MOTU audio monitor read outs inaccurate?

[toodamnhip]

I have noticed that when I record a full mix into a stereo track by busing all main outputs to a stereo track through aux routing, I have noticed the input monitoring meters in the audio monitor window are in the red. I have a waves L3 at the last stage BEFORE the signal sends to the stero track so I know there should be nothing above digital zero. Also, L3 is set to -.05 output to allow a little head room. When I look at the audio, though it is all the way to digital zero and the L3 may round off peaks etc, the audio is NOT clipping. I play the recorded track and it sounds fine! It seems that the DP meters in the audio monitoring window show red when there is NO clipping. Anyone have this experience or have any info to share with me? It drives me nuts to see those meters in the red.

David

[A. Turner]

toodamnhip -

You're not alone in this. I too noticed this on my system. For a long time my mixes were very, very low, due to me trying to avoid the red. First off it's a well known in music circles that digital clipping means clipping, unlike analog where it's a good thing for the meters to tap the red every now and again. Maybe I'm wrong but I believe that MOTU designed DP with a more analog design than most DAW's, and therefor red doesn't always mean clipping. I first found this out when a friend of mine (fellow engineer) was mixing on my system and I noticed that he ignored the red. He told me: "if you can't hear it 'clipping' it's not clipping. That's what you got monitors for." Second, I notice that when I record 24/48 I seem to get more signal into DP without distortion as opposed to 24/44.1 where a red usually meant distortion. So I now record majority of the time in 24/48. Lastly (don't know if it's science but it works for me), I only watch the red on the master fader. I don't mind the individual tracks being in the red, but since mastering engineers always say "RED IS RED", I try to make certain that the master fader never touches the red throughout an entire mix playback. Like I said, don't know if I'm right or wrong for this, but I haven't had any complaints so far.

[Jim]

I agree with the above.

I most always get red clip indicator in the Audio Monitor when recording. Then I examine the waveform in the editor and look for flattened waveforms at the 10 sample level or so. If they're flattened, I'll discard the track and re-record (or prepare to do some editing). If they're not flat, I'm good.

On mixdown, I avoid clipping on the mixer window because that seems to more accurately represent clipping.

.

[jlafferty]

yes , definitely the audio monitor meters are different (hotter) particularly when bussing...and I have another one for you.

It seems when I buss or send things to an aux, they magically appear on my audio monitor inputs in strange places. It doesn't do this in 3.11, so it's a 4.5 issue.

(example: I send 8 channels of drums to a stereo aux, 3 of the sent channels show up on inputs 11, 12 and 13 of my audio monitor)

Anyone have a magic setting I am missing?

Or ,is the whole bussing/audio monitor feedback architecture thing wacked?

thanks,

Jeff

<small>[ April 04, 2005, 05:06 PM: Message edited by: Jeff ]</small>

[Splinter]

There is a lengthy thread about this on OSXAudio.com.

In short, DP uses 32 bit floating point processing. This yields about a 1500dB dynamic range within DP. You can easily overdrive a buss - that is, go over 0dBfs - and not clip DP internally. The indicators still show a clip light to indicate you have gone over 0, but the only place you need to worry about distortion is at output where DP must reduce the bit depth to 24 bit. "Overs" at this point will yield distortion.

What you are seeing in the Audio Monitor is that your buss is going over 0, but you are limiting the output of that channel - your mix - and therefore DPs output is still below 0dBfs. However, if your aux went over 0 you could still reduce the master below 0 and yield a distortion free output.

It is somewhat counter to what we've learned about digital, but it is reassuring that there is a ton of headroom within DP. The same applies to DP bundled plug ins and third party plugs that use 32 bit FP processing. Just for grins I've managed to overdrive the Trim plug by 200dB and not heard a lick of distortion with the master turned all but off.

[toodamnhip]

Red level indicators drive me nuts, that's what I have to say!

Thanks for the feed back guys?...

Now..is that real feed back or the kind we call feedback but don't really hear?...lol

[Resonant Alien]

I've noticed this as well. I typically send my final mix to an ADAT Masterlink and use its meters, which are accurate, to set the level. My master fader meters in DP are always hotter than the Mlink. Funny, I sent MOTU Tech Support an email about this about a year ago and got the old..."Um, really? The meters don't match? Hmmmm......maybe your cables to your Masterlink are not the right kind" Nice....

Anyway, another way to accurately monitor if you have UAD-1 is to use the Precision Limiter in bypass mode - the meters still work and are very accurate.

[tremolounge]

Originally posted by Resonant Alien:
Anyway, another way to accurately monitor if you have UAD-1 is to use the Precision Limiter in bypass mode - the meters still work and are very accurate.

Yes, or if you don't have UAD, try the excellent (and free) Inspector from Elemental Audio.

[hsten]

Slightly OT, but it may be relevant for Resonant Alien and his setup. The meter on the Alesis Masterlink is not very reliable in terms of transients. I have had situations where the meter showed a maximum of -2dbFS during recording, while it goes into red during playback of the same recording. Another studio where I work have similar experiences. Maybe they Alesis have fixed this on later machines but it might be something to check out. I use a outboard RTW digital meter which is very accurate.

[Splinter]

Originally posted by Splinter:
There is a lengthy thread about this on OSXAudio.com.

In short, DP uses 32 bit floating point processing. This yields about a 1500dB dynamic range within DP. You can easily overdrive a buss - that is, go over 0dBfs - and not clip DP internally. The indicators still show a clip light to indicate you have gone over 0, but the only place you need to worry about distortion is at output where DP must reduce the bit depth to 24 bit. "Overs" at this point will yield distortion.

What you are seeing in the Audio Monitor is that your buss is going over 0, but you are limiting the output of that channel - your mix - and therefore DPs output is still below 0dBfs. However, if your aux went over 0 you could still reduce the master below 0 and yield a distortion free output.

It is somewhat counter to what we've learned about digital, but it is reassuring that there is a ton of headroom within DP. The same applies to DP bundled plug ins and third party plugs that use 32 bit FP processing. Just for grins I've managed to overdrive the Trim plug by 200dB and not heard a lick of distortion with the master turned all but off.

Obviously, no one read my post.

[kwiz]

....I read it man, and you're right.

[Alejandro]

I have the same problem recording on my DP 3.11. The VU don‘t stay clipping but if You see the spectogram in single channels, they are "out of screen". Anyway I don‘t hear clipping distortion, but a little out of dynamics yes. What we must do?

[Splinter]

Originally posted by kwiz:
....I read it man, and you're right.

I just thought it was funny that this thread went on asking the same question and no one responded to my post. I was beginning to think my post was invisible.

[Helen]

Hey Splinter, I read it, and found it quite helpful. I'll keep that in mind when mixing and recording in the future.

I didn't say anything about it 'cause basically my post woulda gone something like, "Oh. Cool. Didn't know that. Now I do. Thanks."

So, thanks, I didn't know that before, but now I do. Cool.