Does surround thickness have an effect on output/cone area?

[SomeGuyDude 10+ year member]

I've wondered this for a while, can't really decide what to think. I first noticed this when I saw a pic of the Eclipse Titanium 15:

That surround seems GIGANTIC to me. It looks like it's at least two inches thick if not more, leaving at best 11" of real cone area in there. Then the DD 3515:

Much thinner surround, more actual cone in there. The Eclipse's cone area looks barely bigger than the DD's dust cap.

Now, does that make a difference in output? It seems to me that the Eclipse's huge surround would turn it into barely bigger than a 12 in "real" terms, but I have no idea if that's accurate or not.

Just an idle musing.

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[T3mpest 10+ year member]

I've wondered this for a while, can't really decide what to think. I first noticed this when I saw a pic of the Eclipse Titanium 15:

That surround seems GIGANTIC to me. It looks like it's at least two inches thick if not more, leaving at best 11" of real cone area in there. Then the DD 3515:

Much thinner surround, more actual cone in there. The Eclipse's cone area looks barely bigger than the DD's dust cap.

Now, does that make a difference in output? It seems to me that the Eclipse's huge surround would turn it into barely bigger than a 12 in "real" terms, but I have no idea if that's accurate or not.

Just an idle musing.

yes it does. IIRC 2/3 the distance of the surround is included when they calculate how much cone area a woofer has.

 

[plugitin 5,000+ posts]

all depends on the company for the measurement of the cone area and the surround...

 

[nu2spl 10+ year member]

yes it does. IIRC 2/3 the distance of the surround is included when they calculate how much cone area a woofer has.

ok is that the standard formula or your formula?

 

[michaellane 5,000+ posts]

good question and great thread

 

[grimreper912003 5,000+ posts]

Wouldnt a bigger surround = more xmech though?

 

[audioholic 5,000+ posts]

all depends on the company for the measurement of the cone area and the surround...

Surround calcs should be the same, no matter whom you buy from. But some companies use high roll surrounds, some use fat surrounds, etc.

Wouldnt a bigger surround = more xmech though?

Xmech can be limited by many things, the surround being only one of them, and usually not the limiting factor. xmech means little to usable performance anyway. If its not playing linear, would you want to listen to it?

To the OP, yes obviously the surround size affects cone area.

 

[SomeGuyDude 10+ year member]

Wouldnt a bigger surround = more xmech though?

My belief is that the surround is intended to accomodate the xmech as determined by the motor itself, meaning if your sub has a 5" throw you'll need more surround than if it only goes 2". But a huge surround doesn't necessarily mean it, y'know?

Not to mention, geometrically, you can give the same "length" of surround but make it jut up higher and fold more severely in order to get more cone, y'know?

And thanks holic, that's what I figured but it seems peculiar that some companies would make their subs have these kielbasa-thick surrounds when it totally limits their output by leaving them with so little cone area.

 

[Papermaker85 5,000+ posts]

id NEVER consider the surround to displace air.. if anything the normal wide roll round surrounds are pointless when you can get good linear high roll surrounds.. the are a few things that surrounds affect.. instance,the foam high roll is the most non linear travel wise, the round rubber are the most linear under high throw, but need to be large and thick making them heavy, the high roll rubber has better integrity, can be thinner smaller and has ruffly the same linearlity as the wide roll foam, without appling force on the cone..

 

[spencer321 10+ year member]

holic was right, it depends on the company, a universal standard should be used but it is not, i've heard 1/3 counts in cone area and i've heard 1/2 counts in cone area. Some companies use a high roll surround like holic said which from above the subwoofer appear narrow but from the side are rather tall off the face of the subwoofer, some use wide and fat like that eclipse and some use the accordian style, like the newer type R.

 

[audioholic 5,000+ posts]

The 'fat' surround was basically the first surround to hit the market when the xmax wars began several years ago. High-roll surrounds have come out since, and many consider them to be superior, but some people swear by the fat surrounds.

Surrounds do move air, and Id 'never' say they 'never' factor into air displacement.