This week I noticed all sound coming thru the audio interface into the amp sound system has an echo to it, like from the empty 55 gallon drum sound. I don't think it is Sonar related but this audio interface has little adjustments and none have changed anything. Anyone run across this. Been working fine for months. Only changes: added a video screen recorder. I suspect a Win8 thing. thanks captg

Can you describe the chain of devices?
Sonar to ?? to?? to?? to an amp?

If this is only when your are using Sonar you may have input echo on which will add the latency of your system. If it is on all playback, including Media Player, then you might have one of those sound "enhancement" gizmos happening. If your interface has a GUI mixer make sure there's no DSP effects in the chain. 

What's your audio interface? Some have built in hardware effects. For example on a built in GM-synth or the incoming signal. You might have routed an echo effect to the master or some other output that sonar is using.

check your audio inface user manual and see if it's got built in effects and, if so, how to route them.

What you are experiencing is called 'Latency' and its easily fixed if you have a reocmmended audio interface/sound card.
Here is how to fix your Latency
 
CJ