After a decade in storage, it's time to knock the dust off of my Khorns. I put these away 10 years ago in a fit of frustration, as they simply did not work well in my room. But the mighty khorns have been calling from the storage room, and I finally gave in and brought them back out. My wife got to shake her finger at me and say "I knew this day would come".
So for the last decade I've been designing and building my own speakers, and have had some excellent successes. I've also added a significant amount of room treatment, and tweaked the rest of my system to the point that I was very pleased with my sound. So now it's time to screw something up so I can fix it again
I've attached a few diagrams below. The first is a picture of the room, showing that everything just barely fits. It does double duty as a theater, so it's important that the sound can be configured for both. What is not shown is that it is also an L-shaped room (I'm standing in the L). There may be nothing more evil than an L-shaped room. It took a lot of work and room treatment to get rid of the annoying modes and achieve a decent stereo image without having the speakers out in the middle of the room. I had a horrible mode right at 250 Hz that I was finally able to squash with bass traps. Also the walls are wood, and it was pretty lively before treatment.
The fundamental difficulty with the khorns is that they were spaced pretty closely together. So the sweet spot was several feet in front of the seats. Because of the movie screen, as well as the limited width of the room, full size false corners were not an option. Tucking these tightly into the corners I have is the only way to go.
Now for the mod. Since I last had these out, there have been some very good looking mid-horn replacements that have hit the market. I've always been leery of the k400 horn, as it beams like a flashlight, and can be pretty shrill on top of that. I've been reading some great reviews of the eliptrac 400 horn, and also the v-trac horn. What I would like to do is use one of the newer horns that uses a 2" driver. They are considerably shorter than the k400, and that would allow me to try something that I only dreamed of 10 years ago. I would like to angle the horn baffle so that it points more directly into the room. This would allow me to keep the bass bins tightly coupled into the corners, while directing the mid and tweet horns more toward the seating arrangement. I'm envisioning building a wrap-around grill that has no baffle board that will fit in the top hat and look like stock from the front. Behind the grill, I would have the two horns angled about 15 degrees pointing forward. If you look at the two diagrams, you will see what I mean. The first is top-view of the khorn containing an eliptrac 400 and a JBL 2404. It looks like there is plenty of space to fit the new baffle in the top hat. The second diagram shows the setup in my room. The blue lines represent the "sound" shooting straight out from the stock khorn. The red lines are shooting straight out from the angled baffle. The red lines are how I typically toe-in box speakers, where they cross just in front of the seating. This seems to sound best in this room.
So - I had a couple of questions. First - has anyone tried something similar? My one big concern is diffraction created by moving the baffle inside of the top hat. I was thinking that putting acoustic foam above and below the horn mouth might help to counteract any negative effects. The second question is has anyone tried the eliptrac horns? What do you think? I've read many good things, but before I march down a path that might lead me astray, I'd ask for any opinions.
Thanks,
Mark
So for the last decade I've been designing and building my own speakers, and have had some excellent successes. I've also added a significant amount of room treatment, and tweaked the rest of my system to the point that I was very pleased with my sound. So now it's time to screw something up so I can fix it again
I've attached a few diagrams below. The first is a picture of the room, showing that everything just barely fits. It does double duty as a theater, so it's important that the sound can be configured for both. What is not shown is that it is also an L-shaped room (I'm standing in the L). There may be nothing more evil than an L-shaped room. It took a lot of work and room treatment to get rid of the annoying modes and achieve a decent stereo image without having the speakers out in the middle of the room. I had a horrible mode right at 250 Hz that I was finally able to squash with bass traps. Also the walls are wood, and it was pretty lively before treatment.
The fundamental difficulty with the khorns is that they were spaced pretty closely together. So the sweet spot was several feet in front of the seats. Because of the movie screen, as well as the limited width of the room, full size false corners were not an option. Tucking these tightly into the corners I have is the only way to go.
Now for the mod. Since I last had these out, there have been some very good looking mid-horn replacements that have hit the market. I've always been leery of the k400 horn, as it beams like a flashlight, and can be pretty shrill on top of that. I've been reading some great reviews of the eliptrac 400 horn, and also the v-trac horn. What I would like to do is use one of the newer horns that uses a 2" driver. They are considerably shorter than the k400, and that would allow me to try something that I only dreamed of 10 years ago. I would like to angle the horn baffle so that it points more directly into the room. This would allow me to keep the bass bins tightly coupled into the corners, while directing the mid and tweet horns more toward the seating arrangement. I'm envisioning building a wrap-around grill that has no baffle board that will fit in the top hat and look like stock from the front. Behind the grill, I would have the two horns angled about 15 degrees pointing forward. If you look at the two diagrams, you will see what I mean. The first is top-view of the khorn containing an eliptrac 400 and a JBL 2404. It looks like there is plenty of space to fit the new baffle in the top hat. The second diagram shows the setup in my room. The blue lines represent the "sound" shooting straight out from the stock khorn. The red lines are shooting straight out from the angled baffle. The red lines are how I typically toe-in box speakers, where they cross just in front of the seating. This seems to sound best in this room.
So - I had a couple of questions. First - has anyone tried something similar? My one big concern is diffraction created by moving the baffle inside of the top hat. I was thinking that putting acoustic foam above and below the horn mouth might help to counteract any negative effects. The second question is has anyone tried the eliptrac horns? What do you think? I've read many good things, but before I march down a path that might lead me astray, I'd ask for any opinions.
Thanks,
Mark
