REW Primer for Apple MacBook Pro using the internal soundcard (work in progress)

[spreston]

First shot at a REW Primer for the Apple MacBook Pro using the internal soundcard (work in progress)

I have found that REW works quite well with the Apple MacBook Pro and its internal soundcard, and suspect that many of the attached comments will apply to other Apple machines. I have successfully run REW on both Windows XP and the most recent OS X (Version 10.5.2); I found that both operating systems required some basic tweaks to optimize REW but did not find either system install especially difficult. While I am just a novice with REW, my own thoughts for a successful MacBook Pro install follow; these may not work for you but hopefully will save you time and lead you to a successful REW experience:

* Install software at
http://www.hometheatershack.com/foru...oads-page.html
- Update your Java platform
- Install appropriate REW software for your operating system

* Open REW and open the help file (F1) and study this from start to finish before doing anything else

* Once you begin to calibrate the soundcard with a stereo 1/8" cable connecting your soundcard's line-in and line-out, you should check the following system settings

**In REW, click on the settings button and under the settings tab, under the soundcard tab
--- set the sample rate to 44.1khz
--- set output device to Default Audio Device ("Java sound audio engine" seems to work also, but I noted slightly worse performance on calibration)
--- set input device to Built in Input

** Open Audio MIDI Setup program on the Mac
- Under Audio Devices tab
-- Default input should be Built in Input
-- Default output should be Built in Output (don't remember if MIDI outputs) changes if you choose to use "Java sound audio engine")
-- System output should be Built in Output

- Properties for Built in Input should read
-- Source: Line In
--Format 44.1khz
-- I use 2ch 24bit but 16bit also works for my system

- Properties for Built in Output should read
-- Format 44.1khz
-- I use 2ch 24bit but 16bit also works for my system (regardless, I suspect input and output should be at same bit rate)

** Remove all sound effects in Mac system; these wreak havoc with REW. I found the following, but there may be others
- In the Mac's System Preferences, sound file
-- Under Sound Effects Tab unclick any soundeffects items like
--- Play user interface sound effects
--- Play feedback when volume is changed
--- Play front row sound effects

- While iTunes should not impact REW, I have read that sound effects in a variety of programs, regardless of operating status, may change the Mac's soundcard, so I did the following just to be safe
-- Open iTunes
-- select preferences under the itunes menu
-- select playback tab
-- deselect crossfade playback, sound enhancer, soundcheck boxes
-- accept changes and close out of iTunes
---You may need to check out any audio programs you have installed for sound effects issues

**Go to the Mac's System Preferences, sound file, input tab
- Make sure Line in is selected (not internal microphone)
- You can make preliminary input volume and output volume adjustments here FYI

** Wait a minute and recheck settings in REW settings tab and Audio MIDI Setup tab

** IMPORTANT** Check the above settings the first few times you open REW, making sure your Mac does not reset a any parameters (mine tends to reset the bit rates and and 44.1khz format occasionally)

Hope this helps and please let me know of any suggestions or corrections.

[bing]

I can get the internal soundcard running pretty well. Still having problems with the mobile pre. I got it to work once but then not again. Anyhow, the internal soundcard on my MacBook isn't that great. Maybe your Pro is better. Can you post your calibration response please? I'm curious.

[brucek]

Actual it isn't bad at all for an internal. Quite usable for REW duties.

Look at the vertical scale. It's only plus and minus 3dB.

The signal is only down 1/2dB at 20Hz and has some small (less than a dB) deviation above 10KHz.

If you want to see its use in REW, simply use that soundcard cal file and measure a straight cable. It will be flat, because REW applies the deviations against what it measures.

brucek

[bing]

If you want to see its use in REW, simply use that soundcard cal file and measure a straight cable. It will be flat, because REW applies the deviations against what it measures.

That's what I thought. I was spoiled by the response of the mobile pre, which is flat until 10k, then it's up only 0.25db. Thanks Brucek.

[devicente]

I also have a Pro, What setting should i use for the REW Output Device? One place says to use the Java sound engine and else where is says to use the default device. If i use the default device i really have to crank the volume of output from my Pro, what should i use?

And Should I use the calabration i made for the sound card or should i the "Use Left Channel as Calabration Reference."

[brucek]

Should I use the calabration i made for the sound card or should i the "Use Left Channel as Calabration Reference."

Use the soundcard calibration file and uncheck the "Use Left Channel" box....

brucek

[spreston]

I also have a Pro, What setting should i use for the REW Output Device? One place says to use the Java sound engine and else where is says to use the default device. If i use the default device i really have to crank the volume of output from my Pro, what should i use?

Thanks for taking the time to post this question Steve. The REW Help file (F1) titled "Getting Started with REW" notes the following for the REW button "Settings/Soundcard/Output Device and Output:"

Where possible, select the soundcard itself rather than the OS drivers "Primary Sound Capture Driver", "Primary Sound Driver", "Java Sound Audio Engine" or similar. REW needs direct access to the controls on the soundcard if it is to automatically adjust levels, this may not be possible if the OS drivers are selected.

My MacBook Pro does not offer the particular soundcard as an option; only "Default device" and "Java sound audio engine." I have not tried using the "Java sound audio engine" yet. Previously I successfully used the "default device" and also noticed this volume issue, which I thought was related to a mediocre gain adjustment knob on my MAudio Buddy mic preamp.

I will try the "Java sound audio engine" tomorrow and see if that helps; let us know your experience and, if we are successful, I will edit the above primer based on our experience.

[mrsollars]

I am just a fly on the wall in here bc i'm trying to make sense of this stuff for my macbook and rew in a few months
thanks guys
matt

[spreston]

My MacBook Pro does not offer the particular soundcard as an option; only "Default device" and "Java sound audio engine." I have not tried using the "Java sound audio engine" yet. Previously I successfully used the "default device" and also noticed this volume issue, which I thought was related to a mediocre gain adjustment knob on my MAudio Buddy mic preamp.

I tried using the "Java sound audio engine" option this weekend. It worked fine on my Mac, but the calibration file response was slightly worse than that from the "Default device" at higher frequencies; well above 1k and probably not enough to really matter.

I found no difference in volume/gain adjustments for calibration purposes for either option. For both, I set:
- systems preferences>sound>output volume (close to max)
- systems preferences>sound>input volume (about 50%)

In general, when I tried calibrating with the Mac output volume much lower, I found that during measurements, I needed to compensate by turning up the amplifier volume dial to avoid a low level warning from REW. To prevent undue stress on the amp and mains I am trying to send a reasonably high line level from the Mac so I don't have to put the volume dial on my amp too high.

[nickwin]

I have a macbook pro, and I'm trying to calibrate the internal sound card, but I'm having trouble setting up the input. I put input on "built in audio line-in port" on the system preferences, and in the MIDI settings, but it seems to still be using the built in microphone input. Its not picking up anything in the input on REW soundcard calibration when I play the 1khz test tone, but its picking up ambient sound in my room.

Is there somewhere else I need to switch the input to audio line-in? has anyone else had this problem on a Mac?