You're welcome!

Even if Haigner's has rear vents I can't imagine it having what I consider proper bass response for good bass attack. Vents tuned high enough will have an 'impossible' phase response through the XO BW and tuned low enough will lean out the mid-bass too much for the TH's to fill. Like bowtie noted, the physics of the situation is against it.

Then again, the pair of DSL DTS20s I auditioned in Gainesville, Ga. didn't strike me as either punchy or fast, just 'accurate', like a good TL or very low tuned EBS, so have to wonder if we're having a failure to communicate. The Synergy horns OTOH had plenty of punch, speed, but then look at how deep they are, then you would have to add the depth of the compression chamber.

GM