SPDIF setting

    Hello,


    I love the possibility of using the SPDIF output for digital recording. The only downside is, that it's only possible to record (and re-amp) at 44.1 kHz, 24 bit. I work a lot in a studio that records only at 48 kHz. Is it possible to change the sample frequency and maybe the bitrate of the SPDIF output? When we work with digital devices (Kemper, Logic, Nuendo), I'd like to keep it all-digital, no need for DA and AD converters (using the XLR outputs). Of course, I could re-sample the 44.1 kHz files to 48 kHz, but in this conversion step I also lose some of the audio quality. And that's where the magic is :-D. I hope to hear from you soon!


    Best regards, from the Netherlands,


    Reinout Vrijhoef

    It's not possible, sadly. And there hasn't been a word from Kemper if there's a chance this situation will ever change. Same applies to the fact that the Profiler has to be S/PDIF Master, which is a real problem if you use lots of digital gear in the studio. Nobody wants to sync his studio to one of potentially many external devices.

    Quote from lightbox

    Sure there are, if you disconnect the sync source. You'll have to switch the audio interface's sync to internal or another external source.


    Just that! I used to use the SPDIF output from my GT8 processor for recording and it was also limited to 44.1 khz sampling rate, 24 bit.


    When I was done recording though, I would often just disconnect the SPDIF and my Fireface would go back to using its internal clock.


    Didn't seem to run into any problems, but then again, my guitar recordings have always been shite. Hoping the KPA changes that!

    Quote from nightlight

    In connection with the thread topic, are there potential synchronisation problems if one is to record the Kemper audio using SPDIF with the 44.1 khz, 24-bit setting and then record other instruments (drums, vocals, etc) by disconnecting the Kemper and using another clock source, naturally at the same sampling rate (44.1 khz)?


    Nope.


    Quote from ReinoutV

    I work a lot in a studio that records only at 48 kHz.


    Why is that? Is it a post production facility?

    Quote from Trazan

    Why is that? Is it a post production facility?


    I really wonder why so many people think that 48kHz isn't used in the music industry. It's simply not true. Of course it's best to have a choice, but there's a LOT of equipment that defaults to 48kHz sampling rate. To give you just one example: The Korg Kronos X workstation is 48kHz @ 24bit, no matter if you use USB audio or opt. S/PDIF.

    Thank you for all the replies. For a piece of studio gear like the KPA, I sure expect it to run on different sample frequencies. Hopefully this is just a software thing, and it can be added in some future update. When it's a hardware thing, the whole situation changes, of course...


    Regarding the studio: it's a studio where thay make mostly midi-productions, with occasionnaly a real instrument. Why he workes on 48 kHz, I don't know. I just know that he does. I personally think 88.2 kHz is better, you lose less digital information downsampling to 44.1 kHz (normal CD). But hey, that's just me. Are there more people who would like to change the sample frequency from the SPDIF output on the KPA?

    Quote from lightbox

    I really wonder why so many people think that 48kHz isn't used in the music industry. It's simply not true. Of course it's best to have a choice, but there's a LOT of equipment that defaults to 48kHz sampling rate. To give you just one example: The Korg Kronos X workstation is 48kHz @ 24bit, no matter if you use USB audio or opt. S/PDIF.


    I've been working full time with this for almost a couple of decades and have never, ever encountered working on projects done in 48k. Except for motion picture specific projects (and skip ADAT hangovers 8)). It might differ in some countries, but at least it has never been the case with any projects I've gotten from either Europe or USA. Since into hard disk recording days it's been either 44.1 or 96.


    There may of course be various personal choices for project studios etc, but in proffesional context I have yet to encounter 48k in music production.


    At least, I vastly prefer Kemper's fixed 44.1 over the Axe's 48! 8)

    The majority of studios record at 44.1 kHz and it's been the standard for music production for a very long time for a reason.
    Since studio people with "golden ears" keep failing blindtests of 44 vs higher it clearly shows that our ears are much more important than theory and numbers. The conclusion I've seen on several studio forums about this topic is that there is no need at all to record higher than 44 for music production.

    We have no plans to provide sampling frequencies other than 44.1 kHz and sync master. There are technical reasons that prevent us from implementing this.


    Since there is some voodoo aspects about sampling rates, I would like to point at some important aspects.


    1. We see in this thread that many other hardware units have fixed sample rates as well. The reason for this is, that it is quite challenging to run a system at different sample rates, since countless variables and values need to be adapted to the sample rate.


    2. I suspect many hardware devices to use internal sample rate converters (SRC) to fullfull the request for different sample rates. SRCs are suspected to affect the audio quality by many people.


    3. Especially the availability of the double sample rates (88.2 and 96 kHz) are often realized by SRCs. Otherwise the hardware device had to have double calculation power available for this case.


    4. in contradiction to what is mentioned here and there, todays SRCs have a tremendous good quality. Especially offline SRCs of premium DAW companies should create a 100% perfect conversion result. Offline SRC happens when you change the sample rate of a recorded clip.


    5. Running double sample rate (88.2 and 96 kHz) on your DAW is wasting half of your computer power, without gaining sound quality at all. Can someone post a link to a scientific test result that contradicts this thesis? If not, then it's a very expensive myth.


    CK

    If you use your analog outs then the sound quality depends alot on your interface or the converters of your interface. I don't know for sure but I'd guess since SPDIF is digital there shouldnt be any differences between audio interfaces. So if you don't have a great interface use the SPDIF connection.
    Or record both and a/b them and hear for yourself what sounds better to you. I did that and I couldn't hear that much of a difference


    Tempted to post this on gearslutz.com and watch the sparks fly 8o


    Good enough for me, Mr CK!

    You can cite me anytime you want!


    I am an engineer for electrical sience, acoustics and digital signal processing.
    I have yet to see a scientific test that 96 kHz makes a difference.
    If there was such a positive result, it would be great!
    Where can I read it?


    But it's a myth already, since it's not cool to say "I cannot hear a difference".
    The tests would be easy, but nobody is performing it. Stupid.


    The myth is not even uncovered by journalists, they are probably afraid to loose their reputation.


    Analog summing and the respective devices is another very expensive myth ...