Zu Tone/Druid Tonal Anomalies


I like to hear anyone with Zu speakers if they have had a similar problem. I recently acquired a pair of Zu Tone speakers. Certain aspects about them are very good, such as soundstaging and speed, but it seems to me that unless my pair are defective, there is a serious issue with tonal accuracy. Right away when I set them up, I noticed that they sounded quite hollow. I then made a lot of measurements, both close miked and at the listening seat, with both a Behringer DEQ2496 and an RS sound level meter (using both pink noise and frequency generation). In both cases, it fairly closely matches what I am hearing, which is a severe rise in the upper midrange. I am trying to use a Z-Systems RDQ-1 digital EQ device to correct this problem, and have gotten much closer to a natural tone and flatter curve. What this required was a 7.6 db cut centered at 1.4kHz at a width of 1.5 octaves. This is quite a cut! For reference, I've had two other sets of speakers (Monitor Audio GR60 and NHT ST-4) in the room at almost exactly the same position, neither of which had this problem. I spoke to Sean Casey at Zu about the problem, and he thought it might be room interaction, which might be true to a point, but the anomaly is just too severe, and makes this point less viable since my other speakers didn't show the problem. I noticed in another thread here, that a couple of people heard what seemed like a similar problem with the Druids.

I am very curious as to what others have experienced with any of the Zu speakers in this regard.

Thanks,
Stew
smeyers

Showing 5 responses by smeyers

I'd to hear from people that don't feel they have this problem with the speakers. Is it possible that certain batches are defective? If they all sound like this, how can they have such positive reviews? I am correcting this problem with digital EQ, so now they sound quite good, but this is certainly a band-aid, and of course won't work with analog sources.
>>You might check out the Zu Audio circle at Audocircle.com.<<

Thank you; I will.
Thanks Mihilli, I was told the speakers had about 70 hours of playing time when I received them, so I do plan on spending some time to see what happens after they break in a bit more. I find it a little hard to believe that they will change that much however.

Miklorsmith, yes room interaction might have something to do with it. But as I mentioned earlier, I also did some close miked measurements. I do realize that my room is not an anechoic chamber, but the anomaly seems more than would account for that. Have you tried to measure the response of your Druids and/or Defintions? It might be that you do have an upper midrange spike that you find pleasing.
I agree that the speakers (I have the Zu Tone's) image best when pointed directly at the listener (I have commented on this in other threads), but it seems to me that tonal balance is better with them not toed in much, mainly due to some excessive high frequency energy coming from that super-tweeter. When I was experimenting with this, I put my ear close to the super-tweeter, and you can hear some 'hissing' that actully hurt my ears! This 'hissing' is tamed somewhat, when the speakers are not pointed directly at the listener.
Glreno, I'm trying two different sets of tube amps.

1) AES Sixpacs with KT-66 tubes

2) Wright Sound Mono 10's with EH Gold 2A3 tubes, and now with Sophia Electric Princess 300b 2.5v tubes

Both are connected in balanced mode from a BAT VK-5i preamp. I also use a Muse 296 DAC fed from a Krell MD-20 transport.