Soundcard problems: Native Instruments Audio Kontrol 1

[warrensomebody]

Well, I'm finally ready with all the equipment I need to do a proper round of room measurements -- almost! I bought a FBQ2496 and ECM8000, and this nifty external sound card from Native Instruments called the Audio Kontrol 1 (AK1). It has built-in phantom power, can do 24/192, and supports full duplex operations (verified). (It even comes with some nifty DJ software!) One problem though... it doesn't seem to work with REW.

When I fire up REW on my Mac (MacBook Pro, Intel Core Duo, Mac OS X 10.4.10) I get the following exception:

Unable to access the selected device


Message:
javax.sound.sampled.LineUnavailableException: Unexpected Error
Level:
SEVERE
Stack Trace:
com.sun.media.sound.SimpleInputDevice.nOpen(Native Method)
com.sun.media.sound.SimpleInputDevice.implOpen(SimpleInputDevice.java:275)
com.sun.media.sound.AbstractMixer.open(AbstractMixer.java:286)
com.sun.media.sound.AbstractMixer.open(AbstractMixer.java:334)
com.sun.media.sound.AbstractDataLine.open(AbstractDataLine.java:103)
com.sun.media.sound.SimpleInputDevice$InputDeviceDataLine.open(SimpleInputD evice.java:632)
roomeqwizard.O.I(Unknown Source)
roomeqwizard.M.actionPerformed(Unknown Source)
javax.swing.JComboBox.fireActionEvent(JComboBox.java:1197)
javax.swing.JComboBox.setSelectedItem(JComboBox.java:561)
javax.swing.JComboBox.setSelectedIndex(JComboBox.java:597)
roomeqwizard.O.A(Unknown Source)
roomeqwizard.O.C(Unknown Source)
roomeqwizard.O.A(Unknown Source)
roomeqwizard.M.actionPerformed(Unknown Source)
javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1882)
javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2202 )
javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java: 420)
javax.swing.JToggleButton$ToggleButtonModel.setPressed(JToggleButton.java:2 69)
javax.swing.AbstractButton.doClick(AbstractButton.java:334)
javax.swing.AbstractButton.doClick(AbstractButton.java:282)
roomeqwizard.M.A(Unknown Source)
roomeqwizard.RA.<init>(Unknown Source)
roomeqwizard.RoomEQ_Wizard.main(Unknown Source)

I can however fire up REW with the native sound card, and after it's running, using the Audio MIDI Setup control panel, change to the AK1 (44.1kHz) -- the output will work, but not the input.

So I grabbed my wife's laptop that runs Windows XP Pro SP2. I installed all the latest AK1 software and drivers and this time set the sample rate to 48kHz. When I attempt to perform the soundcard calibration measurement, this time I get the 1kHz output tone, but with the output feeding back into the input (Line In 1), I get no input. I've tried every combination of inputs and settings -- Line In 2, setting the input device from Default to the AK1 explicitly... nothing seems to work.

I know this thing can support full duplex operation (I verified it with the DJ software) -- is it possible that it somehow recognizes that its output and line input are connected together and shuts down to avoid a feedback loop? Or is it just something about the REW software that doesn't like this box? Any suggestions?

Thanks,

Warren

[JohnM]

The problem of being able to change the default output for a Java app (i.e. REW) on the Mac but not the input is a "feature" of Apple's JRE, unfortunately.

Your sound card would seem to have the right features to work under XP, the problem there is more likely a setting on the card's mixer software than anything to do with REW - just leave REW set on default input and output and use the card's own software to find the right setting. If the card has a choice of driver types, make sure you load WDM drivers. Focus on getting any input to the card recognised, once that is sorted out it should become straightforward. Make sure monitor is turned off to prevent feedback loops.

[warrensomebody]

I finally got this AK1 working. My problem was that the patch cable I was using for loopback was bad(!). So I'm finally able to measure the response of this soundcard. I'm using Windows XP, and running it in 24/192khz mode. Looks like the 3db point is at ~7Hz, and extends flat to 22kHz.

I'll post my system measurements with it in another thread.