Help me understand how to optimize bass on the Zu Definition Mk IV


I am a longtime owner of Zu Definition Mk1.5 speakers and recently also bought a pair of Definition Mk4's. I based this decision partly on the reviews / feedback posted here on Audiogon in various threads by members such as 213cobra, gsm18439, spiritofmusic and others. I'm really hoping some of you Mk4 owners can chime in and help me out here!

Basically, my issue is that I found the Mk1.5's put out incredibly deep and impactful bass, especially with some of the music I love, like R&B and reggae. And this was with the bass amplitude knob at 12 or 1 o'clock. However, after setting up my new Mk4's, I find the bass underwhelming and anemic, even after fiddling around with various settings and with the volume and PEQ cranked. I have them on spikes into bases on a hardwood floor, with about a 1.5" gap on the bottom. What am I missing here?? Based on the reviews I read, I was expected the bass to equal or exceed the lowly 1.5's. 

Thanks so much in advance for any helpful advice! 


temicxoch
My Def 4s are nos.179 and 180. Where does this fit in the production run re sum amps' gain?
Phil, you don't know the half of it LOL.

I'm trying GSM's suggestion of subs at 45Hz and 9/10 Level.

My default setting is 38Hz and 6.5/10.
Marc, while I was waiting for Phil to come back with info about the bass gain (keeping me in suspense haha!), I was reading some of the threads here and elsewhere about the Definitions. I noticed that you previous had Symposium roller blocks under yours, but now you are onto the Revopods. I happen to have a couple sets of roller blocks lying around that I used to have under my preamp and DAC.... how did you find them under the Zu's? I always figured spikes / cones would be better for speakers and roller blocks better with components that would be affected by micro-vibrations. What made you move on to the Revopods? (Though I might regret asking, since they are $$$!) David
Temicxoch, all this stuff is buyer beware, and critically, room dependent. My old space was a converted industrial loft with a bombproof solid concrete floor overlaid w timber, which meant that the option of Rollerblocks replacing spikes under the Zus was possible, and indeed these did have the edge on stock spikes.

Here, my floor is much more flexy, being an 1861 actual roof space. Even though I didn't realise it to start, the Rollerblocks were deleterious on this floor. I noticed existence of Revopods as I went to trial IsoAcoustics Gaias footers, tried both out, and the Revopods totally ruled. I can't say w any great confidence why this is the case, but for me the Revopods have really pushed my Definitions performance to the next level, incl the ability to get deeper, tighter and more extended subs output, which I know is your ongoing issue.

I'm not going to claim they are your solution, it's room setup and subs settings that needs to be yr current focus, but these footers could then be the icing on the cake.

For the record, the Revopods sit on Panzerholz slabs, themselves on Symposium Acoustics Svelte Shelves.