Infinite Baffle Wtf Is That? Car? Home? Pro?

[kryptonitewhite 1]

There seems to be a lot of misconception about an infinite baffle, so here goes my stab at it with a link to a forum that has a lot of dedication and experience to them.

What I have gathered:

A baffle is a board a speaker driver is mounted to.

When a speaker is not attatched to anything, and the front and rear wave are completely allowed to go around the driver and are not in any way isolated or coupled, it is free air.

When it is on a baffle, the sound waves are forced to travel further to intersect. The smaller the baffle, the higher waves (upper frequencies) are no longer cancelling out as the baffle separates them. As we increase the baffle size, the longer it gets, the lower the waves that no longer cancel depending on 1/4 wavelength and total wavelength.

The 1/4 wavelength for 33Hz is 8.5 feet, the total wavelength is 35 feet. For a driver to effectively recreate 33Hz without any cancelation and all the way up from there, the baffle would have to be 35 feet out from the driver, or a total of 75 feet in diameter.

An infinite baffle is a "sealed" ROOM with a minimum airspace of 25 times the drivers Vas, so that the driver does not "see" the enclosure. Anything less, and the air acts as a spring.

http://www.hometheatershack.com/foru...er-system.html

[Juslivin 1]

Nice post, I didn't know all that much about IB set-ups.

[kryptonitewhite 1]

I made a mistake, I haven't read the link in quite a while but i figured since I posted it I better reread it.... he states 10 times Vas, and as low as 4 times can work... but I have heard minimum of 25 is desired. Really, if you model your driver with any modeling software, you can determine what will work for your desired responce. If you type 4 times for one, do another project and compared 4,10, 25, and kept going... you will see that there is a point where making huge increases in sealed size makes very little change in responce. That is the "true" desired airspace per driver. I guess that can be said too... to model a driver in IB, you use a large sealed enclosure and keep making it larger until there is little change in the FR curve from a drastic change in volume

Edited January 29, 2009 by kryptonitewhite

[tc3k101 0]

i was about to say i thought it was 10x the vas. nice right up forsure

[kryptonitewhite 1]

people from that same forum were trying to tell me a while back when i was thinking of doing it IB in a Toyota Camry..... put it in IB and port it! I couldn't believe it, because it's really just a sloppy/flexing/leaky sealed box, with the trunk lid moving out, and sheet metal fleaxing out... cubic feet will go up, and as it sucks in, verse vice.... so the cubic feet will always varry.... how can you "tune" that???

bastards