Zaph / Madisound ZRT 2.5 Problem

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I bought the full kit with prebuilt crossovers from Madisound for the Zaph Audio ZRT 2.5 way. I originally built them 3 years ago and was not very happy with them. I deviated from the original front panel layout and thought that might be my problem which is why I never mentioned it anywhere as you guys would definitely tell me to try that first.....

Fastforward to today... I built new boxes using the box and layout that Zaph recommended for this design. I am also in a new home so the music room is different. Surprisingly I am finding not much difference at all from my incorrectly built box in my old living room. I looked over all the components in the crossover and my wiring. Everything looks to be OK physically.

They are very harsh sounding and fatiguing, the exact opposite to what Zaph called a "Listen to all day" kind of sound. If I use my Yamaha Aventage Rx3030 measuring mic and have it auto eq, I have consistently been getting a peak of around 6db at 1kHz which extends to some extent (~3db) to a few kHz. Of course this is taking the room into account but it has been the same in both rooms and I have tried moving the speakers around. These speakers are supposed to have full BSC but even when placed against the back wall, the amp wants to boost the midrange (~250hz to ~750hz) at least 6db up relative to the 1kHz.

EQ tames the peak, but the harshness is still there. They sound OK for TV or rap music and not bad with very simple music that doesn't have a lot going on, but with complex music, it just starts to fall apart and forget about listening to complex music loudly. So shrill! Even with EQing. I can't see that this is how they are supposed to perform.

I'm not sure what I am asking here but any suggestions are welcome. I don't know if I want to cut my losses and try to sell the kit, or start replacing crossover components or even the entire crossover. I really can't see that room or boxes can be the issue since I changed so much in those areas. I am just so disappointed in these. I have had them for 3 years and they really limit the music I can listen to and tolerate. :(
 
This is a wonderful and interesting problem, IMO. Sort of thing that makes my little heart leap with joy! :D

I don't know what your original cabinet was, but, IIRC, the main thing is to keep the baffle about the same width with variations.

I get in terrible trouble when I suggest a design is fundamentally flawed, but the Zaph ZRT or ZRT 2.5 just looked like one to me.
Zaph|Audio - ZRT - Revelator Tower.

Dear old Zaph aka John Krutke is in the American school of thought that all can be fixed by a low crossover. Maybe 1.7kHz. To me this is just a way to design what Lynn Olson calls a "LGWAG" or "Little Girl with a Guitar" speaker. Useless for complex Classical Music. Fatigueing. :eek:

The European school of thought is that a 1" tweeter should be crossed reasonably high to avoid distortion. I don't much care what the 6" bass is. It always has issues around 4-6kHz for cone-breakup. Cone breakup is terrible stuff. Best reduced. Troels Gravesen favours a tank notch across the bass coil.

Then we have a certain midrange shout with smallish drivers due to cabinet issues. These things can be notched or reduced with an LCR.
Illumina-66

In general, regardless of two way or 2.5 way design, I'd think that notching the cone-breakup is a plan. Maybe reducing the midrange around 1kHz with an LCR. More controversially, I detest soft-domes. A flawed concept if ever there was one. Scan usually do a ring-radiator version of most of their soft-domes.

Overall, I think this speaker can be fixed. Notch the bass cone breakup with an added tank around 22R and 0.33uF across the current 2.7mH bass coil. Ought to be nicer. But that doesn't fix the stressed tweeter. Some serious redesign needed.
 

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I get in terrible trouble when I suggest a design is fundamentally flawed, but the Zaph ZRT or ZRT 2.5 just looked like one to me.
Zaph|Audio - ZRT - Revelator Tower.

While that's not impossible and I have experienced the limitations of a 6+1 design in the past, I really can't think that Zaph's construction sounded like this when he built and tested his. There is no way a reasonable person could call this a "non-fatiguing, listen-to-all-day" sound. The 6600 is supposedly a pretty capable tweeter and I have heard lower end tweeters do OK enough at ~1.7khz xo. Also, the harshness tends to be there a fair amount even if I don't put it loud although it is less annoying at low volume I suppose.

I really am not wanting to start modifying Zaph's design. If I start to feel that this problem is just inherent in the design, I will be moving to something else. I don't have proper measurement equipment and have never designed a passive crossover before.
 
I don't see any inherent problem in Zaph's vented ZRT 2.5-Way design. The horizontal dispersion plot even looks perfectly balanced. Well done, Zaph! :D

The woofer filter has indeed to deal with a strong resonance at 1.5 kHz. An RC (60 uF in series with 5 ohm or 2x10 ohm) is used to damp that resonance. Your description points to a wiring error or to burned resistors there. It's worth to inspect that part of the crossover particularly.
 

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Have you tried different electronics with these speakers, or different speakers with these electronics? No or different EQ?

I have no idea what your Yamaha thingy is, but I am always suspicious of "auto" anything.

Peace,
Tom E

It's their flagship home theater amp from 3-4 years ago. Most high end HT amps have some kind of measurement mic and auto EQ nowadays as far as I know. I just let it do the measurement so I can have an idea of what it thinks is going on and then I adjust with that in mind to try and improve things.The entire DSP processing of the amp can be also bypassed with the push of one button. It sounds even a bit worse with no processing at all.

I have tried using an external power amp (DIY Honey Badger... but still needed the DAC from the Yamaha). It made very little difference to the sound and all that harshness was still there. I guess I should find some way of trying another dac to take the Yamaha out of the equation, but if that turned out to be the problem, it has been that way since brand new and it was a $2000 amp!

The harshness is pretty obvious. moving the speakers in the room, changing power amp, and even complete reorientation of the drivers on the front panel of the box all make very little difference in comparison to how annoying the problem is.

I have been in contact with Madisound today and have a couple ideas from you guys above on where to look at the crossover so I will need a bit of time before I can get it looked into further. Thank you for your suggestions everyone.
 
Merlinx, I've tried to suggest that Zaph just messed up his ZRT design in a polite way.

My suggestion to you is that you just listen to Daniel Barenboim playing Liszt on an Arthur Steinway piano on headphones and tell me this Zaph guy got it right.

Liszt - Consolation Nr. 3 - Daniel Barenboim - YouTube

My suggestion is to just dump the low crossover. Dump the soft-dome. And get real. At a certain point, we are listening to music. :)
 
Not yet. I have been on the phone with Madisound and got another set of eyes from them to look over pictures of the crossover to see if anything looked wrong. They looked all correct to me and their tech said it looks right too.

I tried disconnecting the tweeter and tweeter crossover to help narrow down the problem and it really seems like the issue is still just as bad with just the woofers playing. There is an annoying resonance or ringing that should not be there. The Madisound tech said that this was probably their best kit they every sold and that I should be happy with them if they were working right but he was out of ideas. I got another amp to try tonight just to be absolutely certain it is not an amp issue. I will try another source too but the only other source I can try is is an iPod. I was currently using optical SPDIF from my PC.

The next step after that will be for me to mail them the crossovers so they can test them on their demo model I guess. At least they are trying. I appreciate their service for a speaker I bought 3 years ago.
 
Yeah both speakers sound pretty much the same to me. I dont know what to say. They sound harsh as hell. There is no way that nearly everyone that bought them would be happy with them if they sounded like this.

Like I listen to the popular Adele song from awhile back "Hello". Sounds pretty nice at the start, while she sings quietly with just the piano... Then, as soon as she starts singing strongly, I just get an irresistible urge to turn it off. There is no enjoying music with these the way they sound right now. I would rather listen to my mini Logitech PC speakers.
 
Along with what's been mentioned, I'll add the possibility of a mislabeled inductor, wouldn't be the first time. Inadequate sound absorption material in the cabinet can cause significant upper midrange peaks. Generic (non-acoustic) type foam can sometimes have very poor sound absorption qualities.
 
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