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SUPPORT FORUMS FOR DECWARE SPEAKER PLANS >> Deathbox Support Forum >> symmetrically even cone pressure
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Message started by thedude on 01/12/07 at 22:41:20

Title: symmetrically even cone pressure
Post by thedude on 01/12/07 at 22:41:20

The deathbox loads the driver cone evenly to increase performance. The white paper says it does this through use of the slot design. The fact that the slot design terminates halfway across the cone has something to do with it too. I've thought of another way to do this and I'm looking for problems or reasons it won't work. Steve may have tried this already as he said in the white paper that during development they moved the position of the port 13 times. Basically, I would put the port in front of the driver. In most bandpass boxes the port is at a right angle to the driver. What if we swung the port around so its pointing directly at the driver and center it on the center of the driver's cone. Then we make the port flush with the inside edge of the box so its flat against the wall opposite the driver.

http://www.audio2.homestead.com/files/clear_bandpass.jpg

Basically so its like this but with the port centered on the driver and sticking outside the box. Does anyone see any reason why this arrangement would not load the driver evenly?

-Matt

Title: Re: symmetrically even cone pressure
Post by Jet-Lee on 01/13/07 at 01:30:28

That pic looks a little off-center, but I understand the idea.

I don't understand why it wouldn't work.

Title: Re: symmetrically even cone pressure
Post by thedude on 01/13/07 at 02:13:47

The only thing I could really think of is that the lack of pressure on the center of the cone would cause an issue. But I'm not sure it works like that at very low frequencies unless cone breakup is an issue. I guess my real question is, is this method going to provide a performance increase over conventional port placement in the same way that the deathbox would? If I had the resources to build and test this right now I would be all over it. Unfortunately I don't. So, I'm left with speculation.

-Matt

Title: Re: symmetrically even cone pressure
Post by 60ndown on 01/13/07 at 03:00:05

aka housewrecker top port or death box 2?

camera angle is not perfect but the actual hole is close.

Title: Re: symmetrically even cone pressure
Post by thedude on 01/13/07 at 12:53:12

Like the HW top port, but with the port sticking out of the box so its flush on the inside. That seems like it would provide even cone pressure wouldn't it.

Title: Re: symmetrically even cone pressure
Post by Adrian D. on 01/13/07 at 15:10:57

it could increase the pressure in the middle of the cone compared to the edges.
but that wouldn't be too much of a problem.
imo, the beauty of the db lies in the port that acts like a varo-vent and in the ability to tune.
because of the varo-vent you have much less cone excursion compared to a normal bp4. you run into thermal compression before force and suspension compression and you have a lot smaller risk of over-excursion.
imo, aligning the port center to the woofer center seems better than a side-firing bp4, but it won't have the goodies the db has to offer.