channel levels at low volumes, sound coloration, channels dying after a few months etc. quality issues. I know it's not as handy to use the HDSP mixer panel but it sounds far better than buying a so-so analog volume control. 

I'd really like to hear any ideas because it's time to start thinking about all the cables and stuff I'll need. HeadScratch

  • From: Houston, TX
  • Registered: 2007-05-11
  • Posts: 1,191

Re: Digital gain reduction quality in HDSP 9632

This is a much debated hot-button tiopic.  I'd use Totalmix and be done with it myself.  If you are seriously worried about any loss of resolution (what little there actually is), change your monitor's sensitivity for moderate moitoring and for loud monitoring (maybe Loud for tracking and playback for the band, and a more sensible average 85dB SPL for mixing with a little headroom).

I've avoided the cheap monitor contollers, and the more expensive ones just don't seem worth the money vs using Totalmix and a few Monitor Calibration tweaks as needed (I don't mind stuff like that if it saves me thousands - others might find it destructive to their workflow).  I actually use Digital Dynaudio AIR monitors that have an AES input, and have their own wired volume controller - problem solved wink

Some people swear by high-end monitor controllers - well how much "Better" can they be vs running the DAC at Full Scale direct to the monitors and adjusting the Monitors' sensitivity accordingly?  Might be a PITA, but you'll have less stuff in the analog path, and you'll save thousands :-)

If you need tactile talkback controls, monitor selection + inter-monitor calibration, and input source selection - then a monitor controller might make sense in more ways than one.  Just don't expect the cheap ones to be completely transparent.  I'd spend the saved cash on a great mic or something else that will make a marked improvement in your RECORDINGS...

Next opinion :-)

cool

MADIface-XT+ARC / 3x HDSP MADI / ADI648
2x SSL Alphalink MADI AX
2x Multiface / 2x Digiface /2x ADI8

3 Reply by anttipi (edited by anttipi 2010-10-09 14:22:39)

  • Registered: 2010-02-18
  • Posts: 51

Re: Digital gain reduction quality in HDSP 9632

Randyman... wrote:

If you are seriously worried about any loss of resolution (what little there actually is),

Actually, I'm not. I'm sceptical whether I'd be able to hear any difference, especially in a small room that is acoustically compromised even though I'll be adding some DIY acoustic treatment. Sure, I'm able to distinguish compressed mp3 from CD quality through my quality D/A, headphone amp + AKG k701's but we are talking about a much smaller (possible) difference here, right?

I've avoided the cheap monitor contollers, and the more expensive ones just don't seem worth the money vs using Totalmix and a few Monitor Calibration tweaks as needed (I don't mind stuff like that if it saves me thousands - others might find it destructive to their workflow).
...
If you need tactile talkback controls, monitor selection + inter-monitor calibration, and input source selection - then a monitor controller might make sense in more ways than one.  Just don't expect the cheap ones to be completely transparent.  I'd spend the saved cash on a great mic or something else that will make a marked improvement in your RECORDINGS...

My thoughts exactly. At the moment I'd rather invest the money in better monitor cables with proper shielding etc. I have a separate high quality D/A + amp for headphones (which I feed from the 9632's optical out) so all I would really need is one volume knob for the monitors. But there should be no low level balance issues or other problems I've been reading about.

4 Reply by Randyman... (edited by Randyman... 2010-10-09 22:34:47)

  • From: Houston, TX
  • Registered: 2007-05-11
  • Posts: 1,191

Re: Digital gain reduction quality in HDSP 9632

Not through Totalmix - it should be accurate within 0.1dB or less since it's is a digital attenuator.  The level imbalances happen with cheap analog pots that don't have identical ganged response - generally the more attenuation the more deviation.

I wouldn't sweat it unless you were to get into some uber-expensive DAC's and very high-end monitors, etc.  If your current standalone DAC has a volume knob on it you could certainly use it to feed your monitors as well.  Comapre attenuating in Totalmix vs attenuating with the DAC's volume knob and see if you can hear a difference.

cool

MADIface-XT+ARC / 3x HDSP MADI / ADI648
2x SSL Alphalink MADI AX
2x Multiface / 2x Digiface /2x ADI8