Originally Posted by f1nels
You can send me a PM on how to measure that. I know you've posted it before, just can't remember where. Don't have much time for monkeying around with measurements (little kids), but the Omnimic sure makes it easier.
Hey, if you're ever in this neck of the woods and feel like doing some measuring...
I know the feeling, got a 4 year old and another on the way. Not much time for anything these days.
.... and my MobilePre went bust a few days before I met with Jim and Bill at Jim's house (Sputter). Here's a thread where I "think" I got it right near the end (see post 80) ... admittedly no one responded as to whether it was a correct method.http://www.avsforum.com/avs-vb/showt...1#post20284941
Hmmm .... looking at this now I think my room gain numbers are off as I was comparing to the post EQ'd line at the LP vs the pre-EQ line at the LP.
In a nut shell you'd need to measure the following way:
1. Make sure Audyssey is disables for all tests.
2. Make sure the Dayton amp is not providing a boost or any EQ.
3. Unplug all speakers from your AVR. Plug the subwoofer into a single FL or FR preout. Ensure the FR and FL speakers are set to large to defeat any crossover.
4. Put the sub in the center of the room (actually, this isn't overly necessary as my measurements were almost identical at 0.5" regardless).
5. Put the mic on a stand, and place the end of the mic directly facing the center of the driver, about 0.5" away.
6. Run a sweep in REW or OmniMic (make sure you don't have clipping so you may need to keep the volume low given the mic is so close).
7. Plug the sub back into the subwoofer output, and and run a sweep with say a 120hz cross-over (no rhyme or reason to the x-over).
8. Now put the sub into it's main position. Place the Mic at the LP and keep it in that exact position.
9. Run the same sweep with the 120hz crossover.
10. Plug the sub back into the FR or FL preout and again set the speakers to large and defeat any crossovers.
11. Run the sweep again with the mic not moved from the OP.
Once you have all these sweeps, you then have to figure out where to "line them up" on the graph. I'm assuming Omnimic (I think you use that) has functionality similar to REW that lets you put all those sweeps on one graph, and then let's you move each sweep line up or down on the grid?
Hard to explain in words, but once you have the sweeps you'll see what I mean. I think you only need 3 measurements but I just can't recall which.
I'll have to go back to that session one day to check the measurements an remove the smoothing (just found smoothing helped with figuring out where to line them up).
Edit: May be worth starting another thread here or in the DIY section on doing these measurements as others can help out. Or just tack on to my thread above.