How to measure a room's response

Hello everybody - newbie here I've downloaded and installed the Room EQ Wizard, and calibrated my sound card. My new SPL meter should come tomorrow so I can get the levels right when measuring the response of the room - after which I'll post details about my room and it's woes. But...how do I actually take the EQ measurements? For instance, is my large-diaphragm condenser mic (studio projects C2) appropriate for the job? My room is a combination recording/mixing room, and I have near-field monitors. Should I have both speakers on? (a post I read here somewhere said you could get SBIR - huh?) Do I place the mic at the listening position? That would seem to make the most sense from a mixing standpoint, but what about the measuring the room response from a recording standpoint? Also, I would think that when I sit at the desk, my body attenuates some sound from the rear wall. Where do I position *myself* when taking the measurements? Am I making this way harder than it is? As I said, I will be posting details of the room along with my EQ measurement results when I'm done, but in the meantime, here's some specs in case it matters: the room is about 13'9" X 14'6", ceiling is 6' at front wall and 9'5" at rear wall, my listening position is centered about 66" from front wall. Thanks in advance -Chuck

Hi Chuck. Welcome! There is an announcement at the top of the forum about what to do to assure getting as many responses as possible. The announcement leads to this post. Actually, several people, who are experts on this forum, will not reply if you do not do what is written in the post. Many others who are very helpful, will not reply out of respect for the moderators' wishes. - Stuart -

chuckswenson wrote:

how do I actually take the EQ measurements?

This article explains how I use the ETF software, but the principles apply to all such programs.

For instance, is my large-diaphragm condenser mic (studio projects C2) appropriate for the job?

See this: Comparison of Ten Measuring Microphones

Should I have both speakers on?

Yes. The reason we measure a room's bass response is to know how things will sound at the listener's ears. In most pop music the bass and kick drum are panned to the center, meaning it comes from the left and right speakers equally. So from my perspective, at bass frequencies anyway, measuring a room with both speakers active more closely emulates how real music will be played. That said, I think it's good to also measure each speaker separately for additional confirmation.

Where do I position *myself* when taking the measurements?

Probably out of the way if possible. I'll also add that measuring a room is not strictly needed. The main reason I tell people to measure their room is so they'll understand how awful it really is. Most people have no idea how skewed the LF response is in their room. It's not like you need to identify problem frequencies to know how to approach treatment. Regardless of what is measured, you need as much bass trapping as possible, and absorption at the side-wall and ceiling reflection points. Just doing that will get you 90 percent of the way there for any room. --Ethan

Awesome, Ethan - exactly what I was looking for. I've read a lot of your articles on room treatment, and bass traps in particular. I've also watched some of your excellent videos on youtube on room treatment (as well as the way-cool tele and cello vids!). Floor to ceiling bass traps in each corner, along with similar treatment at 1st reflection points, already form the foundation of my treatment plan. When I get the room measurements I'll post them along with my room details. Thanks again! Chuck