The Hurricanes- A multi-woofer open baffle 3-way tower

[DanP]

http://projectgallery.parts-express....he-hurricanes/

I thought I'd link here to my latest Project Gallery submission. These are a very airy, sweet sounding speaker with surprisingly full and clean OB bass in a nice tight package.

Dan

[andykriech]

Re: The Hurricanes- A multi-woofer open baffle 3-way tower

Very nice and unusual, too.
With the open baffle, do you set them up further out in the room?
Andy.

[bullittstang]

Re: The Hurricanes- A multi-woofer open baffle 3-way tower

Very nice and inventive design! Really, really great job. You're pretty brave posting a FR graph with no gating, but when it's that smooth I guess there's nothing to gate for. Two thumbs up, sir!

[isaeagle4031]

Re: The Hurricanes- A multi-woofer open baffle 3-way tower

Very cool Dan. Hope to hear them soon

[ani_101]

Re: The Hurricanes- A multi-woofer open baffle 3-way tower

Very interesting... Looking forward to hearing these... These would top all driver counts at 20 for the pair.... That's a lot of driver screws.....

[kenny_k]

Re: The Hurricanes- A multi-woofer open baffle 3-way tower

Was there a ripole influence?

[Wolf]

Re: The Hurricanes- A multi-woofer open baffle 3-way tower

AH! A DIY-AMT-LAT woofer!

Nice!
Wolf

[Navy Guy]

Re: The Hurricanes- A multi-woofer open baffle 3-way tower

Wow! Really cool project. This is one of the most creative ones I've seen in a while. What was the cause of the dip at 700 Hz?

[DanP]

Re: The Hurricanes- A multi-woofer open baffle 3-way tower

Thanks guys! This was a cool experiment to do and the results were much better than I expected.

Andy - I don't have a big enough room to pull them too far from the rear wall, so I've got them about 18" from the wall and they sound great. I'm curious to see what they can do in a larger room.

Paul - I was shocked when I took the first set of measurements and saw that the ungated curves looked so good. I moved the mic and speakers around to make sure it wasn't just lucky positioning and the general curve remained very similar while the minor peaks and dips jumped around a little. The end result was a pretty flat ungated FR curve in multiple room locations.

Kenny - I've heard of ripoles and looked into them a bit but I can't say the Hurricanes were really influenced by them. I really just wanted to jam as many woofers into a standard tower speaker as I could and see if it sounded ok. The great part is that it sounds better than ok and there was an unexpected (to me anyway) bonus of the slot loading raising the Q and lowering the FS of the woofers enough to provide legitimate low end extension.

Kerry - The dip was present in the midrange measurement, and others can speak more intelligently about this than me as this was more of an experiment for me, but the dip seems to be the valley between a couple of dipole/diffraction peaks. When I tried to knock both the peaks down to flatten out the valley, it caused more trouble than it was worth. Based on how narrow the dip is, and the fact that even knowing it was there I didn't notice it in listening tests, I decided to leave it as is.

Chuck, Wolf, Ani and anyone else who will be there - these will definitely make an appearance at InDIYana this year.

Dan

[greywarden]

Re: The Hurricanes- A multi-woofer open baffle 3-way tower

That's awesome, I have a handful of those 8s, too and I've considered something like that with them before.

[Mike220]

Re: The Hurricanes- A multi-woofer open baffle 3-way tower

Very cool design. That's an awesome way to stuff as many woofers as possible into the smallest space possible. I wish it had less woofers.....said no one ever.

[philthien]

Re: The Hurricanes- A multi-woofer open baffle 3-way tower

Very impressive design work.

Where does the sensitivity end-up for eight woofers running OB? Is enough output lost to cancellation that your mid and tweeter don't have to be amazingly sensitive?

[Wolf]

Re: The Hurricanes- A multi-woofer open baffle 3-way tower

My guess is that since 4 are in series, and then the quads in parallel, he only gained +6dB. This is good for BSC.

Later,
Wolf

[JasonP]

Re: The Hurricanes- A multi-woofer open baffle 3-way tower

These look terrific, and the write-up in the project gallery is well done. Can't wait to hear them at InDIY.

[DanP]

Re: The Hurricanes- A multi-woofer open baffle 3-way tower

Very impressive design work.

Where does the sensitivity end-up for eight woofers running OB? Is enough output lost to cancellation that your mid and tweeter don't have to be amazingly sensitive?

Wolf is right, but the 8SW-4 is already a few dB more efficient than the DA175, so my plan was to pick a reasonable F3 for the woofers and tilt the response down from there to match the DA175. This assumed my measurement would look like a ramp starting "very low" at 20Hz and rising to "very high" around the dipole peak with not much of a plateau in between. When I took the in-room measurements of the woofers though, my plan went out the window. Remarkably, the unfiltered, ungated 8 woofer measurement @ 1m on the tweeter axis was +/- 3dB from 40Hz to 300Hz with a 10dB peak at 400Hz before rolling off. The level of this nice 3 octave plateau was serendipitously similar to the DA175 in-room response level.

I was shocked and I'm still not sure of all the variables that contributed to this happenstance. As I do more open baffle projects and observe the similarities and differences in the measurements, I'm sure it will become more clear. I'm assuming that room gain (perhaps a more stable contributor with the open baffle format?) and the high Q bump flattened the response out down low, but just how flat it was is still impressing me. I'm not ashamed to say I think there was a fair amount of luck in that aspect of the design.

Dan