Setting levels

[fouiz]

Hello,
i'm starting with REW (what a nice piece of software) and 'm not sure to do one thing correctly :
As i'm gonna use an ECM8000 for measurements, should i set the levels with an SPL meter (i have on e too) or using the ECM ?
This is a part which is not clear in my mind, despite the help files.

[atledreier]

You set the reference level with the SPL-meter.

[brucek]

should i set the levels with an SPL meter

Just the 75dBSPL at the listening position using the SPL meter hand held with no connections. (There's no other way of knowing what 75dB is without an SPL meter - some do it by ear, but that's tricky). Then put it away and carry on with setting the input levels while using the ECM.

brucek

[fouiz]

So, if i understand correctly,
first of all, i do the "Checking levels" with the SPL connected to the card to set the levels at 75db using a combination of the external card input volume and preamp volume.
Then i should calibrate the spl reading using the SPL just for checking, but with the ECM8000 connected to the card.
Right ?

[brucek]

So, if i understand correctly

No. Hook up the ECM8000. It is the only mic you'll connect. During the sequence where it asks you to adjust your receiver volume to provide 75dBSPL at the listening position (which is where the ECM will be sitting), pick up the SPL meter and adjust the receiver volume until you get about 75dB on the Radio Shack meter itself. Then put the Radio Shack meter away. Carry on....

brucek

[fouiz]

I knew i was wrong
Thank you Bruce !