[capace]

I'm new to OB. Are they particular specs I should look for in a driver that might be mor compatible with OB? Like QTC etc?

[holdent]

I think one of the best places you could start that discusses passive OB design is Martin King's site -- see http://www.quarter-wave.com/OBs/OB_Theory.html

[mcgsxr]

No worries about noob questions - who hasn't ever been new?

Here is the thread most likely a good one, started here a while ago - http://www.audiocircle.com/index.php?topic=31240.0 - What makes a good OB driver?

Here is one that gives the background of many people's journey in OB, myself included - http://www.audiocircle.com/index.php?topic=19253.0 - Gravitywell thread - only 68 pages of collaborative exploration!

If you search this circle, there are more to discover, but those two should get you started.

Feel free to list drivers under your consideration etc.

I would say that the combo of QTS over 0.5, a lower FS (say 50 or so for a full ranger), and XMAX to support some movement in the lower registers are the 3 to focus on.