Well, here we go!
Ever since Ricci unveiled his fantastic GJALLARHORN build a while back, I have been dying to build a pair. My desire got even stronger when the folks at data-bass.com
measured the beast!!!!
However, I already had a Danley DTS-10
that has served me very well. I really did not want to part with it, but after moving to much more rustic house there was simply nowhere to hide the monstrous monolith.
I thought this would be the perfect opportunity to start building. However, the GJALLARHORN was not much better at blending in with the decor.
So, I embarked on the quest to locate another replacement (or two) that is/are more aesthetically pleasing for the room. Fortunately, I do have a long and low space behind a sectional couch in my hybrid theater room.
I could not find any proven horn designs floating around that utilize an 18 in something long and narrow. I checked other designs and was about to settle for a compromise, possibly a sealed enclosure that would fill the space nicely, but would require much more power.
My thoughts never strayed far from trying to utilize an 18 in a horn and more specifically, the amazing 18" LMS-5400 Ultra
driver. It is just such a bonus having that horn efficiency coupled with very low THD.
Instead of compromising, I posed a question in a new thread; is there anyone willing to re-fold the GJALLARHORN into something long and low?
Fortunately, LTD02 took the ball and ran! He along with input from others in this amazing community of bass heads yielded a design that is nearly perfect! Kudos to all those that helped with special mention going to LTD02 for his willingness to share his expertise!
He graciously answered all of my questions and was a tremendous help! He is one of the all-star members of this community.:)
The final design ended up being ~25.5 X 30 X 72
and like the original GJALLARHORN design can be loaded with the UXL-18 or LMSU for best results (and less than optimal options are the Dayton 460 HO and Stereo Integrity 18 HT). The FR is very close to the GJALLARHORN as well, just a revised form factor with a slightly smoother curve and slightly better lower end extension.
After strongly considering the UXL-18 which is a fine driver for much less money, I gave into peer pressure and decided to bite the bullet and add to my LMSU collection.
In doing so, I decided to only build one in the interest of mitigating the cash outlay for yet another LMSU and five more sheets of ply. After all, I am replacing a single DTS-10, which with the help of two sealed LMSUs easily produced 120db+ peaks in my room with so little power and excursion.
And two 72" horns end to end would protrude beyond the end of the couch and designated space by roughly 8-10 inches. Also, as mentioned, this is a five sheet (4' x 8') build and not a trivial wood purchase. Even at $50-$55 a sheet for birch, maple or oak ply, there is a significant expenditure. Also, there is a fair amount of waste with this one due to the long segments. Some of it can be re-purposed in the form of bracing. But, there is still close to a full sheet of pieces left over.
With all the wood in the form panels and bracing, combined with the driver, the weight comes in at over 300lbs...plan on having a friend or two to help with any movement or transport.
Wood - $275 (using 5 sheets of premium hardwood veneer 3/4" ply, standard 3/4" ply could be used for less than $30 a sheet)
Driver - $925 / $530 (can often be purchased for ~$875 with discount codes, UXL-18 is the alternate driver at $530 shipped or even less via a goup buy)
Misc - $25 (only 3-4 tubes of PL Premium are required, terminal cup is optional depending on orientation, the LMS comes with mounting screws)
Most of the images below are courtesy of LTD02:
Green is the sides, the others are rips down the center yielding the internals and bracing. There is no official cut list for this project. I prefer to cut each internal panel as needed allowing for adjustments along the way. Also, it gives the builder a choice as to how to overlap the panels.
GJALLARHORN (light) vs LOWARHORN (dark) sim:
The internal width can be adjusted slightly if necessary with little penalty;
LOWARHORN at ~25.5" wide vs. 24" wide:
Ringing at around 70Hz is inherent in this design. A sharp cut (high Q, 9 or more db) at that frequency significantly mitigates the problem...or crossing at 60-70Hz eliminates it.
I typically cross my subs at 60Hz, so it is a moot point in my setup.
In the mouth sweeps, TEAL without EQ, PURPLE with some EQ and HPF applied (house curve):
WARNING: A high pass at 13-15 Hz is REQUIRED to protect the driver.
Here is the excursion with only 1200w:
As shown, the driver unloads quickly below ~15Hz.
In case you are running the Behringer DCX2496, the HPF can be set below 20Hz this way:
These are the DCX settings for it (courtesy of Ricci), resulting in a roughly 13.5Hz HPF for this application.
24dB octave BW HPF at 20Hz
24Hz 12dB HP Shelf filter -15dB
20Hz 12dB LP Shelf filter +1.5dB
21.5Hz BP filter Q of 2.0 -1.8dB
Also, if one desires an alternate mouth/exit location, you can try the dual-side firing option as shown below. This will allow additional placement options and orientations.
Don't ask me why LOWARHORN has to always be in caps!
Let the games begin!
Once again, kudos to LTD02 for making this build possible! :) If you choose to build this design, please thank LTD02 for his efforts.