USB audio degradation.. Help!!

Judkins401

New member
I made an interesting, but annoying discovery tonight that my audio signals are being degraded, pretty noticibly through USB. I’m hoping you guys can help me figure this out. This may be long. I apologize!!

I just bought a Kemper Profiling Amp and was playing with some settings as none of the modeled guitar amps sounded very good inside my DAW. What I realized after hours of tinkering was that the Kemper sounded like crap in the daw, but actually sounded really good through the monitors when they weren’t connected to the computer.

My kemper was plugged into a Tascam US16x8 interface which was plugged into my Windows PC. I use Reaper as my DAW, so kemper to daw, daw out to studio monitors. This gave me a lack luster sound.

When I eliminated the computer, and just played the kemper into the Interface, and out directly to monitors, it sounded great.

So I tried a different interface, a Berringher 404. Same exact result. Bad sound in Daw, great sound with no PC connection

Both interfaces, reaper, and windows audio settings and sample rates were the same. So to rule out a computer issue, I then plugged both interfaces into my MacBook Pro, and had the same result with both. I experimented and played a few songs from an MP3 player into the interface next. The songs sounded fine in the daw, I would have never thought anything of the audio quality, but when I played directly though the monitors, just like the kemper, the audio was MUCH better! This leads me to believe all of my audio, in and out via USB is degraded and although not bad, or even noticeable until I experimented today, it’s not nearly the same quality.

Can anyone explain this? I did try 2 USB cables. Neither are premium, I ordered a higher quality one (cinnamon) on Amazon but it’ll be a few days and from my google research it “shouldn’t” make a difference either way. Is this just a USB thing in general? Does USB degrade audio signals, and if so, what’s is a better option for home recording?

Thank you for your time and any suggestions!
 
I would not rule out problems with/in the pc
could be microslop or could be something with reaper
have you tried a different DAW?


What do you think is good
and
what is the difference between the pc and direct w/o pc
Can you state it in numbers db freq and other such parameters or is it all subjective.

I doubt the usb cable will make any difference although a different usb port on the pc might
was anything else using that usb cable at the same time eg a hub or other conenctions ?
 
Since the issue was present in both the PC and a Mac, and it was the same I’m not sure it could be a computer issue.

As far as what I liked/didn’t like, the kemper sounded grainy, fizzy, flat, and just not right, which started my down this rabbit hole. Both the kemper and the mp3s had more depth, warmth, and clarity through the monitors directly. The mp3 files played through the computers were just lack luster in comparison. Nothing I’d have noticed before, but after playing them side by side, it was a very noticable difference. I can’t give any numbers, as I have no way of measuring or quantifying what was coming out of the monitors without making that usb connection and sending the audio through it. I did have 2 other people listen, without telling them what I was looking for initially, and both said the monitors alone sounded much better in comparison too.

Edit: I did try all of the USB ports on both computers, no hubs, and eve disconnected all other USB devices. I felt I was pretty thorough trying to weed this thing out.
 
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Since the issue was present in both the PC and a Mac, and it was the same I’m not sure it could be a computer issue.

As far as what I liked/didn’t like, the kemper sounded grainy, fizzy, flat, and just not right, which started my down this rabbit hole. Both the kemper and the mp3s had more depth, warmth, and clarity through the monitors directly. The mp3 files played through the computers were just lack luster in comparison. Nothing I’d have noticed before, but after playing them side by side, it was a very noticable difference. I can’t give any numbers, as I have no way of measuring or quantifying what was coming out of the monitors without making that usb connection and sending the audio through it. I did have 2 other people listen, without telling them what I was looking for initially, and both said the monitors alone sounded much better in comparison too.

Edit: I did try all of the USB ports on both computers, no hubs, and eve disconnected all other USB devices. I felt I was pretty thorough trying to weed this thing out.


well if it happened with both of them then it is not likely to be the computer per se but could be reaper and how it was used
so it is also unlikely that the usb cable will change any of the results

personally i find almost all mp3 to be terrible so i would never use those for a listening test as they are all lackluster imho
do you have the same problems with other material ? preferably wav files
do you have a test cd with wav files that is meant to check how a system works soundwise?

could the problem be in/with the kemper? were the settings always identical? did you try other settings including none at all?

hopefully some other folks who have some experience with these will jump in soon with their ideas
 
I'd be interested in finding out a number of things, like . . .

Does an MP3 or WAV of song played through media player sound ok via interface?
Load an MP3 or WAV of a song into Reaper and play that back. Is that ok?
Does Youtube sound ok through interface?

If the answer to these is no, it sounds like there is an output problem.
 
I'd be interested in finding out a number of things, like . . .

Does an MP3 or WAV of song played through media player sound ok via interface?
Load an MP3 or WAV of a song into Reaper and play that back. Is that ok?
Does Youtube sound ok through interface?

If the answer to these is no, it sounds like there is an output problem.

Everything sounds okay in browsers and media players (but I thoight all of my audio did until this comparison enlightened me that it could be much better) audio files loaded into reaper and media players sound the same so I think this rules out reaper as the culprit?

I can’t directly compare YouTube and media player audio through the interface because those files would have to travel through USB to the interface, so I can’t test them without the usb connection. Which is where everything else has been shining. I suppose could compare a YouTube video played on my pc to the same video played from my phone to the interface, but since it’s a different piece of hardware I don’t think it would be a fair comparison. I’m at at a loss here!
 
I'm confused. I have the Tascam interface. I didn't even know you can connect an input to it and have that come out of the output sockets, WITHOUT the computer being connected. I get no sound from it until the computer is connected via USB. On mine the quality of all the inputs, mic/line/instrument are as far as I can tell, identical. Once you use the USB connection, then, this is data from then on. If the data is created well and accurately, it stays that way. I'd skip the USB cable idea - this is audiophool stuff. USB cables might be tougher when they get more pricey - so you can stand on them without crushing, and some have better screening - which to be honest is often more important stopping the data escaping rather than being impacted on by external noise sources. Other than that, with the usual limit on length, a cable is a cable, and spending money on esoteric ones is a Barnum experience.

I have numerous audio applications on all my computers and I have never found any of them worse or better in audio quality. 44.1 on all of them sounds the same.

I'll have to look at the Tascam and find out where the direct sound output from the mixer stage is? Probably a knob I've simply never used. Might be interesting to see if I can hear a difference between the direct vs in/out of the computer loop. Might have time later today.
 
I have the Tascam interface. I didn't even know you can connect an input to it and have that come out of the output sockets, WITHOUT the computer being connected.

I don't know how the Tascam works. However, I have a Presonus, and I can get audio output without being connected to the computer through its direct monitoring function. In other words, if I was desperate, I could operate it as an extremely basic stand-alone mixer.
 
There's no direct control on my interface - but I discovered mines the earlier model. I compared the manuals, and there is a difference. No knob or button, but with USB disconnected there is I've found, a one to one link when the USB is disconnected - input 1 comes out of output one, and 2 from 2, 3 from 3 etc. I suppose this does mean that there could be a difference in the audio introduced in the analogue to digital stage? Sorry can't be definitive because my one does NOT have this link in to out function at all. I assume, that as you can hear it, the volume control on the output defaults to outputs 1 and 2.

Sorry can't help more. I googled the model you have and it looked the same, but isn't. Mines been 'archived' now I note! I also didn't know the new model has a software mixer function too!
 
When you say the sound from the Kemper is good when the monitors are plugged directly into it - are you using the same audio outputs as when connected to the interface? Are you plugging into LINE inputs on the interface?
 
When you say the sound from the Kemper is good when the monitors are plugged directly into it - are you using the same audio outputs as when connected to the interface? Are you plugging into LINE inputs on the interface?

Yes sir, nothing as far as cabling with the kemper or the interface changes at all, nor do any settings. The kemper simply goes into the interface and out of the speakers when it sounds good. The trouble comes when the signal is instead sent through the computer via the interface and then sound is returned to the interface to be played out of the speakers via USB connection.

Again while I discovered this using the kemper, my tests with audio files yielded the same result. So frustrating! I feel like I need to re record every track I’ve ever done once this is figured out, since I was apparently working with sub par quality! lol
 
Yes sir, nothing as far as cabling with the kemper or the interface changes at all, nor do any settings. The kemper simply goes into the interface and out of the speakers when it sounds good. The trouble comes when the signal is instead sent through the computer via the interface and then sound is returned to the interface to be played out of the speakers via USB connection.

Again while I discovered this using the kemper, my tests with audio files yielded the same result. So frustrating! I feel like I need to re record every track I’ve ever done once this is figured out, since I was apparently working with sub par quality! lol
The cables have nothing to do with the sound. It's digital content so noise-free, in effect. If you are hearing anything, it's the A/D conversion, though somewhat puzzled how all this is happening.

I'm confused about the comment saying "tests with audio files yielded the same results." How are you getting the audio files (digital) to go direct to the analog inputs of the interface(s) so they use the direct-out path to the monitors? You're using a different D/A converter, or???

Set up a simple project with the Kemper (MAIN outs) into either interface, and record as a single, stereo track at 44.1/48/96, 24-bit, whatever you are using, in Reaper. Find the project raw audio file(s) (WAV) and post a link to it in Dropbox or similar.
 
I’m interested to hear what you find. Until this little experiment I never would have ever known there was a loss of quality, I mean my tracks and the music I listen to sounded great to me, but Right away realized that some of the stuff I was spending so much time EQing out on distorted guitars isn’t even there on the direct track! I didn’t know it worked without USB connection either, but it most certainly does. Let me know what you find.
 
The cables have nothing to do with the sound. It's digital content so noise-free, in effect. If you are hearing anything, it's the A/D conversion, though somewhat puzzled how all this is happening.

I'm confused about the comment saying "tests with audio files yielded the same results." How are you getting the audio files (digital) to go direct to the analog inputs of the interface(s) so they use the direct-out path to the monitors? You're using a different D/A converter, or???

Set up a simple project with the Kemper (MAIN outs) into either interface, and record as a single, stereo track at 44.1/48/96, 24-bit, whatever you are using, in Reaper. Find the project raw audio file(s) (WAV) and post a link to it in Dropbox or similar.

I played audio out of my phone into the interface and compared the direct audio vs the audio through the usb cable. It was pretty disheartening to hear such a noticeable diffrence and I am by no means an audiophile.

I will get something uploaded for you to hear tomorrow when I get home from work. I appreciate your time!
 
I played audio out of my phone into the interface and compared the direct audio vs the audio through the usb cable. It was pretty disheartening to hear such a noticeable diffrence and I am by no means an audiophile.

I will get something uploaded for you to hear tomorrow when I get home from work. I appreciate your time!
What you hear in the first case is analog audio that is (my assumption) going direct to the monitor speakers with no A/D->D/A conversion. But, it is, or was, digital when it was on your phone.

Since you seem to be A/B testing, I'm assuming you're playing the same digital file (MP3/AAC) file on your phone that you're playing on the computer?

This is confusing because you've switched everything and report the same results, which kind of rules out the interface A/D converters, barring the chance they have the same bit of firmware for that, and swapping playback software as well as Windows/OS X means different D/As are being used, so it's a real puzzle to me.
 
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Are you monitoring the track output from your DAW or input signal? You should be monitoring your input signal when you are recording with the Kemper. Also, make sure your interfaces are setup for stereo etc.
Lastly, if your interface supports it, use S/PDIF from Kemper to PC as that will allow you to keep everything digital and makes reamping much easier. Hope that helps.

By the way, if you do use SPDIF, make sure the sample rates match or you won’t get any signal passed.
 
I'm confused. I have the Tascam interface. I didn't even know you can connect an input to it and have that come out of the output sockets, WITHOUT the computer being connected. I get no sound from it until the computer is connected via USB.

I'll have to look at the Tascam and find out where the direct sound output from the mixer stage is? Probably a knob I've simply never used. Might be interesting to see if I can hear a difference between the direct vs in/out of the computer loop. Might have time later today.

I change the output direction of my Tascam 6 x 6 through its associated (and very light) mixer/eq software. The setting stays wherever I leave it. I need to turn on the pc again to change it.
 
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