Can anybody eles hear the difference in sonic quality be

[waterstrum]

Big bummer!

I finally solved my stuck MIDI notes problem by switching to low priority. (Medium priority still had stuck notes on Triton and Motif)

No more stuck synths, but audio sounds like 10 bits.

I'm using all MOTU hardware.
Original 2408 and MTP and 128 Express with dual 800.

Will a faster computer fix this?

[thermos]

Yeah, a new computer should do it. The motu stuff works great at high priority.

[thermos]

UPDATE
Too much time on my hands.......also just really bugged by this stuff.
I did a test just checking how work priorities affect RECORDED performance. It does (noooooooo!). I took my ipod, (not a lot of top end information) and recorded it throught the fireface at both high and medium priorities. I then lined up the waveforms absolutely perfectly and flipped the phase to see if there was a difference. There was, and it was even visually different between the 2 waveforms. There was quite a lot of high end discrepancy, starting at 3 kish or so, (I used elemental audio inspector). There was also some stuff going on lower, but it was more pronounced in the high registers.
So just so you know, work priorities conclusively affect playback AND recording audio quality. Time to sell the firefaces.....

[tommymandel]

Re:High or Low Work Priority - you're gonna kill me, but on my PB G4/667-DVI, with 512 MB RAM, using the Core Audio, and the PowerBook's built in input and output, I get vastly superior results with Work Priority set to low. When it was set to high, I was getting the crackles here and there, just not able to keep up. I set it to Low and the crackles went away.
I reasoned that setting the Work Priority to low in DP, allowed CORE AUDIO itself more processing power. A bit like in old OS DP, they said leave memory free for MAS, don't assign it all to Performer.
The sequence in question had 13 stereo, 3 mono, 5 aux tracks, no MIDI tracks, no VI's and 22 inserts including Auto-Tune on 2 tracks.
Look, I realize that with that computer I shouldn't expect more, and I'm happy that setting the Priority to Low makes it more usable. When I mix, I Bounce to Disk 32 bit AIFF, so I guess processing power isn't an issue at that point.
Last bit: I have the buffer set to 1024, and I haven't tried resetting Priority to High since upgrading to v. 4.52 from 4.51.

[waterstrum]

Low priority is the only way I can avoid stuck MIDI notes.
I hear the big difference in audio quality.

I'm not sure how to procede.
I need to have both audio and MIDI working well.

What is the link between the priority mode and MIDI?
Does MOTU explain what these work priorities really mean?
Why does audio suffer at lower priorities?

<small>[ January 18, 2005, 12:43 AM: Message edited by: waterstrum ]</small>

[thermos]

Work priority won't affect the quality of your bounces, BUT it will hinder your ability to monitor correctly when mixing itb. I tried a mix ITB recently at medium work priority and dang it thurned out really Bright!

[Kris]

Off topic... that's Tommy Mandel two posts back. Tommy's a keyboard God, played with Brian Adams and John Waite among others! Glad to see you here Tommy!

Kris

[rockinsage]

Reviving an old thread...

Just ran across this thread, I'm concerned. Just want to make sure I have all this straight:

1 - Lower work priorities result in lower quality audio, both during playback and recorded to disk when tracking.

2 - This is not interface-specific to RME or MOTU. For instance, my interface supposedly requires a work priority of Low in DP (Yamaha i88x), so I'll have these problems as well.

3 - Even though this affects audio quality during playback, BTD is not affected. So a Bounce will sound different than the multitrack playback. But if work priority affects the quality of audio recorded to disk, the tracks being bounced will already be at a lower quality. So the best bet is to track at High priority (if your CPU/interface can handle it), then mix at Low priority (assuming your CPU/interface can't handle High priority during mixdown)? Does a real-time BTD matter vs. a non-real-time BTD?

4 - This issue exists in the latest DP 4.52.

Do I have this right?

Thanks... just trying to do whatever I can to alleviate a bad situation. I don't want to switch sequencers (again).

[magicd]

Where was I the first time this thread went around?

Changing the Work Priority in DP does not change the way DP records or plays audio. Changing the Work Priority setting allows for some audio hardware drivers to work more efficiently, and this is most noticable in Powerbooks, iBooks, and older G4 Macs.

Work priority in the DP hardware driver changes the way DP interacts with the thread priority of the OS. If the priority is set to low or medium, DP allows other applications/drivers to take OS thread priority when they demand it.
We put this setting in because we found that the drivers for some audio interfaces were demanding top OS thread priority and on some computers (like Powerbooks), this would conflict with DP and audio performance would suffer. The symptoms would be dropouts in the audio, and as some have reported, audio performance issues could even have an effect on MIDI record and playback. In a case like this, lowering DPs thread priority in the OS allows the interface driver to do it's thing and NOT adversely affect DPs operation. There is no difference to record or playback quality in DP, regardless of Work Priority setting (other than if you have a dropout or performance problem at a High setting, you won't have that problem at a lower setting).

As a user has already pointed out, you can prove that there is no difference inside DP by bouncing mixes at different priority settings, inverting one of the bounces, and summing together. The mixes cancel each other out, showing that they are identical.
In reading earlier posts in this thread, a user talks about sending out of the interface, through an analog processor, and back into the computer. I am suspect of the validity of the test. A more accurate test would be to send a digital signal out of the interface, and back in to the interface to be re-recorded. This way you would know that A/D, D/A conversion and analog processing were not involved in the test. If you do this test, make sure that the audio you record back in is lined up to the sample with the original audio before you invert phase and sum.

Magic Dave

[corndanb]

Thank you, Dave, for putting out this little flash fire. I use an Apogee Rosetta 800 with a firewire card. I had experienced some popping and cracking and talked to both MOTU and Apogee. I was told essentially what Dave said above. I had to satisfy myself that there was no degradation so I listened carefully on my Genelec 8040's. I heard NO difference when I set the work priority to low. Thanks, Dan

[Splinter]

I went back and reread my posts. MD is right about the validity of the test through the D2B... too many variables and the analog circuitry could be/would be introducing harmonic distortion. The reason I suggested this was the realtime playback may be subject to audio degradation, where a bounced mix may not be. using the digital out to digital in test would be more accurate.

Thanks, MD.

[composer11]

Originally posted by thermos:
Yeah, and the worst part is is that it records poorly at high work priority also. (clicks pops etc). I did report this to RME, because they didn't believe that work priority makes a difference. Hopefully they care, we'll see.......
Plug in latency definitely was spot on still, as I was using powercore plugs and uad vsts and they were perfectly alligned. So I don't think thats the problem. It really is audio quality. I'll try to post later.

Thermos, VST and UAD cards don't like to play together from what I understand...will research this some more and post back my findings. I believe there is an article on this at S.O.S. UK.

Although not ready (yet) for the MAC, there is also something else that may be an option for increasing CPU power (until moved to x86/dual/quad cores).. http://www.bionicfx.com/ Turns fast GPU from nvidia into AUDIO processing units.

You can read more there as well as here
http://www.tomshardware.com/hardnews/20040902_135943.html
and here:
http://findarticles.com/p/articles/mi_zdext/is_200409/ai_n7184593?cm_ven=YPI

I'm not using a MAC presently, but priority is a MAC function yes as this problem also lies within the RME devices?

[composer11]

Originally posted by composer11:

Originally posted by thermos:
Yeah, and the worst part is is that it records poorly at high work priority also. (clicks pops etc). I did report this to RME, because they didn't believe that work priority makes a difference. Hopefully they care, we'll see.......
Plug in latency definitely was spot on still, as I was using powercore plugs and uad vsts and they were perfectly alligned. So I don't think thats the problem. It really is audio quality. I'll try to post later.

Thermos, VST and UAD cards don't like to play together from what I understand...will research this some more and post back my findings. I believe there is an article on this at S.O.S. UK. This can introduce pops and crackles..

Although not ready (yet) for the MAC, there is also something else that may be an option for increasing CPU power (until moved to x86/dual/quad cores).. http://www.bionicfx.com/ Turns fast GPU from nvidia into AUDIO processing units.

You can read more there as well as here
http://www.tomshardware.com/hardnews/20040902_135943.html
and here:
http://findarticles.com/p/articles/mi_zdext/is_200409/ai_n7184593?cm_ven=YPI

I'm not using a MAC presently, but priority is a MAC function yes as this problem also lies within the RME devices?

Or is this a DP issue?

[Shooshie]

Thanks for stepping in, MagicD. I was getting a little concerned about the validity of the tests, what with the D2B box involved, and all. Tommy Mandel posted what I had reasoned, and you confirmed it: we have to allow room for all the other drivers in the audio chain. If DP is allowed to hog the space, the results would be somewhat like assigning all the memory to DP, back in OS9, leaving no memory for MAS.

Still the discussion was an interesting one. Splinter and thermos really had me thinking and rethinking everything. Looks like medium work priority is still the way to go at least for those of us with older Macs, though I might experiment again with buffers. Since upgrading to 10.3.9 I've had trouble with clicking that I didn't have prior to that. Sounds strange, eh? Everything in my Mac has slowed down since that upgrade. I'm preparing to wipe the disk and install Tiger clean, so maybe it won't be an issue for long.

Shooshie

[thermos]

This is funny. To me the audio quality difference is BLINDINGLY obvious, and has shown itself so many times in so many different situations (whether its an unaffected 2 channel playback, or a full on mix). BUT, in Tiger, things seem to work much better. I can pretty much get a full mix going at high priority without any droputs so I'm happy.
I honsetly can't believe that noone else can hear that, believe me I wasn't looking for it. I also don't see how an analog test would be less valid than a digital test, bit I 'll try the digital one just for the hell of it.
Anyway, DP 4.52 in Tiger is ROCKING so I'm happy all 'round.