REW Forum

**htguy** · **05-21-08, 12:40 AM**

I have tried to answer my questions from readling posts, but am confused. I am just starting with REW. For now I only want to test my subwoofer. I have the radio shack analog meter, a laptop (mac) and the m-audio firewire solo. (Later I may upgrade to the Behringer mic.) I don't have a BFD yet, because I want to test my sub and see if I really need it, or if I can make some correctlions by moving the sub a little.
So, my questions are:
- I connect the meter to the unbalanced input on the m-audio?
- My output choices are Balanced Line Output or S/PDIF or headphone. I believe the S/PDIF is digital, and I should stay with analog. So, should I use the Balanced Line Output?
- I am using REW to generate the test signal, and for some strange reason I am not getting any sound from the subwoofer. I connected the Balanced Line Output (not sure if that is the right one) to one of the inputs on my AV receiver. I did not want to connect that line directly to my sub without checking here first because I did not want to damage my sub.
Thanks in advance.

**brucek** · **05-21-08, 06:03 AM**

Quote:

My output choices are Balanced Line Output

That's the correct output, but you want to operate in the unbalanced mode.
To use unbalanced, you require a 1/4" phone TS to RCA cable.

You first need to do a soundcard calibration. This step is useful in telling you that everything is working before you hook up to your system.

For the soundcard cal you'll use a 1/4" TS to 1/4 " TS loopback from line-out to line in.

brucek

**htguy** · **05-22-08, 02:45 AM**

Thanks Brucek for your help in the PM's. I am at the calibration stage of the M-Audio, and I think I am getting a lot of feedback. If I turn the output level knob on the front of the unit down, that cuts the output of the line out and I do not record anything. I will try to post a graph tomorrow. I have connected the Bal output to an unbalanced input using 1/4" TS/RCA plugs (connected by a cable). Does someone have any tips on calibrating an M-Audio?

**brucek** · **05-22-08, 06:39 AM**

Quote:

and I think I am getting a lot of feedback

This is a common problem. Most soundcards have a "monitor" feature that is used to listen while you record. It is called many things, but it's basically a monitor and must be turned off to use REW. Look in your soundcard application for this feature. In the end it enables line-in in the playback mode, which is what you don't want.

Also note, that one of the things I remember JohnM (author REW) saying is that you should use Mac OS 10.5 when using REW. There were some fixes that helped Mac / REW problems that were present in version 10.4. Something about the Macs access for Java programs to the inputs of USB-connected soundcards.
I am quite clueless about Macs, so hopefully John can help in that department.

brucek

**htguy** · **05-22-08, 10:27 AM**

I should have posted that I tried to find the monitor feature in the M-audio software, but coud not find it. I was hoping someone else knows. I emailed M-audio tech support.
I was planning on upgradding to 10.5 on my laptop in a few months. I have an imac running 10.5 in a room next to the room where the speakers are. I will try putting all of the software on that computer and see what happens. I will need long cables. This also will not solve the possible loopback problem. If I get an answer to that I'll post it for others to see.

**htguy** · **05-22-08, 12:44 PM**

I am confused about the monitoring. If I cut out monitoring in the M-audio software, doesn’t that mean that the output signal being sent via the firewire back to the computer will be cut? Then, the REW software will not have any input signal for the calibration?

**brucek** · **05-22-08, 02:26 PM**

No, the monitoring feature directs and enables the information from the recording line-in port to be delivered also to the playback speakers (for monitoring). This loop causes feedback.

brucek

**htguy** · **05-23-08, 12:20 AM**

I got the same results connecting the M-audio firewire solo to the imac running 10.5.2. If the problem is feedback, I tried everything the tech support guy from M-audio told me to cut out the monitor, and that did not work. When I muted the output, then the REW input did not register any input. I will call again tomorrow and see if I get different advice from someone else. If ANYONE knows how to solve this problem, I would really appreciate it.
I have inserted the page from the audio monitoring section of the m-audio manual if someone can use that to help me.
I did notice there is a thread going for imac line in connection. My imac is in another room from my speakers, but if that works longer cables may just solve the problem.
Thanks

**JohnM** · **05-23-08, 09:48 AM**

Can you post a screenshot of the Mixer tab of your Firewire Solo control panel?

**htguy** · **05-23-08, 12:51 PM**

Quote:

JohnM wrote:

Can you post a screenshot of the Mixer tab of your Firewire Solo control panel?

Here is the screenhot. I tried just about every combination of settings I could, and I could not get a good calibration. If I remember correctly, the only way I can get REW to register an input signal during calibration is to select the ½ button on the “out” under “½ sw rtn.” Muting the other three options (spdif sw rtn, analog ½, and spdif in) did not make any difference.

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