Hi all! Here's what I want to do, and some of the problems I've encountered: I want to have four mics (3 SM 58's and an old audio technica) running live sound via two different interfaces - with two ports for XLR's each - into my Macbook Pro (10.5.8, 2.4 GHz Intel, 2GB RAM) running Logic 8. I also have several MIDI instruments running through a USB hub into Logic as well. The MIDI works fine, I've done it before with little to no problem, but this is the first time I'm trying to incorporate audio in the same way. I'd like to record all audio and MIDI performances live as they are being performed in Logic. The two interfaces I have are an M-Audio Fast Track Pro, and an M-Audio Firewire410. Both have worked fine in the past when used individually. I am now running them in aggregate into Logic and they work fine together sometimes, with all four mics producing the desired sounds, but then I get this buzzing sound when either one of the mics running through the Firewire410 gets signal. Sometimes the buzzing is only heard when someone sings, speaks, or plays into the mics, and other times it just buzzes constantly. I believe I've set up everything correctly in Audio MIDI Setup in order for the two interfaces to work together as an aggregate device, and as I said, they seem to work fine for a while. So, that's the first issue. My solution has been to go into Audio preferences in Logic, change the core audio device, and then just change it right back to the aggregate device, and then it usually works fine. This is very undesirable, though. I highly doubt that it's bad cables, or even a bad firewire 400 to 800 cable. I wiggle them and pull them, and I hear nothing out of the ordinary. Is there something I'm missing about setting up the aggregate device, or something else? Here are some screenshots: [img]http://img843.imageshack.us/img843/4379/audiomidipic.png http://img593.imageshack.us/img593/967/preferencespic.png [/img] Also, is there a way to save a project with all tracks, audio and MIDI, record armed so that when I call the project up, it's ready to record everything, without any additional setup? I've done this before with MIDI, where I can have several tracks recorded simultaneously as soon as the project is called up, if saved correctly. When I try this with audio tracks added, the audio tracks are never record enabled upon opening the project, even though I save it that way. If I save it with the audio tracks' input monitoring enabled, that is saved, but that's not 100% what I want. I still have to record enable any audio tracks, and then all the MIDI tracks that were saved record armed become disabled, and have to be set individually before I can record any MIDI and audio together. Is it possible to do this? Any help would be greatly appreciated. Thanks much, Adam

trying to upload those pics again..... http://img257.imageshack.us/img257/4379/audiomidipic.png http://img842.imageshack.us/img842/967/preferencespic.png hope that's better.... Adam

Hi Adam, Have you checked grounding issues and mic/instrument cables? Does the issue persist if you use only one device? What's the I/O Buffer Size set to? Best Rounik

Hi Rounik, Thank you for your response. Hope you are well. No grounding problems and cables are all good. Each device works fine on its own. Today was a little better, but there was still a similar noise. Today it was more like crackle then a buzz, but it was not as loud, and it seemed to have died away if no audio was going through for a while. Yesterday it didn't die away, but only got worse. The difference may have been that I changed the structure of the aggregate device today, and made the Firewire410 the first interface. Yesterday, the Fastrack Pro was first. Is this something you've heard of before with aggregate devices? Is there something else I can try? The I/O Buffer is set to 256. Not sure if I want to change that because of all the live MIDI I have being played into Logic. That setting has worked for me before, but let me know if you think changing it would make a difference. Do you have any thoughts about the second part of my first post in this thread? My students' show is Friday, and I'd like to record everything into Logic this time, if possible. Any advice you may have would be greatly appreciated. Oh, btw, I won a grant to use the iPad in the classroom. I just received 9 new iPads to use with the students! Can't wait to start. Found out the Tech Coordinator of my district is and ADE. (She awarded me the grant.) She said the application process starts next week.

Hey Adam! Good thanks... aside from this crazy cold snap that's hit the UK early... and hope you're doing well. That's fantastic news about the iPad. Do you know what apps you're going to get for music making yet? Back to the issue... 1. Make sure you have the latest drivers for the fasttrack and 410 installed. 2. Do a restart and repair permissions on your Mac. I have actually heard of some issues with aggregate devices and M-Audio interfaces in the past. I believe this might be down to the quality of the drivers, but don't quote me on that... 3. What's your CPU meter doing when both devices are set up as an aggregate device and you arm track to record? 4. Also try opening the Activity Monitor (in Applications/Utilities/) to see whether your Mac is suffering.... 5. Do you have many plugins on the tracks. Which ones/how many? 6. If you set the I/O Buffer Size to 512 (just as a test) do you find the issue persists? 7. Just to check you're using a sample rate of 44.1? 8. Try using different cables if you have the chance - sometimes a wiggle might not highlight the issue ;-) 9. Can you remind me of the version of Logic and OSX and Mac you're using... is it 10.5.8 and MBP with 2GB ram? 10. Are you recording direct to the system drive of your MacBookPro? If possible record to a fast (7200rpm) external Firewire drive. This might also help... Let me know if any of this helps... :) Rounik

Hey Adam, Almost forgot to address the second issue... It's not possible to get the record ready state of Audio tracks saved in a template or a project unfortunately... this is as safety feature to prevent feedback I believe. But, opening a template with record enabled SI tracks and then record enabling audio tracks, shouldn't disable record ready mode on the SI tracks, unless you click directly on the track header as opposed to directly on the Record-ready button itself. :)

ok... as soon as I moved on to something else, a lightbulb turned on (for your 'record enable' question)... 1. Create your template as you normally would. Open the Mixer and swipe across all the audio channel strips & Software Instrument channel strips too (to highlight them). 2. Click in the 'Group' slot of one channel strip and choose 'Group 1'. 3. In the Group Settings deselect all group settings except for "Record". 4. Close the Group settings window and the Mixer window. 5. Save your template or project. When you open the project in the future, simply click on one Record enable button on a track header to place all the tracks in the group into record-ready mode. :) Rounik

Hi Rounik, Thanks so much! There's a lot of useful info and stuff to try in your reply. It's a hectic day today, being right before the show. I'll try to do the procedures you've outlined, and the other suggestions. I'm turning off my airport now to rehearse, but I'll get back and let you know if I've been able to do any of what you've suggested. Thanks, Adam

Hey Rounik, Thanks again for all the info this morning. I just have too much to do and too little time to do it, so I'll have to wait on some of what you've suggested until next time I have a student performance. I have to say, though, that your solution for putting all cs's in a group is awesome! I'll probably have that implemented for tomorrow's show. Great problem solving! I've decided to just use one interface, therefore having only two mic channels running into Logic. I can get by with that on most of this show's numbers, and on the one or two that need three or four mics, I'll run those additional mics directly through the board (just like the old days). I'm wondering what would happen if I used the Firewire410, and in addition to the two mic inputs on the front, used the two quarter inch inputs on the back for mics (with XLR to quarter inch adapters)? Would that be a possible solution for using four mics and one interface? Would it work ok? (Would have already tried this out, but I don't have adapters - it does seem awkward to me though, but if it works.....). Also, about your suggestion to record to a 7200 external firewire drive, that's something I've been thinking about, but since my MBP (yes, it is running 10.5.8, 2GB) only has one firewire port, would this work with a firewire hub, since I might use the Firewire410? My experience with USB hubs is that they handle audio devices very poorly (they're great with MIDI, though), so I don't know if it's the same with firewire hubs. Well Rounik, let me know what you think, and I'll be back in touch after the show to let you know how it went, and about the iPad apps, etc. Take good care, and a million thanks for always being there as such an invaluable resource. Your time and efforts are greatly appreciated, and highly valued. Take good care, Adam

Hey Adam, No problem at all!! I just hope it helps.. The thing about interfaces... are they are not all made equal ;-) Some will perform better than others... and some will work great when used in an aggregate device setting... others may not. It tends to come down to drivers. You may run into issues trying unless you use a decent xlr to 1/8" adaptor or preamp. Better to get a small mixing desk that can then be used to do this... I wouldn't use a firewire hub, but some audio interfaces are fine with being daisy chained via a Firewire drive. I've done this with a Duet and Presonus Firebox without any issue. But check with M-Audio. If they don't recommend it, then it may be a no-go :( Most of all I want to say have a Great Show!! Hope it all goes really well. Best :) Rounik