M-audio and subwoofer basic set up

[htguy]

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]

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]

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]

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]

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]

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]

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]

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]

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

[htguy]

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.

[htguy]

Here is the screenshot. If I mute the 1/2 sw rtn or uncheck the Out 1/2 on the 1/2 sw rtn, that cuts the input to the REW program.

[htguy]

Progress, sort of. On my imac, running 10.5.2, with a loop from the headphone out to the mic in, I am getting the same results. I don't think the problem has anything to do with the M-audio. I'll post over on the imac thread.

[JohnM]

You definitely need to mute the 1/2 sw rtn, and you need to unmute analog 1/2 in.

[htguy]

JohnM wrote:

You definitely need to mute the 1/2 sw rtn, and you need to unmute analog 1/2 in.

If I mute the 1/2 sw rtn, then I get no input signal to REW. I posted on the imac thread that I am getting the same calibration problems using a different computer, different OS, and using the built-in input/output. I suspect the calibration problem has nothing to do with the M-audio. There is some setting either in REW or in MIDI or sound or someplace else that is effecting this. I will keep at it, and can use all of the help you can give.

[JohnM]

htguy wrote:

If I mute the 1/2 sw rtn, then I get no input signal to REW.

That is most likely because you have analog 1/2 in muted, with the settings you posted the only signal source is the software return monitor, you need some input unmuted and the correct one is analog 1/2 in.

[htguy]

JohnM wrote:

That is most likely because you have analog 1/2 in muted, with the settings you posted the only signal source is the software return monitor, you need some input unmuted and the correct one is analog 1/2 in.

I know this thread is supposed to be closed, but this is driving me crazy. The only way that REW gets an input signal is if the 1/2 sw rtn "out" is selected, and if the mute for 1/2 sw rtn is not selected. With those two options, no combination of mute or out 1/2 on the analog 1/2 in makes any difference. I still do not get a good calibration of the M-audio.

[JohnM]

To do the loopback test you need the following setup:

- M-audio front/rear selector set to rear (switch pushed in)
- 1/4" TRS to 1/4" TRS cable from balanced output 2 to unbalanced input 2
- On 1/2 sw rtn "1/2" selected in the "out" section and not muted (this looks to be the equivalent of "Wave" on Windows systems)
- On analog 1/2 in nothing selected in the "out" section and not muted - this is the input source for REW, if it is muted REW gets no input
- M-audio 1/2 set as the default output and analog 1/2 as the default input in your Audio/Midi preferences (set this before starting REW)
- In REW soundcard settings audio input and output device set to default and "Right" input selected

[htguy]

Thanks. I have been using a TS cable. I'll get a TRS cable.

"- M-audio 1/2 set as the default output and analog 1/2 as the default input in your Audio/Midi preferences (set this before starting REW)"
My options in Audio Midi Setup is "firewire Solo multichanel" or "Built in audio" for input and output. I will select "firewire Solo multichanel"

[htguy]

JohnM wrote:

1- On analog 1/2 in nothing selected in the "out" section and not muted - this is the input source for REW, if it is muted REW gets no input
2- In REW soundcard settings audio input and output device set to default and "Right" input selected

1- muting analog 1/2 makes no difference to whether or not REW gets the input signal. REW appears to get its signal from the 1/2 sw rtn.
2- If "input device and input" is set to default, then REW does not get an input signal. I need to set it to OS to register an input signal.

[JohnM]

Sounds like Apple still have a bug in making inputs from Firewire devices available then. sw rtn is, as far as I can make out, the output from REW (which is on both channels as shown in your screenshot). If you disconnect the loopback cable does the level disappear from analog in 2 on the Solo mixer panel? When you say "OS" what device setting is that? What do the REW input level meters show with that selection on left and right inputs?

[htguy]

If you disconnect the loopback cable does the level disappear from analog in 2 on the Solo mixer panel?
- Yes. When I disconnect the loopback cable, the meter shows no input.
When you say "OS" what device setting is that?
-Mac OS X, Coreaudio, Audio hardare.
What do the REW input level meters show with that selection on left and right inpu
-The left input shows no input signal. The right shows an input signal. (That is because the loopback cable is connected to channel 2 (corresponding to right). The volume goes up or down if the output vol in increased, or the mic vol is increased.

[JohnM]

So what do you get when trying a soundcard calibration with those settings? Everything would seem to be working fine from that description.

[htguy]

I get the same graph as I posted above. Every graph looks virtually idential to the one I posted above.

[brucek]

Hopefully you don't have the "Use Left Channel as Calibration Reference" checkbox in REW checked?

brucek

[htguy]

brucek wrote:

Hopefully you don't have the "Use Left Channel as Calibration Reference" checkbox in REW checked?

brucek

The "Use Left Channel as Calibration Reference" box is not checked.