Infinte baffle characteristic?


2011-04-05 6:47 am
I've found the following characterizes a good infinite baffle:
*strong such that vibrations and resonance are minimized
*separates the front wave from the rear wave very well; no leaks
*arranges the speakers dual opposed; force cancelling design

Efficiency will depend on the frequency in question and how much cancellation exists around the baffle. Typically, IB is more efficient than sealed but less efficient than a ported box.

Ron E

2002-06-27 10:41 pm
hypothetical driver
Fs 20 Hz
Qts 0.405
Qes 0.45
Vas 100 Liters
Re 2.7 ohms

case 1 is infinite baffle
case 2 is a 40liter sealed box
case 3 is a 100 liter vented box tuned to 20Hz

All produce the same midband SPL - 89dB at 2.83 volts


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I thought that an IB driver had to have a higher Qts. Something around .8 to 1.2

If you have any way to EQ the signal then it is much better with a much stronger low Q driver. You need a lot of voltage-swing but not a lot of current if you use high efficiency pro drivers. B&C 15TBX100 is a good OB driver for bass duty. You can get great efficiency from OBs. It is as usual a large radiating surface, low moving mass and lots of BL (motor strength) that will create efficiency.