Analog vs. USB recording in Axe fx II!

bkrumme said:
Alright guys. Here's a clip of all 3 methods. Same riff three times once with USB, once with Analog and once with S/PDIF.

Click to expand...


Thanks man!

The first one sounds cleaner (USB?), the second one sounds more natural with highs slightly rolled off (Analog?), the third one definitely sounds brighter (SPDIF?). I would have thought the USB and the SPDIF would sound exactly the same, but there seems to be a slight difference.

Maybe the highs are rolled off in Analog because, when a signal go through a D/A converter, the digital signals (steps - discrete signal) are sent through a low pass filter to smooth out the signal and make it more like an analog signal (continious signal). So maybe the highs are lost in the process of conversion? Just a guess....
 
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Try the same test but don't tell us which version is which.

If you tell people which is which than their own pre-conceived notions about "analog" vs "digital" sound color their opinions and they will think there are differences even if there are none.

If you do a blind test then the true results come out.
 
AdamCook said:
Try the same test but don't tell us which version is which.

If you tell people which is which than their own pre-conceived notions about "analog" vs "digital" sound color their opinions and they will think there are differences even if there are none.

If you do a blind test then the true results come out.
Click to expand...

Plus it really should be a wave file. mp3 loses too much info especially in the high end.
 
When I get home this evening I'll re-arrange the three methods so its not exactly the same and post a wav file. Then only I will know which is which and you guys can tell me what you think.

I didn't even think of doing a blind test. Silly me.
 
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hmm..I thought I did a blind test.

Now I read his post again, I realize he had mentioned it already. haha. :)
 
Thanks bkrumme.

Mind you, file #3 is louder which alters our perception. For the most accurate and informative listening test, bkrumme could lower file #3 to match and then repost it or each listener could volume match ourselves.

If you use Quicktime, there is a trick which is not widely know to play them side by side simultaneously in sync, but solo'ed.

1) Open all three files up in Quicktime but do not play them.
2) Make sure the playhead is at the far left in each of the three open QT players.
3) On a Mac, hold command down and press return. (control+enter on a pc?)

This will start all three players at the identical time. Then you bring the QT file player you want to audition to the forefront, the other two will be muted, that way you can rapidly toggle between each file while they are playing in sync to compare.
 
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The first clip seemed slightly darker, all three sounded good and differences are negligible and could be easily tweaked to sound the same.
 
Sounds like Clip #1 is analog. Clip #2 and Clip #3 sounds identical to me beside some volume difference. So those two should be USB and SPDIF.

I guess USB and SPDIF SHOULD exactly sound the same if they are basically the same unaltered digital data (sampled at same rate). Right?
 
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relaxo said:
Thanks bkrumme.

Mind you, file #3 is louder which alters our perception. For the most accurate and informative listening test, bkrumme could lower file #3 to match and then repost it or each listener could volume match ourselves.

If you use Quicktime, there is a trick which is not widely know to play them side by side simultaneously in sync, but solo'ed.

1) Open all three files up in Quicktime but do not play them.
2) Make sure the playhead is at the far left in each of the three open QT players.
3) On a Mac, hold command down and press return. (control+enter on a pc?)
Click to expand...
relaxo said:
This will start all three players at the identical time. Then you bring the QT file player you want to audition to the forefront, the other two will be muted, that way you can rapidly toggle between each file while they are playing in sync to compare.
Click to expand...


I agree #3 sounds a little louder, but I think that's important to the test. It's not exactly a "tone" test, but more of a recording method test. These WAV files are cut directly from the original WAV that was posted on Soundcloud with no changes made. The loudness of #3 in comparison to the others is inherent to the method used to record and not the level in the mix. For what it's worth, if I put a level meter on the tracks in Logic the levels are all within .2dB of each other. Both peak levels and RMS levels are within these boundaries. I believe these variations are due to the different recording methods.
 
Izzyprad said:
Sounds like Clip #1 is analog. Clip #2 and Clip #3 sounds identical to me beside some volume difference. So those tw should be USB and SPDIF.

I guess USB and SPDIF SHOULD exactly sound the same if they are basically the same unaltered digital data (sampled at same rate). Right?
Click to expand...

All three were recorded at 48kHz/24bit, then downsampled to 44.1kHz to represent CD quality WAV. If you like, I can re-bounce and post them at 48kHz.
 
jdolll said:
The first clip seemed slightly darker, all three sounded good and differences are negligible and could be easily tweaked to sound the same.
Click to expand...

This is important. There is ZERO post-procesing being done here. With EQ and compression as in a real mix you get something completely different sounding.
 
If you can post the clips with original sampling rate for USB and SPDIF and leave the Analog at 44.1 Khz, then that would be great! Now that does not mean rebouncing 44.1 Khz to 48 Khz for USB and SPDIF. You will have to use the actual wave file recorded at 48 Khz.
 
Is the first wav still the USB one? It seems that to me if there is any difference at all, I seemed to perceive slightly more low end in the USB one. However, if it's louder, that's why. Now here's the thing, the difference is ridiculously (to me) neglible, so as to be a non-factor. The only reason I'd use the analog outs to record is to add coloration from a mic preamp. Other than that, no biggie. I'll probably go USB or into my Babyface and not worry.

I listened through an SSL Duality using Yamaha NS-10's, Genelec 8050's (with sub), Genelec 1031a's, and at home with a 002 through NS-10's and the conclusion I came to that was worthwhile was that I'm really sick of this riff! No offense. :lol Didn't bother to check with the RME.

o.
 
They're slightly different at best. It's important to you. I find this to be completely ascenine, because if I recorded a tone and it was not bright enough, I'd simply make it brighter in one of the many ways that could be done, if the volume of two digital signals is different(spdif vs USB) raising the volume will not make it any noisier, it will sound exactly same. You don't see in any way how you might be blowing this out of proportion? Completely different? Not unless you're using a different eq and compressor
 
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jdolll said:
They're slightly different at best. It's important to you. I find this to be completely ascenine, because if I recorded a tone and it was not bright enough, I'd simply make it brighter in one of the many ways that could be done, if the volume of two digital signals is different(spdif vs USB) raising the volume will not make it any noisier, it will sound exactly same. You don't see in any way how you might be blowing this out of proportion? Completely different? Not unless you're using a different eq and compressor
Click to expand...

I don't know that anyone is blowing anything out of proportion. It's just a simple test with a simple riff using the simplest recording methods with the Axe-Fx.

I agree, however. The differences are so negligible it really wouldn't make a big difference in a full mix with drums/bass/vocals/keys/etc.
 
Izzyprad said:
If you can post the clips with original sampling rate for USB and SPDIF and leave the Analog at 44.1 Khz, then that would be great! Now that does not mean rebouncing 44.1 Khz to 48 Khz for USB and SPDIF. You will have to use the actual wave file recorded at 48 Khz.
Click to expand...

If I do that, then the Analog one is downsampled while the others aren't. To me, that would throw off the test since the conditions for each clip aren't consistent.
 
I appreciate the idea behind your thread, I just can't imagine recording with my axe 2 and not doing it over the USB so I can have the dry tracks for reamping. I can't tell you how many times I've wished I could have a track with more or less gain
 
jdolll said:
I appreciate the idea behind your thread, I just can't imagine recording with my axe 2 and not doing it over the USB so I can have the dry tracks for reamping. I can't tell you how many times I've wished I could have a track with more or less gain
Click to expand...

And really I think that's the best part of USB. Re-Amping is the golden ticket right now, and being able to do it without a DI and crazy routing is a HUGE bonus.
 
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