• Registered: 2011-07-03
  • Posts: 6

Topic: Babyface frequency response

I have the Babyface and have gotten some worse than expected low frequency response measurements for the device itself. Here's how it happened:

I loaded up Room EQ Wizard (REW) (acoustic measurement program for taking room response measurements). REW first requires a frequency response test of the soundcard itself, in order to account for its influence when subsequently measuring the room response. It does this using a frequency sweep when the soundcard output is connected directly back to its input.

So I connected the Babyface Analog R output directly to analog R input (i.e. the two breakout cables directly connected), and performed the frequency response sweep test with a sample rate setting of 44.1 kHz in REW and Babyface set to 44.1 kHz as well.

The Babyface manual has frequency response specs of:
   AD analog IN: Frequency response @ 44.1 kHz, -0.1 dB: 5 Hz – 20.6 kHz
   DA analog OUT: Frequency response @ 44.1 kHz, -0.5 dB: 5 Hz - 22 kHz

However, the low frequency results for the Babyface don't extend even close to as low, falling off to -0.5 dB already by 40 Hz and falling off rapidly from there:

http://img.photobucket.com/albums/v346/dcrhythm/RME%20Babyface/RMEBabyfaceresponse.jpg

I figured this had to be wrong, as I had also run the same exact test with the same settings against my old $170 Echo Mia still installed in my PC (with a short TRS patch cord for the loopback) and the low frequency results had looked as expected, reaching down to about -1 dB at 5 Hz:

http://img.photobucket.com/albums/v346/dcrhythm/RME%20Babyface/EchoMiaresponse.jpg

So then I verified that I had the lastest Babyface drivers and H/W version (1.010 and 184 respectively) and I verified that there were no EQ settings active in TotalMix, which there were not (image shows TotalMix settings during sweep test):

http://img.photobucket.com/albums/v346/dcrhythm/RME%20Babyface/RMEBabyfaceTotalMixsettings.jpg

I'm hoping I overlooked something here, because these results aren't even close to spec.

Can anyone replicate this? (REW is free software, so you can easily check, just use the calibration wizard in the soundcard tab in Preferences of REW).

2 Reply by MC

  • MC
  • MC
  • Administrator
  • Offline
  • From: Germany/Thailand
  • Registered: 2007-04-06
  • Posts: 24,842

Re: Babyface frequency response

I will check that tomorrow. Thanks for the note on REW.

Regards
Matthias Carstens
RME

MC's Website

  • Registered: 2007-06-16
  • Posts: 214

Re: Babyface frequency response

You compare Echo Mia with Babyface using swept sine signal. Such measurement is influenced with soundcard's buffer size and actual I/O latency (which I guess is a variable in your case). Longer sweeps minimize this problem. I would also try with different measurement signals (such as pink noise or MLS). I would also use asio driver for audio I/O as it provides the lowest latency and does not "play" with internal sample rate conversion.

In case of my old FF800 and my own measurement software I get nearly perfect frequency response as stated in official specifications.

4 Reply by Victor (edited by Victor 2011-10-19 00:42:56)

  • Registered: 2007-05-01
  • Posts: 26

Re: Babyface frequency response

i can confirm that measurements with RightMark Audio Analyzer show similar results - not happy at all ... :-(

http://www.midiland.de/kunden/bilder/bf_fg.png

  • Arty
  • Arty
  • AD/DA expert
  • Offline
  • Registered: 2011-10-16
  • Posts: 38

Re: Babyface frequency response

Yes too. unexpected news HeadScratch

BabyFace  / Windows 7 pro 64 Bit
  • Registered: 2007-06-16
  • Posts: 214

Re: Babyface frequency response

Ok, different software, different people, same results. Something is obviously wrong.

7 Reply by MC

  • MC
  • MC
  • Administrator
  • Offline
  • From: Germany/Thailand
  • Registered: 2007-04-06
  • Posts: 24,842

Re: Babyface frequency response

I checked and the -1 dB at 30 Hz is indeed by design and not correctly documented. Sorry. The (quite low) hi-pass is part of the input stage. The output is perfectly linear as documented.

Regards
Matthias Carstens
RME

MC's Website

  • From: Germany
  • Registered: 2007-04-10
  • Posts: 9,551

Re: Babyface frequency response

When using these inputs for microphone signals, a very soft roll-off will hardly be noticeable in real-world applications and may even be beneficial in some situations... Many pressure gradient transducer microphones will not go as low to begin with.

That said, if a straight frequency response down to 20 Hz is of the essence, the BF has an inbuilt solution or workaround... These EQ settings will produce the straightest bass frequency response curves I could come up with for now. Activate "EQ for Record" in the settings dialog to apply the EQ straight to the recorded signal.

Regards
Daniel Fuchs
RME

(Lower end of scale is 20 Hz - not sure if my older 5.5 RMAA version allows lower frequencies to be displayed)

http://archiv.rme-audio.de/download/bfeq.pdf

Regards
Daniel Fuchs
RME

RME Support's Website

9 Reply by dcrhythm (edited by dcrhythm 2011-10-19 16:49:22)

  • Registered: 2011-07-03
  • Posts: 6

Re: Babyface frequency response

Ok, the below results (sending Babyface OUT to Echo Mia IN) confirm that Babyface OUT stage does not have the same high pass that Matthias says is on the IN stage, although still looks slightly less than spec (-2 dB at 5 Hz here, and Echo Mia results above lead me to think it is not contributing all of the -1.5 difference from Babyface spec)... but then again, Echo Mia is not a great alternative input, a better AD would make for a better confirmation. Also, the more pitched downward slope from 10-22 kHz below does appear to be due primarily to Echo Mia, not Babyface:

http://img.photobucket.com/albums/v346/dcrhythm/RME%20Babyface/RMEBabyfaceOut-EchoMiaINresponse.jpg

  • Registered: 2010-09-10
  • Posts: 60

Re: Babyface frequency response

And remember, it is just -2dB at 20 Hz.
In case you want to use those frequencies, just push them 2dB with a shelving filter.

  • From: Germany
  • Registered: 2007-04-10
  • Posts: 9,551

Re: Babyface frequency response

hermste wrote:

And remember, it is just -2dB at 20 Hz.
In case you want to use those frequencies, just push them 2dB with a shelving filter.

As shown in post # 8 above...


Regards
Daniel Fuchs
RME

Regards
Daniel Fuchs
RME

RME Support's Website

12 Reply by jojomusic (edited by jojomusic 2012-04-05 16:27:27)

  • Registered: 2012-04-05
  • Posts: 5

Re: Babyface frequency response

MC wrote:

Well, in that case it's a nice confirmation of its quality :-)

yikes oh, I just ordered babyface yesterday after carefully reading reviews.

Would you supply a present of EQ TotalMix which completely makes the curve flat? I think I can test and find a good EQ setting to do that, but you have better equipments and knowledge to make it more precise.

Thanks in advance.
Jojo

  • From: Germany
  • Registered: 2007-04-10
  • Posts: 9,551

Re: Babyface frequency response

See post # 8 above. Resulting curves are flat within 0.5 dB.



Regards
Daniel Fuchs
RME

Regards
Daniel Fuchs
RME

RME Support's Website

  • Registered: 2012-04-05
  • Posts: 5

Re: Babyface frequency response

Thanks Daniel. Do I expect this roll off only happens for microphones inputs or this roll off also happens to the instrument input?

RME Support wrote:

See post # 8 above. Resulting curves are flat within 0.5 dB.



Regards
Daniel Fuchs
RME

  • Registered: 2012-04-05
  • Posts: 5

Re: Babyface frequency response

Is totalmix 3 band EQ a hardware related or a pure software one? If it is a pure software one, I might want to use a 10-band or even 30-band EQ to compensate.

A deeper question is: was this roll off by design in the analog part (before AD) or after the AD conversion? These different ways will lead to different signal to noise ratios.

RME Support wrote:

See post # 8 above. Resulting curves are flat within 0.5 dB.



Regards
Daniel Fuchs
RME

16 Reply by MC

  • MC
  • MC
  • Administrator
  • Offline
  • From: Germany/Thailand
  • Registered: 2007-04-06
  • Posts: 24,842

Re: Babyface frequency response

All inputs. EQ is DSP in hardware.

Regards
Matthias Carstens
RME

MC's Website

17 Reply by polynasia (edited by polynasia 2014-08-02 12:18:36)

  • Registered: 2014-08-02
  • Posts: 3

Re: Babyface frequency response

Hello,

can you please put up images for EQ in post #8 again?
Since I am having the same issue when doing room measurement with REW and recording from external sources, it would be nice to see those settings.

Thanks.

Although I am pretty happy with my Babyface ;-) , the mentioned roll-off makes it a little bit doubtful recording other sources than microphones.
Does the Fireface UC suffer from the same "optimization", or only at its mic-inputs?

  • From: Germany
  • Registered: 2007-04-10
  • Posts: 9,551

Re: Babyface frequency response

I've reposted it in the form of a pdf above. The UC's inputs are linear.


Regards
Daniel Fuchs
RME

Regards
Daniel Fuchs
RME

RME Support's Website

  • Registered: 2014-11-13
  • Posts: 1

Re: Babyface frequency response

I also have the babyface and i just measured it... its flawless, great freq. response, about 0.5@20hz.
http://i1373.photobucket.com/albums/ag397/gyalpom/babyfacecalib_zps69b407b5.jpg

  • cn_md
  • New member
  • Offline
  • Registered: 2019-10-11
  • Posts: 3

Re: Babyface frequency response

Hi RME team,

Can the PDF from post # 8 please be uploaded again?

I am thinking of upgrading to a BFPro in the near future - does the Pro have the same HP filter (-1dB at 30Hz)?

21 Reply by MC

  • MC
  • MC
  • Administrator
  • Offline
  • From: Germany/Thailand
  • Registered: 2007-04-06
  • Posts: 24,842

Re: Babyface frequency response

The BF Pro manual states the low end as -0.1 dB @ 18 Hz, -0.5 dB @ 7 Hz,  -1 dB @ 5 Hz for the mic input, so there is no such low cut anymore.

Regards
Matthias Carstens
RME

MC's Website

  • cn_md
  • New member
  • Offline
  • Registered: 2019-10-11
  • Posts: 3

Re: Babyface frequency response

MC wrote:

The BF Pro manual states the low end as -0.1 dB @ 18 Hz, -0.5 dB @ 7 Hz,  -1 dB @ 5 Hz for the mic input, so there is no such low cut anymore.

Hi Matthias, this HP filter exists for the instrument and line inputs as well (on the original Babyface).

Can someone at RME upload the PDF again, or at least mention the EQ settings?
See post # 8.

  • From: Germany
  • Registered: 2007-04-10
  • Posts: 9,551

Re: Babyface frequency response

Will do....

Regards
Daniel Fuchs
RME

RME Support's Website

24 Reply by MC

  • MC
  • MC
  • Administrator
  • Offline
  • From: Germany/Thailand
  • Registered: 2007-04-06
  • Posts: 24,842

Re: Babyface frequency response

http://archiv.rme-audio.de/download/bfeq.pdf

Regards
Matthias Carstens
RME

MC's Website

  • cn_md
  • New member
  • Offline
  • Registered: 2019-10-11
  • Posts: 3

Re: Babyface frequency response

Thanks Matthias, much appreciated.
(Grüße aus Australien)