Sealed Box Design

[yzf7steve]

Ok I've been racking my brain on this for a few months now and I'm lost. My subs are the Hifonics HF12D4. The spec sheet recommends .5 ft^3 with loose poly-fil. I was researching the QTC of enclosures and found that box would have a QTC of over 1.3 which is horrible. In an attempt to reach as close to a QTC of .7 as I could, I built a 2 ft^3 per sub box. This got me down to a .9 QTC but is 3x larger than recommended. Then I saw where if the box volume to VAS ratio is less than 3 your speaker is in an infinte baffle. So I am lost one set of data tells me I'm basicly destroying my subs while another is telling me they are getting closer to excellent sound. Any help would be greatly appreciated in this matter. I can list what stats I have for my subs if you would need them to help. It's not a full list of T/S parameters but enough I think.//content.invisioncic.com/y282845/emoticons/verymad.gif.3f39c5c2fd57527b671fad3efdfac756.gif

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[NissanKicker 10+ year member]

What exactly are you asking....

... If you're destroyin' your subs? ( No, not @ all )

If you're gettin' Excellent sound out of them? ( No, not @ all - not in that Sealed box... HF12s sound SOO much better in Ported Enclosures )

 

[KRYPTO 10+ year member]

You get better SQ in a sealed box, ported will have more SPL

With a sealed box there is less chance of destroying the sub and they are able to handle more power.

 

[kr15 5,000+ posts]

I have always heard that the Hifi subs need quite a bit more volume then manufacturer specs

 

[yzf7steve]

I guess the point I was trying to make was that Hifonics recommends .5 ft^3 with light poly. But to get the QTC alignment where i want it is taking a huge box. My VAS is 4.3 on my 12's so I guess I don't understand how it could be considered and infinite baffle (a.k.a.) not having enough spring to not shred my subs when I'm well below 4.3 feet. As for ported I understand the whole argument on pro's and con's. If all I listened too was rap/bass I would port in a heart beat but I am mainly a Death/Black metal guy who enjoys all other music as well just not as often. Sealed gives me the tight response I love with my music as some songs can hit over 300 b.p.m. So my confusion comes in why the company would say that the best box size for my or any other sub would be in a box that would sound so peaky instead of flat? I had a box that was recommended size and the bass was so weak it was sad. It sounds really good now but I was concerned with being so far above recommended size. I wanted to make sure there wasn't something I was missing in the construction of the sub that would lead one to think, "OMG! It's gonna burn up in a box that big" If you get what I'm asking now. //content.invisioncic.com/y282845/emoticons/eyebrow.gif.fe2c18d8720fe8c7eaed347b21ea05a5.gif

 

[Phoenix Risen 10+ year member]

as long as your not hitting the mechanical limits of your sub than youll be fine, i ran an mb quart 10 in a sealed box that was quite a bit too large for it and never had an issue running it on the rated power and a little more.