Here are some more options - the Bass drivers by Goldwood first a 15 inch driver GW-1558 and also their 18 inch Bass driver GW1858 , both are fairly inexpensive work great , and are used in many Open baffles speakers. The Mid-bass driver Eminence LiL' BUDDY at 98.8db with a Med-High Q, and is - 79.95 has been used by several people and is very recommended. The Eminence B102 woofer is also used in several Open baffles.
- Several people are also running an Open Baffle Speaker with a Ciare CCH250 full range driver, and here is one quote - "The Ciare's are running without any filter network and sound surprising good". To repeat and augment an earlier recommendation Troels Gravesen who is a very respected and highly prolific speaker designer has used the Ciare NDH 15-4S bass drivers, as well as the Faital 15PR-400 bass drivers in several of his Open baffle designs, his designs are available with all the documentation and can be used by diy people - The speaker KITS are also available thru his website /and Jantzen Audio if you want to not have to do the leg work of finding the parts yourself. The JA8008-HMQ is one of the mid Range drivers he actually designed and is using in several OB's and is available online. And surprisingly the SEAS T35C002 Dome tweeter is also used in Open baffle with a T35C002 Waveguide . Jordan Audio, and Mark Audio Alpair speakers are good candidates, and some Fostex drivers are too , all are full range Open Baffle candidates.... also the Tang Band 1808 is a good driver. Lastly for a new Mid-Range option the PRV 5MR450-NDY is a very nice driver that can be used with a baffle or even no baffle at all! Here is a quote from someone using 4 of them in a vertical array with no Baffle ... " I am using a quad array of PRV 5MR450-NDY 'full range' drivers (which roll off at about a 150Hz) " --- after going baffle-less he says - "Not to everyone's taste, admittedly, but after going baffle-less as an experiment. I was so shocked by the result, there is no going back!"
There are also some great used drivers floating around that work extremely well too for OB's - the Audio company Bastanis made Great 12 inch drivers for open baffles , and if you can find them Hammer Dynamics had a very nice 12 inch driver designed specifically for Open Baffle speakers!
There are Many Vintage options too! Vintage drivers can be found on ebay and other places, many Coral drivers are good candidates, as are vintage drivers that come out of old stereo consoles - Zenith drivers are very in demand , especially the Zenith 49CZ852 which is a highly sought after 12 inch driver - see glowinthedarkaudio.com and various forum threads. Another vintage driver option are Saba Green Cone speakers as well. If you are really committed , a high end idea are french EMS/Fertin Field Coil drivers which work very well in Open Baffles, and are said to be very musical.
Best Regards,
Dean