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Getting around the limitations of JavaSound on OS X

86K views 170 replies 41 participants last post by  mikaelb 
#1 · (Edited)
John Reekie has produced a great blog post about how to work around the problems Java has on OS X with audio input from Firewire cards, multi-input USB cards and 48kHz sources. You can find the cure for these JavaSound ills at Room EQ Wizard on the Mac - An Input Workaround. Great work John, and thank you!

Edit 12th September: Here is a related post on using HDMI output with REW on OS X, thanks to EmagSamurai: 8 channel HDMI output from REW on the Mac.

Edit 29th June 2014: Use V5.01 beta 21 or later (available here) for OS X 10.7.3 onwards, removes the need for workarounds.
 
#3 ·
I have a 2008 Macbook Pro running OS X 10.8 (Mountain Lion) with a Presonus AudioBox USB. I tried to running REW last night for the first time on the Mac, but couldn't get past the calibration stage. I kept getting Impulse Response and Range errors (I forget the exact wording at the moment). I have no problems at all using the AudioBox USB on my Windows 7 based laptop.

I just came across this blog about Mac/Java and look forward to trying this method out. I'll report my findings once I test it.
 
#4 ·
It worked fine with me... Thanks a million! :wave:

I had installed today REW 5.01 Beta 13 on my Mac Mini (running under OS X 10.8.2 Mountain Lion). My sound card is a UltraLite-mk3 Hybrid to which I hooked a Behringer ECM8000.

At first, when using REW with the Behringer calibration file, there was no result. I tried to set the level through "check levels" on Preference / Soundcard tab and got only a signal on the "out" display.

I have then tried the "Getting around the limitations of JavaSound on OS X" workaround, which allowed me to see results on the "in" display.

Now I have to understand why I see crazy results... but my room acoustics is far from being simple - hence my quest to analyse it with REW...
 
#10 ·
Im working with a 2007 MacBook (yeah, I know, time for a new computer -- but a solid state hard drive and software updates to 10.7.5 have kept it viable).

Im very new into the measurement game. I have a Behringer UCA202 and a UMIK from miniDSP. Since I only have the problem with a 48kHz in put device, do I need to load all of the software discussed in the blog post? If I load the software discussed, do I leave REW input set to 44.1kHz?

Thanks for the help!
 
#11 · (Edited)
Hi,

I can only offer limited help because my main use of REW is on a PC ( & I don't own a UMIK-1 or any USB type mic ) .

That said ;

There's no real need to use the UCA202 just for output . You can use the heaphone output ( with adapters ) from your MacBook to drive signal over to your AVR .

The very real problem with using your UCA202 for output , is that the Behringer typically utilizes/monopolizes the Macs ( or a PCs ) generic USB driver ( the one built into the system OS ) . The problem is the UMIK-1 will also want & need to use that same driver / creating a conflict.

Only one device can "claim/initialize" ( & then use ) the builtin generic driver . I suggest leaving it available for use by the UMIK ( by not using the UCA202 ) .

That "generic" USB driver looks like this :





I would unplug the UCA202 , bootup REW with the UMIK-1 plugged in ( while making sure that it's selected within REW's preferences window ) , & then open REW's Levels window & then tap the mic to see if there's any input ( all the while with the preferences set to 48K ) .

If there's input, I'd proceed to try to make a measurement .

If you can't get input ( under the circumstances I just described ) then there's a good chance you need to use the mentioned work arounds ( which is really meant for users of multiple input soundcards, be they either USB or FireWire / " multiple input = more than 2 " ) .

:sn:
 
#14 ·
Many Thanks for this Tutorial.

It works fine with OS 10.6.8 and Focusrite Saffire Pro 40.
In Saffire MixControl I routed the DAW 1-2 Out direct to the Monitor Out. I unchecked the HW-Control-Button and adjusted the Output Level.
I saved this as a Preset, so i have only to load this Preset before measuring.

Yesterday I tried to use JackOSX - didn't work.
 
#17 ·
Dear John M,

unfortunately John Reekies' workaround does not work in our case which is:
MBPro OS X 10.8.2
Focusrite Saffire 40 PRO, 44.1kHz
Jave updated to latest version
REW 5.0, 44.1kHz
Since we could not get FireWire to work for the input (output worked fine), we configured only the output via FireWire (then to Sub, Crossover, Speaker, Room, Mic) and came back from the Saffire via its Analog Out to the MBPro LineIn, which seemed to work in the beginning.
I started with 2 sweeps per measurement and got caught by a 30dB dip around 11k in the FR.
To analyse, we spared out the Speakers and the Mic, connected the two cables directly to each other ('wired loop') and found in a mostly flat response the mentioned dip.
Tire Automotive tire Tread Synthetic rubber Auto part

After quite a while and mostly by chance I found that reducing the sweeps to 1 per measurement gives me a flat result. See the 1sweep vs. 2 sweeps in the next image
Text Line Design Pattern Parallel

Diggin deeper I wondered, what happened, if I'd increase #of sweeps, and here's what I got for 4 sweeps
Text Line Parallel Slope Pattern

and here for 8 sweeps.
Text Line Plot Slope Font

I only guessed, that, since these results are very reproduceable, it's got nothin to do with WiFi or Laptop CPU overload or sg. - nevertheless I checked, turned everything off, dips are still there.

Then I came across the above mentioned input workaround. We did it according to the descriptions, but what we got was, instead of getting better, that signal generation, output and input "reacting" extremely delayed. With the meters on the screen, after hitting check levels, or measure, or calibrate we could wait and then see with more than a sec delay the REW pre OUT meter showing the signal, then, approx another sec later the focusrite input meter, and then, slowly rising, the REW pref In meter - showing the signals.
We got error messages, that the IR is not at the expected position, so we tried a loopback as a t0 reference, which gave us a flat result till 3kHz, but then jumped down into noise (sorry - no pic from that).
After restarts, of Saffire, MBPro, REW etc and no improvment, we were forced to go back to our initial solution and uninstall the input workaround (Soundflower).

So we are still stuck with the limitation to only being able to do 1 sweep, which I'd like to overcome, to improve S/N, apart from increasing the sweep length, since it is a bit noisy around where we have to measure...
To me, it looks like an issue related to either windowing or aliasing or similar, but I did not manage to put my finger on it...
Any ideas regarding our dip-pattern, John M maybe?
Many thanks for your thoughts on that!
Markus
 
#19 ·
Dips with multiple sweeps are caused by loss of synchronisation between the individual sweeps. The sweeps are generated as one continuous signal, but there seem to be some audio setup combinations that result in either gaps or missing data, possibly related to sample rate changes along the chain. When that happens there is a sharp null at a frequency corresponding to the time slip and the impulse response shows a separate peak for each sweep, separated by the amount of the time slip.
 
#20 ·
I suspected our FireWire & LineIn combination as well to contribute to this, but I cant get it to work with the FireWire only, or the LineIn workaround, respectively. I can not think of any SR changes along the process, when REW and Focusrite are on 44.1k... could you? REW 5.01 Beta 17 would not help in this case? Markus
 
#21 ·
Hi,
i am using a mbp 15" early 2011 with os x 10.7.5 and run REW 5.0.17beta. My Interface is a Presonus Firebox Mobil with FW 400. The MacbookPro use a FW 800 Port.
Using the discription of John, brings no result. (Thank you! It is a very good description)
Triying other presets did not produce a satisfactory result.

Can anyon help me in this case? Could it work with REW 5.0 13beta? Cause John dit it in his description with that version. Were can i get REW 5.0 13???

Thank´s a lot!!!
 
#22 ·
Hi muscape, I've used the workaround with beta 17, it works fine (for me). I don't think beta13 will make any difference.

Could I request please that you provide more detailed information, "brings no result" is not descriptive enough to help in identifying the problem;) Screenshots of all of your settings panes would be the most helpful. I forget what the minimum number of posts to add images is, but you may need to make a few more posts. Or post a link to a site where you have put screenshots.
 
#24 · (Edited)
Dear HifiZine,
thanks for your reply - we worked with REW 5.0.
According to Johns Reply, multiple sweeps can be a problem with some AudioSetup combinations. We did a 7 day Workshop-Session and I flew back home yesterday.
I guess John M would have indicated to use a later version of his SW, if he had improved anything with the later beta releases.
Anyway, I do not have access to the gear where I am now but I am definitly interested how to overcome the multi-sweep trouble, since the studio is in the course of being built now and I plan to be back to check on the progress.

Regards,
Markus
 
#25 ·
Hi HifiZine,

thank you for your answer. Now, i must did some more posts for adding pictures, so this is one of it.
I will lock forward to take some screenshots.

I will deinstalled all the programs an will install it new to take a nother try form Zero.
Hope it fix the problem. If not, i´m going to look for a cheap usb interface. Seems to be the easyest way…


See u...
 
#29 · (Edited)
Macs don't work.

Just got my new UMIK. I have tested this workaround extensively.
There are random latency issues caused by LineIn, which give rise to the 'Impulse Response peak is not at the right....' There are low level warnings due to the recommendation to set AMS to 0.32 or 0dB.
Ultimately I have persuaded it to work, but not reliably due to random issues.
I have the AudioMidi Setup level at 24dB which is also described as 1. This delivers reasonable measurement levels without warnings for being at -30 or -40dB.
In order to tame the SPL meter, I had to rewrite the sensitivity in the Cal file from -6 to +12 dB.
Now, I have have excellent correlation between a real Calibrated SLM and the one in REW, and mostly successful measurements. But I have to say, I wouldn't wish this on anybody. Conversely the onboard Mac Line I/O work perfectly every time.

DD
 
#30 ·
Hello! I'm using REW for a non-standard application where it would be useful to be able to measure audio above 20 kHz. It would be nice if a future release of the software supports true 48 kHz sampling rate or even higher.

Thanks for reading and hats off to the developpers!
 
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