There's no one and done method of speaker placement. Horn or otherwise. Its a process of trying to reach the best (in your judgment!) balance of frequency response and timing. If you go through the process you will probably wind up as I did with pretty much the Cardas arrangement of speakers about 6 feet out from the back wall and about 3 feet out from the sides. But what about "about"?
The really thorough systematic way of doing it is to start somewhere like that, play some bass warble tracks at various frequencies and write down your Radio Shack SPL meter readings with the meter where you will be listening. Which where you will be sitting matters as much as where the speakers will be. So each speaker placement generates several readings as you vary the listening position a foot or so closer or further back for each speaker placement. Of which if you are thorough there will be a lot.
Imagine a grid on the floor under each speaker. You might start 6' out and 3' in. Then 3' 4" in. Then 3' 6". Etc. Then try 6' 6" out by 3' in. You get the idea. Don't forget to check the frequency response at each of your three listening positions for each speaker placement!
Tedious yeah, but you know a better way? There isn't one!
Okay now you got speakers positioned for frequency response. Next you work on imaging. This is where you have to get really nitpicky precise. If your room is symmetrical you can measure from the wall to a corner on each speaker. If not then you will need to use a framing square and straight edge or line. This is also the method you will have to use if your room is asymmetrical in any way. If this sounds beyond anal well sorry, it works. We struggled forever in the Talon Audio room at CES one year until I said hey these conference room walls are FUBAR lets forget them and go to the framing square tape measure method. Boom. Done.
Yeah folks I set up the Talon Audio room at CES one year. Consider that when second-guessing this advice.
Final step is to fine-tune the toe-in. Toe-in varies a lot by speaker type and listener preference. What does not ever vary is that it must be absolutely symmetrical. As little as 1/16" off and you start to lose it.
The final final step is to double-check toe-in with a laser level. This is because its easier to measure the base (speaker base not speaker bass, oh never mind) but midrange/tweeter level is what counts and this will be off and everything becomes a lot harder if the floor isn't level. Then you get to tweak the speakers to get them level and double-check yet again.
What? You didn't do all this?
Whatever you have now, it will be a whole lot better when you do.
The really thorough systematic way of doing it is to start somewhere like that, play some bass warble tracks at various frequencies and write down your Radio Shack SPL meter readings with the meter where you will be listening. Which where you will be sitting matters as much as where the speakers will be. So each speaker placement generates several readings as you vary the listening position a foot or so closer or further back for each speaker placement. Of which if you are thorough there will be a lot.
Imagine a grid on the floor under each speaker. You might start 6' out and 3' in. Then 3' 4" in. Then 3' 6". Etc. Then try 6' 6" out by 3' in. You get the idea. Don't forget to check the frequency response at each of your three listening positions for each speaker placement!
Tedious yeah, but you know a better way? There isn't one!
Okay now you got speakers positioned for frequency response. Next you work on imaging. This is where you have to get really nitpicky precise. If your room is symmetrical you can measure from the wall to a corner on each speaker. If not then you will need to use a framing square and straight edge or line. This is also the method you will have to use if your room is asymmetrical in any way. If this sounds beyond anal well sorry, it works. We struggled forever in the Talon Audio room at CES one year until I said hey these conference room walls are FUBAR lets forget them and go to the framing square tape measure method. Boom. Done.
Yeah folks I set up the Talon Audio room at CES one year. Consider that when second-guessing this advice.
Final step is to fine-tune the toe-in. Toe-in varies a lot by speaker type and listener preference. What does not ever vary is that it must be absolutely symmetrical. As little as 1/16" off and you start to lose it.
The final final step is to double-check toe-in with a laser level. This is because its easier to measure the base (speaker base not speaker bass, oh never mind) but midrange/tweeter level is what counts and this will be off and everything becomes a lot harder if the floor isn't level. Then you get to tweak the speakers to get them level and double-check yet again.
What? You didn't do all this?
Whatever you have now, it will be a whole lot better when you do.