Checkpoint SA-S P-770 laser alignment tool Robert Deutsch November 1998
When it comes to positioning loudspeakers in the listening room, you can never have too much accuracy. The ideal is to position each speaker in such a way that the distance to the listening seat is exactly the same, and the speakers have exactly the same vertical orientation and angle of toe-in. Once the speaker-to-listener distance of the two speakers is closely matched (you'll need a measuring tape and the help of an understanding Significant Other), you'll need to adjust the toe-in. The amount of toe-in is partly a matter of personal preference: less toe-in normally results in a wider soundstage, but may lead to a hole in the middle. Whatever toe-in you decide is right for you, it must be the same for both speakers. Vertical orientation is just as important; if it's not the same for both speakers, the listener could be on-axis for one and off-axis for the other.
Checkpoint's SA-S P-770 laser alignment tool is the ideal device for positioning speakers. I found out about this gizmo from Lonnie Brownell's "Industry Update" item in Vol.21 No.1, and my review of the Dunlavy SC-IV/A elsewhere in this issue provided the first opportunity to check it out for myself. Essentially, I concur with Lonnie: The P-770 should be in the tool chest of every audiophile who wants to get the best sound from loudspeakers.
To use it, you turn on the laser, hold the P-770 against the speaker's front panel, and adjust the speaker's position until the appropriate toe-in and vertical orientation are obtained. I used a large piece of cardboard placed in the listening seat to see exactly where the laser was pointing. Using the P-770 is more accurate than any other method, like the common one of eyeballing the speaker from the listening position. The P-770 looks and feels like a precision instrument, and is good value at $189.95. There are a variety of accessory devices available for it, but they're mostly for use by custom home-theater installers. (The Checkpoint Sound Alignment System has been approved by THX.)