OK I fixed it and it only took an hour of looking at things - a new record! Somehow my Vegas had switched to 48khz which I knew looked a little odd because I started back in the days of 44.1khz when that was a giant leap forward in sound quality (and I've tried higher rates but can't hear any difference). I was able to go into Vegas and tell it to stay at 44.1khz and now everything seems to sound OK again. My music DAW (Sonar) is at 44.1khz and I had just left Vegas at whatever it installs at as a default, which I assume is 44.1 but somehow it was saying it was now 48khz. Never knew this could be so problematic. Earlier today I installed a new, 3rd third monitor, to my system which is a touch-screen. It attaches with HDMI and a USB for the touch function. I recall going into some audio settings for the monitors and trying to disable the little speakers in them. Maybe somewhere along the way I pushed a wrong button. Oh well, thanx Nick for such a quick reply.

48kHz is more of "a standard" than 44.1kHz for audio that goes with video (rather than CD audio etc.). Personally I can't hear a difference, and it may not matter, depending on your purpose.

Vegas should convert between these frequencies without the issues you were getting.

You need to make sure that Sonar, your audio players, etc. are closed when Vegas is open. because they can hijack your audio drivers and change Vegas' sampling frequency.

Be sure that ASIO driver is selected in Vegas, and not Mapper!

Do render video at 48 kHz audio, even when your source is 44.

You need to make sure that Sonar, your audio players, etc. are closed when Vegas is open. because they can hijack your audio drivers and change Vegas' sampling frequency.

Be sure that ASIO driver is selected in Vegas, and not Mapper!

Do render video at 48 kHz audio, even when your source is 44.

Are you sure it's not Windows 10 doing the switching with the "AI" codec controls?

JJK

Musicvid & JJKizak, I do recall Sonar was open when Vegas was open and started giving me these strange results. I think that may have had something to do with it but I keep Sonar at 44.1khz so it didn't hijack the correct number. I did notice that when I looked deep into Vegas the audio device was set to a device called something like "mapper" and not my Apollo sound card which I didn't think seemed correct. Not really sure how it happened. I also recall hearing clicks from the sound card which was unusual but now think that's what happens when the frequency is changed from a 44.1khz project to a 48khz project (or any other frequency). I've learned to keep an eye on this potential problem but I'm thrilled I fixed it so quickly. I recently retired and spend lots of hours having fun making music. I also like to make little "karaoke" style music videos to scroll my lyrics, hence the use of Vegas here and there.

...Do render video at 48 kHz audio, even when your source is 44.

Why? For minimizing quality loss, my logic (not my half-deaf ears) tells me to leave it at the source frequency unless it needs to be changed for the destination's requirements.

Nick, the standard for video audio has always been 48k. 44.1k was the standard for music CDs.

Nick, the standard for video audio has always been 48k. 44.1k was the standard for music CDs.

Right, but if it's going to a destination like AVC/AAC for the web, then that doesn't matter, and there's no problem with 44.1kHz.

Just about every piece of stock music "for video" that I've ever licensed has been 44.1kHz. And YouTube still deliver 44.1kHz, even if you send them 48kHz (and despite 48kHz/96kHz being their current recommendation). So to convert to 48kHz surely just entails 2 unnecessary resampling operations?

And YouTube still deliver 44.1kHz, even if you send them 48kHz

That's good to know, and I agree that upsampling is not needed for modern codecs and players. I'm stuck in th last century.😳​​​​​​​

So it sounds like you experts are saying I should put Vegas 13 back to 48khz as it is the default for Vegas and at the same time, don't have my DAW (Sonar) open at the same time as it's set to 44.1khz? However I'm sure I've had both open in the past with no issues editing or rendering but for some unknown reason it went haywire last night. Today I've tried everything again at 44.1khz and everything is sounding and working well. I also use ProShow at times, I'll have to see what sampling frequency it uses. I imagine having all of my sound oriented software at the same frequency would be the best way to have one's system configured.

Have you selected ASIO driver in Vegas Preferences?

I have "Universal Audio Thunderbolt" selected as the audio device type in Vegas preferences. I notice the sample rate is automatically set to 48khz in Vegas when the first blank screen pops up and I hear my Apollo Twin Quad make some clicking sounds as it switches from 44.1khz to 48 khz which I use in my DAW (Sonar/Cakewalk). The Apollo driver is ASIO as far as I know. Hmm.. I just rendered a few seconds of an old 5.1 surround video project that was created in 48khz and I left my soundcard at 48khz and rendered a few seconds of it and again, everything sounds wacko. The video has pops and crackles and my MP3 collection plays faster than normal, and most importantly, my Apollo sound card stays at 48 khz. But when I stop all sounds and set the sound card manually back to 44.1khz both the little video and my MP3s sound fine. Strange. I think I'll contact Universal Audio about this recent development. I just bought some new plugins from UA and they came out with a new version of their console mixer. Maybe these new tweaks in their software have created my current situation. At least I figured out how to fix it although both Vegas and Sonar had been coexisting in harmony for my first 8 months with the Apollo system.

Found lots of info in the Apollo manual below but don't know why the Apollo had worked and now is having some problems going between the 44.1 and the 48.

Windows WDM System Audio Operation Notes Windows WDM system audio is used for audio input and playback in media players, web browsers, audio conference, and similar programs. To ensure proper audio system functionality, follow these guidelines when using Apollo as the input and/or output device for Windows WDM system audio. • Disable system notification sounds. Turn off all Windows system alert sounds using the procedure detailed on the previous page. • ASIO and WDM sample rates must match. All sample rate values in ASIO DAW programs and WDM audio programs must be set to the same sample rate. If the ASIO and WDM sample rates are not the same, audio from one or more programs will not be heard correctly. • WDM sample rate changes. Set the sample rate in the Apollo Console Settings>Hardware panel before changing sample rates in the Sound>Playback or Sound>Recording control panels within Windows. Note that WDM programs may need to be closed then reopened to be heard correctly if the sample rate is changed in the Sound control panel within Windows. • DAW sample rate changes. If the DAW sample rate is changed, WDM audio will no longer be heard correctly because the sample rates no longer match. In this case, the WDM sample rate must be changed in the Windows Sound>Playback panel to match the DAW sample rate.