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Stephæn was the sawyer, running the circular saw against a clamped cleat to make each cut. All hands helped carry cut panels up ladders. Up in the loft were Ron and Joel, two Titan prime movers putting the whole thing together (stand back children) along with various assistants. 


Cleats were screwed and caulked to the walls. Top panels were screwed to the wall cleats. Vertical panels were glued and screwed to the top panels with a cleat at the intersection. The vertical panels were glued and screwed to a cleat at the floor.  All in all there were 17 panels, the largest being 9.5 feet by three feet. Clark hooked up the plate amp and made electrical connections to the left and right channel power amps and to the speaker cable for the pair of paralleled Altec drivers at the horn throat. 


A good time was had by all. Late the next afternoon after some had departed and the dust settled, I ventured into the loft, crawled into the horn and ran latex caulk wherever I could see a sliver of light coming in. I also added more bracing here and there.


It was great having the Monster in the Attic built and playing beautifully. But it is far far greater to have the memory of such a wonderful assortment of loving friends come together to do a task and have so much fun doing it. This day was one of the high points in my life. Everyone had so much fun. That said, we all were totally beat by the end of the day. We could not have put in a second one like it.


 
The fruits of our labors: My initial reaction was favorable. As usual, time went on and Stephæn and I were less satisfied. We initially used the Monster in the Attic only as subwoofer, rolling it off above 40 or 60Hz.  Eventually Bill Wassberg, an old friend of Ron Barbee, came to visit with Ron. About the sub he was not so hot. Bill suggested that for such a considerable piece of apparatus, we were not putting it to much use. When Bill and Ron left and inspired by Bill’s suggestion, I turned the rollover frequency dial on the plate amp to 160Hz. Voilà! Beautiful bass. One possible explanation is that the bass horn and sub horn just work together well in the two octaves between 40 and 160Hz.


Another might be that the fundamental of the big horn is quite significantly delayed from the main system. Perhaps by increasing the rollover frequency to 160Hz, the timing of the harmonics is the same as the timing of the fundamental, creating an overall better feeling for what is going on in the bass.  Whatever, this is one helluva woofer when allowed to run over a 4-octave window. The remainder of this article is a compilation of emails, which flew during the conception and planning for the Monster in the Attic. Have fun with these.

1/7/09: Pete Riggle to æ - I wanted to mess with horn calcs this evening. Had to choose between the vertical horn for your new project and the sub horn for the Garden. Decided to do the easiest calc first. The Garden. Okay, imagine this. A horn that starts on the rear wall of the loft 9 feet from the southwest corner, makes a bend at the corner and progresses 12 feet to the front of the loft. The horn is 8 inches high at the throat. Height increases in a straight line to 3 feet high at the corner, then increases in a straight line to 6 feet high at the front face of the loft (this is the full height of the front face of the loft). The horn is 8 feet wide at the mouth and 6 feet high. Half the surfaces of the horn are already provided by the floor and walls of the loft. I think the remaining surfaces can be gypsum drywall. I'm pumped. I'll draw you a picture.
Pete 

Comment: Eventually the horn started 21 feet from the southwest corner and now has a throat height of 12 inches.


1/8/09: æ to Pete -  You're a sick boy, Pido.


1/8/09: Pete Riggle to æ - Yup. Sicko. And who do you hang out with? And what are the implications? It's a lot more fun than hanging with well people. I hang out with cats. They are so accepting.
Pido


1/10/09: David Adams to Pete Riggle
- Hi boys, I don't see any particular problems but wonder about what driver you intend to use and if you will have only one of these beasts. From my conversations with Kevin Brooks, the expansion is of little consequence but length and mouth size are, with length being most critical to good bass delivery. It looks like you have enough length but you may want to design expansion from an 18" throat. As you know and can see, curves and folds don't matter in a sub horn either since the big fat notes just roll through and don't bounce too much.


Comment: This is some nice input from the step dad of Josh Stippich of Electron Luv fame. Dave lives in Salt Lake City near Kevin Brooks who has become a significant figure in the world of large horns. Dave mentioned to Pete a few years back that Kevin’s horns do something very special with the music.


1/11/09
: Pete Riggle to David & æ – David, it is a pleasure to hear from you. We had a very sweet Christmas holiday and hope the same for you. Thank you for your useful thoughts on bass horns and for the pics of Kevin's remarkable setup. I'm guessing it sounds delicious. The Po’ BoyZ started out sounding pretty wonderful and are getting better as we dial them in. At this point we are getting very enjoyable liquidity and clarity at low listening levels. I started out my sub horn scheming looking at a 22.5Hz flare frequency hoping to get -3dB at 30Hz. At the urging of Steve Schell I'm now looking at a 15Hz flare frequency hoping to get -3dB at 20Hz and paying some attention to matching the expansion rate at the horn mouth to the expansion rate provided by the room corner. I'll send along the details as they evolve.
 

Regarding leakage of high into low and low into high, we started with a 4th-order filter on the bottom and top, which sounds very nice. Right now we are using the octave equalizer in iTunes to voice the system. This is very helpful. When we are sure of what we want, we’ll go to Spice and see what we can do passively to mimic what we are getting with the digital filter. I'll keep you posted.
Pete


3/20/2009: From Harry Zweben to Pete Riggle -  Subject re: Al McGuire quotes (first of which is: "The Bounce Pass is the Best Pass in Basketball") -  I'm happy to drive out to help with construction of the sub horns any weekend.
H


3/20/2009: Pete Riggle to Harry & æ
– Harry, for amusement of others I am giving this email fairly wide distribution. What I'm doing this afternoon is figuring out the dimensions of each of the wood panels of the 15Hz flare frequency sub horn. The horn is 29 feet long in the form of an L. The mouth is 9 feet wide and 6 feet high. The throat end is 5.5 inches wide and 12 inches high. The long leg of the L is against the back wall of the loft. The short leg of the L is against the side wall of the loft. The easiest way to put it together is in simple butt-joined sections. There are four 4-foot long sections, three 2-foot long sections and one 3-foot long section. Also there is a corner section, which has an equivalent length of 4 feet.
 

The sub horn is kind of like a long piece of sausage bent into an L. We will cut it into manageable lengths and assemble. Each length of sausage has just a top and one side. The other side is a wall. The bottom is the loft floor. I'm wearing a big shit-eating grin because I just went over to Home Depot to check out materials and found that 3/4" oriented strand board floor panels are $11 for a 4 x 8 sheet. This is really good stiff material. I think 7 sheets are required. So we are talking $90 including sales tax. Not too bad! There will perhaps be another $100 in material for cleats for fastening to the walls and floor, for external stiffeners and for fasteners. This is affordable.
 

Your assistance is accepted. I think we need the equivalent of a barn-raising weekend. The loft will be all cleared out for easy access. I'll get all the hands I can round up and we'll just start measuring, cutting and screwing. You are more experienced with screwing so I have the perfect job for you. I'm thinking a weekend in June when my traveling pal Joe Burdick is here. I'm thinking many hands make light work. Me of course and Stephæn, Joe, you and Kara. Maybe Ron, maybe Christy's guy Dwayne, maybe Bill and his son Eric, maybe my son Joel. We won't turn away anyone who still has 10 fingers. The cutting will be done with a skill saw outdoors in the shade over a sheet of expendable material. No fancy joints. We will use 3 sheet wall screws to temporarily fasten down a wood cleat as a guide for each cut.  All the joints are butt joints. See, another good job for you. I have the assembly concept all figured out. Stephæn is rolling his eyes as I type. This doesn't have to be pretty.  It just needs to be stout. Think how much fun this will be.
Pete

Comment: Stephæn rolling his eyes is all about Pete’s uncontrollable sanguinity. When Pete says it will be easy, it always ends up complicated. Hence the picture at right.


3/20/09: Pete Riggle - Greetings friends, progress on our horn loudspeakers continues. The Po’ BoyZ sounded good from the outset and are getting better as Stephæn and I beat them into submission. He is such the task master! Now we are preparing to get the final two bottom octaves with a 29 foot long L-shaped sub horn that will fit into the loft of the Garden of Earthly delight, the lair of the audio friends known as the Bad BoyZ Benevolent Association. 

This horn should get down to 20Hz. Attached are images of a 1/10 scale model of the sub horn. I built the model to verify that the cutting diagrams for the full-on project will work. Looks like they will. Friend Kara Chaffee has named the scale model The Little Bighorn. If we hold to schedule, the sub horn will be playing by mid June.
Pete


Comment: As it has turned out in the end, the sub horn makes its best contribution to overall sonics when allowed to span four octaves from 20 to 160Hz.


3/24/09: Jeffrey W. Jackson to æ
- Hey Stephæn, now you are walking off into the deep waters. Once you have a bass horn, nothing else will do. Wrecked for life. I heard that some half Po Boys may be headed your way. [Here Jeffrey makes reference to a plan for a horn system whose bass has just half of the area of the Po’ Boy bass horn.] I lived and loved the old RCA phenolic midrange for years. I can still hear them in my head and that B&C 8" you heard in my horns at VSAC. I now am using four per side. Sounds wonderful.
Peace
Me

Btw, migrating to jeffreywjackson.com as my old website was hijacked and is being held ransom in some foreign country. I'm giving them the finger Johnny Cash style. Not a penny from me for that old site, much less thousands. 


Comment: Here’s the image Jeffery was likely referencing.


3/24/09: æ to Jeffrey W. Jackson - Hi Jeffrey, ah yes, I think Pete and I are ready to embark on the Po’ BoyZ Jr. We'll use the same B&C drivers and RCA midrange, just in a smaller box that will fit in my living room. We measured a single jhorn/bass bin the other day and the frequency extension is not much less (if at all) than the double so this could actually work :-)
Stay happy!
æ


Comment: Here Stephæn makes reference to Po’ BoyZ Jr. The name went from that to Po’ GurlZ to Po’ HoZ to the Po’ Lil’ Things. The latter seems to have stuck. They can be seen in Part 3 of this series (coming soon).

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