open baffle / free air

[Kal]

Hello,

is a bass/mid-driver really faster (better transients) when build as an open baffle design, which means operating at its free air resonance, compared to a critically damped Q of 0.5?

What Q-values should be used in such a design?

Thanx

[hiendaudio]

In an open baffle, the woofer operate at free air resonance, and the Q is the Qts of the driver. (in very near field measurement)

This is thrue in a infinite baffle, in an open baffle the rear and front waves tends to cancel.

This is the reason that open baffles need equalization to have a flat bass response.

For an open baffle, is better a woofer with a high Q.

The transient response is given for the Q of driver and the EQ used.

Here, the most important factor is the open baffle radiation patern. Not the trasient response.

If you want an open baffle, want it for the OB radiation patern, not for the transient response (of course, better that bass reflex!!!!)

[Timn8ter]

Would it be high Qts or would high Qms be enough?

[till]

http://melhuish.org/audio/baffle.html

Open baffle speakers require drivers with relatively high Qts values, preferably over 0.5.

[Timn8ter]

So the Adire DPL12 or the Eminence Lab12 are not suitable since they both have Qts below .5?
I guess I'm thinking woofer more than mid/woof.

[Drew Eckhardt]

The Peerless 10" XLS (Qts = .17) work wonderfully as an open baffle woofer with Q=.5, and people (Steve Dodds) have had good results with the DPL12.

With appropriate equalization you can have the Q and poles you want, and are free to choose drivers based on displacement+distortion.
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