MiniDSP 2x4HD used with a high efficiency system

belyin…  Thanks for the input.  Yes, if I use only as a low pass on the base cabinets the Oris are dead silent.  I was trying to give them a hi-pass filter to keep the sub 100Hz off the drivers to extend their life.  Good idea on the PS, I'll give it a try.

Out of curiosity, what drivers are you using with your 150's?  I'm trying the new Voxactiv AC-2.6's and really like them.  Which base cabiner are you using?

tinear . . . I am using AER drivers which replaced Lowther DX-3's. The Voxativ look amazing but out of my price range. On-the-other-hand, the AER's now need refoaming, and I am not sure I have any option other than sending them off to Germany to AER for what seems to me to be a very high price. The bass cabinets are JBL 4648's from their professional cinema series–two 15 woofers in a ported cabinet. I never thought about blocking the low frequencies in terms of preserving the drivers; I am certainly no expert but I it seems to me that the natural roll-off provided by the horn loading eliminates any deep bass response from the drivers, and they are designed to play full range in any event. That said, there should be some benefit in limiting the low frequencies in terms of the horn's amplifier performance which could be accomplished with a simple passive line-level filter in front of the amp. 

belyin... Once I get farther into the tuning I'll give you some feedback on the Voxativ AC-2.6 drivers.  I do like very much the AER's but have had a hard time keeping them alive for any reasonable length of time.  I looked at a number of driver options.  The Voxativ line spans from ~ $1.5k/pr to of course $25k/pr much less than the AER DB-2 or 3.  The AC-2.6 is the middle 8" and lists for a sensible $3.7k/ matched pr.  For the base I am using Bert's BD-15 Reference Compact design at present but am considering change.  I really like the transient response of the La Scala "W" horn.

tinear . . .  I bought my AER's lightly used quite a while ago. I think they correspond to DB-1 in their current line-up. Do you know anyone in the States who can refoam them? I saw a post somewhere recently that related someone's effort to do it themselves, and it sounded daunting. I have never heard true horn-loaded bass in a home setting--as always one picks one's compromises! 

I heard of someone servicing AER in the DC area a while back.  Let me see if I can find the info.  The tolerances of these drivers is very tight.