# REW on Mac: No Input Signal



## Jaypin (Oct 22, 2010)

Hi all,

New here. It's great to find a freeware program such as REW, but I've got a problem.

Firstly the program mostly seems to run quite smoothly. I've got Java updated. (J2SE 5.0 [32bit], Java SE 6, J2SE 5.0 [64bit]) 

I use a Mbox-2 for the output device, and I can play a clean, audible tone through it, but for input I want to use my Zoom H4n Handy Recorder (Mic Audio device), which can operate via usb.

*Problem:* I've tried to 'Measure' my devices before Calibration, but neither my Macbook Pro's internal Mic (Built-in Microphone), nor the recognized H4n ('H4') indicate signal. Strangely, I can still select them in the 'Input Device' pull down list. The input meters are empty, and only the output meter shows a level when the tone is played.


Also, I've found a site (sorry I'm not allowed to post a link yet) that addresses ASIO drivers, if that matters. The page is entitled "Java Sound Resources: FAQ: Miscellaneous", and it addresses the compatibility of ASIO drivers:

_Yes, there is an open source implementation of a MixerProvider based on the ASIO driver API. The implementation was written by Manuel Esparza as part of his master's thesis. See jsasio binary and source code._​
However, while I don't understand how to install those code files, I don't think it's necessary anyway, since the Mac internal mic probably doesn't need that driver to work. So drivers may not be a problem. Just thought I'd mention it in case it bears relevance somewhere though.


Any ideas how I can get signal? There's no necessity for gain controls as far as I know, both inputs should at least give me a small signal; I'm very surprised that there's nothing at all. I've seen similar threads but thought this was better to be posted here.

Thanks, any help much appreciated!


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## EarlK (Jan 1, 2010)

Hi Jaypin ,

*Disclaimer ;* I don't own any of the mentioned hardware , so take that under consideration ( though I'm a longtime Mac head / I'm just not currently up to date with Mac stuff) .

*Comments ;* You're wise to focus on first getting REW to recognize signal ( from your Macs internal microphone ) before wasting your time trying to do a calibration of any soundcard.
- The computers builtin mic represents the simplest form of input ( or "plumbing", as I call it ) and if REW won't recognize it / then it's unlikely that REW will ever recognize any other input type ( call it the "canary in a coal mine" syndrome ) .

*Direction ; *Boot up REW, select the internal Mac mic as your default input source, select the RTA module, hit the RED button in the top right ( of the RTA window ) to start measuring in RTA mode , if you don't see the RTA reacting to room sounds or your voice ( you may need to move the left scroll bar to move the display downwards to a lower db range to get into an active area ) . If you can't get an active RTA under these circumstances, then REW will have a problem recognizing any ( or all types of ) input . 
- ie ; If nothing is registering within the RTA mode, then the problem is likely a compatibilty issue between your Macs OS/JAVA/& REW, ( ie; the plumbing is just not connecting for various obscure reasons ). 

- If this describes your present scenario, then unfortunately there's little you can do to fix it / though ( from what I've seen JohnM mention here ) certain older Mac OS systems work better with older versions of JAVA ( for running REW ). 
- Rolling the system OS back to a previous version and installing an older version of JAVA is really not that palatable to most .


<> EarlK


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## Jaypin (Oct 22, 2010)

Hey Earl,

Thanks for the reply. At first it seemed like bad news, because almost nothing of what you suggested gave any signal, _UNTIL_ I went to the Mac 'System Preferences' -> 'Sound' and selected the Internal-Mic Input, tested it there (signal detected; no surprise), then went back inside REW, refreshed the input (reselected Built-In Microphone and/or pressed 'Measure') and then suddenly I started picking up signal. 

However, after so much fiddling and trial and error, I kinda got lost as to what was influencing or sourcing the signal! It turns out that the settings work best when they're set as default I/O in Mac System Preferences first. Actually, below I'll explain why it appears that unless the input device is set to Default in the Mac preferences, it won't work at all!

I can see that it is explained in the small help box at the bottom of the REW 'Settings' window that it might be ideal to be using the system defaults. But I found that selecting _specific_ devices in the pull-down menu *does not work!* I can select almost every Input device and each time it will just source the signal from what I have set as Default Input in my Mac preferences. This might have something to do with the second pull-down menu, which is always unchangeably labeled 'Default Input'. If it does, there seems to be a bug; the settings seem redundant and since they're running straight from my Mac Sound preferences, there may as well be no Input settings displayed at all.

:blink:

Weird. So I must've had my default Mac Input settings set to 'Line In' before, because I had no Line connection/signal at the time.

Well at least I can work around it and otherwise still use the program properly! 


I'll keep posted if anything other issue arises. 

Thanks again and I hope that made sense.


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## Wayne A. Pflughaupt (Apr 13, 2006)

Don’t know anything about Mac so I can’t speak to those issues, but...



> I use a Mbox-2 for the output device, and I can play a clean, audible tone through it, but for input I want to use my Zoom H4n Handy Recorder (Mic Audio device), which can operate via usb


...it looks to me like you have some redundancy here. The Zoom is a USB audio interface in itself, so you don’t need both it and the M-box. HOWEVER, since the Zoom has a headphone/line output, it could function as your mic feeding a signal to the M-box.

But either way, using the Zoom as your mic presents problems. Unless you have a calibration file for it, your measurements won’t be accurate.

Regards,
Wayne


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## Jaypin (Oct 22, 2010)

Wayne A. Pflughaupt said:


> ...it looks to me like you have some redundancy here. The Zoom is a USB audio interface in itself, so you don’t need both it and the M-box. HOWEVER, since the Zoom has a headphone/line output, it could function as your mic feeding a signal to the M-box.
> 
> But either way, using the Zoom as your mic presents problems. Unless you have a calibration file for it, your measurements won’t be accurate.
> 
> ...


REW says the calibration is for the soundcard - I thought this means the output device? I am not using the H4n as an output device, I'm using it as a Mic (input) and as I said in the above post, I've found out how to use both the H4n and the M-box; I set them as default I/O in the Mac Preferences first. I'm not sure what the problems could be; please excuse me if I sound naive. I'm not seeing the purpose of needing a Line signal to the M-Box, or needing it to be connected to the M-Box Inputs (what exactly will be calibrated then, anyway?).

Thanks.


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## Wayne A. Pflughaupt (Apr 13, 2006)

I understand your connection scheme. It just doesn’t make any sense. From what I can see, the Zoom is a USB audio interface w/ on-board mics. The M-box is also a USB audio interface. What’s the M-box doing for you that the Zoom isn’t? The Zoom should be able to do everything (unless you can’t USB it directly into the computer because it doesn’t “play well” with Macs).

Either way, the problem is that unless you have a calibration file for the Zoom’s mic, your measurements will not be accurate.

Regards,
Wayne


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## Jaypin (Oct 22, 2010)

Wayne A. Pflughaupt said:


> I understand your connection scheme. It just doesn’t make any sense. From what I can see, the Zoom is a USB audio interface w/ on-board mics. The M-box is also a USB audio interface. What’s the M-box doing for you that the Zoom isn’t? The Zoom should be able to do everything (unless you can’t USB it directly into the computer because it doesn’t “play well” with Macs).


The M-Box is my output device, so it is used to play sound - which transfers through to my studio monitors. The Zoom can't do this; it only has a basic built-in playback speaker but I ain't using that! I use the Zoom USB because it's the only way I can get a good Mic signal to the computer. Why can't this work? As far as I know, the calibration is for the Output device, isn't it?

Thanks Wayne.


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## Wayne A. Pflughaupt (Apr 13, 2006)

Calibration is needed for both the sound card and the measurement mic. Have you read Sec. 3 of the REW Help Files? Or the REW Cabling and Connection Basics info?

In the latter thread you’ll find this picture:










This shows a USB audio interface with a mic plugged into it. 

The Zoom is an interface with a built-in mic, so it can be used instead of the M-box + mic (setting aside the Zoom's mic calibration issue for the moment). The Zoom has a headphone/line out that you can send to your studio monitors for the purposes of taking your measurements. 

But it won’t work using the M-audio USB’d to the computer for the output, and the Zoom USB’d to the computer as the input (unless John thinks otherwise; he knows more about this than I do).

We can go 'round and 'round about your hardward connection options, but in the end it gets down to this: You need a mic calibration file in order to have accurate measurements. If you don’t have one for the Zoom, then you need to get a mic that does, or have the Zoom calibrated by a professional lab (assuming it even _can_ be calibrated as part of an all-in-one package like this).

Regards,
Wayne


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