It depends on the application?

In a sub woofer application it a more defined choice in terms of output and extension.

An 18 comes into its own if you want both extension and output.

The 2245 is not a sound reinforcement woofer as such. They may have been used in commercial cinemas in banks of four or eight when first introduced.

In a multi way hifi system application l think it comes down to the specific system and what’s most important. The enclosure location and height Off the floor is often optimised for the smoothed bass response.

If you want linearity the 2245 is my preference.
I have used dual 2235’s and it’s not the same. The 2235 sounds like a loudspeaker. In comparison on a double bass acoustic recording the 2245 doesn’t sound like a loudspeaker (In my system at least abs that’s the feedback from other listeners)

Edit

http://www.audioheritage.org/vbullet...hp?10654-2245H

http://www.audioheritage.org/vbullet...hp?10651-2235H

The primary difference is sensitivity, cone area and diaphragm displacement for equivalent output.

At 50 hertz a 15 inch drivers cone has to move four times as far as an 18 inch drivers cone for the same acoustic output. That is where the linearity of the larger driver has the advantage.

I read that from a red loudspeaker book written by Don Davis and Alex Bradmanoff. I think Mr Widget also has a copy of that book. Don’t ask me what happens with two 15 inch woofers!

In a plug and play situation differences may be apparent. But l have rarely found plug and play a successful approach to comparisons.

The 1400 driver used in the S9500 was set up and tuned up for the Japanese market. They tend to prefer a leaner damped bass. The blue baffle systems (as they are known in japan) have the traditional Jbl bass which a lot of Jbl users prefer. That’s why they did two ranges.

Some DD67000 users plug the ports because that is their preference.

If you are after a sub woofer for Home Theatre that goes louder and is this and that there
are a number of specialist drivers that will meets your expectations. They have large spiders and surrounds, heavy stiff cones and massive Xmax but they generally don’t mix well with a hifi loudspeaker.

In diy loudspeakers anything goes and as such opinions are diverse which is fine. But l don’t feel asking for an opinion on a forum of one loudspeaker or driver over another holds much weight without a detailed account of the circumstances or conditions.