# OS Stroker 18 NIB



## SHAGGS (Apr 24, 2011)

Stumbled upon this. If it's legit, it's really tempting, even if I have absolutely no use for it, at the moment. Always wanted one.

Cerwin Vega Stroker 18 18D 18" Woofer Subwoofer Old Stock USA Made New in Box | eBay


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## JuiceMan88 (Jun 13, 2012)

Really not a bad price, not a bargain by any means but that's fair for sure. Sick subs!


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## TrickyRicky (Apr 5, 2009)

Ahhh, Stokers my favorite sub of all time. Four of those would make a sick SPL system.


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## etznova (Jan 14, 2009)

Holy balls 4 brand new untouched strokers. These things are practically extinct and he has four new ones


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## Tnutt19 (Dec 22, 2010)

ever so tempting to try one! Any one know what size sealed box they call for?


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## putergod (Apr 23, 2008)

Tnutt19 said:


> ever so tempting to try one! Any one know what size sealed box they call for?


Not sure why you want sealed. These subs were NOT meant for SQ. They are/were all out SPL subs.

From my understanding, they sound like crap, as they are designed to play around 40Hz very very loudly. Producing actual music wasn't their strong suit.


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## Tnutt19 (Dec 22, 2010)

That makes since, I was thinking it would be interesting to drop in my current box just for comparisons and fun. Seems it wouldnt make much since to do that though.


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## TrickyRicky (Apr 5, 2009)

putergod said:


> Not sure why you want sealed. These subs were NOT meant for SQ. They are/were all out SPL subs.
> 
> From my understanding, they sound like crap, as they are designed to play around 40Hz very very loudly. Producing actual music wasn't their strong suit.


Oscar may chime in as he has all versions (12,15,18). As far as I know (been told) is that the 18" cone flex and that may be an issue with certain frequencies. This I was told by Jeri McCord (help design the woofer with John Fairchild). 

But from my experience the 12" could be considered for SQ as I powered a pair with 500-600watts TOTAL and it sounded very nice (theater like).


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## putergod (Apr 23, 2008)

TrickyRicky said:


> Oscar may chime in as he has all versions (12,15,18). As far as I know (been told) is that the 18" cone flex and that may be an issue with certain frequencies. This I was told by Jeri McCord (help design the woofer with John Fairchild).
> 
> But from my experience the 12" could be considered for SQ as I powered a pair with 500-600watts TOTAL and it sounded very nice (theater like).


I'm a SQ guy myself, and I still love the original Strokers. They are, IMO, the baddest subs ever assembled.

I remember when they launched, and the CV van was running either 8 or 12 (cant remember the exact qty) 18's on modified LP amps, and became the first, unofficial, vehicle to ever bust the 160db barrier - 160.27. They never got credit for it because they were just goofing around and not in competition when it happened.


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## 07azhhr (Dec 28, 2011)

He is in Phoenix. I could save a few bucks lol. I have always drooled over these too. Shows 5+ cft I assume ported. HMMM I would only have to double my current box and port it.


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## putergod (Apr 23, 2008)

Looking at these makes me tear up that CV isn't what they used to be...


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## Oscar (Jun 20, 2010)

There is nothing wrong with any of them, IF you consider what they _are_, and not what you _think_ they are. 

They are a standard over-hung drivers (with possibly the exception of the 18" because of the 1" top-plate). None the less, they are no different from any other driver built today with dual spiders other than the fact that they are extremely low-Q drivers, which not a lot of people know how to implement properly in an enclosure. They are no less SQ than any other driver made today with similar parameters and motor/coil specifications. I have a feeling a lot of these old wives tales keep coming from people in the 90's who had no idea they were trying to (essentially) install pro-audio woofers into a vehicle installation. Imagine going up to the sound engineer who rigs up sound systems in your favorite concert stadium/arena, and telling him/her "_hey these pro-audio subs are gonna sound like $hit, they can't play music!!_". They'll laugh in your face and walk away laughing with a memory that they will be able to tell their great grandchildren about how stupid people can be. Well, the Strokers are the same way pretty much.

Will they compete with modern drivers that have shorting rings, proprietary cones/spiders, Klippel-optimized, etc in the SQ dept? Likely not. But I would bet $100 that all of you have been to a great sounding live concert that _you didn't even know_ had standard woofers with nothing more than a coil/cone/magnet/spider with no SQ-features that we are accustomed to seeing in "SQ" woofers today. 

That aside, the main issue that "cripples" the Strokers is the low Qts and high Fs (more so the 12s & 15s than the 18s). When you try to tune low in a big box like we car audio buffs have been doing for decades (low as in ≤35 Hz), BUT using very low Q drivers (≤0.3) such as Strokers, you end up leaving a "void" or a dip in the response [which can at times be up to 6dB of dip or more] from about Fb+10Hz, all the way up to the *mid-band*.....

Since we all read books (hahaha!), we know that the mid band is the range of frequencies where the sensitivity rating of the speaker _"is"._ A lot of people think that because a speaker is 90dB/1W/1m sensitive, that it will hit 90 dB at _ALL_ frequencies. Not the case. Mid-band range is from EBP to 2*EBP. Since we are all audio engineers here (LOL), we know that EBP= Fs /Qes; and since we all have math degrees (LMAO), we can immediately tell that shifting Fs↑ and the Qes↓, moves the EBP range higher→in frequency.

Example: One of my ten Stroker 12D4's has an Fs: 35.66hz and Qes: 0.23.
The EBP frequency is 35.66Hz/0.23 = *155 Hz*. 2*EBP is therefore 155*2 = *310 Hz*.
Therefore the *mid-band* of my Stroker 12D2 is *155-310 Hz.*
It is ONLY in this range that I am guaranteed the 92 dB/1W/1m sensitivity rating (unless the inductance cuts it off earlier). This range is where the raw driver _efficiency_ (which is not to be confused with the 92dB _sensitivity_) manifests itself strongly.
Above this range, nothing is guaranteed because it cannot be predicted with Thiele/Small analysis--it must be measured because cone pistonic behavior, cone break-up modes, traveling waves, surround geometry, cone curvature and thickness profile, and a plethora of other things are what determine how high in frequency a typical cone driver will be able to go.
On the low side of things from the EBP-frequency and downwards, the sensitivity of the system as a whole will be ultimately determined on how well the enclosure designer/builder can manipulate the inherent efficiency and the system resonance.
Here is a picture to illustrate what I mean by the previous bullet in this list (although it doesn't necessarily represent Strokers as we are discussing, it is valid none the less)...

OMIT THE "98 Db" THING...IT DOES NOT PERTAIN TO THIS DISCUSSION...THE GRAPH IS FROM A RANDOM PRO-AUDIO 18"



















The same basic thing applies to ALL moving-coil electrodynamic speakers, except with "traditional" mobile audio subwoofers, the mid-band range is much lower because Fs is lower and Qes is typically higher. 

Here is one my ten Stroker 12D4s, in a now-a-days typical 1.5 ft³ box tuned to 31Hz. It's easy to see that if someone doesn't know what they're doing, and just swaps it into this hypothetical box that sounded great with a more "typical" higher-Q subwoofer where the response is nice and flat, how they would attribute it to having disappointing bass response (of course it_ is_ disappointing, LÒÒK at that missing 32-110 Hz GAP! Of course, the uninformed user is just going to say "_aww hell! this speaker sucks for music! it ain't got no punch! This must be an all-out SPL woofer!_". No šhit Einstein, the enclosure/tuning was decided by a monkey!  (Also notice how the response doesn't hit 92 dB until the high 150+ Hz, just as I predicted before )










Same exact speaker, in the RIGHT enclosure. Very flat, from ~32-175+ Hz. *100* dB/1W/1m. Not in-car....2π _outdoor ground plane response_. In-car would be even _more_ sensitive. This is the kind of response that rattles teeth-fillings loose, and then pulls your underwear up over your head and punches you in the face and chest simultaneously.












Overlay of a good enclosure and a bad one. Both with 1W input, 2π radiation.










Anyways, I wish I had the money for those Stroker18s, I'd pick them up in a heartbeat to add them to my collection.


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## SHAGGS (Apr 24, 2011)

Looks like someone scooped one up. Only three left!


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## Revdoc (May 28, 2010)

Oscar said:


> Here is one my ten Stroker 12D4s, in a now-a-days typical 1.5 ft³ box tuned to 31Hz. It's easy to see that if someone doesn't know what they're doing, and just swaps it into this hypothetical box that sounded great with a more "typical" higher-Q subwoofer where the response is nice and flat, how they would attribute it to having disappointing bass response (of course it_ is_ disappointing, LÒÒK at that missing 32-110 Hz GAP! Of course, the uninformed user is just going to say "_aww hell! this speaker sucks for music! it ain't got no punch! This must be an all-out SPL woofer!_". No šhit Einstein, the enclosure/tuning was decided by a monkey!  (Also notice how the response doesn't hit 92 dB until the high 150+ Hz, just as I predicted before )
> 
> 
> 
> ...


I wish I had this knowledge back in '99 or so when I had a 12D Stroker running off a MTX 2300X in my '91 Camaro. I ended up with a 2.2 cubic foot box tuned to 32-33 hz, and my response curve looked just like the first one you posted, huge dip from right above tuning freq. until the HPF kicked in at 80 hz. The sub played lows with authority and shook the hell out of the car but had no punch at all. I figured the box was too small, because I think CV recommended 3.5 cubes. Do you mind telling us box size/specs for the second graph you posted?


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## Oscar (Jun 20, 2010)

Revdoc said:


> I wish I had this knowledge back in '99 or so when I had a 12D Stroker running off a MTX 2300X in my '91 Camaro. I ended up with a 2.2 cubic foot box tuned to 32-33 hz, and my response curve looked just like the first one you posted, huge dip from right above tuning freq. until the HPF kicked in at 80 hz. The sub played lows with authority and shook the hell out of the car but had no punch at all. I figured the box was too small, because I think CV recommended 3.5 cubes. Do you mind telling us box size/specs for the second graph you posted?


I don't know the box size, but it is BIG. It is not a vented enclosure. The specs are in the white column on the left side of the screenshot. The excursion graph has clues in it as to what kind of box it is.


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## n8skow (May 7, 2011)

Horn FTW
=)



Oscar said:


> I don't know the box size, but it is BIG. It is not a vented enclosure. The specs are in the white column on the left side of the screenshot. The excursion graph has clues in it as to what kind of box it is.


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## instalher (May 13, 2009)

I ran my 18d in a aperiodic box barely 1 cubic ft. Off of two croosfire bmf 1000d. Thing whalled and barley any cone movement. NICE!


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## Guido_b (Mar 29, 2008)

Great subs! I used to work for CV when John Fairchild was there...RIP John. I still have a few 12s, 15s, and 18s laying around. They are great subs. I have put them in anything from 3cf to 10cf boxes. The sound really good if you know how to tune your ports. Plus they play loud with little wattage b/c of their high sensitivity. These are selling for about the same as we could buy them as employees of CV back in the day. Grab one while you can. Even if you were to play with it for a while, you could resell it for almost the same price. Anyone remember Chilli's (Aaron's) 74 VW stroker van that beat Alma Gates? He was under 10kW and was a full db over her 64 subs with 45kW. That speaks volumes. RIP Alma also. Dam I feel old now.


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