Dual spider designs

[sandt38]

I've been doing some research lately and have come to a point of, well confusion.

Dual spider designs are rather rare, yet to me, seem most effective for use in high output/high SQ designs.

My thought is the VAS rising so much higher makes for an unrealisticaly small sealed enclosure, but is this correct? I mean, weaken the spiders some and we have a sweet small sealed enclosure ideal for automotive use.

Why is it that the suspension cannot become more compliant, overall, through softer spiders? I guess overall isn't a good choice of words, but proportional maybe. It seems to me that linear increases, thanks to a dual spider design, can be huge, and the simple fact that it can maintain it's linearity throughout a greater cone excursion thanks to the mechanical assistance of such a design could yeild HUGE benefits (in sealed enclosures). I continue to express sealed as I have yet to find a ported enclosure that I consider SQ oriented. Could it be due to the fact that a more compliant spider reduces the seemingly ideal affect it has on linearity thanks to it's compliance? Still it would seem to me that it MUST have a beneficial affect on driver linearity. Maybe if my thoughts on the reduction of the mechanical affect it may have holds true, stiffening the spiders to a point where they have the affect desired should be realistic enough to make it feasible right? Think of a tiny ass sealed enclosure with a truely high excursion, totaly linear driver. Makes me cream my jeans...

Any input?

[trifle]

makes sense to me...multiple spiders are popping up here and there, i think elemental has implemented them on the sp series, they have a damn high vas if i remember right it's 158.5 or something check the site though, and seem to model well in small boxes for a massive sub....

trying to see what you're getting at with the spider stiffness, i think basically what you're saying is that if you decrease the stiffness, but not enough to affect the linearity, so that it didn't "hold back" the motor/excursion...you'd have a higher VAS and longer throw which would be obviously beneficial? and going out on a limb, having multiple more "loose" spiders keeping it linear as opposed to a single stiff one? and finding the "compromise point" between number of spiders and stiffness of each?

if that's what you're saying...ya damn straight, not quite sure how stiff the spiders on today's drivers are compared to what they could be....but quite an interesting idea, and something worth noting to manufacturers if they aren't already working on stuff like this....

[The_Ancient]

well I am far from a sub designer

but there are many thing that could be implemented IMO to accomplish your gaol

one of which is to use multiple "progressive" spiders.......


unless i am not understanding what your saying

[bigsexxxy69]

beyond audio in humans and the new shockers have multiple spiders

[sandt38]

Product Fs Qts Vas Qes Qms SPL BL Re Le Mm

18" Quad INHUMAN
(triple spider) 39.29 .8838 2.464 1.02 6.4537 88 20.75 3.89 6.6179 458


Triple spider? Uhh, I wish I could see one!!!!

[Regal1975]

also keep in mind that many of the subs that have multiple spiders do so simply to allow a stiffer suspension... DD uses several spiders, all of them glued together.. so n oreal added linearity there.. but it does allow for a woofer that handles gobs of power and has a fairly high fs, helping for spl...the treo csx uses 4 spiders, 2 groups of 2 about 1/4" apart... and DD claims to use 7 spiders on the 9500, though rumor has it they use from 4-6, all of them glued together in the same spot..

[sandt38]

Originally posted by Regal1975@Sep 2 2002, 04:27 AM
also keep in mind that many of the subs that have multiple spiders do so simply to allow a stiffer suspension... DD uses several spiders, all of them glued together.. so n oreal added linearity there.. but it does allow for a woofer that handles gobs of power and has a fairly high fs, helping for spl...the treo csx uses 4 spiders, 2 groups of 2 about 1/4" apart... and DD claims to use 7 spiders on the 9500, though rumor has it they use from 4-6, all of them glued together in the same spot..

I didn't realise that Regal. I was thinking like an upper and lower spider, say for a rough example, one in the normal location, and one at the other end of the coil. See what I mean? Maybe the rise in Fs you pointed out is why it isn't used in SQ applications. I never considered that.



Last edited by sandt38 at Sep 2 2002, 07:39 AM

[sandt38]

By the way Regal, pardon my ignorance, but who the **** is that guy in your avatar?

[DanWiggins]

Originally posted by Regal1975@Sep 2 2002, 09:27 AM
also keep in mind that many of the subs that have multiple spiders do so simply to allow a stiffer suspension... DD uses several spiders, all of them glued together.. so n oreal added linearity there.. but it does allow for a woofer that handles gobs of power and has a fairly high fs, helping for spl...the treo csx uses 4 spiders, 2 groups of 2 about 1/4" apart... and DD claims to use 7 spiders on the 9500, though rumor has it they use from 4-6, all of them glued together in the same spot..

The 9515 suspension I saw had one Nomex spider on the bottom, and 6 cheap chinese linen spiders stacked on top of it. Tinsel leads were run out in-between the spiders. All were squished together to make one "thick" spider.

Multiple spiders can be an advantage if rocking is a concern; however, it is NOT an advantage from a linearity or SQ standpoint; with multiple spiders, your resulting Cms curve is the product of all the spiders. Any problem in one spider is carried on to the resulting final value. Thus you don't get the "best" of each spider, but rather the "worst" of each spider, from a Cms standpoint (stiffest spider dominates).

Multiple spiders do offer extremely stiff suspensions, which as Regal points out is a great thing from an SPL standpoint. If that's all you're after, dual or triple (or more) spiders can be a good thing. It doesn't help linearity at all, though. And significantly limits what you can do with the rest of the parameters (Fs, Qes, etc).

Dan Wiggins
Adire Audio

[sandt38]

OK...

*puts gun in mouth and pulls trigger*