Hello,
 
I am new with Sonar 8.5 and excited to get started. but I am having major trouble. I have a laptop specifically to run Sonar, and I use a Presonus Firebox as an audio interface. I will be recording myself playing my Martin acoustic/electric with it plugged into a line in on the Firebox. Everything will be fine, but half an hour to an hour after starting, the sound on the guitar (playing through or recorded) will suddenly change drastically. It will become much quieter and will start to sound distorted. Frankly, it sounds like the guitar did when I was mistakenly plugging it into a channel that has a pre-amp on the Firebox. When the guitar goes bad, everything that has already been recorded, including on the same track, remains sounding clean and good. I do not have another guitar on hand to see if it is the instrument, but I can't see what else it could be. The mic and electric guitar I run through the pre-amped inputs seem to have no trouble. Does anybody have any thoughts on what the problem might be or suggestions on troubleshooting?
 
Thanks,
 
Sean

If your laptop has a WiFi adapter, these are notorious for causing massive DPC Latency spikes, which can do horrible things to the ability of your computer handling streaming audio processing, like what Sonar does.
 
So, try this: Just before launching a Sonar session, look for a physical switch to turn off the WiFi - or it may be a function key. If neither, than go into Windows Device Manager and temporarily Disable the WiFi adapter (NOT uninstall - just Disable).  Then, launch your Sonar session and see if things sound better.  When finished with your Sonar session, turn the WiFi adapter back on, or it it was Disabled, go back into Windows Device Manager and Enable it again.  That will restore access to the web.
 
If the above does not fix things up for you (it does for lots of folks though, so I am hoping it does for you), you can always download some freeware called LatencyMon and run it for a few minutes while Sonar is NOT running, and it will give you its opinion on your computer's ability to handle the streaming audio needed for applications for Sonar, and will give you an idea of which routines may be causing audio performance issues that you can then try to resolve.
 
I hope the above helps, 
 
Bob Bone
 

Thanks for the suggestion. Is this a latency issue though? There is no delay, just the change in the volume and quality of the sound from the guitar. The laptop was purchased specifically to run Sonar and was built with that in mind. The specs are great, and the wireless adapter is disabled. I do not use the laptop to go on the web. I will try the tool you mention, but am not sure if it will assist, if it is meant to assess latency issues.
 
Thanks again,
 
Sean

Check your cable?

Also try replacing the battery in the guitar.

gotta go with this as a +1
 

Kev999
Also try replacing the battery in the guitar.

Swhalen
Thanks for the suggestion. Is this a latency issue though? There is no delay, just the change in the volume and quality of the sound from the guitar. The laptop was purchased specifically to run Sonar and was built with that in mind. The specs are great, and the wireless adapter is disabled. I do not use the laptop to go on the web. I will try the tool you mention, but am not sure if it will assist, if it is meant to assess latency issues.

Don't confuse DPC latency with audio latency. Though often related, they're not the same thing. DPC latency can indeed cause an effect that sounds like extreme distortion.
 
In your position, however, I would suspect the instrument's electronics first and the interface second. Could be a bad jack on the guitar, for example, or a flaky cable. I'd try running through a preamp or mixer prior to the interface, and also try the other line input on the interface to see if the problem moves. Maybe you have access to, say, a synthesizer that you could plug into the interface; if there are no problems then the issue must be with the guitar.
 

Thanks for all of the suggestions. I am really new and learning quite a bit already.
 
 

Usually it is consider as a best practice to record acoustic guitar with a mic, not with a piezo. Or to use piezo as addition to main mic sound.
Concerning your problem, if new battery wouldn't help, it sounds that it might be an issue with your guitar's electric part. But what you do to return good sound back?

I just had the exact same scenario happen at a practice session I was recording this past week.
 
One of the guitar players' direct acoustic guitar signal would play just fine, then turn into a really "grungy", distorted sound, then back to normal again.  It turned out that the batteries in the guitar AND the direct interface box he was using were low.  He replaced the low batteries and things sounded consistently good once again.
 
Paul