Infinite baffle vs Sealed enclosure

[IG81]

How big does a sealed enclosure have to be in relation to a driver's Vas to be considered an infinite baffle enclosure? Is there a rule of thumb?

Thanks!

IG81

[fwater]

In the strict sense of the definition, infinite baffle IS a sealed box. That is to say, the baffle is infinite because one could not trace a path from the front of the cone to the rear; they are seperated. When you see what is commonly referred to as infinite baffle, it's usually a woofer that uses a household boundary (walls/floor/ceiling) to seperate the front wave from the backwave. A line could be traced from the front of the cone to the rear- through a doorway, down the stairs into the basement, etc.

I suspect your question could be rephrased as "In relation to Vas, how large does an accoustic suspension (sealed/IB) enclosure need to be to get the Q of the system close to the Qts of the woofer. Any rudimentary box modelling program (or even a comprehensive one, of course) can spit this number out with a little trial and error. Start at 1:1 box volume to Vas, and increase until you get close enough to satisfy your needs. Decrease to see the effect on the curve. Bear in mind that most people have varrying opinions on what sounds best when it comes to sealed box system Q. Low Q vs. high Q have their own set of drawbacks and advantages.

[IG81]

Yes, you rephrased my question correctly and thanks for the answer. I kinda ended-up answering myself by downloading and playing around in WinISD.

I was looking for a ~4-5" fullrange that fits a sealed box to make a low-Q IB, but those are hard to find, most have high EBP...

IG