Infinite Baffle

[delormea397]

Question for the masses here. When you hear or speak of 'infinite baffle' loudspeaker design are you generally referring to a very large enclosure- ie. an entire trunk as the enclosure? My reading is showing me that infinite baffle is a term for any box where the baffle is 'infinite'. As in, has no edges or ports or openings. As such, these sealed enclosures are best suited for drivers with compliant suspension to help with the air suspension that arises. But this goes against what I had kept hearing about IB setups being huge enclosures.
Is this maybe because IB setups work better with large enclosures due to the lesser effect on resonant frequencies? Basically...a driver sized "x" compresses less air when the enclosure is large compared to smaller.

I guess my question is- when you hear IB do you think "any sealed enclosure" or "really big enclosure"?

[Threehz]

IB is generally used in homes. For instance, say you have an attic. You would cut a hole in the room of the house you play movies that connects up into the attic. You mount a subwoofer in that hole shooting down into the theatre room.

You could say that the attic is a 'huge enclosure' ... The idea of IB is that you are COMPLETELY separating the back-waves from where you are shooting the woofer into. With a proper woofer this can give a really flat response.

In my E30 I have a semi-infinite-baffle set up. I say semi because the trunk of the E30 is not proper size for a perfect IB setup. It's also not 100% sealed, though I'm working on that.

I call mine an infinite baffle because my woofer is mounted on a board which separates the front section of the trunk from the rear. This amounts to most of my trunk acting as a giant enclosure. I just happen to have a woofer that is suited pretty well to this application, generally car subwoofers are not as they are made for small boxes for the most part.

Hope this helps.

[delormea397]

It does help...though not completely. If the idea of IB is separating the front and back waves completely, then any sealed inclosure is an IB setup. Is it just considered IB when the speakers suspension is compliant enough that there is no air suspension adding to the mix? ie- compliant speaker or decently compliant speaker with a large enclosure so that no compression happens.