[CalypsoCowboy]

I'm wondering if I can get this answered without specifics.


I have a pretty normal rectangular room with a front projector system. I'm currently sitting about 13 ft away from the screen. My front three speakers are the same distance from the center of viewing position. I tried for a equilateral triangle between listening position and front speakers but didn't quite get it. I am however within the Dolby specs of 22 to 30 degrees I believe. My front speakers, forward facing ports are about 2 ft from the front wall and 1 1/2 ft from the side walls.


My question is regarding direction of the front speakers. Obviously I can go from forward facing or toe-in the speakers so they are facing the viewing position. I know that this changes the characteristics of the sound but what should I be listening for when I'm playing with the angle of the speakers, are there things I should avoid or things I should shoot for. I do have access to a spl meter, should I use that in my testing? Basically it all boils down to how do I set the toe-in for my front speakers?


Thanks

Josh

 

[Greg_R]

Quote:

I tried for a equilateral triangle between listening position and front speakers but didn't quite get it.

The seating is too close to the speakers. Try setting the listening position 1.5X the distance between the speakers. In other words, if the speakers are 6ft apart, put your listening position at 9ft away from the plane of the speakers.


As for toe in, start with _zero_ toe-in. If you get a solid center image, then no toe-in is required. If the center image is not clear, toe each speaker in slightly. If you toe-in too much, the soundstage will collapse (all sounds will be compressed into the center of the soudstage). With a proper setup the soundstage should extend to the left and right of your speakers (vs. being contained between the 2 speakers). If the seating position is too close then you will probably require more toe-in.


If you can't get the speakers to image very well then take a hard look at your room acoustics. This is the single most important item in your system (yes, more important than the speakers).

 

[CalypsoCowboy]

I'm guessing the speakers are around 9-10ft apart. So when I'm setting the imaging, I'm guessing I'm just using a normal cd or music in a stereo setting. Then what I'm looking for is a good right, center, and left image?

 

[jsalk]

Setting the right toe-in is the process of optimizing imaging and sound staging. As the speakers are toed in more, imaging will improve. As they are moved outward, the sound stage increases in size. The optimum between these two will be reached when imaging is still very good, but the sound stage is as large as possible.


This is rarely accomplished with the speakers pointed straight forward.


Here is what I would recommend: Start with the speakers pointed directly at the listening position. Put on a good recording of a female vocalist that is panned dead center. Make sure that it is not a recording that has a huge orchestra or band behind her (jazz or classical works well).


Listen to the track a few times making sure that, from the listening position in the "sweet spot," she is dead center.


Once you get used to the way she is imaged, start reducing the amount of toe-in gradually. Listen to the same track, making sure the imaging is still precise.


Keep doing this until the imaging begins to suffer. Then back off to the previous setting and you are done.


It's really quite simple. It just takes a little time and some critical listening to get it right.


I hope this helps.


- Jim

 

[rynberg]

To add to what the other posters said:


1. Increased toe-in will also result in a little more high-frequency energy being directed to the listener. It will also reduce the effects of reflections off of the sidewalls (good thing).


2. Increasing toe-in will also make the "sweet spot" narrower. A wide listening area will be better served by less toe-in.

 

[CalypsoCowboy]

Perfect, thanks for the help.

 

[dsmith901]

My speaker/sitting position arrangement is very close to yours, and I have my full-range speakers pointed directly at my seat. Imaging and soundfield are perfect. You don't have to arrange a perfect equilateral triangle, but if the speakers get too far apart you start to lose accuracy in imaging. Anyway, at your sitting distance room modes dominate - about 60-70% of the sound reaching your ears is from the room - not directly from the speaker. And your speakers are pretty close to side walls so you are probably on the high side there. I would not move the speakers any closer together, although you might move your seat about a foot closer to the screen. But you should find a real benefit to some acoustic treatment in the room, and especially to the side walls where the speakers make their first reflection. Use a mirror flat against the wall to find that position and put absorption there, about 2' X 2' minimum size. If you have not already done so you should read up on room acoustics - it will pay off.

 

[biomed_eng_2000]

Most speakers' response RAPIDLY fall off on the high end at anything over 15 degrees. I always try to angle the speakers so they face me directly. You then use room acoustic treatments to tailor the soundstage.


Edit: I changed 10 degrees to 15. Most speaker measurements use 15 degrees as a standard, not 10 degrees.

 

[rynberg]

Quote:

Originally posted by biomed_eng_2000 Most speakers' response RAPIDLY fall off on the high end at anything over 10 degrees. I always try to angle the speakers so they face me directly. You then use room acoustic treatments to tailor the soundstage.

What do you define as the "high end"? 30 kHz? A 1" tweeter doesn't become that directional until above 10 kHz.....

 

[RCbridge]

Trial and error!!

Whichever angle sounds best to you!!

 

[biomed_eng_2000]

 http://www.soundstagemagazine.com/speakermeasurements/


If your speaker is listed above, then you can see how much or how little angling will or will not effect the direct frequency response.


Room acoustics must be used to get the best sound.


As it has been said, the worst sounding component of an audio system is usually the room.

 

[John Robert]

Interesting link...

 

[samandnoah]

Quote:

Originally posted by biomed_eng_2000 http://www.soundstagemagazine.com/speakermeasurements/ If your speaker is listed above, then you can see how much or how little angling will or will not effect the direct frequency response. Room acoustics must be used to get the best sound. As it has been said, the worst sounding component of an audio system is usually the room.

Can someone provide a simplified explanation of how to use those charts:


A) In thinking about toe-in required? I'm assuming that the more the drop off as you go further off axis, the more toe-in would likely be required


B) Comparing 2 different speakers with each other?


Regards,

Rich

 

[jcilarry]

Well not much new to ad to the comments above but I have been using stand mounted speakers for years and the toe in is one of the easiest significant changes you can make. Sounds like your seating distance is fine, a change I do in a new set up is to listen to the speakers set at different distances apart. Your seating will probably be determined by traffic flow in the room, a desire to not be against the back wall to optimize surround and so on. I usually end up with the speakers set not quite facing the sweet spot. My current speakers are very forgiving with this so I have the luxury of then going to each of the most side placed seats for movie watching and confirm a decent sound stage from the cheap seats as well during listening trials. Nothing screws up the side sound more than speakers facing directly forward.


Anyway it is fun to make a change you can actually readily hear the difference with as opposed to trying to discern a difference in speaker wires for example.