8th order bandpass - Page 2

Jet-Lee · #16 10-27-2005, 02:04 PM

http://www.the12volt.com/caraudio/boxes6.asp

sr20de4evr · #17 10-27-2005, 02:07 PM

Look at that picture, the two main enclosures are the same size and tuned to the same frequency, that's a normal 6th order just with a common chamber instead of separate chambers. That's not what you're doing.

Jet-Lee · #18 10-27-2005, 03:33 PM

how does the tuning of the port effect the type of box? 3 chambers, all ported, 2 drivers = 6th order bandpass. The fact they share a chamber makes it a dual reflex. What does tuning have to do with the TYPE of box?

That's like saying because my car is N/A and my buddies is turbo'd, regardless of the fact they are both 1999 Escort LX's, the fact that his is turbo and mine isn't, then my car isn't an Escort, or his isn't, because they're not "tuned" the same.

sr20de4evr · #19 10-27-2005, 04:31 PM

Because the two outer chambers are tuned to the same frequency, the two subs move identically. Because of this, the inner chamber can be assumed to have a wall in the middle separating it into a chamber for each sub, just like having a pair of identical 6th order bandpass boxes sitting side by side. Your box does not function that way, the alignment changes drastically depending on what frequency you're playing, I hope to god you found a program that can model this box for you, if not you're just shooting a bb gun into the sky hoping you hit a satellite.

If you take a 2cf 30hz box designed for 2 10's, you put a 10 in one hole and a PR in the other hole, it's no longer a 2cf 30hz box, it's just fucked up is what it is.

A 6th order bandpass is called a 6th order bandpass because you have a 4th order rolloff on the bottom end and a 2nd order rolloff on the top end. I highly doubt yours behaves this way, so it can't be classified as a 6th order bandpass IMO.

Jet-Lee · #20 10-27-2005, 05:27 PM

I'm making one tonight, with 3 slot ports, will let you know tomorrow how it sounds.

CBFryman · #21 10-27-2005, 06:51 PM

want to see how a dual chamber 6th order SHOULD be designed?
http://www.soundsolutionsaudio.com/f...showtopic=4316

Jet-Lee · #22 10-28-2005, 08:16 AM

okay, the 10" version is built.

It is the exact opposite of what I thought, but it's unique none-the-less. It's a drop in volume from my previous design(horn loaded), but the quality is 10x better than any setup I have ever heard anywhere. dropoff does not occur till ~25hz. That's already below the limits of my subs (28hz) so I don't care. Pretty level on up to the crossover at 90hz. The accuracy is just astonishing! You can tell the smallest of tone changes, or tiniest thumps. I love it for the quality aspect, it still has some spl, but not what I had.

CBFryman · #23 10-28-2005, 01:30 PM

that funny because proprly designed horns are not only the most efficent but also the most accurate and natural sounding alignments.

Jet-Lee · #24 10-28-2005, 02:04 PM

My horn wasn't sized right in the least bit. I just took some wood and slapped it together to see what the big deal was.

CBFryman · #25 10-28-2005, 08:19 PM

Then i can understand a great improvement

CBFryman · #26 10-28-2005, 08:30 PM

a lil horns 101 (im no horn expert)

a true bass horn has a mouth size the size of the wavelength of the inteded frequincy, however due to horns small roll off frequincy smaller mouth area's can be used, especially if the sub is being designed for corner or wall placement in an enclosed area.

http://melhuish.org/audio/hornshape.html

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