USB audio at 48kHz

    Christoph Kemper commented already in another thread of this forum:


    Hi! Thanks four your question.


    Modern DAWs such as Apple Logic work seamlessly with different sample rates, independent of the project sample rate. That means:


    - recording with automatic sample rate conversion, when the audio interface SR does not match the project SR

    - playback reverse the same way

    - offline-rendering the master mix to any target sample rate and bit width etc.


    Having to match the SR of the audio interface to the project is not necessary here.


    CK

    I, like every other actual audio professional I know, work at 96k for music and 48k for video projects.


    So I take the Kemper into a mic pre, or line in, as an analogue input; just like a guitar amp.

    it sounds great and I avoid all the faffing about.

    Every additional option adds complexity and triggers additional questions. We would like to keep this as much plug and play as possible for the vast majority of users.

    Quote from Burkhard

    Every additional option adds complexity and triggers additional questions. We would like to keep this as much plug and play as possible for the vast majority of users.

    the vast majority is 48k minimal.

    CD’s Were the only thing 44.1 and there are people today that weren’t even alive when those were the thing. Furthermore - I think a Kemper user can easily set up sample rate - I mean look at all the other Kemper features that aren’t “plug and play”. This thing is deep. Default it to 44.1 but have a 48 option. Protools is the industry standard - so should have that in mind - and why put excessive strain on the host computer recording. ALSO - sample rate conversion is re-sampling - might as well go analog… so this feature is great, but if it can’t do 48 - it’s worthless to many.

    Sorry so harsh - but “plug and play” translates to an excuse to me.

    But thanks for the “kind of usb” option.

    I tried to understand the difference between 44.1khz and 48khz and its just not sinking in. So my question is: Is there a difference between both of them as far as quality goes? Or is it a compatibility thing.

    From what I have read 44.1khz is what most people use at home and 48khz is what most studios use. If this is not correct please feel free to educate me because I really don't understand sample rate.

    Quote from Tony G

    I tried to understand the difference between 44.1khz and 48khz and its just not sinking in. So my question is: Is there a difference between both of them as far as quality goes? Or is it a compatibility thing.

    From what I have read 44.1khz is what most people use at home and 48khz is what most studios use. If this is not correct please feel free to educate me because I really don't understand sample rate.

    It's not that 44.1 kHz is used at home and 48 kHz is used by studios. Plenty of studios use 44.1, and plenty use higher sample rates.

    48 kHz is the standard sample rate if you're doing stuff for movies or TV.

    Sound quality is debatable - as to whether the human ear can detect a difference or not. In any case, if you want to use the DAWs monitoring, then higher sample rates generally have lower latency. This can be relevant if you want to monitor through plugins in the session, not just use the plugins after recording (say, you want to monitor the vocals through compressor and reverb in the DAW while recording.


    For the vast majority of us I suspect that sample rate is the least of our worries insofar as the quality of the end product is concerned

    Higher sampling rates equals lower latency. Since most music today is on some sort of video format then 48k makes sense. Making something "easy to use" or to keep it "simple" for the benefit of the user makes no sense to me. There is nothing easy about learning guitar but we do it anyway because we want to. Sorry, I don't get Kemper's logic on this. Giving the user more options makes sense.


    If Kemper said raising the sample rate requires too much processing power then I could live with that.


    BTW, a 3ms latency is about 4 feet/1 meter from the drummer, cabinet, etc.

    Larry Mar @ Lonegun Studios. Neither one famous yet.

    Edited once, last by BayouTexan ().

    Like 1

    My 2 cents:

    - The highest freq a digital device can create is 1/2 the sample rate (Nyquist rate).

    - 44.1 kHz was chosen for Compact Audio in the early 80's. So it can reproduce 44.1/2 = 22.05 kHz audio.

    - When digital video chose a standard many years later they chose 48 kHz. 48/2 = 24 kHz audio.


    Everyone who creates standards for video is a moron. They always choose the dumbest things like HD 1080 interlaced. Then 2 years later they go "Oh, we suck. Everyone told us to do progressive but we went interlaced. Uh, how about we do a 1080P version now. You know years after everyone has built tv's, dvd players, etc." Complete drooling goons.


    Most people run 48 kHz on their PC because you spend a lot of time watching video.


    If the Kemper was written for 44.1 kHz, all of its delays, reverbs, chorus, etc are based on that sample rate. Changing the sample rate internally would mean rewriting code. The only clean option would be the Kemper adjusting the final output from 44.1 to the desired sample rate 48, 96, etc.

    It's one thing if the unit isn't capable of 48k. However, there are a number of valid reasons for the higher sampling rate, including the construction of the low pass filter necessary on the back end. For one thing, 44.1 requires a much steeper filter, where 48 can use a gentler slope. You can rely on the SRC in your particular DAW to handle the conversion, but not all SRCs are created equal and the conversion can introduce artifacts. (That's the best reason for setting everything to the same sample rate rather than relying on conversion after the fact.) Now, if Kemper simply relied on SRC to produce a 48k signal then that puts the responsibility on them to deploy a high-quality SRC - so again, if the unit is actually designed to operate at 44.1 only then it's debatable as to whether that's really the best thing for them to do.

    Quote from franknputer

    It's one thing if the unit isn't capable of 48k. However, there are a number of valid reasons for the higher sampling rate, including the construction of the low pass filter necessary on the back end. For one thing, 44.1 requires a much steeper filter, where 48 can use a gentler slope. You can rely on the SRC in your particular DAW to handle the conversion, but not all SRCs are created equal and the conversion can introduce artifacts. (That's the best reason for setting everything to the same sample rate rather than relying on conversion after the fact.) Now, if Kemper simply relied on SRC to produce a 48k signal then that puts the responsibility on them to deploy a high-quality SRC - so again, if the unit is actually designed to operate at 44.1 only then it's debatable as to whether that's really the best thing for them to do.

    Good point on the slope of the low pass filter.


    Isn't SRC (in the digital domain) a non-issue this days, though?

    Quote from danielmedeiros07

    Would be very nice if was possible. Protools don't accept open a 48 session with Kemper. I have to open with my onboard audio then save a new session with 44.1 to open with Kemper.

    Hi!


    As mentioned, there are DAW's out there that do exactly that.

    If ProTools doesn't feature this very helpful and smart method, it might be time to ask them to improve, not us.


    There is only a handfull of relevant DAWs out there, while many dozen audio interface solutions are available.

    It would be a better world, if all DAWs would take any sample rates independend of the chosen project sample rate.


    Especially for musical instruments, where the audio interface feature is an accessory rather than the main purpose, it is very inefficient to circumvent those shortcomings of DAWs.

    DAW makers have a much larger workforce and different economy of scale to provide the appropriate solution.


    CK

    Quote from franknputer

    It's one thing if the unit isn't capable of 48k. However, there are a number of valid reasons for the higher sampling rate, including the construction of the low pass filter necessary on the back end. For one thing, 44.1 requires a much steeper filter, where 48 can use a gentler slope. You can rely on the SRC in your particular DAW to handle the conversion, but not all SRCs are created equal and the conversion can introduce artifacts. (That's the best reason for setting everything to the same sample rate rather than relying on conversion after the fact.) Now, if Kemper simply relied on SRC to produce a 48k signal then that puts the responsibility on them to deploy a high-quality SRC - so again, if the unit is actually designed to operate at 44.1 only then it's debatable as to whether that's really the best thing for them to do.

    All that is said was written before, and was very true until the early or mid 90ies.

    But not for today.

    The good age started with terms like oversampling, 1 bit conversion and noise shaping.


    Todays AD and DA converters run at sample rates in the MHz region. They utilize digital filters that can be easily designed as steep as needed, without drawbacks.

    The same is true for digital sample rate converters, that use a similar kind of filtering.


    CK