First time REW -- Need help

[todd612]

http://i56.photobucket.com/albums/g1...rew_091009.jpg

First time REW user here. I tried hooking up everything according to the guides here in this forum and made my first measurement above. Except I don't think I have my interconnections setup correctly.

My setup:
LINE OUT: ATI 4850 HDMI --> Denon 4306 HDMI --> MFW-15 and front speakers
LINE IN: ASUS motherboard audio line-in R only <-- Radio Shack SPL meter 33-2050

Things I'm confused about:

• Anything wrong with my setup? i.e., using MB line-in and HDMI out is okay or not?
• What do I set the range to on RS meter? The other settings are C Weighing and Slow Reponse.
• My calibrate doesn't work. I run REW and click on Calibrate button. My receiver is off and I get the following VU Meter readings.

http://i56.photobucket.com/albums/g1...EWVUMeters.jpg

[Wayne A. Pflughaupt]

Welcome to the Forum! You might want to take advantage of our post padding thread. Once you're racked up 5 posts you can upload your pictures to our server when you make a post.

Also, we like to see all graphs scaled to 45-105 dB vertically (your 15-200 Hz horizontal scaling is fine).

Anything wrong with my setup? i.e., using MB line-in and HDMI out is okay or not?

Not okay. You need to use analog for both ins and outs. For one you can't calibrate your sound card any other way - which tells me you probably skipped that step?

What do I set the range to on RS meter? The other settings are C Weighing and Slow Reponse.

Set it for 80 dB, C weighting. Response doesn't matter.

My calibrate doesn't work. I run REW and click on Calibrate button. My receiver is off and I get the following VU Meter readings.

Not sure about that one - brucek will have to tell you. Maybe using the analog only connections will help.

Regards,
Wayne

[brucek]

My calibrate doesn't work. I run REW and click on Calibrate button. My receiver is off and I get the following VU Meter readings.

You need to run the soundcard calibration before connecting anything up.
Connect a single loopback cable from right channel line-out (HDMI not allowed) to right channel line-in .
Run your soundcard calibrate routine and save the file and point REW to it.

Remove the loopback cable - (that right channel is now the calibrated channel you'll use). The left channel is not used.
Connect right line-out to your receiver and connect the SPL meter to right line-in......

Check Levels.
Calibrate SPL
Measure.......

brucek

[todd612]

Thanks for the quick responses. Here's what I did so far now...

Using the ATI HDMI output on my graphics card was bad. And I didn't have the latest audio drivers installed. I was using the default Windows 7 drivers. On top of that, I was using a bad cable and the default audio settings had feedback loop.

Okay, here's my first real measurement:


soundcard loopback calibration:


checking out calibration reference graph:


Does this look right, now?

[brucek]

Yep, looks good now....

[todd612]

Alright, my setup is working now. But how do I interpret the graphs? e.g., I got a couple of dips at 50Hz and 80Hz. What does that mean? How to correct it? etc. Any guide or further reading on this? And I don't mean to become an expert but just to understand the basics on how to read the graphs and then correct or treat my setup.

[brucek]

You don't really have any significant peaks or dips to worry too much. You can move the sub around and try and change the response for the better if you wish or you can add equalization.

brucek