EQ Wizard Question

[Rolyasm]

I am using the M-Audio soundcard with ecm-8000. I have the REW loaded. I installed the ecm-calibration files, chose M-Audio as the soundcard, but I am having an issue. Do I still need to calibrate the soundcard to the SPL? I thought using the calibration file for the 8000 would eliminate that step. Also, when using a processor in the setup, is it correct to connect the M-Audio output to the Aux In or Direct SW input? That is how I have it now. Also, I have double Sub outputs on my Processor, which I am using to connect to the BFD. So far no sound. I am trying to troubleshoot.
Roly

[Amphiprion]

Which M-Audio card are you using?

[ThomasW]

Do I still need to calibrate the soundcard to the SPL?

Yes

I thought using the calibration file for the 8000 would eliminate that step.

Nope calibrating the soundcard is completely different than the calibration file for the microphone.

Also, when using a processor in the setup, is it correct to connect the M-Audio output to the Aux In or Direct SW input? That is how I have it now. Also, I have double Sub outputs on my Processor, which I am using to connect to the BFD. So far no sound. I am trying to troubleshoot.Roly

[Rolyasm]

M-Audio mobile usb. Phantom power. I also just got my first sound. I just had to turn the volume up on my receiver. I was a little hesitant, just because I don't want to do anything to fry my woofers. :T So now do I use my SPL to make sure the SPL level is reading the same on my REW as it is on my SPL, or is that in the calibration file and I just have to turn it up and get measuring?

[Dennis H]

So now do I use my SPL to make sure the SPL level is reading the same on my REW as it is on my SPL, or is that in the calibration file and I just have to turn it up and get measuring?

Yup, use the SPL meter. The cal file is just referenced to 0 dB and the actual in-room SPL will depend on where you set all your knobs and software controls.

[Kal Rubinson]

Yes
Nope calibrating the soundcard is completely different than the calibration file for the microphone.

Are you sure about that diagram? I use a jumper from out-in on one channel as a reference with the other channel used for line out (to amp/speakers) and mic in for measurements.

EDIT: AH. You are describing the connections for SPL calibration. OK

Kal

[Rolyasm]

Ah. Guess I need one more cable because I only have one Aux channel on my reciever being used. So my question : after the RS SPL calibration, I connect the ecm-8000 mic to the XLR on the soundcard, put the SPL away, and keep the rest the same? Thanks

[Kal Rubinson]

Ah. Guess I need one more cable because I only have one Aux channel on my reciever being used. So my question : after the RS SPL calibration, I connect the ecm-8000 mic to the XLR on the soundcard, put the SPL away, and keep the rest the same? Thanks

I never connect my RS SPL meter to the system. I run the main mic and the SLM at the same time so that I can match the pink noise levels, thereby 'calibrating' the REW.

Kal

[Rolyasm]

Kal,
Is SLM a sound level meter? Same as SPL? If so, are using the XLR mic input and the other input at the same time? What sound card are you using?
Roly

[Kal Rubinson]

SLM is sound level meter. SPL is sound pressure level, I believe. I use the M-audio MobilePre. On one channel, I use the XLR input for the mic and the 1/4" output to feed my preamp. On the other channel, I use a loop-back jumper between in and out.

Kal

[Rolyasm]

Interesting. I am pretty sure an SLM is the same as an SPL. Just different lingo. So Kal, on my pictures above and on the HomeTheaterShack forum, there is nothing mentioned about in-out looping the other channel. My left channels are both open. Why are you looping yours?
Roly

[Azeke]

I certainly find this topic interesting, I currently use the M-Audio Fast Track Pro. I am using both Audacity 1.3 Beta (freeware) and Sonar Home Studio 4 software.

Anyone using either of these s/w packages?

Peace and blessings,

Azeke

[Rolyasm]

So far Azeke, I am just trying to figure out the Room EQ Wizard.
I am very close to making this all work. I set my processor level so my SPL was reading 0 on an 80 range. I installed the calibration files for M-Audio and ecm-8000, and hooked up my mic. I ran my first sweep and the error I got refered to a low input level of around -64, when it should be greater than -10. I will post the exact message tomorrow when I get home from the night shift. Anyway, I checked my Windows volumes, and they are all up. I turned my M-audio levels up and I turned the gain on my EP2500 amp up, and it helped, but not enough. I got the levels up to around -37. What are the gains supposed to be set to for the soundcard and the amp? Anywhere else I can check for control levels. The message said to check for mutes, volume levels and that sort of thing.
Roly

[Kal Rubinson]

Interesting. I am pretty sure an SLM is the same as an SPL. Just different lingo.

Nope, Just a common misuse.

So Kal, on my pictures above and on the HomeTheaterShack forum, there is nothing mentioned about in-out looping the other channel. My left channels are both open. Why are you looping yours?
Roly

From the REW instructions: "The left input and left output channels are connected together and provide a local loopback connection, this is used to prevent frequency response variations in the soundcard from affecting the measurements."

Kal

[Rolyasm]

Kal,
Looking at the pics above it shows NOT to use the left channels. Is that a picture for a different level of setup? Am I just not to that point yet? Also, I checked HomeTheaterShack's REW pages, and it shows not to use the left channel. Do you have a different setup page? Did you try not using the left channels and test the difference? Thanks
roly

[Dennis H]

Don't take this as gospel but, as I recall, early versions of REW required the loopback but later ones don't. You can do a loopback in the initial calibration to get the sound card's response and save it as a file. Then you don't need it when you are measuring. The best place to ask REW questions is over at the author's AVS thread.

http://www.avsforum.com/avs-vb/showthread.php?t=529224

Edit: I see John has moved his official support over to:

http://www.hometheatershack.com/forums/bfd-rew-forum/

.... and Roly is already quite active there so we can all shut up now.

[ThomasW]

[Kal Rubinson]

Kal,
Looking at the pics above it shows NOT to use the left channels. Is that a picture for a different level of setup? Am I just not to that point yet? Also, I checked HomeTheaterShack's REW pages, and it shows not to use the left channel. Do you have a different setup page? Did you try not using the left channels and test the difference? Thanks
roly

I do not know where that figure came from. My connections are based on the help files that accompanied the software. I did set it up that way about a year ago and I have not changed it.

Kal