I have some speakers and I want to ... predict locations for them.

[dalewestae]

Hi guys and gals.... Need some help creating an excel equation to help solve a real word problem.
I have some speakers and I want to create an excel file that can predict locations for them. The speakers will all be placed along a straight line with a fixed gap between them (this number is variable but the gap is the same in every instance). Lets call that gap "X"

Some times the speakers need to be grouped in pairs or groups of 3 or more. Again these groupings apply to all speakers. For the rest of the description I'll cal them blocks. I.E. blocks of two or blocks of three and so on. Let's call the block size "Y"

The speakers are exactly 1.7 feet wide and I am trying to solve for the center point of each speaker (0.5*1.7)

The set up will be symmetrical from center stage (0) so if X=3 feet than speaker "A" would be (0.5*3)+(0.5*1.66) = 2.3
I can easily make an inverse in order to figure out left from right of center.

I would attach my xls file but it wont let me. Ultimately I would like the excel sheet to only have two edited cells. X and Y

I hope I've given you all the info you need to help me out. questions are welcome.
I appreciate you taking a look!

 

[stapel]

I have some speakers and I want to create an excel file that can predict locations for them.

What will be the (mathematical or other) basis for their locations?

The speakers will all be placed along a straight line with a fixed gap between them (this number is variable but the gap is the same in every instance). Lets call that gap "X"

In what manner is the gap variable but also fixed?

Some times the speakers need to be grouped in pairs or groups of 3 or more. Again these groupings apply to all speakers. For the rest of the description I'll cal them blocks. I.E. blocks of two or blocks of three and so on. Let's call the block size "Y"

What is the (mathematical) point of these blocks?

The speakers are exactly 1.7 feet wide and I am trying to solve for the center point of each speaker (0.5*1.7)

Why would the center of a speaker not be "0.5 * 1.7"? Why are you needing to "solve" for the center point of each speaker?

The set up will be symmetrical from center stage (0) so if X=3 feet than speaker "A" would be (0.5*3)+(0.5*1.66) = 2.3

On what basis have you decided that no speaker would ever been exactly in the middle? What is the source, in your computations, of the "1.66"?

Are you maybe saying that you're attempting to set up a spreadsheet which, when you input the stage width and depth, number of speakers available (or allowed), how you want to group speakers (if at all), and maybe some other data, will then tell you how to space the speakers and where to set them out? Thank you!

 

[dalewestae]

What will be the (mathematical or other) basis for their locations?

Based on a per case basis. Factors like stage length, number of speakers that will be used and wavelength of sound

In what manner is the gap variable but also fixed?

Sorry I realize that was poorly worded. They're fixed because the gap between every block is identical. They are variable because depending on the logistics above and the opinions of the designer every set up will be different. Usually between 2 and 5 feet

What is the (mathematical) point of these blocks?

The blocks don't have a mathematical point. Their only relevance here is that they have an effect on the relative speaker locations. Looking at the PNG I attached speaker - The top example shows speaker "C" being after the gap. In the bottom example it isn't. One thing I didn't say in the initial thread is that this equation will be 20 speakers (40 total) so after 10x possible gaps the location of speaker "T" will be very different depending on "block" size.
I hope that clears it up....

Why would the center of a speaker not be "0.5 * 1.7"? Why are you needing to "solve" for the center point of each speaker?

Because I'm taking these points into a prediction application that wants the center point. Unfortunately it doesn't do this spacing math for me and I'm tired of doing it by hand every show. The 1.66 VS 1.7 was my editing mistake. Technically its 1.66 but in real life 1.7 makes it easier to deal with.

On what basis have you decided that no speaker would ever been exactly in the middle? What is the source, in your computations, of the "1.66"?

I always have an even numbers of speakers.
1.66 (rounded to 1.7) is the width of this speaker as per its datasheet.

Are you maybe saying that you're attempting to set up a spreadsheet which, when you input the stage width and depth, number of speakers available (or allowed), how you want to group speakers (if at all), and maybe some other data, will then tell you how to space the speakers and where to set them out? Thank you!

Not exactly. What I need is a spreadsheet that tells me where the center point of each speaker is based on my decisions as a designer. Then I can enter those points into prediction software to see how the each speaker interacts with one another. Unfortunately the prediction software doesn't do this kind of spacing math. Only a perfect symmetrical spacing, no blocks and I cant enter in the spacing I want.

Thank you