Cool. It's a good read and an extremely useful reference for obtaining acoustic offset with PCD. So, do the tweeter and mid together and then the woofer alone. You're just trying to get a summed response of all the drivers to use as the overlay for the offset value, nothing more. Go ahead and spend this time to get as accurate measurements as you can for all the drivers without moving the mic or changing the output level or any gating you use with Omnimic, these are all constants that must remain the same. From there you can enter all the frd and zma files for each driver and simulate the crossover. First thing first though, have fun! 
Ok so there's the first wrinkle: gating? Is that the marker I use when looking at the impulse response (timing)
BTW all the frd and zma files are loaded.
Breaking into the woofer enclosure was not fun. Had to bypass the XO, damn what a pain, but at least once it's done and I have the measurements I'm good.
BTW all the frd and zma files are loaded.
Breaking into the woofer enclosure was not fun. Had to bypass the XO, damn what a pain, but at least once it's done and I have the measurements I'm good.
Well, I'm not familiar with that software, but I took a peek at the manual and "blended" is just supposed to merge the un-gated response onto the LF end. That doesn't explain your approximately flat responses for every measurement... Are you able to post the impulse graph? How many ms. do you have highlighted? Turn the smoothing to 1/24 or so. How loud are playing your test signal? Just focus on one of the drivers until you get a good measurement.
I will post Impulse graph later. I used 8msec as the instructions said. I am using 1/12th smoothing now, do i really neede 1/24th? I am playing the signal pretty low because i am not using a cap on the tweeter. It doesn't sound too low though. OK so it looks like you agree that the graphs are suspect. I'll redo the measurement and post tonight. Thank you for your input and advice.
1/12 is fine for PCD, I just wanted to make it more obvious when reflections kick in while you're figuring it out. Maybe just stick to measuring the woofer on axis until you get something that looks right. That way you can crank it up and run all frequencies without fear. It seems like you almost have to have a noise floor problem in what you posted above... While I'm at it, how to you have the speaker situated in the room? If you can't get at least 5' or so from all boundaries (floor/walls/ceiling), try it on the floor pointing at the ceiling so that you're as far as possible from every boundary but the floor, and the floor is behind it.
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Impulse graph
Duh, never mind it is with out XO.
I am including a impulse response (doesn't look to shabby)
And I didn't move the speaker it is near a room boundry (but at the rear of the speaker and there is some interference on one side. I'll have to move it after these series of measurements.
Duh, never mind it is with out XO.
I am including a impulse response (doesn't look to shabby)
And I didn't move the speaker it is near a room boundry (but at the rear of the speaker and there is some interference on one side. I'll have to move it after these series of measurements.
Yeah, you still need at least a couple more ms free of reflections. Separate from that, I'm a little confused on why you seem to be hitting a floor around 48dB (or approx. -20dB, as it were). It would make sense if that was the environmental noise floor, but that should be getting filtered out, unless this system is very bad at that...
If that's the farthest you can get from floor/ceiling, you may need to go to having the speaker on the floor pointing up, but that's a problem because of your dipole mid. Maybe if you put a whole ton of fiberglass/etc. behind the mid you could suck up enough of the rear radiation to make it an insignificant reflection...
What's your measurement distance? You can get in pretty close, probably 35-40", and still get relatively useful results, though you'd probably have to replace the woofer measurement with an on-axis one after figuring the z-offset.
What's your measurement distance? You can get in pretty close, probably 35-40", and still get relatively useful results, though you'd probably have to replace the woofer measurement with an on-axis one after figuring the z-offset.
Firstly I want to thank you for you patience in advising me .
I am currently measuring 60 inches away. I could move in to the recommended 40 inch and see if it makes a difference. So are you saying measure the woofer twice? Keep the mic in one spot without moving it (for all 3 drivers) then measure the woofer again on axis?
.I am currently measuring 60 inches away. I could move in to the recommended 40 inch and see if it makes a difference. So are you saying measure the woofer twice? Keep the mic in one spot without moving it (for all 3 drivers) then measure the woofer again on axis?
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