inverted sub box

hello all,

I don't know if I am thinking too much into this or not but hopefully someone can clear my brain up.  For an inverted sub, does the sub box (made of MDF and Fiberglass) need to be of a specific size on the inside?  Example, for a sealed enclosure, depending on the kind of bass you want, you build your box to different specs.  But for an inverted sub, do you still need to follow those same basic priniciples or not?  If you have a huge box with no compartments, will that affect it?  Or just the opposite, if the box is really small, will it affect the performance?  This is more general, not to any specific sub/wiring/amp/box.  Just something I've been pondering over and wondered if anyone had any input.  Thanks everyone!

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people who live in glass houses sink ships

Yes, you still have to build the box to the same volume as if you were mounting the sub normally. The air inside the box still needs to be correct for the sub to perform. By inverting the sub you are putting the pressure of the air in the box on the front of the cone reather than the back of the cone. It still affects how the speaker performs. The box still needs to be the recommended volume but you do not have to calculate for the speaker displacement and you have to wire the subwoofer reverse phase, i.e. positive from amp to negative of sub, and negative from amp to positive of sub.

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Good Luck!
-Thad

Thanks Sound Audio.  never knew it made much of a difference but after reading that, it certainly makes sense.  Thanks again!

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people who live in glass houses sink ships

i thought you only have to reverse the polarity if you had two subs in a box and one of them was inverted...

i dont understand why inverting the sub would require you to reverse the phase of the sub...

but yeah like he said build it to specs, and dont include the displacement of the sub in your volume calculations...if the sub calls for 1.2 cubes then that is how big you build the box...

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Fiberglass Guru.

Well, in theory it is so that your sub will still be in phase with the rest of your speakers, but that relies on placement and frequency, and time correction if any so there are a lot of factors. Regular polarity could be better in some cases. I, in general and to start with wire it in reverse, because you wouldn't wire a regular mounted sub in reverse to start with unless you have done some calculations for time correction. I also know a lot of decks and amps allow you to reverse phase in the settings.

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Good Luck!
-Thad

I currently have mine with the polarity reversed.  previously I had it done normally.  When I first read about switching it, I was hesitant but eventually decided to do it.  In the setup I have, it does sound alot better and makes the sub hit harder (for whatever reason!)  but in my buddy's setup who also has one inverted sub, it sounds better with normal polarity.  Really weird, I know, but just to share some input.  I think it all depends on the sub, box, and other factors that can only be deteremined by you and a couple pair of ears.

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people who live in glass houses sink ships

Thats wierd... cuz if its not switched power wise it would be firing at the wrong time the wrong way. Sound like crap

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I have a my 10s inverted and they sound better out of phase. HOWEVER my brothers truck sounds better in phase. so im gonna have to say that its gonna be install specific

i'm with you drgonzo. there are too many variables that come into play to decide which way it should be wired.

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people who live in glass houses sink ships