Single sheet TH challenge

[jbell]

Ok, so being 'never satisfied' I'm trying to better 'the cube' that I just built a few of.

Since there are several hornresp tapped horn quarterbacks that are better than I.... Here's the challenge.

1. Single 4x8 sheet of plywood. All panels, including bracing/reflectors, etc..
2. Most SPL 'area under the curve' from 40hz-140hz (minimum 100db average +-3db 1W1M)
3. Minimum 125db single cabinet from 'about' 40hz on up in 2pi space (understand, some designs in single cabinet won't 'quite' be able to hit 40hz, that's ok...)
4. Under $200 driver.

Bonus points for a better shape than a cube.

EDIT:

This section of the original post will be used for navigating this thread, and will be updated occasionally.
This sub was designed for the eminence series of drivers, 4015lf, 3015lf, Kappa Pro 15-LF2. Others work too.

cad drawing --Single sheet TH challenge
General Layout --Single sheet TH challenge
cut sheet --Single sheet TH challenge
note about using PL premium poly glue -- Single sheet TH challenge
High pass filters and excursion -- Single sheet TH challenge
First thoughts on 'cone correction' -- Single sheet TH challenge
Directivity Testing -- Single sheet TH challenge
Non US driver, (monacor) -- Single sheet TH challenge
US Drivers/PowerRatings -- Single sheet TH challenge
Nice little comparison chart -- Single sheet TH challenge
One of my favorite pics of FlipC's dozen -- Single sheet TH challenge
Quick post about construction technique -- Single sheet TH challenge

[polviggen]

the cubo15 seems to do that pretty ok.

Cubo 15

it's very easy to built, maybe try one and compare to your cube ? I built the extended version with an 3015LF and the output is pretty damn good for that size.

just remembered, the extended version can't be built out of one panel, had to use a leftover piece for that.

[Brian Steele]

Originally Posted by polviggen

the cubo15 seems to do that pretty ok.

Cubo 15

it's very easy to built, maybe try one and compare to your cube ? I built the extended version with an 3015LF and the output is pretty damn good for that size.

just remembered, the extended version can't be built out of one panel, had to use a leftover piece for that.

Just curious - how would you go about simulating the "Cubo" design in HornResp?

[djk]

I don't buy the performance numbers presented.



The larger EV MTL-1X with an 18 doesn't go as deep? Isn't as efficient?

Show me the sim !

[tb46]

Hi Brian,

Looks like a "horn vented bass reflex/tapped horn", see:

Novice stereo subs project with stereo amp.

Just take that Hornresp input (change to the respective numbers for driver, length and areas, if you like), and turn on TH.

Regards,

[polviggen]

hornresp is a bit negative on this type of enclosure. in reality it goes lower

here are the inputs i got

[jbell]

johan (rademakers) posted something VERY similar to the cubo in one of the TH threads way back.. I'm too lazy to look it up right at the moment. My problem with most of the hybrid cabinets are they are 50hz boxes, and it takes a pile of them to get to 40hz.

Because of that, I have kinda dismissed a hybrid... but maybe I should play around with a large chamber/short horn and see if there is something there I haven't seen in the past. I've also played around with compound horns at 3:1, and found something similar... Just hard to get to 40hz.

The folding is also the trick.. how to most efficiently fold with the fewest boards possible, while still having a good performing cabinet.

any creative thoughts?

[polviggen]

that probably was the cubo

[Xoc1]

My attempt
12mm Ply 1off 8' x 4' sheet Eminence 3015LF driver
Trouble is that as you tweek the bandwidth and efficiency you loose the low frequency extension. The only way I can see to get it back is to increase the size which would take more timber....
Maybe a longer path length would be possible if the width of the horn was reduced to 400mm
Spl response grey line is J Bell Mini TH for comparison.

[djk]

The 'iron law' still applies to a TH enclosure.

I don't think 40hz and 100dB are possible from a 2' cube.

50hz, yes, 40hz, no.

#9 is a good example of that at 90dB at 40hz.

"in reality it goes lower"

With room gain, I might buy that. In 2Pi or 4Pi, no way.