Forgive me if this has been gone over before. (Probably has, dozens of times)
I'm trying to convert my midi recording to audio with no success and wondering if I'm doing something fundamentally wrong.
I have MIDI recording of two keyboards, these go to a midi interface and through to sonar 7 on a laptop.
I want to create an audio of those midi tracks. To do this I'm taking a line from a mixer to the stereo input on the laptop.
First I got nothing, and after downloading ASIO4ALL and tweaking, when I arm the audio track and start record I end up with white noise only, not even a hint at anything musical!!.  So, am I missing some hardware or just not making the right settings?
I'm at a bit of a loss at what to do and would be really gratefull for any help.
 

Welcome to the forum!
I take it you haven't done the tutorials or read the Help files about MIDI and soft synths?
 
MIDI has no sound, it's like digital sheet music, and you need to route it to something that plays the sheet music with the sounds you want. That is either soft synth or hardware synth.
What is producing the sound now? If you want to record the sound of your keyboards (do they have sounds or are they MIDI controllers?) you need to either record the audio output of them directly (in real time), or route the recorded MIDI back to your keyboards and then back from the audio outputs to your soundcard and to an audio track.
 
Using soft synths you simply bounce to track, no recording required. You don't mention what verrsion of SONAR you are using, so I can't check what soft synths you have, if any.

Hi, thanks for the reply.  I do know that MIDI is not sound, just information to trigger sounds.  I'm not using soft synths, I'm using two keyboards (a Roland digital piano and a Korg M50).  I'm using their own onboard sounds.  These are linked to the laptop via a USB MIDI interface. So, recording the midi info and sending back to the keyboards is all fine.  What I'd like to do is then route the audio from the keyboards (which both go to a mixer) back to the audio-in on the laptop and create an audio file but want the benefit of using the keyboards' own sounds. I'm using Sonar Home Studio 7. 
I should also mention the laptop is windows 8 so not even sure if Sonar is even fully compatible even if the midi side of things is working well.  I get the feeling it's possibly a sound card issue or if I need to invest in an external audio interface. 
Hope I've given enough information.
Thanks again.

Welcome to the forum.
What do you have set for Recording in Windows control panel>Sounds?
What is listed in SHS 7 Options>Audio>Recording Timing Master?
What do you have set as the audio track inputs in SHS 7?
Is it an audio track and not a MIDI track?

I'm going to check all this in the next couple of hours. I'm already thinking it may be a fundamental thing in that I'm plugging into the Mic-in socket and don't think there's a line-in socket!
It is an audio track that I'm trying to record to and the inputs are asio4all (the software I downloaded, the sound card is realtek HD).  Beginning to think I may need an external audio interface but will update you with the settings I have soon.
Thanks

Yes you really do need an audio interface or it might be a struggle. Some audio software will work with asio4all and an on board chip, But all cakewalk products prefer ASIO or WDM drivers. Other wise all sorts of timing issues and pops and clicks and dropouts will happen. 
 
And your talking very pour quality connections when using the mini jacks on a laptop. 
 
Because you have your hardware keyboards you'll want a audio interface with MIDI jacks. 
Unless your's use USB connections. 
 
You should really learn about using soft synth's inside the DAW software as you'll have less hassles working that way. Just about every sound is easily found with an "in the box" soft synth. You could then use your piano as a midi controller to input. 
I still have a few hardware synths all hooked up and ready to go, but I don't think I've used one for over a year. 
 

Yes, I think you are right. I did have some success with a little tinkering but the quality isn't great. My keyboards do all have USB but haven't found that to work at all, so I think I'll either get a good audio interface or go the soft synth root. Thanks for taking time to respond.

so I think I'll either get a good audio interface or go the soft synth root. Thanks for taking time to respond.
 
Actually the soft synths need those good audio drivers more than anything else. So you will still need the interface. Audio drivers are the key to working successfully in a computer system. A computer out of the box is not made for audio. 
 
The good news is you will not necessarily need midi ports on your interface.