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
Hi guys,

Sorry for the long delay in getting back to you. With the nice weather arriving, my focus has shifted to outdoor chores and adventures!

I did get the amps back from Sean and clearly the bass amplitude range is much more serviceable now. I still need to spend some time dialing it in perfectly, but it's an obvious improvement. 

I also don't hear any hum at all now, so whatever he did to float the transformer seems to have worked. 

Once again, thank you guys for all your help with this. I'm looking forward to some long evening listening sessions once the cooler weather comes back around. 

David