MIR recording

[gilles1234]

 Hello all,

I have a question regarding MIR output recording. MIr is running at 13% on an 8-core  i7 960 with 24 GB ram.

The MIR output through my soundcard speakers (5.0 and 5.1) and thru the headphones sounds absolutely beautiful, without any artefacts or crackle or stuttering.

But when I try to record electronically (e.g. "what you hear") or even by feeding the analog signal to an external DAT, to my surprise I find the sound is full of crackling and stuttering!!

I've set my ASIO card latency a bit high (1024) and assigned 8 threads to MIR and with this I can manage a 25 piece orchestra without any crackling and stuttering noise that I can hear in the speakers. But even a small configuration like a single flute and piano piece becomes full of artefacts when I'm recording it electronically.

I though it had to do mich matching the smapling rate of MIR and tried recording at 41kHz and 32 bits wide, then 16 then 24, I tried also a 96kz sampling rate, but then I gave up when I found the noise was there even during analog recording of the flute piece!

I must be doing somehting wrong, so I'm curious to know how you folks achieve proper recording (or manage to avoid the mess I'm in)?

Cheers and Tks

Gilles

[Dietz]

I think it is save to say MIR is not  an active part of the problem. It's hard to do that kind of trouble-shooting from the distance, but my first guess would be that both the computer and the DAT try to be the digital clock-(a.k.a. "WordClock")-master. Try to make sure that the DAT-machine syncs to the incoming digital connection. It's worth noting that right now, Vienna MIR work with 44.1 kHz sampling rate only. (... this will change with MIR Pro.)

Please let me know if this helped.

Kind regards,

[gilles1234]

 Hello

I agree with you, I don't think that MIR is an active part of the problem.
You also make a very good point about the clocking: it is always better to have a single cook in the soup ;-)

While I research how to configure the clocks, I have tried running three standard software recorders (Adobe Audition, Creative recorder and Audacity) all using the audio card's "What you hear" - becaue in those cases there is only one clock involved - that of the audio card. And yet, I still have the problem (clicks and stutters).

I also lengthened the latency of the ASIO Card and that hasn't made any difference.

I hesitate to ask but... do you have a suggestion?

Tks
Gil

[Dietz]

Gilles,

I just realized that you didn't tell us the basic specs of your system. Without this information it's pretty hard to make an educated guess what's going wrong. :-)

It could very well be that there are two applications fighting for the the same hardware. This can even be a problem with good, multi-client-compatible systems as the ones from RME as soon as the same physical output is addressed by two different programs. (... this wouldn't explain the problems you seem to have when recording with an external DAT machine, though).

The concept is explained in the MIR manual from p. 78 onwards.

Kind regards,

[gilles1234]

Tks for the kind suggestions.

I run Sibelius 6.2 and MIR with Vienna Special Edition PLUS instruments on an Intel 8-core i7 960 with 24 GB ram and Windows 7 ultimate. The audio card is Creative SB X-FI with built-in ASIO.

I normally run Sibelius with Vienna Ensemble Pro (6 instances of 12-15 instruments) and I don't and never have heard any artefacts in the speakers, even with a full orchestra, neither when using the Sibelius embedded wave recording function nor when using an external softare like Creative Soundblaster or Adobe Audition, all on the same computer.

However, I do get crackling and stuttering noises when recording MIR output ( .. ) - but I'm sure the answer is just before the eyes.

My reading of page 78 is that a routing bus configuration would be a solution to allow BOTH MIR and Sibelius to output to the same sound card at the same time. However, in my setup, Sibelius doesn't use any additional VST instrument sound, it routes all 6 midi streams to virtual ports connected to MIR.

To test this out, I shut down VE PRO and Sibelius and worked exclusively with the VI inside MIR. I double-clicked a Violin instrument and using the mouse I scanned back and forth the keys of the small embedded piano to produce a lengthy up-and-down sound stream. Meanwhile, I recorded using Audacity, then using Creative Sound Blaster recorder and then using Adobe Audition. While there were no crackles or artefacts in the loudspeakers, all electronic recordings (the wave files) produced cracks, pops and stuttering over the violin sound (??!)

At this point, the only music producing software in the test is MIR, hence my quesiton about a possible mismatch in the recording format or rate. I set the Audition and Audacity software to record at 41.1 Khz sampling rate and 32-bit float sample format and there are lots of cracks and stuttering. I tried smaller sample formats and higher sampling rates but to no avail. I guess that`s not the problem either. As you were thinking, it could be a contention problem for channels or ports - but which one? 

Tks. I appreciate all suggestions as I really want to buy this software.

Gil

[Dietz]

This sounds very much like a problem with the ASIO-driver nonetheless. Any chance to use different audio-hardware, just for testing?

BTW - what's the system latency of the Soundblaster? It should show powers of 2, i.e. values like 256, 512, 1024 samples and so on.

Kind regards,

[gilles1234]

 Dear friend

Firstly, tks for your kind help, patience (!) and (as always) good suggestions.
Indeed, the latency is set to, and should be, a power of 2 - as I noticed this is also enforced by MIR.

But following your hunch about ASIO, I did some more tests and then it sprang on me that the audio card has 3 modes: ASIO, Playback and gaming. So I switched to Gaming mode and ... the problem went away (so did the latency but at this point, who cares!)

I am now gradually convincing myself that the solutuion is to replace this 'Soundblaster' stuff by a real professional audio card.

...Which will let me not only listen but also record the beautiful sounds generated by MIR ;-)

Tks for everything

Cheers
Gil

[Dietz]

Good hardware is always the best foundation for a smooth workflow. :-)

... may I look at this case as "solved"?

[noldar12]

Gilles, FWIW, for professional audio use Soundblaster is generally not recommended.  It is great for movies, gaming and other casual use, but tends to be the source of all sorts of problems when used for audio content creation.

Depending on your budget, there are good inexpensive cards by Echo (and a few by M-Audio), to E-MU (the pro end of Soundblaster, and these are ok for audio - though I've never used one), on up to Lynx and RME on the high end.  If you can afford an RME, they are a known good thing.

[gilles1234]

Good grief, RME's sole dealer listed as Canadian (Synthax Inc) is actually located in...Ohio, USA. However, reading the product documentation, it sounds like day and night from this blaster thing.

So, tks again for all the help, great info! I noticed that many other members of the Vienna cummunity are RME customers. I'll see what I can do.

You may close the case.

BTW it would be nice if MIR had an option to do the recording as well ;-)