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Posts by Scott C.

I compared the tweeter to some measurements BWaslo posted (the woofer used was the Delta 12 LFA) and it looked pretty close to me. Here's the overlay: (link here: http://www.diysoundgroup.com/forum/index.php?topic=9.msg488#msg488) Purple is my measurement (smoothed to try to match a little better)
That'd be great. Looking at the manufacturer response for the 2512 , it looks reasonably close until about 400-500Hz when it starts dropping more quickly.
Ah, didn't notice that.
Yeah, the frustrating part is that I don't really know if any of it is right. If the measurement issues aren't limited to just the low frequencies, then I've been adjusting my XO to account for whatever's going wrong with that.
I forget which thread it was, but it seems like someone used this fan: http://www.digikey.com/scripts/dksearch/dksus.dll?vendor=0&keywords=3110sb-05w-b20-e00 It's got the same CFM, and slightly less noise than the one you posted.
It's sealed, so I would expect the rolloff to look like that, but not starting at 400-500Hz. Would a leak cause that? I'm using the stock gasket on the woofer because I didn't want to raise it anymore from the baffle, but I can put some more on in case that's the problem. The box is about 2cuft (maybe slightly more), so this is where I expect it to be:
So after messing around some more, and testing outside, I've decided that I don't trust my measurement setup for low frequencies. Whether or not I should trust it up higher is up for debate. In case you're wondering what I'm using, I have a Tascam US-122 mkII USB soundcard/microphone preamp powering a Dayton EMM-6 microphone. The reason I no longer trust it is first because I don't think the sound of the speaker matches the frequency response I'm getting from the...
I noticed that as well. I think it's likely due to the small size of the room causing reflections. As I move the microphone off axis, it unavoidably gets closer to the wall. Someone more knowledgeable than me probably has a better answer, though.And thanks! It's that low camera angle. Makes everything look cooler
Ryan, you're right about the 3rd order LP on the woofer. I put a .5ohm resistor in series with the cap, and it definitely helped smooth that bump you mentioned. I also added a bit of an RC contour to help the high frequency extension. As a side note I've been pretty much ignoring everything below about 600 Hz due to a combination of gating, and some measurement weirdness mentioned earlier in the thread. Basically the low end will randomly appear to roll off way too...
The baffle step is there for sure, but I've been measuring pretty far from walls, so I was hoping it would go away with better placement since I didn't see any baffle step compensation in Bwaslo's design. I'll measure against the wall to see what happens.Here's what it looks like (smoothed 1/24 octave to make it a little easier to see)
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