mixdown with just internal synth

[jeffsaun]

I am trying to mix down MIDI tracks to audio, using the built in synthesizer. From what I have understood from the FAQ and other forum postings, this should be possible without any external connections. But I haven't figured out how to get it to work. The audio tracks I have been getting have just been empty.

Following the FAQ instructions, I created an audio track and record enabled it, and opened the digital audio dialog and set it to stereo, and then started recording from the transport window. The audio source was set to "Built-in audio controller", which was the only option (I have no external hardware interface, just the sound card). I was unclear on what to choose for "Device Options". It defaulted to "Zoomed Video". I tried that, and also "Sound Input" and "Internal microphone". The first two yielded completely blank audio files, and the internal microphone appeared to have recorded (very dimly) ambient noise.

There is probably something basic here that I am missing. Any help would be appreciated. Thanks.

Jeff

[Jerm]

Jeff,

I am not sure what you mean by built-in synthesizer. You cannot mix down MIDI with the built-in synthesizer unless you are using the the DLS/SoundFont or other VSTi type plug-in.

If the tracks are internal, i.e. quicktime, then you can export MIDI file and import it as an audio file. The quality of quicktime synth is not very good however. I would recommend using a synthesizer plug-in for best results.

Jeremy

[Fred]

Here is a simple procedure to test the functionality of *internal* MIDI -> Audio conversion:


Launch Metro, all ports initially set to 'Internal', first track selected.

Open Plug-Ins Window and Effects Window, drag 'Apple:DLSMusicDevice' into Effects Window. Port of the selected track changes accordingly. (if not, you may change it using 'edit ports')

With Graphic Editor insert some notes. Hear the notes on inserting and on playback.

Choose File>Mix Audio Tracks. Audio track is generated.

There is only one minor oddity: The Effect Window says with big letters 'Select audio track ...' which is not quite true in this case

[Jerm]

Thank you Fred and quite right about the message. That is a bug(let).

[jeffsaun]

Jerm and Fred,

Much thanks for the info. I had been using the quicktime synth (which, as you said, isn't so good anyway), but will now try it with apple's soundfont device.

The quick feedback was a pleasant surprise - this forum is a nice resource.

Jeff

[jeffsaun]

The internal mixdown worked fine with the apple's soundfont device - this is just what I had in mind. Thanks again.

Jeff

[mackayb]

I was really happy to see this thread about mixing down soundfont instruments to audio tracks. I, however, am getting some sound distortion that sounds like helicopter noises in the background on the mixed down audio tracks. I've tried it with several packet sizes...and the only ones that work are less than 2048. Anything 2048 or higher gives me a "too many frames to process" error. I'm not sure what that means since my Dual G4 should be able to handle anything that I'm doing (I've only tried one track at a time so far).

Any help is appreciated!

[Jerm]

The 'too many frames to process' error is reported by the sf2 audiounit plug-in. It does not want packet sizes over 1024 apparently. Make sure you are using Metro version 6.05i5.

[mackayb]

Jeremy,
Wow! Thank you for the quick response! Knowing where the error comes from helps. And yes, I am using Metro SE 6.0.5 - the one that was available for download just yesterday (believe me - once I finish grad school and can afford it, I'll be upgrading to the full version ).

Could the helicopter like distortions from mixing the tracks to audio be from the soundfont? Interestingly enough, the smaller the packet size, the smaller & less obvious the distortion...

[Jerm]

I do not know what this problem is. If you can send me the source MIDI data as a metro file and direct me to the soundfont you are using I will investigate.

[Jerm]

Okay. Here is an update on what I know:

Occasionally noise crops up during mix down (much worse in 10.2.4) when using the built-in Apple SoundFont / DLS synth. It is definitely related to apple's reverb audio-unit. We do not have a fix for this problem at this time although we are continuing to investigate a fix.

For now the workaround is to go to the Apple:DLS MusicDevice's edit window and turn down the reverb all the way before mix down. Reverb can then be applied after mixing if desired. Alternatively a different reverb (I recommend the wavearts masterverb reverb) can be placed after the Apple:DLS MusicDevice. (SE user's cannot)

Please also note that if the Apple:DLS MusicDevice is installed on an aux buss all 4 outputs can be used. In this configuration if you turn off the main buss (output 1+2) then the Apple:DLS MusicDevice will output dry output on buss 1.

[mackayb]

Just want to pass on a great thank you and appreciation for Jeremy's help in this. The support he offers is great! I tried the workaround suggested and it functions perfectly - clear sound.

Thank you.

[Jerm]

Progress Report:

There are some problems with the Apple Reverb. They are working on a fix. It is related to buffer sizes. The Apple:DLS Music Device uses the apple reverb internally.

You may be able to get good results in 10.2.4 with Metro 6.05 but you need to be careful. Try setting both the Digital Audio Packet size and the Mix Audio Tracks packet size to 512 before mixing down. You may need to play the piece first before mixing.

In OS 10.2.3 and before there are also problems with the reverb and Mix down in some cases, but they are much more subtle.

Mixing will work better with the DLS under OS 10.2.4 and Metro 6.06 when released.