What does 'toe-in" and 'box design" mean? [Archive] - Audio & Video Forums

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Doc Adams
06-14-2004, 06:29 AM
I posted a 'sound out of balance' question. One of the friendly answers I got stated that:

"Going to a box design speaker, Platinum Studio 3, toe-in and recalibration seem to solved the problem for me. "

I just don't understand the terminology yet. Too new to the hobby.

Thanks again,

Doc

Bryan
06-14-2004, 06:49 AM
To toe in a speaker is to angle more towards the listening position. Rather than having it face straight out you are pointing it towards where you sit.

A box speaker is generally either square or rectangular in looks. Clean cut edges and lines. My Rocket RS550s could be considered box or traditional looking speakers. My nOrh 4.0s and 5.1s, OTOH, would not be even close as they look closer to either hams or jet engines.

kexodusc
06-14-2004, 06:59 AM
Doc Adams, toe-in is quite useful and may help your situation, but be careful...I've seen too many people "over"toe their speakers.
Here's a useful link for stereo (front 2-channel) speaker placement you may or may not have seen already with links to other good sources:
http://www.gcaudio.com/resources/howtos/speakerplacement.html

topspeed
06-14-2004, 11:34 AM
In my experience, a "box speaker" is anything that is not a panel speaker such as Magnepan magnetic planar or Martin Logan electrostat. It seems enthusiasts are quite emotional about one or the other, sort of like the tube vs. ss argument. I'm not quite sure where line array speakers such as Epiphany(sp?) fall into this debate...hybrid maybe?

Toe-in is exactly what Bryan and KC say. Some manufacturers even recommend pointing the tweeters so the sound intersects a foot in front of the listening position. I've found it best to start w/ zero toe-in (i.e. speakers are perpendicular with the wall firing straight ahead) and slowly toe-in as necessary to solidify the image, much like focusing a camera. It helps if you have someone help you btw.

Good luck

Worf101
06-15-2004, 08:03 AM
Sit in the listening position. Shine a flashlight on the tweets or woofers or some reflective surface until the reflection bounces back just right...

Da Worfster

skeptic
06-15-2004, 11:30 AM
Well RL, here's one of those questions you would not have us answer. Like many seemingly simple questions, this one might have a lot of ramifications to it.

Loudspeakers do not propagate their energy omnidirectionally. Not only that, but to a fairly great degree, the degree of directionality depends on the frequency. In general, loudspeakers become increasingly directional as frequency increases. One reason many tweeters are small and dome shaped is that this serves to reduce this tendency towards high frequency beaming but it does not eliminiate it by a long shot. Therefore what you hear depends to a degree on where you sit relative to your loudspeaker. If you sit directly in line with it, not only will it be loudest for a given distance but the relative high frequency content will be proportionally greatest. As you move off to one side or off its axis, the loudness will decrease and more importantly, the relative loudness of the highest frequencies will decrease to a greater degree. Since stereophonic sound reproduction requires two loudspeakers, and since our sense of directionality is to some degree dependent on high frequency cues, our perception of the stereophonic effect including what some people refer to as imaging depends on our relative position with respect to the speakers, the tweeters. Normally, people tend to aim their speakers straight forward with their axies in parallel so that no matter where they listen from, they will be off to one side (off axis) from at least one of them. By pointing them directly at you in your optimal listeing position, usually on a line midway between them, you can be on axis with respect to both of them at the same time. The difference may be very subtle or substantial depending on the particular speakers you own and your installation.

pdawg17
06-29-2004, 03:06 PM
Worf-

Is the flashlight method true for all speakers? So the speakers should be facing directly at the listening position? I know it may need to be adjusted but is that a good place to start?

Worf101
06-29-2004, 06:21 PM
Worf-

Is the flashlight method true for all speakers? So the speakers should be facing directly at the listening position? I know it may need to be adjusted but is that a good place to start?

I'm not sure but most conventional "Box"type speakers could be adjusted in this manner.

You sit equidistant to the two mains, kinda like a point of a triangle, there's a formula for the "optimum" distance between mains for a given listenting distance, but it escapes me. Whlie you're sitting in this seat, have someone toe in the mains till you see the reflection shining right back at you and voila, the speaker are pointing right at ya.

Da Worfster

skeptic
06-29-2004, 06:51 PM
I didn't address the question of "box design."

Most loudspeaker drivers, especially woofers are intended to be mounted in an enclosure of one sort or another. Besides providing a convenient physical platform for them to exist in, the enclosure performs several important acoustic functions. Because the sound as seen from the back of a speaker is in the opposite sense (out of phase) with sound from the front, without an enclosure, when these sound waves meet, they will tend to cancel each other out. This is most pronounced in the bass. A loudspeaker without an enclosure will generally produce much less bass. I'm not going to get into the many different design philosophies of how an enclosure or box should be designed for a particular loudspeaker but it is enough for this purpose to say that there are several important different types based on different design concepts with names like folded horn, horn, bass reflex, infinite baffle, transmission line, and acoustic suspension. Each concept has its advantages and disadvantages and each has its partisans who favor it and argue for it above all others. Examples of each type run the gamut from excellent to poor. The "box" also holds the other drivers in a fixed relationship to each other and can play a role in how sounds from each driver in a multidriver system interact with the others. The goal is of course to minimize such interaction and some designers go to extremes towards this end. There are also loudspeaker types which are flat panels having no conventional enclosure whatsoever being mounted on a free standing frame. To a significant degree, these types usually don't have the low frequency capability of the better "box" speakers unless special measures are taken. One measure is to enhance the panel speaker's bass with a subwoofer, a box speaker specifically designed to produce only deep bass. This is one limitation you accept as part of the package when you buy a boxless speaker. Owners of flat panel speakers sometimes use the word "box" referring to speaker systems in enclosures in a derogatory sense. They especially ridicule unintended bass resonances many box designs suffer from.

pdawg17
06-29-2004, 10:13 PM
I have some in-walls (Paradigm) for surrounds (per wife request)...would it be helpful to try and create an enclosure for them? I did put some insulation in the walls and I know they can never sound as good as boxed speakers but I'm up to try anything...they actually sound fairly good for in-walls...since Paradigm designed them to be intended for in-walls, could building an enclosure actually make it worse?

topspeed
06-29-2004, 11:25 PM
I have some in-walls (Paradigm) for surrounds (per wife request)...would it be helpful to try and create an enclosure for them? I did put some insulation in the walls and I know they can never sound as good as boxed speakers but I'm up to try anything...they actually sound fairly good for in-walls...since Paradigm designed them to be intended for in-walls, could building an enclosure actually make it worse?
Yep.

In walls are designed with "free-air" or "infinite baffle" considerations. The drivers for such applications are usually much stiffer as they don't enjoy an enclosure to help pressurize them. By putting your Paradigms in an enclosure, I'd venture that you'd actually get poorer sound. I'm no engineer but I know this is true for car subs.

ksing44
07-06-2004, 04:01 AM
My understanding is that the high frequencies are directional, so you want the tweeters aiming at your "sweet spot" for listening. I like using a laser pointer to help me aim my speakers. Just hold the pointer against the side of the "Box" and adjust the different speakers in your system. I align my speakers in a symmetrical pattern. My main speakers are toed in toward the listening position. The laser light crosses just in front of me and lands on the back wall on either side of my listening position. My main speakers are also angled up, just slightly, to align the sound with my seated listening position. I also toe in the rear speakers by aiming them toward the TV. I donít aim the rear speakers directly at the listening position, because my understanding is that the rear effects are supposed to be less localized to any specific location. My center speaker is placed on a shelf over top of the TV and it is angled down so the light/sound shoots right where I am sitting in my listening position. The low frequencies are not directional, so aiming the subwoofer is not an issue.

Here is a link to see my system with a photo and a diagram.

http://forums.audioreview.com/showthread.php?t=3358