Mir Pro + Protools = crackles

[songman]

I am testing Mir Pro and really wanted to like it. It is after all an amazing piece of software. However, I have problems. My setup is a MacPro hexacore 3.33 GHz with 16GB RAM running an HD3 Protools HD (PT 10) system on MacOSX 10.6.8. I insert VE Pro in my protools sessions to avoid the 4GB limit of PT. Typically I will have 10-12 VI Pro's in VE Pro. I also have some other VI's running in PT which do not go through VE Pro. Now I inserted Mir Pro on all the channels of VE Pro and also (following the directions given in another thread) inserted some audio inputs to pipe VI's in PT to VE Pro so that I could also apply Mir Pro to them. Actually everything works like a charm, if it wasn't for ... crackling. If I run my protools session without Mir Pro it is smooth as butter not a single crackle or anomaly to be heard. But running this setup with Mir Pro results in crackles. I've unloaded and reloaded the session several times to see that I did not make any mistakes. To no avail, when running Mir Pro in this setup I will have the random crackles.

Any ideas?

Thanks, best regards, Bob.

[Dietz]

Hi Bob,

sorry to hear about your problem. Would you mind to tell us what buffer setting you use for VE Pro Server, and what latency you have chosen for MIR Pro in its Preferences? And what are the RTAS latency settings of ProTools?

Kind regards,

[songman]

Hello Dietz,

RTAS latency in PT is 512 samples with 3GB disk cache size

Buffer in VE Pro is 2 threads per instance

Latency of MIR in VE Pro is 512 samples

 Best regards, Bob

[DG]

Try whacking up the MIR buffers to the maximum and see if there is an improvement.

DG

[Dietz]

In this case, it might be that the opposite is true, Daryl.

Bob, like pointed out on pages 7 and 8 of MIR Pro's preliminary manual, there are actually two numbers to take into account here - namely the host buffer size and MIR latency setting. The latter should either be 0 (which is usually ideal) or a number greater than the host buffer size. MIR latency below or equal to the host buffer size will give sub-par results.

IOW: I would try to leave the latency of the RTAS engine at 512 samples first, while resetting MIR Pro's latency to the default 0 samples. If this doesn't do the trick, I suggest to use a higher latency for the RTAS engine first (1024). As a last resort, it might be advisable to use at least twice the size of the RTAS latency for MIR Pro.

HTH,

[Dietz]

PS @ Bob - Just asking: How many cores did you reserve for RTAS processing in ProTools' Playback Engine Settings?

[songman]

A big thanks to everyone for the replies and questions. Please excuse the delay in getting back to you on this. I will only be back on my system later this afternoon. I will then try all suggestions and reply to the questions. Thanks all very much again. I really hope to solve this problem.

Best regards, Bob.

[Cyril Blanc]

Hello Dietz

Is VE using CPU power for a VI that is not used ?

If I mute a VI does it uses power too ?

From your experience what is the max number of VI used should I get on my Macpro

Best

Cyril

[songman]

Hello Dietz,

These are the settings of the PT playback engine:

HW buffer size 512 samples

Host processors 10 (out of 12)

CPU usage limit 95%

disk playback cache 3GB

plugin streaming buffer level2 (default)

I changed the settings of the MIR Pro latency from 512 to 0. So far so good, no more crackles!

I still have threads per instance on 2. Is that optimal? From the explanation in the preliminary manual it seems this should be more. I usually have 2 instances (one 32 bit and one 64 bit). Further I need to reserve of course threads for PT and the system.

Thanks for your help! I continue testing this, but if all goes well I will quickly go and buy MIR Pro. It is awesome.

Cheers, Bob.

[songman]

Sorry to have to let you know that the problems are not solved. I tried with latency = 0, and the crackles were ... almost ... gone. Definitely far less than with latency = 512, but they were not completely gone. Then I tried with higher settings and the result is the same. There will be the odd crackle. 

Best regards, Bob.

[Dietz]

Hmmm ... hard to say from the distance.

My suggestion: In ProTools' Playback engine, assign 8 threads for RTAS processing (... or mabye 7 are even better: I seem to remember sombody writing that uneven number are preferable). Restrict the CPU Usage limit to 70% (just for testing). Keep the number of threads for VE Pro at 2 for now (like mentioned in the manual, higher numbers will increase performance, but will of course tax the CPU). Set RTAS system latency to 1024 and MIR Pro latency to 0.

Does this help?

[songman]

Hello Dietz,

Thanks for the reply. Unfortunately nothing helps. I have now tried a lot of possible combinations of the various settings and although clearly better than my original setup where I would have a digital crackle every 30 seconds the crackles are still not completely gone. I can play a sessions once, twice, .. without crackle and then bang all of a sudden the next time there will be a crackle. They are completely random and occur at no given fixed position nor do they always sounds exactly the same either. I have now tested this with 2 different sessions: in PT without MIR no problem, smooth as always, with MIR the occasional crackle. This is very disappointing, I had very much hoped to be able to go the MIR route because it really works very well and the audio results are very nice, alas it seems that for the time being it is not to be.

Best regards, Bob.

PS I should also point out that I did the sessions in two ways: one with VIPro instruments in VE + audio inputs from other tracks in PT and one with only the VIpro instruments in VE going through MIR. It makes no difference, both in the more involved setup and in the simple setup there will be an occasional crackle.

[Cyril Blanc]

Looks we have the same problem with Logic

[songman]

Hello Dietz,

Do you have any further ideas as to what may be causing the problems in my setup and how I might avoid the crackles. As I said before I really like MIR Pro very much and if possible I would like to be able to solve this problem. Thanks for all your help so far.

Best regards, Bob.

[Dietz]

Hi Bob,

I was thinking about your problem, but as much as I tried, I can't figure out a good reason for that behaviour.

Are there any background activities going on that could interfere with the pretty high CPU demands of MIR Pro? Virus scans, firewalls, network activities, power saving options, or (a wild guess) MIDI SysEx transfers ...? There must be some well hidden conflict somewhere as soon as ProTools is part of the equation, because you wrote that MIR Pro behaves correctly when used stand-alone.

Kind regards,

[Dietz]

PS: I was talking to Florian Walter (the driving force behind MIR's convolution engine). He kindly asks you to send the two simple test-setups you were describing above to , with something like "For Florian" in the subject line. He will look into it as soon as he finds the time. Please include all the information that is necessary to recreate your setup as closely as possible. The main difference will be that he uses PT 10 Native, not HD, though.

Best,

[Cyril Blanc]

Hello

It looks that Protools user are having almost the same problems than with Logic

My buffer in Logic are set to 1024 and 0 in MIR

I made more test yesterday and it has improved

• I have remove the left window of VE (the horisontal faders) 
• I have also modify the setup of the buffer in Directory Manager

           raid 0 of  4 x ssd = 2048

           256 gb ssd = 3072

           If you do not have ssd leave it to default.

• You can also check that there are no old effects on VSL tracks in Protools

Tell me if has improved in Protools too ?

[songman]

Dear Dietz,

I do have McAfee Virus scan which is standing on on-access scan. So that might be a problem. I also have the firewall of the mac on. Neither however give any problem with PT, and of course I have followed all the Avid directives to be followed so that PT runs without problems.

In the meantime my demo has expired. There is something strange with the demo. At a certain point when starting VE a warning window came up to say I had 25 restarts left and then because I had to force quit VE (clicking OK in the warning window does not make it go away and VE simply hangs) and restart it several times always because of this warning window the number of restarts went down to 5 without so much as having started anything. I would like to suggest that it might be worthwhile to consider changing this system. A time limit of say 14 days without limitation on the number of restarts would probably be more interesting and less cumbersome. I hope you do not find me presumptuous it is just an idea.

With best regards, Bob.

[DG]

1. Virus software is always a bad idea on a DAW. I suggest you disable it whilst working on music, when you're not connected to the Internet.
2. firewalls can be on, as long as you have set them to "allow" VEP, which by the sounds of it, you have.
3. You can refresh the starts as many times as you need to, within the month, via the eLicenser software installed on your computer.

DG 

[songman]

Thanks DG! I did not know that, I'll restart the trials then and do some more testing.

Virus scan is now off of course.

About firewall: I do not seem to be able to allow anything, it is just on or off. It does say that it will block all sharing services and all incoming connections except those required for basic internet services such as DHCP, Bonjour and IPSec.

Best regards, Bob.