Using SubAligner for crossover alignment is simple, but sometimes getting accurate distance measurements is not.
If you use a laser disto then you may have run into some challenges getting good data in direct sunlight. 😎
Here are some of my favorite tips to get accurate measurements:
- Get closer. If you calculate your alignment position with Merlijn’s Sub Align calculator, you will often find that the best alignment position is a lot closer than you thought. This will make a distance measurement a lot easier to do.
- 3D design. If you can get the distances from an accurate 3D model ahead of time, that’s the easiest way.
- Target. Many laser distos come with a mirror that you can attach to the speaker. Anything reflective will work. Of course, you’ll need to figure how some way to attach it to the front of the speaker that you can remove afterwards. Consider attaching a string or nylon line so you can pull it down when you’re done measuring.
- Camera. My laser disto has a camera on it. This makes it much easier to aim. You still need something shiny to aim at, though, and for longer distances you’ll need a tripod for accurate aim since your hands will never be still enough.
- Right triangle solver. If you can’t get a lock on the speaker, you can put the disto on the ground and aim at a target on the ground below the speaker. Then measure the height of the speaker. If it’s an array you’ll need to figure out the distance from the bottom of the array to the center and add that on. Then use a right triangle solver (just google it) to find the hypotenuse. This will also save you if there are obstructions like chairs in the way of your sub measurement. (You’ll find a handy triangle solver in the SubAligner app.)
- Right triangle solver v2. You can get insanely powerful lasers online for cheap. My wife bought one to play with our cats and it’s widely bright. If you were to strap that to your inclinometer, that would give you the small angle of a right triangle. Then, you just need one other measurement, like the height of the array, and you can solve the whole thing.
- Range finder. I keep a golf range finder as a backup. It’s only accurate to within 1m, but it’s better than nothing and can be used to verify questionable laser disto readings. I have heard from colleagues that higher quality range finders are much more accurate than this.
- Alternatives: tape measure, measuring wheel, or proxy loudspeaker (see quote below). You can use an audio analyzer in conjunction with a proxy loudspeaker to get the time of flight between it and your microphone.
- Get a better laser. I’ll put this one here at the end because it makes me sound like an asshole, but it’s important to point out that laser distos in the $500-1,000 range can have superior lasers that are easier to see.
Delay finders struggle with subwoofers because subwoofers reproduce only a fraction of the audible spectrum leaving too little data for the delay finder to lock onto.
The proxy loudspeaker’s sole purpose is to add the frequencies which are missing from the subwoofer, allowing the delay finder to detect arrival time again.Subwoofer Alignment: The Foolproof Relative / Absolute Method
I wish there were some glasses you could wear that would highlight the laser dot or some kind of scope or sight. I see that the firearm community has a lot of cool toys like this, but haven’t found one that would actually help us.
Is there something in the consumer product range that can give the accurate distance between two locations or probes?
What are your favorite distance measurement tips?