Sealed box for 12" Kicker CVX
 

I just bought a 12" Kicker CVX and having same sealed box issues trying to get the best SQ, power and size for the sub. I would like to go ported, but in search of the perfect box for a flatter response, sealed is just easier, and cheaper

here's the manual:
http://assets.sonicelectronix.com/ma...2010CompVX.pdf

I ordered a 1.0 cu ft box and a solo classic, which is designed for 1.0 cu ft, but the sub order fell through, so I'm stuck with this box for now. The manual for the CVX says 1-4.6
Also the rms power fluctuates quite a bit between the 2 sizes. I'm running an MB Quart Onxy with 500w @ 4 ohm. Saying it does 600 rms, what would the perfect sized box be to hit all range of notes and pushing the sub right to its technical limits?
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Alright. Below are 4 plots. Sorry it's a little blurry.

The yellow is your CVX12 in a 1cuft sealed box. It's not bad but can be improved upon IMO. The pink line is the 4.6cuft 'Sealed SQ' box which looks to be a complete waste of space. 2 extra db at 30hz is a shitty tradeoff IMO. Plus your power handling goes away.

The orange and grey plots are typical of what we see when we vent an enclosure. Same 1.5cuft enclosure, one tuned lower (30hz) for more flat extension, one tuned higher (35hz) for a little more jam. Look at all that free bass above 25hz. SEVEN db more at 40hz for the grey curve over the yellow. You would literally have to feed the yellow curve FOUR TIMES the power to make that up. wow. :retard:

Anyway - you have the 1cuft sealed box. Try it out. Then when you get bored and want some more blammo, get a little bigger vented box and hang on :smokin:

http://www.canadiancaraudio.com/atta...ine=1318969550

^^exactly what i was going to post for you. Sealed might be easier and cheaper...but you can see the difference in output above.

Dukk, thanks man, I really appreciate the work. Can I get you to send that graph to me in full res?

Also, I see you have 1.5 cu ft. for each 30 and 35hz ported box, how did you come to that size? Compact @ 1.75 (300w rms) - SQ @ 2.25 (750w rms) is what is listed in the manual. Wouldn't 2.0 cu kind of be the optimal middle range? I'm not questioning you, but this is according to Kicker and I'm just curious to see what the answer is :D

As for the sealed vs ported. I'm all for ported, but in terms of making a box, I would need the exact specs, measurements and port lengths etc to build it to 30hz for flat responsiveness, as I'm not good at calculating such things or using box programs. I'm am actually very surprised that the 1.0 cu box sounds as good as it does, but I know I can push that sub a bit more, and ported will do just that, I just don't want to loose the nice flat range I have right now.

Now as for some settings, I have subsonic around 20hz, any need to change that for more efficiency and/or more usable power, 22-25hz? It read somewhere it can do down to 19, if that's the case I don't know. 80hz for top end? I guess I should list my setup:

Alpine SPR-60C Comps up front

MB Quart ONX116 Coax in the back

Alpine MRP-F250 4 ch amp bridged to 100w rms @ 4 ohms for the Comps

MB Quart Onyx ONX1.1500D amp for the Kicker CVX wired @ 4 ohm for 500w rms

AND lastly the MB Quart running off the Pioneer Premier deck. The deck has sound retriever set at 1 (off,1,2) and loudness at med (off, low, med, high). HP filter @ 80hz. LP filter @ 80hz. Bass @ 0db, NO bass boost anywhere.

Any changes I need to make? I apologize, I had links to each of the equipments specs and it wouldn't let me post it without 5 posts.

WinISD suggested 1.698cuft tuned to 29hz. I moved that down to 1.5cuft as that size is not much larger than the 1cuft box you have now, and the number is convenient. Performance isn't wildly different.

I would move your subsonic up to 25hz for sure, even 30hz. Your equipment will thank you.

What the plots don't say is the poor upper bass and mid bass transition you will get when tuning a subwoofer box that low, as well as the need for steeper slope crossover as well as a subsonic filter of some sort to optimize the ported box design, but there is no question that you will get more output from the ported one but not necessarily better bass

Why do you assume there will be poor midbass transition? That's nonsense. So is the notion that a vented box requires a subsonic filter while a sealed does not. Neither require one and both can benefit from one.

I'm not assuming, tuning a sub box that low almost always has a transitional issue with Midbass in my experiences. A subsonic filter is always beneficial to a ported box, more so than in a sealed application, but you right it does benefit both, but more so in a ported box. Below the tuning frequency of a ported box there is little control of excursion, limiting the frequencies below that frequency will always be beneficial, a woofer has little output below it's tuning frequency as well and excursion increases, increasing excursion with little output makes little sense. I hope this helps you to understand, as well if you re read my post it doesn't say anywhere that sealed boxes don't need subsonic filters

I did read your post and you state that a vented box requires both a subsonic filter and a steeper crossover point. The intimation is that, conversely, a sealed one does not. My response was that a vented box does not require a subsonic filter and I clarified that one is also useful in a sealed application as well (all applications really) I left the crossover part alone as it does not make sense.

Another look at the plotted curves shows that the 35hz tuned enclosure has more output than either sealed box above ~25hz. How is that "... little output below it's tuning frequency ..." ? As for excursion, for a well designed enclosure, typically excursion is controlled to a half octave below tuning, the point that a subsonic filter should be set to, making this a non-issue.

That still leaves the issue of midbass transition. I suppose if you routinely underpower your midbass, and/or don't understand gain setting, then the extra output of a vented box may overrun them but poor system design is hardly the fault of the enclosure.

Ok, now this is what I am trying to avoid at all costs. I like more output, I don't like missing notes or that higher midbass range. I like the way it sounds right now being sealed, but is there anyway to have the same tight, flat response range in a ported box? Basically I compare it to my home theater sub, which hits low, tight and hits the higher bass as well surprisingly. I know I shouldn't compare, and it's a different sound stage, but I shouldn't need to sacrifice good sound when there should be a ported box that has the best of both worlds.

Also, is there a post that explains porting, tuning to a specific hz, and how it affects the sound etc? I'm vague on "tuning to 30hz gives it more control over that range", do you loose everything under 30? Does tuning to 40 give you louder bass at 40 hz?