Question about toe-in for speakers.

[Rambo4]

Hi, I am wondering if there is a general rule regarding toe-in for your front speakers in a 18 x 14 dedicated HT room. My setup has a 92" screen with two bookshelf speakers approx. 4 feet off the floor and 9 feet apart facing me directly, as well a center channel 7 feet off the floor above the center of the screen. My seating position is 12 feet from the screen. Should I be concerned about sound quality issues with this sort of setup? Should I have the speakers facing a bit away from me for better quality?

Thanks for any input.

[Ethan Winer]

Rambo4 wrote:

My seating position is 12 feet from the screen. Should I be concerned about sound quality issues with this sort of setup? Should I have the speakers facing a bit away from me for better quality?

Loudspeakers should be pointed directly at you. Also, the main problem I see with your seating position is you're only two feet in front of the wall behind you. The inevitable peaks and nulls are always worst right in front of a wall. So you should consider absorption on that wall, especially the area directly behind your head.

--Ethan

[Rambo4]

Hi Ethan, thanks for the response. I guess I labeled the room dimensions in the wrong way. The depth of the room is 18 feet. and the width is 14 feet. So there is about 6 feet behind me. Sorry for the confusion.

I will keep the speakers pointing at me, thanks for the confirmation.

[atledreier]

That is not an absolute truth, though. My speakers' manufacturer recommend nearly straight forward placement, with close to zero toe, and they definetly sound best that way. So I'd say read the manual and go with the recomendations in there.

[bpape]

Agreed. Every speaker is different. Frequency response can vary drastically with just a few degrees difference in on and off axis. In general, I prefer to point most speakers about 3' behind my head. Others work better direct or straight ahead.

Also, it makes a difference whether you're listening nearfield or farfield. In a studio with monitors, you're normally VERY nearfield where in home situations, especially home theater, you're in the far-field.

Lastly, in a home theater, there's more than one seat to consider. If you point the mains right at the center seat, you're horribly off axis on the side seats of the row.

Bryan

[tonyvdb]

As some have suggested. Toe-in varies from speaker to speaker. Some speakers need to have some toe-in due to the design of the cabinet and placement of the tweeters. To continue getting the proper stereo imaging speakers should not be over angled thus causing over lapping of the sign waves just like the issue with MTM centre channel speakers. The farther back you sit away from the speakers (more than 10ft) the less toe-in is needed.

[Rambo4]

Thanks for all the helpful responses. I had written the manufacturer of my speakers (Athena - and from the email signature it also says Klipsch Group Inc.) to find out from them what their recommendation would be, as I could not find any information in the user guide or their website.

Within a few hours I was emailed a response from one of their tech support specialists. He said, as you have said here, that there is no hard and fast rule. He said I should experiment, but he also gave me the THX recommendations for viewing and speaker placement. (Which I will use as my starting point.) Then I should watch the same movie scene over and over with changing the angle/location of my front speakers.

I will give it my best shot.

[WmAx]

DS-21 wrote:

I disagree with the lattermost point, because one other benefit of toeing in speakers is that one minimizes interaction with the near side walls. If anything, at longer distances maximizing the direct sound compared to reflections becomes more important.

Depends entirely on the speakers and distances involved. If the speaker has an off axis response at the reflection point that is very similar to the on axis response, and if the speaker system is of low resonance, and if the delay between on axis and arrival and reflection arrival at the listener is at least about 4msec, then the reflection is highly desirable. Such a reflection under these rare set of circumstances would be distinctly beneficial, increasing timbre resolution in the signal and increasing perceived sound quality and in better giving an impression of the recorded spatial information(if present), according to the credible perceptual [1][2] texts on this subject.

With many speakers, in many environments? Absorbing the reflection points is probably a benefit more often than not.

-Chris

Footnotes

[1]The Modification of Timbre by Resonances: Perception and Measurement", Floyd Toole, Sean Olive, JAES, Vol. 36, No. 3, 1988, March, pages 122-141

[2]Loudspeakers and Rooms for Sound Reproduction—A Scientific Review
Floyd E. Toole
JAES, June, 2006, Vol. 54, pages 451-476

[bpape]

... and in most cases, reflections are longer than that and the off-axis response is VERY different from the on-axis so the reflection should be absorbed.

All of this assumes we're speaking of mid and high frequencies. Low frequency reflections off of very near surfaces can cause severe response abberations and need to be absorbed.

Bryan

[WmAx]

bpape wrote:

... and in most cases, reflections are longer than that and the off-axis response is VERY different from the on-axis so the reflection should be absorbed.

All of this assumes we're speaking of mid and high frequencies. Low frequency reflections off of very near surfaces can cause severe response abberations and need to be absorbed.

Bryan

Well, the ideal delay is roughly in the 4-10 msec range. Which is dictated by spacing of the speaker from wall and the vector path to the listener. A 2-4' space/distance from the side wall would be sufficient in most cases. However, it is unfortunate that not many speakers will have an off axis response sufficient to make this reflection a real benefit. This side reflection would roughly correspond to about 55-60 degrees off axis response of the speaker, on average, considering typical set ups and slight toe-in. I don't know of many speakers(at any price range) that have a very similar response of the on axis response at such an angle. Typically, at 60 degrees, the off axis is a radically different curve; not ideal.

-Chris

[Rambo4]

Whoa guys. Slow down. Don't lose me here...

From what I can ascertain, from the posts, is that off axis or on axis response may be better perceptually depending on speaker and acoustic treatment on the walls. My speakers are known for sounding "bright", so perhaps a bit of an off axis placement combined with my Auralex acoustic treatment on the side walls at reflection points, may do the trick.