12" and 8" bass coupling to room

[Valentin]

Let suppose that you have to woofer in the exact same positions in the same room and you tested Them with a tone of 100hz

The difference between both is one is 12 inch and the other 8"

if both were driven at the same level would the sound be different
do drivers couple too the room differently is the radiation different in some way

wy do big woofers tend to sound more ample or is it just psychological

[timc]

Woofers of different size have different radiation pattern.

If you say that the drivers are built to the same standard and are give a good input signal the 8" driver will have to work much harder to produce the same SPL at as the 12" driver. Because of this the 8" will have a greater amount of distortion.

Tim

Edit: I also get the impression that large (good designed) drivers sound more relaxed and natural, and at the same time packs a greater punch. Ive been told that this is due to radiation pattern but I cant confirm this.

[Robh3606]

I will run a simulation for you and post it later tonight so you can see the changes in the radiation pattern.

Rob

[Valentin]

thanks rob and tim

[Robh3606]

Here are the plots I promissed. They are for a 2118 8" woofer and a 2206 12" woofer. You can clearly see the differences on the polar plots. Each color is response at a given frequency and the plots gives you the angular coverage and SPL at that frequency. If you look next to the curve you have Frequency BW Q and DI. The BW is the angular coverage arc covered by the driver at that frequency centered on 0 deg. So at 2.56K on the 2118 you have 36 Degrees of coverage left and right before the response is 6db down from your 0 reference point. The Q and DI are the Q and Directivity Index at that frequency.

Rob