Hi,

With a limiter in the output path you would also lower the dynamic range of the system - which is not intended in most cases.

A good way to avoid excessively loud noise is to calibrate your speaker gains (or at least totalmix fader levels) to achieve a safe listening level (for you and your equipment) with a 0dBFS output signal.

Greetings,
viper

Thanks for your input.
To answer both of you -

A software "look ahead" limiter should not reduce the dynamic range at all if it only kicks in at say -1 dBfs
and you are mixing with proper gainstaging and headroom.
During the mix process you should not even be close to the 0 dB anyway.
For the mastering process - sure, but not during the mixing stage.
If, in the final process, you want to push for the top 0dB, then you could just switch the limiter off.
To have this option would be great!

To constantly mix at lower gains is definitely not desirable due to the fletcher/munson effect and should
of course be up to the engineers own preferences. Most professionals do not mix a lower gainsettings.
In the analog world of mixing, we never had this type of issue.
This nuisance with peaks/spikes is a serious problem!
- and it could easily be solved with a protective limiter.

A hardware limiter would obviously add some unwanted artifacts,
a software version would be the best solution in this case.

Regards
Lachlan

I've never had this issue either, and my main tracking DAW also feeds a 4000Watt PA System at full tilt (capable of well over 115dBSPL).  I'd also agree that a digital limiter with a -1dBfs threshhold would only reduce the (non-existant in my experience) digital glitches/crashes by 1dB, so instead of hamering the speakers at, say, 100dB, you'd get 99dB of digital glitches out of the speakers - not really of any benefit IMO.

Hands down the best way to handle this (and to handle monitor volume control in general) is with a dedicated monitor controller inbetween the DAC and the Amp.  Then, if your monitors are cranked down at the monitor controller, even a 0dBfs burst woudn't be extremely distracting or damaging.  You also retain full digital resolution of the DAC since it's running "wide open" 24/7 and being attenuated in the analog domain.  That said, I go directly from my Digiface > ADI-8 Pro > 4000Watt PA System w/o any other volume control besides Totalmix, and again, I've never had this issue in 4 or 5 years, and I don't notice a loss of resolution even when cranking Totalmix down to -30 or so (even @ -30, it is still pretty loud from the PA).  Maybe the fact that I'm running HDSP PCI setups opposed to Firewire has some effect on my lack of damaging digital glitches that you are experiencing?

You are 100% correct in that I am not understanding this concept in the slightest if my previous post did not make sense.  So, lets say you mix around -6dBfs out of your DAW, and you generally run Totalmix around -18dB to -12dB for your Monitors to get a comfortable ~85dBSPL level and to allow a bit of headroom and to get a bit loud if need be (95dBSPL or so).  You have a limiter on the output with a threshhold of -1dBfs (and digital maximum is always 0dBfs, no higher).  So, your driver freaks out and sends 0dBfs through Totalmix (ignoring the -12dB attenuation in Totalmix).  The limiter's threshhold is tagged at -1dBfs, so the output is limited to -1dBfs.  Your speakers are still blairing away at a very loud level (however -1dB lower in amplitude).

If you have an ANALOG monitor controller betwen the DAC and the Power Amp, the analog attenuation will not be affected by a Totalmix/HDSP driver crash, and would still attenuate the 0dBfs signal (likely +24dBu or so) blairing out of the DAC.

I'm probably misunderstanding what you wish to acomplish here - My skull can be a bit thick at times :-)  Please do elaborate as you have piqued my curiosity now...

AHAAAA!    

NOW I see what you mean!
I thought you didn?t know what you were talking about.
I see now, that is not the case at all.
Sorry about that Randyman.  :-)
No thick skull, I didn?t explain the problem properly.

You are assuming that a signalburst from the D/A never gets louder than 0 dB.
And it shouldn't.
From that point of view you are absoutely correct ? the limiter would only push down the peak 1 dB
and your thoughts regarding the listeninglevel make a good point.

However - In my experience, these nasty and horrible peaks get much, much louder than 0 dB.
I?ve been in situations where the music was in the -5 to -3 dB region when the peaks
that jumped out of the speakers was at least 4 times as loud. :-O
Whether this takes place before or after the D/A - I don?t know.
And how it can happen ? I don?t understand.  HeadScratch
That is the big problem.

Hope this makes my point more clear.

Peace

Lachlan

I don't have a lot of useful input, though I want to add that it also happened to me once, maybe about two years ago: I was working with headphones (fed by the headphone out of my FF800) and somehow I managed to screw up the audio driver using several audio apps simultaneously... Although the headphone level was not turned up too loud, suddenly noise blurred out of the cans at a freakishly loud level... It happened never again and I was not able to reproduce it back then - but since then I know what Lachlan is talking about...

All I can say is that it scared the crap out of me and I was a little bit worried about my hearing and insecure using headphones for a while... Not funny! no:

Hi again Randyman.

Your explanation makes alot of sense.
Thank you!  :-)

Yes indeed - a mutingfunction would be a better idea.

Have the same experience as Laex. At one occasion two musicians were considering a lawsuit
against a swedish studio, claiming they are responsible for causing permanent hearingdamage,
one of them ended up with tinnitus.   

Regards
Lachlan

Tinnitus here too. Soooooo annoying!
I have been playing Scottish bagpipes, drums and playing around with shotguns in my youth,
not always using proper hearingprotection.
Being that stupid I actually deserve to have tinnitus.
But this makes me even more sensitive to loud sound nowadays, wich is
the reason this issue really concerns me.

It sure would be great if RME would implement this mute-function in their software.

I'm not aware that this function is available from other manufacturers.

      It could be a great selling point for RME!

Thanks for your patience, Randyman.  :-)

I have a new Fireface UCX and have been using it with my Beyerdynamic DT990 headphones lately at night (so as not to disturb the neighbors).  A few nights ago, I was trying to adjust the volume down but accidentally double clicked or something, which made the volume max out and it almost blew my eardrums! 

I thought the solution would be to turn the physical headphone volume knob on the interface down to a reasonable upper limit and then control the volume up to that limit through Totalmix.  Unfortunately, the  physical volume control is controlled digitally, so any changes made in Totalmix "override" the volume previously set through the knob.

The above discussion is rather technical for me, but it's been several years since the last reply and I'd like to know if there's any solution for this issue yet?  IMO, it's a critical need since everyone deserves hearing protection (even iPods have a max headphone volume limit setting, for example), and RME's products won't sell nearly well if their customers go deaf!   I'm open to any suggestions here, only have one pair of ears and just can't afford to have this happen again.

I'd really advice everyone to use analog attenuation where possible! That analog volume knob is easily readable and no corruption or brainfart will override its position. A software limiter for the output could just as easily get corrupted. I don't see more safety in additional code. The maximum voltage that can be provided at the output must be limited, and that's an analog issue.

Yep, that will set the analog output reference voltage to its lowest. If your headphones are sensitive enough and you get enough loudness from it, you can leave it there.

By analog attenuation I meant using an analog potentiometer of sorts after the UCX's output, to control monitor/headphone levels. E.g. like THIS or THIS (I'm not familiar with the ones in the links, just using them to explain what I mean!)

Set Digicheck's input device setup to software outputs instead of hardware output. The main acts on hardware outputs.

JM

Ah, nous sommes entre francophones :-)

If you are on a Mac, i's a little bit trickier. First, choose an unused H/W output, set the fader to "0", and activate the Loopback function. Then open the Digicheck's software input (as for the main) for this H/W output. In Digicheck's input device setup, choose this unused output as source (input).

Et voilà !

For me, Pro Tools ouput to AN1/2, routed to main (of course) and ADAT 15/16. ADAT 15/16 in Loopback mode and as input for Digichek.