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-   -   I have the answers to how speaker configuration will affect volume. (http://www.talkbass.com/forum/f15/i-have-answers-how-speaker-configuration-will-affect-volume-1011630/)

 danielfnj96 08-30-2013 10:07 PM

I have the answers to how speaker configuration will affect volume.

2 Attachment(s)
Well i known that there are many factors i'm not accounting for like the enclosure the speakers are in, how the speakers were made, ect. but i have a chart that will help estimate a cabinets volume. The chart simply shows the moving surface area in various cabinet configurations. Hopefully there should be a file and a picture below.

 CL400Peavey 08-30-2013 10:13 PM

Surface area doesnt tell you anything but the surface area. Displacement is what matters.

 walterw 08-30-2013 10:17 PM

still, cool chart; thanks for posting it.

 Vince Klortho 08-31-2013 01:55 AM

There are three problems with it. First, surface area is a two dimensional quantity, not three - square inches, not cubic.

Second, displacement is what matters and that is the product of surface area and excursion. Excursion is not accounted for in the chart and varies widely among speakers.

Third, the formula for the speaker's surface area is not quite correct because it does not account for the surround. As an example, Eminence lists the surface area (Sd) of the 3010HO as 0.03661m2 which corresponds to 56.75in2 whereas you have it listed as 78.6. That is a considerable difference. If we solve the area equation for the radius we find that the 3010HO has a radius of 4.25 inches which means it has a surround of 0.75 inches. A typical 12 will have a surround of about 0.875 inches and a typical 15 will have one of about 1.0 inches and even those can vary by around 0.1 inches for speakers of the same size. Yes, I know I have written this many times but people continue to ignore it and the numbers from the manufacturers verify this to be correct.

What you could do is write a spreadsheet with this formula :

displacement = speakerCount x surfaceArea x excursion
where surfaceArea = pi x ( radius - surround )2
and radius = diameter x 0.5

Then you will be in agreement with manufacturer's specifications.

It isn't generally considered a smart idea to measure an area in cubic inches.

 danielfnj96 08-31-2013 03:12 AM

Quote:
 Originally Posted by Jazz Ad (Post 14806750) It isn't generally considered a smart idea to measure an area in cubic inches.
Yeah i just realized that it should have been square inches sorry about that.

 danielfnj96 08-31-2013 03:19 AM

Quote:
 Originally Posted by Vince Klortho (Post 14806746) There are three problems with it. First, surface area is a two dimensional quantity, not three - square inches, not cubic. Second, displacement is what matters and that is the product of surface area and excursion. Excursion is not accounted for in the chart and varies widely among speakers. Third, the formula for the speaker's surface area is not quite correct because it does not account for the surround. As an example, Eminence lists the surface area (Sd) of the 3010HO as 0.03661m2 which corresponds to 56.75in2 whereas you have it listed as 78.6. That is a considerable difference. If we solve the area equation for the radius we find that the 3010HO has a radius of 4.25 inches which means it has a surround of 0.75 inches. A typical 12 will have a surround of about 0.875 inches and a typical 15 will have one of about 1.0 inches and even those can vary by around 0.1 inches for speakers of the same size. Yes, I know I have written this many times but people continue to ignore it and the numbers from the manufacturers verify this to be correct. What you could do is write a spreadsheet with this formula : displacement = speakerCount x surfaceArea x excursion where surfaceArea = pi x ( radius - surround )2 and radius = diameter x 0.5 Then you will be in agreement with manufacturer's specifications.
I really only did this because i was bored and though it could be interesting to see what the gross estimates would be rather than a serious scientific analysis. Even without the 3d aspects though i feel that the numbers are still relevant to how much volume a speaker can put out.

 Stumbo 08-31-2013 03:23 AM

Quote:
 Originally Posted by danielfnj96 (Post 14806865) I really only did this because i was bored and though it could be interesting to see what the gross estimates would be rather than a serious scientific analysis. Even without the 3d aspects though i feel that the numbers are still relevant to how much volume a speaker can put out.
IME, feelings are great for your GF but really don't do that much for measuring stuff.

You can replace "feel" with "believe" and you'll be in the same place.

 Vince Klortho 08-31-2013 04:30 AM

Quote:
 Originally Posted by danielfnj96 (Post 14806865) I really only did this because i was bored and though it could be interesting to see what the gross estimates would be rather than a serious scientific analysis. Even without the 3d aspects though i feel that the numbers are still relevant to how much volume a speaker can put out.
Yes, it is definitely relevant but surface area is only one of the factors in displacement volume. One can not ignore the excursion.

:)

 Arjank 08-31-2013 06:47 AM

Quote:
 Originally Posted by danielfnj96 (Post 14806865) I really only did this because i was bored and though it could be interesting to see what the gross estimates would be rather than a serious scientific analysis. Even without the 3d aspects though i feel that the numbers are still relevant to how much volume a speaker can put out.
Most people(bassists) follow their gut feeling (and ears), there's some truth in cone-area and the (percieved)volume a speaker can put out.

Soundwise I rather have lots of cone-area and small xmax then little cone area and large xmax. Why? cuz the coupling to the air is better and the distortion is lower (remember those ol' Altec, JBL, ect 15" drivers?)
But, nowadays people want heaps of lowend in small packages so small drivers with large xmax are used.....

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