There is no point in all these numbers. They leave you clueless where the difference is coming from. The examined unit, the test software, the setup... The specs of AD/DA conversion are described, measured and presented (and in a way that they are easily understood) by frequency response, THD etc. There exists a lot of useful free software these days to do those measurements. Then we can talk numbers...

MC.

I just bought a BF. I'm very interested in getting that issue resolved. Otherwise it goes back.
It's not that easy to just refer to standard measurements IMO.
You read in above linked thread that they all were surprised on that rather poor measurement result (not the audible performance)  of the BF.
The test also shows that devices which usually are considered to perform accurate are heading the list.
Those measurements are not complete nonsense and probably reflect more real life conditions than other lab conditions. Even the tested HDSP9632 performed ways better then the BF  btw.
Feeding the BF with an Apogee Duet improved the situation slightly but still the result was all but in the green zone.
I'd appreciate a slightly better explanation from the RME side. Just to make sure that we're comparing apples and apples.

THX

Daniel.

I do understand your position.
However. All devices at test are measured under pretty much the same conditions. A track is looped back and recorded. And the recorded track gets compared to the original.
The level of deviations define the ranking for each of those devices.
That's IMO a pretty valid approach.

Instead of referring to RMAA only, you could have a look at the subject. Some people over there tried at least to get the issue nailed down - talking about preamps.  They didn't get that far though. It's been a constructive atmosphere over there after all.

I do understand very well that if there'd be a quality issue with the device, you wouldn't tell us out here in public.
All I can expect is that you outline issues and weaknesses about the way they've done those measurements.
Again, don't forget the good old HDSP9632 ranks pretty well on their list.
I guess you're well aware that the thread over at Gearslutz is all but good press for you guys and your BF product in particular. You better get the discussion off the table.
Just referring me/us to RMAA won't be enough though.  At least it wouldn't convince me.

Good luck.

Cheers

P.S:
I might run that test by myself.  I do also own a HDSP9632 btw.

"How does it sound?"

Judging "sound" through air by ear is
1. subjective
2. heavily depending on your entire chain and room situation

It'll give you a rough indication about what to expect and that's about it.
If something sounds "nice" it doesn't mean it's right.
That's why a loopback comparison in the analog domain IMO is a pretty objective way to compare your DA-AD performance.
Especially if you run that exercise with different scenarios (BF->BF,Duet->BF, asf) as these guys are doing it.
The test at Gearslutz has shown that when feeding from a different source the results won't change much on the BF side.
That should be an indication that the AD stage can be considered a major contributor to that still "questionable" overall result those guys came up with.
Again. I'm not saying that I buy that story. But I think somebody more skilled than me should have a closer look at it.

Cheers

Yep. Probably it is one source. I stepped over the same issue when running a loop test yesterday.
I do find it a funny that RME refers to a documentation problem and as solution than offers equalization. I can't believe that.

Then there are the other discussions over here in the forum ongoing about noise (solution1: use battery power), poor extension cables (solution2:  buy an updated cable) and channel unbalance (solution3:  use the breakout cable instead) Noise discussion
I do think there is some homework to do for RME. This all is IMO unacceptable to me and not typical RME.
My device goes back - just as a precaution. I'll follow the progress on those subjects to see how things are developing.

Sorry RME.
Cheers

Daniel.

I hope I don't over-simplify matters... ...I'm a customer -- having the device at home right now -- and try to make up my mind.
I just try to find an explanation by collecting this or that potential quality problem of your device - which are all discussed in your own forum btw.
If all those subjects are no-issues, you guys can prove it.
But please - no over-simplified excuses... ...such as referring to documentation problems if a crucial and commercially very sensitive performance parameter is not meeting the spec.

Cheers

PS: I would like to know why PS quality questions are not RME related. If a battery delivers better results then USB power. USB power would not be the preferred choice for serious recordings.
Common mode noise issues ( beside jitter/timing issues) are one of the most serious problems on audio interfaces. It's the manufacturers responsibility to get these under control as good as possible.  Beside that I'd assume that recordings will be of better quality from a battery powered device. ( But that's a speculation of course)

What spec? As MC explains in post 7 in the other thread, it is a case of documentation not meeting spec, so to say... The bass-response is by design and can be straightened out very easily...

Not sure which thread you are referring to, please clarify. Also, if USB power on a specific machine is an issue, that does not speak for USB power in general, which works well with the Babyface.

Regards,
Daniel Fuchs
RME

The simple dB figures from diffmaker published on GS really don't tell you anything about the physical nature of the difference. It does not seem as if anyone had actually listened to a difference file, otherwise the nature of the difference would have been apparent.... It is frequency response (by design here), not overall "quality".

Besides the bass frequency response, there is no quality issue with the BF's inputs, as you can see from the other published specs or verify with software like RMAA...
IMHO you are seeing/constructing an issue where there is none. The mic input does not "add unwanted stuff" (again, the dB figure in diffmaker only tells you that there is a difference, but not even whether a component in the signal path "adds" or "subtracts" anything, much less what that would be), and of course these inputs are not exclusively mic inputs. With gain set to 0 dB, they act as regular line level inputs (and frequency response can be straightened out easily, if required).

Your conclusion from the GS thread that the mic input "adds unwanted stuff" is pure speculation with no evidence whatsoever...

Regards
Daniel Fuchs
RME

Let's put some more interpretable facts on the table!

This is the measured filter slope of the Babyface's inputs:

As you can see the -0.5 dB point is at around 45 Hz, the -1 dB point is at around 30 Hz.

Furthermore the Babyface's Input is on average 2 dB hotter compared to its output when set to 0 dB gain. With pure sinusoidal signals the peak difference is about 2.0 - 2.3 dB. So any loop-back measurements must be made with the *output* set to at least -2.3 dB, better use some more for possible variance.

With pure square signals you need to pull down the output level even more. At 1 KHz it's the same -2.3 dB as with sinusoidal, at 50 Hz you need to go as low as -6 dB, and all the way down to 1 Hz you need to use -9 dB. That is because the lower the frequency the more the square will overshoot at its ascending ramp.

So before we go on discussing you need to do new measurements with modified output levels, preferably while running your testfile through the loop to even out the levels. Else any loop-back measurements, be they made with Audio DiffMaker or other software, that does not apply this output level reduction will measure input *distortion*!

Thanks! :-) I'll keep the rest of the discussion in the Gearslutz thread.