DIVA CROSSOVER WHAT'S THE BEST RIGHT NOW?

[DarthDiva]

So, what's the current thinking on a state of the art cross over for the Divas? Go passive? Go active DSP, and if so, a DSP from who? And what about upgrading Apogee's DAX? I've read that as is , the DAX doesn't sound near as good as new passive crossovers, BUT, does anyone have experience with an upgraded DAX? There is a guy in Quebec that offer DAX upgrades. He replaces the op amps and I don't know what else. Has anyone had their DAX upgraded by audiodoctor007.com ? I don't know if he is a part time spy or a part time tec wizard. Thanks in advance for your comments and advice.

[Graz]

To be honest I have heard a good many passive and active crossovers on several Apogee's, old and new. The 2006-2015 Synergy speakers were actually designed with the ability to connect from single passive to triple active in any combination. The best I heard from them were single amps through a passive crossover.

The early Diva passive was not very well designed imho, the inductors (especially bass) were poorly made, the casework flimsy and prone to vibration. The DAX's - I have not had a great experience of them but there have been reports of people that have upgraded them and had improvements. I have not personally heard them, but several clients have given positive reviews. Who is the man in Quebec?


Curious - Graz

[DarthDiva]

Hi Graz,

Below is the link to 007"s site from Quebec regarding the DAX upgrade. There is not much detail about what is done in that process. I haven't been able to find anyone who can comment on the before and after performance of the DAX upgrade. I think I will follow up with them and ask for more specifics on what precisely they do, and why those changes should bring significant sonic improvements.

https://www.audiodoctor007.com/am%C3%A9 ... apogee_dax

[Al^]

I have both the Dax with the readouts and passives for my Divas, The stock dax puts the passives to shame as far as I'm concerned, If you look in the old forums, I believe Brian Beck rebuilt his Dax and explained what he'd done, may even be on this forum
Al

[DarthDiva]

Thanks for your observations Al. I had the passive crossovers before switching to the DAX with readouts, which were in my experience much better as well. I've read that some people have "upgraded" their DAX by changing the op amps. But I am gun shy of letting someone perform surgery on my units. I can't imagine anyone has had much surgical experience and I sure can't find any patients with glowing testimonials. I also have not heard directly from anyone that has had actual experience with a DAX that says the latest greatest passive cross over design will put the DAX to shame. Maybe I will play around with a DEQX , dbx driverrack or mini dsp instead.By the way, have you swapped out your bass panel or the other ribbons yet? If so, what differences did you hear?

[Zardoz]

Hey Al,
Where do you live?? It looks like a rec hall or something. I would love to have a room that big.
Good listening,
Z

[Al^]

DarthDiva, I tried the driverack 260 and 482, DEQ2496, DCX2496, and I still find the Dax best,, but I did find the Divas are very flat on their own.
Sorry about the monster size pic,
Zardoz, I bought a12000 sq ft school, thats the Auditorium

[DarthDiva]

Al, thanks so much for your answer. You have just saved me a lot of messing about with dbx, DEQ etc etc. Monster pic? No worries, you have an auditorium and the pic gives a great feeling of space.

By the way, did you make any changes to your DAX or anything in the DAX type crossover boxes?

No response yet from 007 in Quebec to my email requesting more detail on what they do to "upgrade" the DAX. Maybe he's gone dark, out on a secret mission.

[Zardoz]

I rebuilt my own Diva xovers with much better caps and inductors. It made a huge improvement in the sound. I generally think passive is the best way to go. Active xovers add complexity to the signal path that is probably not really needed. Just more to go wrong farther down the road. Just my 2 cents anyway.

[DarthDiva]

Thanks for your post Zardoz. Maybe one day, I'll get lucky and be able to do an A/B comparison of a well done passive crossover with my old DAX.

In the meantime, here's an update on my DAX upgrade inquiry from 007 in Quebec. I tried to get some specifics on what he does to improve the DAX and why he does it. I asked if he had technical before and after measurements and specs, and if he could refer me to any customers that upgraded their DAX with him so that I could hear of their experience. I asked if he could describe the before and after sonic differences.

In true 007 fashion, I suppose, I did not get an answer to any of my questions. I was hoping for something that would give me a bit of comfort from him to demonstrate audio engineering knowledge and competence.

But I did get this, and more of the same, all of which I won't bore you with:

--It is not our role to convince people to adopt our upgrade on their DAX crossover
--The experience of our customers who had the possibility of making A/B tests between the passive crossover and the upgraded active crossover, has shown that the upgraded active crossover sounds better than any passive crossover.
Furthermore, technically speaking, a passive crossover can never achieve the frequency response linearity and the precision of the crossover frequencies of an active crossover.
--To debate this subject is not in our scope. It can be very long and time consuming. We simply don't have the time for it.

--Our upgrade is meaningful to open minded audiophiles who are in the quest of the highest level of fidelity, to reproduce as faithfully as possible the music, as it was recorded in the recording studio, the day it was made.

Well, for me anyway, I guess I am not an open minded audiophile that makes decisions in the absence of answers to fair questions and honest third party peer reviews.

It would be great to somehow get input from George Short, who I have read worked with Krell, then with Apogee and who designed the DAX to begin with. I think he may now be a designer for Wisdom Audio in Nevada.

[apogee_admin]

From personal experience, all active crossovers, do not sound as good or even close to a high quality part passive one.

The talk about linearly and precision is actually pointless when you see what a room does to frequency response of L and R channels.

I directly compared an Apogee DAX to an upgraded Duetta Sig passive crossover about four years ago. The DAX by comparison sounded totally flat and lifeless, it would have needed the mother of all upgrades to get near the passive.

The reason why the Apogee DAX improves the Diva so much in stock form is the original Diva passive is severely compromised by the switches. When I had Divas I was amazed at how much better is sounded without them.

Also I had the DAX with Duettas in 2000-ish, and to be honest felt a bit stupid for shelling out £1k as it hardly sounded any better than the stock passive, bit more bass control, that was about it.

Jon

[DarthDiva]

Thank you for that Jon. Vert helpful. Good new passive crossovers must truly sound amazing . I have never found my Divas flat or lifeless with the DAX so I am very much looking forward to testing them new passive crossovers.

When you refer to compromised switches on the Diva passive boxes I assume you are referring to the industrial type toggle switches, one of which remains for the mid/tweeters even with the DAX upgrade?

By the way, are you a fan of biamping Divas when using passive crossovers?

[apogee_admin]

Yes the switches on the crossover boxes, you can take them out of circuit pretty easily by just snipping and connecting the wires together. I remember them being particularly egregious on the tweeter adding grain and spit on voices.

I tried biamping once with 2 x Musical Fidelity Nuvista 300's, I had one and borrowed one from a friend. There was a bit more control in the bass, but nothing else that would make me want to spend another £3-4K.

I think if the amp you have is capable, biamping doesn't necessarily give a big advantage.

[DarthDiva]

Thanks Jon, I may try that tweek once i figure out what the permanent switch setting should be. I have been happily bi amping with 4 Ray Lumley 100 watt mono tube amps. First heard the Lumley's driving Apogees many year ago in Toronto. The Lumley totally outperformed the Krell mono blocks of the time, Classe class A's, Stax class A's and whatever else we tried back then. So, I have lived with them ever since. I might mess about with trying a few new amps just to see how things are now but those new contenders will have a serious bit of work ahead of them.

And, I'm going to try to get a pair of a super "updated" passive cross overs to A/B against my ancient DAX. It will be interesting to see if any of the super accomplished cross over designers are prepared to sell a pair to me on a "if you don't like them, you can return them" basis.

Also, I think I will will try to demo a dbx Driverack PA2. Just something to do during covid shut down.

[apogee_admin]

Most amps are better than Krell in my opinion, there are some exceptions, but a lot of them need sweetening with a tube pre at minimum.

I would doubt you would get someone to build custom crossovers to try, you are looking at a days work that is non-refundable.

The DBX will be full of op-amps like everything else, might be better than the DAX though. The best active crossover I heard was a rare Yamaha JFET one my brother had, still sounded a lot less natural.

[novaprod]

Greetings. I haven't been on this site in many years.
I have been running my Divas with a DBX Driverack 482 for many years. I sold off my passives and can't go back. The DBX does crossovers with various slopes and frequency choices, eq with the ability to correct for room nodes and delay to perfectly align the drivers for your seating position.
Audiophile friends tell me it is the best system they have ever heard!
Front end is a Suptratek tube pre with vintage tubes. I was running a Krell KSA 100 on the mids for many years but it recently started smoking so I subbed in a Classe Fifteen. The Audiophiles like it better than the Krell. Bass panels are powered by a pair of Henry's H2Os. I'm older and can't hear over 12k. The TWs got destroyed by a power outage and were turned into tinsel, so I have not pothered replacing them even though I have a spare pair from Graz for the purpose.
That's my 2 cents worrth.
Garry

[DarthDiva]

Well Happy New Year Garry and thanks very much for posting. Can I ask what cross over point and slopes you are using with the DBX? Graz if you are watching and have a moment , what would you say is the optimal slope type and crossover point for bi amping our Diva's? I am about to experiment with a DBX and a Trinnov Altitude 16. By the way, my DAX is still woking perfectly , so I am looking forward to see if I can hear any improvement with the DBX or the Trinnov. There is another amp I am trying with the Divas that perhaps many people do no know of. It is the Magtech from Roger Sanders at Sanders Sound. It has no issues whatsoever driving the Divas . It easily will do 900wpc into 4 ohms and allows the the Divas to perform better than with any other amps I had previously tried from Krell, Classe, Stax, Ray Lumley ( I still love the Lumley's) and Roland. It is really worth reading all of Roger's white papers not only on the Magtech's. His straight shooting honesty related to audio is uniquely refreshing. . I don't know if there are other amps out there with designs similar to the Magtech and for me they perform so well, I am not looking anymore. Sorry to hear about your power outage tinsel event. We are plagued by outages here. I found a pretty cool and not expensive device that guarantees to protect you from surges. So far, it has worked for us. you can check it out at cleanvolt.com I have read that old codgers like you and I can still notice a great improvement in sound if our speakers can produce sound even over 30Kkz, yes, that's not a typo. And yes, thats even if we can't hear a tone over 12kz. Recently, I was able to hear a pair of speakers with and without a super tweeter, and I'll be dammed, but with the super tweeter on I heard more detail , air and "thereness" out of the recording. So, you may just find installing those spare ribbons you have from Graz to be worth the effort. And I am sticking with my Divas and when the Ribbons die or panels start to buzz I'll do the full upgrade. And if I win the lottery, I am flying to Australia to get a new pair from Graz. Have a great 2023.

[Graz]

Those Magtech amps look interesting!

The main problems with any active setup is DC offset and turn-off/on transients from the amp kicking the MR and TW ribbons. With DC, it shifts the ribbon out of center and will move the ribbon to the maximum of the applied force, in many cases stretching the ribbon. Cap protection advised, calculated to just below the operating band. The bass is fine, and does not need such protection.

Some amps have sophisticated dc protection circuitry, but when you get amps that employ a stack of output transistors - even if matched it increases the possibilities of a transistor fail. Caps give the ribbon a chance...

If you can get your hands on a good digital active xo you can test out many options in conjunction with driver correction that the crossover can employ. Slopes - the original were around 400 and 11k at a pseudo 12dB setup - an ok place to start. But the secondary shaping and inherent drive unit characteristics are all part of that equation. The worst part of the early Diva xo was the dreadful dual wound bass inductor, and any active setup absolutely removes that from the equation. Start with the original numbers and tweak around. Usual xo rules apply - change one thing = changes everything! It's fast to get close but the last few percent come dear, and take longer. Do not skimp on the quality of the cap protection!

Take care - Graz

[DarthDiva]

Thank you for your post Graz Have a healthy and happy 2023 !!

[BOB LEWIS]

I run my Duetta Sigs actively with a active crossover that is definately superior to the passive crossover.
The crossover which I built from a kit is all discrete class A;just two 3 transistor buffers per leg.The power supply regulators are also discrete class A ,4 per channel(2 for current,2for voltage).A pair of 180va outboard
transformers feed the inboard schottky rectifiers and Blackgate power supply caps.The 3 signal path resistors
in each leg are Vishay foil and the RC,CR filter caps are Relcap Multicaps.The simple but high performance
circuitry and high grade components produces a very transparent sound.The DAX crossover is highly compromised due to using a bucket load of IC op amps,6 per leg would you believe.
As far as switch on/off DC offset is concerned my amps switch on/off in standby mode,I.E. zero offset.