Best Bass Amp Strategy for Zu Def Pro

Hi folks. I've gotten alot of really helpful advice on this from Phil Ressler, and I'd like to open this to the insight of other Zu folk. I've never given bass amplification any thought until the Def Pro's. The amps for the front drivers are audiopax 88's. I'm leaning toward Mcintosh MC252 for the bass array as per talking to Phil, and a buddy has their 400/ch running his Piega's so although I'm not a big SS fan, they do seem to be tonally rich and musical. I don't want a cyborg bass sound but I do want the bass to have both lots of grunt and be as musical as the audiopax.

Thanks in advance for the feedback.
listen to Phil,the Mac will work great.bass amplification is easy.
The Zu room at RMAF was using a Crown Pro amp for the bass. While not a pro audio fan, they did sound very nice.
Be careful with Pro amps as they sometimes have noisey Fans, unless it is the Crown K series which is like a digital type amp with tons of power...
While the rear arrays of the Pro's seems easy, with their high efficiency, my experience has been anything but.

First, I had a Bel Canto 300, which should have plenty of output. It didn't. Sean at Zu told me to try a conventional Class A/B amp. I found an Adcom 555II, which has 200 wpc and should have been a champ. It wasn't.

I then tried an inexpensive NAD amp which fared no better. All these amps had the same problem of insufficient output and insufficient definition.

Then, I tried the amp circuit of a 60 wpc Audiolab amp - here we go, much better! Then, I went to the local stereo shop and traded the Adcom for an old Hafler 220 DH, with about 110 wpc. I'm sure it gets better, but this amp at $210 is the best I've had.

I'd call Sean and get his votes. Zu has certainly heard more Pro setups than anybody and can surely direct you well. Don't accept anything less than superlative bass. And, don't be afraid to cross over higher than 40 hz. Try 65 hz, which feels to me to blend very well with the fronts and provide some excellent midbass pop which is not possible with the front array.

Good luck, let us know what you find.

I just plugged a new (used) Crown K2 into the subs last night and Wow. I can't say for sure whether I like the sound better but it sure is different. Plucking of bass strings has never been evident in my room before but it sure was last night.

Overall bass definition (pun intended) was incredible, though strong enough to distract from the rest of the performance. I will mess with the EQ for a bit and repost, but this seems like an excellent choice for this function.
Well, I've spent some time tweaking the K2 and it's a winner in this context. It's way overkill in the power department but it's quick, tuneful, and extremely strong. I've turned it down 10 db, based on a TacT corrected curve, to get it balanced. I'm not done but this is by far the best I've heard the subs. In fact, I've never heard this kind of bass speed And power in a home-oriented system.