What are the specs of a full range speaker?

Macrojack, FWIW, as I have no experience with Zu's, what Zu is offering is probably an excellent solution to providing really deep bass in a meaningful way. A parametric equalizer will go a long way towards solving speaker and room integration.

However (and you knew there was a however coming :-)) whether your room can support this type of bass is one issue and whether your sources/components can withstand the distortions that the additional sound pressure created by this kind of bass can produce is another.

A third issue to consider is that typically an equalizer can be very effective in lopping off the peaks of nodes but isn't nearly as effective in raising the level of the nulls to 'flat' without doing some damage to the sounds of the neighboring frequencies and soaking up a lot of the power available from the amp. That is usually determined by the design of the equalizer, the amount of correction needed and the power available from the amp.

Have you mapped out your room and determined its nodes and nulls and how they will effect the sound at the listening position and where the speakers will be positioned for best sonic results considering the upper frequencies which are determinitive of things like sound staging, balance, and good tonal integration? There frequently is a fair amount of difference between good bass requirements and the requirements of the upper frequencies. Most folks end up with some sort of compromise.

If you haven't worked all this out in advance don't be surprised if you not only don't get a 'big improvement' - you might not even break even.

JMHO - YMMV.

Great one Dave.

Getting off topic again with real versus canned, I have to rejoin. I have attended orchestral performances from coast to coast. I sat in a Carnegie Hall balcony with Henry Ho, builder of my amps.

Yet, I can still be brought to tears by great recordings unfolding between my speakers, such works as Rimsky-Korsakov's Sheherazade. Between full orchestra crescendos, Anshel Brusilow plays sensitive plaintive violin solos. I have to brush by a tear every time.

You can bet Henry and I were taking notes at Carnegie Hall. A smile on both our faces told all. I truthfully can say, I FEEL no difference, whether I am home or at famous performance halls.

Macrojack,

Others have answered your question very well and better than I could.

"Small" can be of the order of a few feet at low frequencies.

As Dave points out above, a small amount of EQ (Behringer, Rane, Rives Parc or other PEQ) can help smooth out LF bumps but cannot be used to eliminate nulls (if it aint there it ain't there and besides it is risky to apply boost as this may cause your amp to clip and damage your speakers). A PEQ should always be used sparingly and is probably best avoided above 100 HZ (use shelving functions at most and stay well away from very narrow filters above 100 HZ).

Room design, speaker placement and room treatment are preferable to EQ because this helps with the root cause. These can improve the sweet spot size and will reduce overall reverb levels (delayed vibrations). The reverberations are unlikely to be much improved by an EQ as it reduces the primary signal but has no affect on the relative size of primary signal to reflected energy.

Good luck with setting up your new speakers. Like a Ferrari, speakers with highly accurate extended LF response need careful attention and setup or they may not perform to expectation. Speakers with a smooth LF roll off are easier to handle but, have no doubts, an accurate full range speaker will perfom best under the right conditions.

Yikes. The more I read, the worse I feel. I must be jumping in the snake pit to get away from the snakes. The picture I had in my mind indicated much smoother sailing than what you guys are proposing. Maybe I'll get lucky about the bass in my room. It's pretty good now with an outboard sub (also ZU) but there are definitely places in the room where the bass is more pronounced. It's especially good at my desk down the hall in the bedroom about 50 feet away from the speakers.
There's always Zu's return policy to fall back on but this project is clearly going to cost something no matter how it plays out.