Hi. My son wants to run a techno track when playing live with his band, and I've set his songs up in Sonar where one audio track is just the techno track, and the other track is his click track, which also includes the techno plus some voice queues.
 
The tracks play fine until the band starts playing drums and guitar, then it drops out and stops playing. Obviously, this will not work playing live.
 
Has anyone else experienced this? Why does it do this, and is there a way to make it work? Putting some foam under the laptop seemed to help some, but it still drops out after about 30 seconds.
 
Running X2 on his laptop, which is a Gateway with an i5 processor. Maudio fasttrack interface for the techno track, and the computer's internal RealTek sound card for the click track.
 
Thanks in advance for any help.

Well two things may be a possible cause. I wouldn't use two sound cards for outputting. If the drums are close as you suggest it maybe jarring the laptop too much.
 
  

A hard disk drive has to maintain track in order to write to disk, so it is possible that the buffer is filling up and not enough writes are occurring to empty it. This is not often common since laptop drives are designed to higher specs than desktop drives, but when you mentioned foam helps, this is possible. Another is heat if the laptop is not venting properly, but seems it may be vibration-related (since the band triggers it).
 
If due to vibration, getting the computer as far from the band as cabling will allow will help. More foam may also help, but also be careful that the laptop cannot fall, as well as increasing the Disk I/O buffers (in preferences). Also, I *believe* it is possible to record to a thumb drive (I have never done this), which would require creating the project folder (using per project audio) to that thumb drive. The advantage would be that there are no mechanical parts subject to vibration this way, so writing to the thumb drive would not be affected.
 
When the band is playing, is the table the laptop was on vibrating badly? Could you feel it with your hand?

I want to make it clear that this is strictly playing two audio tracks at once, with absolutely no recording. One track is directed to the PA for the audience to hear. The other track goes to the in-ear monitors.
 
I know it's best to use one sound card with two stereo outputs,  but my only usb interface is this one with only one stereo output. So I'm having to use the internal sound card for the click track that goes to the in-ear monitors. 
 
It won't work to have the laptop in a different room,  as the drummer has to have access to it to control it. This is a pretty common set up in live settings, so I'm not sure what the problem is. 

Maybe using a foam pad under it might help. Also a very solid stand to hold it may help too. I should think the kick would be the main cause.  The disk doesn't have to be writing to have this problem. Reading could cause the problem. Try using a USB stick for storing the project. If you can feel the kick so can the laptop.
 
I don't think its the two cards though you could have sync issues with that but I don't think they are the problem with dropouts. 

I bet the band is loud! LOL
 
Be careful putting foam and things under a laptop. Laptops often depend on air flow they get from under and blocking it off may cause overheating.
 
John's idea of streaming the tracks from a USB stick sounds solid to me. It is a pity that all the music out front has to be mono though. That is a serious compromise in my opinion.
 
Perhaps some sort of multitrack hardware playback device that is designed to handle live situations might be an option.
 
 

Jeff Evans
I bet the band is loud! LOL
 
Be careful putting foam and things under a laptop. Laptops often depend on air flow they get from under and blocking it off may cause overheating.
 
 
 

Excellent point. My new old laptop has a fan. Perhaps a board on the foam might help. 

The table/level on which the laptop is positioned is crucially important, too. If the table is very
feeble, it can resonate so much it's actually shaking. Also, the laptop should not be in front of the kick or a (loud/bass) loudspeaker. The sheer airwave shock can disturb the HDD.
Put bricks first, then foam, then chipwood plate, and if necessary, still pieces of foam under each corner of the laptop. And, as mentioded, do not forget ventilation.

There has got to be something physical going on, and as others have said, I would bet that the vibration from the band is interrupting the hard drive.  Short of accoustically isolating the laptop, the best option would probably be to uprade your laptop's hard drive with an SSD, which is completely immune to vibration.  Probably not what you wanted to hear, but it would be a permanent solution to your problem, and your laptop would be much faster as a happy by-product.  SSDs have come down in price a lot in the last 12 months or so.

I have played several hundred shows with a laptop in the same setting. And I've started out simmilarily to what your setup is. I was using a mid-range laptop for this but there was two things essential to make it work when the environment of the laptop gets LOUD (and possibly hot):
 
a) One soundcard for ALL the audio. For some reason the machine easily got a hickup when running anything from the internal sound card. Sonar has some serius issues with this. Live may give you better results, however, two soundcards is not ideal in any setting.
 
b) SSD or a very fast harddrive with big and fast buffers. I've used both and they worked well. SSD is the only sollution that I could rely on 100%. The USB memory stick thing sounds interesting and I think we tried it once. If that works it's excellent, but you might still have a problem on a stage with big subs and vibrations.
 
If at a venue with lots of warm lights, get a fan or place the laptop between the drummer and the fan. We also used one of those little USB fan things, pointed from the side onto the laptop's keyboard. This usually helped a little.
 
 
Or you could invest in a super powerfull bad ass i7 fitted mega laptop with billions of megaherz and bytes! But that is probably more expensive than getting an interface with two stereo outs and an SSD