Thanks for the great responses so far, very helpful!
Yes, these new MkIV's are in the same room and location as the previous speakers. Unfortunately, I am very limited where they can be placed, but the location worked very well before. They are only about 6" from the back wall and 2 feet from the side walls. Perhaps I was used to the walls reinforcing the bass so strongly with the 4 rear firing 10" woofers on the Mk1.5. Yes, the bass on the MkIV is tight and tuneful, but just pretty underwhelming so far in comparison (the down firing woofers are definitely functional). Hopefully I can get it dialed in, because it has left me with some buyer's regret, hoping for an upgrade, but feeling let down about the bottom end. For context, I am also a bass guitarist, so I do love some very deep low frequencies!
Spiritofmusic, thank you for your very detailed post, appreciated! I will try some of those settings. I wish I could pull them out from the wall as you suggest, but it's just not practical at all for my space. Coincidentally, I also have a 150 yr old suspended wood floor, so I could play around with footers. I just put on the Black Diamond Racing cones that were on my last set of speakers. Have you found that the gap spacing to the floor is critical? In the manual, it suggests even 1/4" is sufficient, but at least one forum post I read said that bass didn't really begin to bloom until the speakers were 3" off the floor.
As for my amplifiers, I don't think they are "bridged," but not 100% sure. They are Cary 300SE monoblocks, with a Cary SLP98 preamp in front, all run with unbalanced RCAs. One odd thing about the preamp is that it inverts phase, so you have to switch around the speakers cables, but I believe I have that sorted properly.
Other thoughts are welcome!
David |
Again, thank you guys for the contributions. Please keep sending along any thoughts you have. So far they are exactly the kind of answers I was hoping for from current owners. Wish I could invite you all over for a drink and a listen! So I played around for a few hours tonight and managed to improve the bass presentation on the speakers significantly. I've had to find my own settings, as the examples posted above just haven't done it for me, in my space, with my tastes. I would still say that these MkIV's in their current configuration here are outputting only maybe 70% of the bass quality I was getting from the Mk1.5's. But steps forward for sure. I've definitely had this realization.... I lived (very happily!) with my previous Zu's for 12 years here and had them dialled in just perfectly. I probably had somewhere around 5000 hours of listening bliss with them. Then I found these used MkIV's locally for a good price and decided to make the leap. Somehow I thought I could just slot them in just where the others were and figured it would be instant love. Now I get it... they are a different speaker, with a different solution for transducing bass frequencies, and I'm going to have to play around and get to know them in time... I was struck by reading this thread -- https://forum.audiogon.com/discussions/zu-definition-4-height -- where 52tiger says he "was running out of options and really wasn't sure if the Def 4 was better than the def3," but after raising the height off the floor "the bass is tight and amazing, the downfiring design is so much better than the rear firing its no comparison." Clearly I have some experimenting to do. I'm having faith in the last line of that thread by dentdog: "With my Def 4s I worked them around quite a bit to optimize... For me it was well worth all the effort." |
Just saw your reply Phil. My MkIV's are new to me, bought used locally. I wasn't really looking to upgrade, but stumbled upon them and... well... you know how this hobby is. They look to be the first version (not rev B, if that makes a difference). My room dimensions are 13' wide by 22' deep, with the speakers on the short wall. They are 8 feet apart, tweeter to tweeter, with the listening position 8 to 9 feet from each tweeter. Almost a nearfield setup, which might be part of the issue in the way the bass is sounding in the sweet spot. Despite the size of the room, these positions can't really be changed, as the other half of the room is a music studio for playing and recording.
My 300b tubes are Full Music 300b/n mesh plates. I've always loved them and they churned out mind-bending bass with my previous mk1.5s.
However, you are right that I may need to wean myself off some of the exaggerated bass from the 1.5s. Being a bass player and a lover of some bass-heavy genres like reggae, those deep frequencies just floated my boat, even if it resulted at times in some smearing of the midrange. That said, I could barely turn the amplitude knobs past 12 o'clock without blowing my head off, while now I'm struggling to get enough bass out of the MkIV's. I do listen to a wide variety of music, so I'd like to get the balance correct!
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Phil... wow, amazing feedback! Yes, the mkIV's seem bass shy at reasonable volumes against the FRD efficiency (almost as if they were tuned brighter than my mk1.5s), but can clearly crank out deep frequencies when turned up. Just checked and the serial numbers here are 007 and 008, so I'd guess these are very early models. I'm working tomorrow and don't really know the Zu guys, so if you'd have time to call and ask Sean, I'd be very appreciative!
I suppose I've liked the 300b mesh plate because I listen to so much music that isn't that well recorded and the rich and creamy character of these tubes hides some of that... 70s reggae made in the ghettos of Kingston just isn't audiophile grade. But I also have a strong collection of jazz, blues, R&B, and rock on vinyl as well, some of which are superb recordings. So for me it has been about finding a balance over the years of a system that's capable of being highly resolving, but also forgiving of poor recordings. It's a delicate dance. I'm certainly willing to try out some new tubes though ;)
Thanks again for all your help!
David
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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 |
Thanks for the info! I do realize footers are less important than getting these speakers properly set up at this point. I was just curious to hear about your experience using roller blocks, since I have a couple sets kicking around. I never thought to try them under the speakers. It's a never ending quest, isn't it? :) |
Thank so much, Phil. I really appreciate your help here!
Interestingly, I did try higher crossover frequencies (along with various settings of the parametric EQ) over the weekend and it was definitely an improvement. I'd still like some additional gain for more headroom, but further steps forward. With my ears not so focussed on the inadequate bass I was hearing previously, the upgraded drivers and Radian tweeters really began to shine.
I wondered, too, if these speakers would benefit from a little less toe in (they are currently pointed directly at the listening position, only 9 feet away), compared to the mk1.5's, which were in the exact same spots. The spray of the Radians is glorious, but perhaps a little too prominent in the mix in this configuration. I haven't yet played with this, as moving these new Zu's is more than a one person job!
I will make contact at Zu to upgrade the bass modules. I've come too far to stop now :)
Once I get everything sorted, I'll close the loop and let you guys know how it all turns out...
Happy listening,
David
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I've managed to remove the sub amps and will send them out today. It was a bit of a challenge pulling them out due to the glue tape! I was surprised how tiny the RCA cables from the speakon inputs to the amps are. Flies in the face of the massive audiophile cables everyone puts on their subs these days.
Perhaps this is actually an ideal time to play around with toe in, as I'll be without the bass output for a couple of weeks. Based on my listening so far, I thought that the Mk4's in my room would benefit from a bit less toe-in, so it's good to hear your input on that, Phil. I'll try your suggestion of some older recordings. I've got some great jazz from the 50s. Interestingly, I asked Sean about this and he said that the ideal positions he has found in various setups with the Mk4's have ranged from toed-in from as extreme as 2 feet in front of the listening position to some distance behind, usually no more than a couple of feet. He estimated 1/10 times directing the tweeters in front of the listener, 4/10 directly at the listener, and 5/10 behind. I always had the Mk1.5's pointed right at my ears, but notice that these new speakers aren't disappearing as well my old ones in that position, with the frequency spectrum tilted upwards (a little too much high end content in comparison to the mids).
Marc, I was just looking at those footers! The company is based in Ontario, about an hour from where I live, though I think they're actually manufactured in China. Crutchfield carries them and has an easy return policy, so it's a no risk proposition to give them a go. I'm just waiting to hear back if they have the alternative threads (looks like the Zu's are 3/8"-16, which isn't included in the box).
David
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Hey Phil,
I actually have older spike receptors from Herbie's that I've been using with BDR cones, similar but different to the one's to which you linked. But in the interest of trying something new, I've ordered the IsoAcoustics Gaia's. I learned they actually come in multiple different sizes. The Gaia III's can only handle 70lbs per set, but the I's are rated up to 220lbs. I managed to negotiate a good deal from a store I've gotten a lot of pro audio gear from in the past, so I'm going to give them a shot. The manufacturer also agreed to send me the correct thread adapters directly. I'll let you know what I think about them!
David
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Totally true, Phil, I was just curious where Marc has gone with his power upgrades. I still have some work to do to reduce some background noise in my audio chain, particularly when using my turntable as a source. I agree that the subs are the least of my worries in that regard. I had wondered, however, if the power cords to the Zu's were introducing the possibility of some ground loop hum (heard through the compression tweeter), as they are currently plugged into a different circuit. Solving grounding problems has yielded tremendous gains for me in the past, on both the listening and recording ends of the spectrum. David |
Hi Marc, when I spoke with Sean yesterday, he also said he generally liked a lower setting around 38-42Hz as well, depending on the setup and type of music (lower for music with deep synth bass, for example). He said he has never had a need to push the crossover higher than 50Hz. I was cranking it up as far as 90Hz to get the bass I wanted, but obviously that began to smear the lower mids.
I'm hoping the adjustment in amp gain, the upgrade to the Lundahl transformers, and the increased gap height from the Gaia's will all yield improvements (Sean did say gap height could slightly increase the bass output). The toe-in may be quite significant as well. You are lucky to have 15 feet, which I'm sure lets the low frequency waves unfold more. I am 9 feet tweeter to ear, pretty nearfield and hard to get a deep soundstage dialled in, though it does make for a very immersive experience. Like front row seats!
Well, lots of positive developments here. I'm not sure why I expected the upgrade from the Mk1.5's to the Mk4's would be easy and instantly gratifying. I should know by now that, as with everything in this hobby, it's a learning curve and a journey to get to musical nirvana...
Cheers,
David |
Can you tell me more about the power upgrades you are describing?
I've found a simultaneous benefit and drawback of the high efficiency of these speakers is how much they reveal noise issues in my system, including very minor ground loops. I had been considering star grounding the components prior to acquiring these new Zu's. It would be great to include them in the scheme, if adding the grounding posts is something that could be done while the sub amps are in for upgrades...
On other fronts, I've played around with power cords, without hearing really significant differences. At one point, I had Shunyata cords on my previous Definitions, but wasn't sure they were any different to the Zu Birth cables that came with them. Upgraded fuses have also been difficult to assess real vs. perceived gains. Did you upgrade a fuse inside the sub amps?
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Yeah, I'm not too interested in spending much on power cords etc. at this point. I was just interested in the grounding posts you had installed on the Zu's and your overall power management scheme, as I've struggled with some hum and slight buzz in my system. I do have the subs on the speakers on a different circuit, which I realize is an issue, but was more practical given how things are arranged in my listening room. Also, I misspoke when I said the ground loop hums are coming out the tweeter... obviously they are oscillating at 60hz. I actually only have a small amount of 60hz hum present in the FRDs and not audible in the sweet spot. I do, however, have some hiss and buzz out of the tweeter when the phono is selected on my turntable. I was able to reduce the buzz significantly by running a ground wire from the lamp above my turntable (on a dimmer, which is a likely source of the problem) to the turntable itself and then to the preamp. I had considered a star grounding scheme for the whole rig, which worked wonderfully to lower the overall noise floor when I did this for the analog mixing setup in my home recording studio. In such a configuration with grounding posts on the speakers, I could then lift the grounds on all but one of the components for a single path.
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Very true, Marc, I'll start from square one with setup once the amps are back. I really appreciate all the help you and Phil have given me here. David |
Hi Phil,
Here's some answers to the questions you posed:
-- no cable TV in my sources
-- no balanced / XLR cables
-- preamp is a Cary SLP-98 with integrated tube phono stage, no SUT
-- no ground lift switches on any components
-- no passive components
-- cartridge is a Clearaudio Virtuoso v2 ebony, tonearm is a VPI JMW-9
-- there is a lamp situated above the turntable, which was causing buzz when turned on, but that was mostly eliminated by running a ground to the turntable and then preamp. The lamp is off when listening anyway. No other power supplies near the turntable.
Interestingly, Sean sent me this response about grounding the sub amps in the Definition (I'm sure he wouldn't mind me posting this): "When I rebuild the amps I float the audio ground, that is one of the benefits of the transformer. Another thing I do is to better float the AC transform, much of the hum you notice is coming from the mechanical singing of the AC transform, the power supply is linear so it’s a big piece of the kit in size and mechanical effect. Things should be much quieter when you get them back."
David
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That's great, Marc! Maybe this thread will end up solving problems for both of us :) |
By the way, I've also installed Isoacoustics Gaia I's to the Definitions. Can't wait to get the amps back to take them for a test drive! Sean said it was about a week turnaround. |
Looks like the sub amps are headed back to me. I'll report back in when everything is up and running. Did you end up deciding to get your amps upgraded to fix the hum issue, Marc? |
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 |
