Paul S wrote:

Scooter, many houses in the Northeast were roofed by people who understand how this works, and the first few courses of shingles are "underlain" accordingly, to preclude such seepage. In Romy's case, I believe he could simply treat the entire horn like a "room", since the conditioned air from the house will moderate the horn's temperature, etc. via the horn mouth, in any case. The floor/ceiling area under the horn would need special attention before the horn was installed, with high-value insulation going into the relatively shallow joist bays, before the horns were slid in.  Then, the horns themselves would need to be fully insulated, probably with foam, and the remainder of the "gable" wall from which the horn mouths emerge should also be fully insulated.  This would complete an insulated shell around the conditioned "space", and the attic, per se, could then be fully ventilated, as it is now.

I would like to keep this site dedicated to audio subject but unfortunately I moved astray. Investigating my insulation dilemma I did not know that I would step in the middle of a huge debate that is going on in industry. My dilemma is that I would like to have my horn insulated and to ask as a “house room” but top sides of the horns are the bottom sides of roof and applying insulation above the horn means to apply insulation under the roof.

I have research the contemporary high-tech insulation products – the open sell foals, like Icynene and alike. I can mix it with led or large sand and get my mass and isolation. The question is if it right thing to do. What I will be doing is creating what the industry call “compact roof” by applying the foam under the room preventing air to move through or around the bottom of the roof, creating a complete air barrier.

This becoming very fashionable practice of foam insulating the attic is raising eyebrows in the building industry because typical techniques call for attics to be ventilated. By insulation attic from room the room get much cooler on summer and much wormer during winter but it also raises the temperature of the roof’s shingles very dramatically and prevents the shingles to be warmed during the winter. The debts are going on between builders and between the people who sell foaming services. The first one hate it, the last one love it. It is not a big deal to buy a set of DIY-targeted TigerFoam or alike and to apply it to my horn’s outside but  I am still not convinced.

Hm, I am wondering …

msaudio wrote:

I Believe You made a mistake not useing a good horn maker. He is not bending long pieces of wood, he is putting a lot of straight small pieces to get away from forming long sides. Why is he not cutting long 1/16 inch slots along the backside of the sides so the wood can bend freely? Doing it his way, you will not have a smooth contour of a horn. Sloppy work and romy you know better. The sad part he has the tools in his room to doit correct.

msaudio wrote:

It clearly showes in your mockup the thin side of the horn with a smooth bent contour not straight pieces. I have not missed anything from this fiasco. People give you way more credit then you deserve, your horn designs are very crude. Maybe You should call Jeffery Jackson up, and ask him to give you a few more pointers, this is sad. Let him know that these horns you are building are to be placed behind listening position and above your head about 10 feet and they are to be used at 42 hz to 180 hz. He might get a good laugh to just like me.  Preaching Horn Religion

Romy the Cat wrote:

OK, I need your guys to participate in brain storm and come up with an idea how the hell we might lift those horns up. They needed to be lifted 10-11 feet up and then very precisely, almost surgically slide 13-15 feet into the prepared attic opening. The leading idea was putting the horns on cobras heads and call 2000 Indians with flutes…. The former idea was to use the skylight and to hook the horns to a hydrogen dirigible…. The leading working idea is to lay 2 pitched 20 feet 4x10 and to slide the horns up using a few 2 ton come-a-long tools. I hope we will have something on attic to attach to. It would be good if we can use a forklift but the house is completely surrounded with wooden deck and I think forklift will crash it. Some king of portable jacks would be nice and the horns are large ... over 10 feet.... Well, I think the final stage of this project – to lift the things will be very funny and I am planning to make some money on it. I think if I film it then it will be a phenomenal example how to curse on all imaginable languages. I am sure the local philological faculty will beg me to sell it as tutorial….

The horns are not really a "framed structure with plywood", but they should be a "Stressed Skin" construction. Glue up everything you can.  The screws are just there to make the glue work better, and it's OK to leave them in. The idea here is to have a "monolithic" structure, especially including the skin (or, shell).  This principle is put to good practice with the "torsion box", which is by now a well-proven concept.  The braces should also be glued to the skin, to be part of it.  Since edge fastening with plywood in these situations is sub-optimal, the "braces" are really just as much "glue blocks", and they also provide better "bite" for the screws that pull the parts together so the glue can do its job.

I've also been thinking it might work best if you could "parge" (with mortar) the INSIDE of the horn.  Anyway, I think you might get better results with less material; under 1/2" should do it on the inside.

(and I agree with Jessie about the "flying bricks"; like Velvet Elvis...)

Best regards,
Paul S