Nautilus Front Loaded Horn

[tHEbLENNY]

I've seen the Nautilus sealed loudspeakers online, but I thought the golden mean might work in a horn design too. I have not modeled this to any specific driver yet. The images show dual 8" subs firing in on each other. The enclosure is ~40" tall and 5.5" wide. The length of the "line" is ~5.5feet. and expands using fibonacci's golden ratio.

I don't have any modeling software to see if this design might be effective, but I like the idea.

Any thoughts?

[epa]

you can use hornresponce to model it.
but since its round you have to guestimate the varius area's.
it gives you an ideer how the varius speakers respond.
looking at it ,my gues is it wont go low,but sq might be good.
looks are good 2

[tHEbLENNY]

Thanks! I'll try to model it. I imagine I'll calculate for the small round chamber in the center and only one throat/mouth ratio since it is one continually expanding horn? I'm going to have to look at the forum you linked me to more closely. Many of these fields and their descriptions are above my current experience.

[planet10]

With a mouth that small, it will stop being a horn well above the passband of a sub driver.

dave

[Cal Weldon]

In spiral horns I've always wanted to go the Cornu route.

Have a look here. There's a post with lots of links.

Cornu Spiral Copy Horn

[revboden]

fyi Großes*Spiralhorn

[tHEbLENNY]

Wow! Thanks for all the great links and info. It took a while to go through it, but I'm glad there has been so much thought in this realm of horns. My original thought was to use the nautilus for a smooth mid-low end and supplement with tweets (and I still want to explore it), but maybe having a single driver setup would be nice for a different type of listening. When I see those Cornus on a wall I picture a single unit in mono as more of a relaxed "walking around the room" application since the imaging has been said to be a bit difficult and the room projection sound is said to be rich. Something to play on Sundays with coffee and menial tasks! With the panel setup you could hide an amp inside and a disc drive or ipod/aux mount either inside or on the front and make it a full self-contained unit that simply needs an outlet.

I'm going to mess around with some more designs until I've had my fill and decide to create some sawdust. I'll keep posting designs when I think of them. Hopefully you'll all comment and we'll get some mutual inspiration going.

Matt

[weltersys]

Matt,
The wall mounted Cornu solves the problem of a “too small” mouth, as the wall becomes an extension of the mouth, but a relatively large diaphragm size makes for a very narrow high frequency dispersion pattern, not conducive to a relaxed "walking around the room" application.

Mixing a long FLH horn and a tweeter will either require time compensation (digital delay) or require the crossover point to be some multiple of the time offset, the two drivers will then be "in phase", even though the LF will lag behind the HF by several cycles.

Getting that type of a passive crossover correct makes the rest of the project seem trivial.

Art

[tHEbLENNY]

Well I've been fiddling with some more concepts. None are supposed to be a model to follow for a build, but more of ideas that could sound great and be conversation pieces or sound horrible (but still conversation pieces) They would obviously need to be customized and tweaked to work with your own drivers etc. I had them floating around in my head and wanted to share them. Please comment about the potential positives and negatives of these concepts.
The first is a quad horn (2 upper and 2 lower) that could be used as a TV stand or coffee table, or just a stand alone speaker enclosure. This enclosure uses a spiral configuration for the horns. There are 3 horizontal layers with the two dual horns in between them, The bottom most layer is solid and serves as the base (some sort of spikes/feet would be needed) Tho top is also solid. The middle layer which separates the upper and lower paired horns houses the drivers. There could be 2 total drivers or four total in this enclosure. The section image below shows the four driver configuration where two drivers are coupled together per side sandwiching the middle horizontal baffle. In this case one driver would be wired in phase the other out of phase. It might not create more output, but might be more responsive and increase sensitivity. Whether using two or four total drivers, if the upper set of horns had a slightly different height than the lower the combination of tuning frequency could possibly smooth apparent harmonics...?

The second is a circular enclosure with a tapered spiral transmission line modeled off a folded tapered t-line sub that I built a few months back for a home theater set up. Here's a link to that project ---> HT Line Array and T-Line Build
The one I built is pictured to the right of the circular enclosure. It uses a pair of Dayton dcs205-4 8" subs. The circular enclosure has the same size closed end and open end as the rectangular t-line for a 10:1 taper ratio. The drivers are positioned roughly 1/3 down the line from the closed end. The only real difference (theoretically) between the enclosure I built and this circular one is the spiral itself. The drivers are on opposing sides and are anchored to each other with hardwood dowels to stiffen the enclosure and to try to eliminate harmonics by balancing the movement of the drivers against each other. The TL I built sounds fantastic to me (Thank you all for this great forum which helped immensely with my research). So I think the spiral might sound just as good but has a bit more visual interest. It could be an end table if you threw some legs on it. The curved raindrop looking cutout could be visible or just be a void inside the box that is covered with the top and bottom walls (maybe filled with "great stuff" to eliminate any possible resonance). So there you have it. Don't keep your opinions and comments to yourself!

[coloredink]

Hey tHEbLENNY,
Nice concepts. have you built any of the circular or spiral enclosures? If so i was wondering how they sound.