[Bingenito]

I'm non-commercial (nonprofit) in the speaker world so I have no axes to grind to support the sales of DEQX or any other gadget for speakers. I'm involved in the design of speakers for my own satisfaction and the ability to use some of my technical skills. I don't need the worry about running my own company or from where my next buck comes.

Having said that, in my mind the DEQX technology is the cutting edge of what direction the industry will likely follow in the next decade. DEQX or equivalent technology promises to eliminate the speaker as the major source of distortion and imperfections in the music reproduction process.

Using a DEQX system isn't for the non-techno inclined person though. You need to have a some understanding of how to make measurements and what the data means once you have it. The procedure is straightforward and the software is maturing in its user interface but you do have to work through the details. It is not surprising that some people who might like to have the benefits of the DEQX system yet can not deal with the calibration process.

I suggest that if you are interested in DEQX (or its results) that you find someone who can demo their unit to show you what it can do and how it sounds.

Assuming that DEQX is in the right hands in it's current form is it better then the same crossover in passive form? If so how and by what margin?

[ncaudio]

Bryan,

There are some advantages to a electronic crossover with correction that you just can't acheive with passive. I'm in the same situation as Jim in that I have no vested interest, just want what is going to work in my system. Basically a advanced electronic crossover allows time alignment of drivers so the baffle can be optimized, it allows easy adjustment of crossover slopes and crossover frequency and much faster slopes than passive can offer. Driver efficiency is a non issue, I'm using ribbons that are probably about 90 db/watt with midrange arrays that are about 98 db/watt. There are advantages in amplifier selection since 2 small amps equal a much larger one (2 50 watt amps equal about a single 200 watt amp). You have direct drive of the speaker drivers, no inductors capacitors or resistors.

On the flip side it is a much more complicated setup, multiple amplifers, more wires etc. and more to go wrong with setup and configuration. In your case you have really good electronics and a lot of SACD's  that  would entail an extra DA and AD conversion. Brad Virgil went away from the Tact stuff, it sounded better with digital and worse with vinyl which now is his main source. If and when Rick comes up with a commercial setup that might be a good option for you, otherwise keep what you have and use it with a speaker with a passive crossover.

Going back to your original question, is a electronic crossover better than a passive? The answer is yes for me, maybe for someone else, it depends upon what amplifier you are using, how good the rest of the electronics are etc. I think the answer also depends on whether you are talking about replacing the passive crossover in a commercial speaker and you have the time, skill end evergy to set it up properly if not then it might not sound as good, but if you are using quality electronics and take the time to set it up then it will probably sound better. There are so many variable that have to be answered before the basic question can be answered correctly.

Not sure if that helped, hope so.

[ekovalsky]

If CD is the primary format, you can run an all-digital setup from the source to the amplifiers.  This is what I am currently doing with the TacT and it is wonderful.  You get all the benefits of the digital crossovers plus room correction and time alignment, the importance of which is vastly underestimated in my opinion.

Also, this type of setup eliminates analog interconnects, all of which act as a tone control to some degree.  Otherwise they'd all sound the same    Digital links can definitely affect the sound, but I have not heard significant differences between several good non-optical cables with different construction as long as the connectors were good quality and the impedance was correctly matched to the inteface specs.

However, if a significant portion of the music library is on vinyl or hi-res digital (as most of these players only output analog) you probably will not be happy with the additional A>D and D>A conversion steps.  The DAC sections of the TacT and DEQX are certainly respectable but they will not hold up to the better outboard units or CD players which have better power supplies and beefier output stages.  I'm not familiar with the ADC of the TacT and DEQX but I would be surprised if they didn't rob the music of some of the analog "magic".

[Bingenito]

However, if a significant portion of the music library is on vinyl or hi-res digital (as most of these players only output analog) you probably will not be happy with the additional A>D and D>A conversion steps. The DAC sections of the TacT and DEQX are certainly respectable but they will not hold up to the better outboard units or CD players which have better power supplies and beefier output stages. I'm not familiar with the ADC of the TacT and DEQX but I would be surprised if they didn't rob the music of some of the analog "magic".

Eric I think you captured my concern. I purchased a Sim Eclipse LE because it's DAC and power supply are just incredible and the sound is so good that it is hard to believe that it is digital. It took me a long time to get a CD player of this caliber and I do not want to take a step backwards in DAC or power supply to take a step forward by improving on a crossover and end up with a slight net difference in sound $7,000 later (after I buy DEQX and 2 new amps).

All of us have heard claims of HUGE improvements before and the net improvement is never huge. At least not in an apple to apple comparison. Normally it comes down to what type of apple you like (green or red).

Anyway I have decided to sit out this DEQX thing until I can have my cake and eat it too.

I will shut up now  

[ekovalsky]

I purchased a Sim Eclipse LE

Great player!!!    I recently read about the upcoming Andromeda  

I think the Sim players have digital ins & outs on BNC.  If you wanted to try DSP, you could insert a TacT 2.0S or 2.2X between the transport and DAC sections using BNC S/PDIF cables.  The 2.0S would only give you room correction, fixing bass and imaging problems.  The 2.2X would also let you play with digital crossovers by adding separate subwoofers.  For instance you could set a 40hz high pass on your mains and 40hz low pass on the subs, then time align their outputs.  The bass on most full range woofer systems improves if you filter out the bottom octave, which is better reproduced by a dedicated sub.

Just wanted to let you know you don't have to bypass the great features of your player to use DSP.

[Bingenito]

I think the Sim players have digital ins & outs on BNC. If you wanted to try DSP, you could insert a TacT 2.0S or 2.2X between the transport and DAC sections using BNC S/PDIF cables. The 2.0S would only give you room correction, fixing bass and imaging problems. The 2.2X would also let you play with digital crossovers by adding separate subwoofers. For instance you could set a 40hz high pass on your mains and 40hz low pass on the subs, then time align their outputs. The bass on most full range woofer systems improves if you filter out the bottom octave, which is better reproduced by a dedicated sub.

Just wanted to let you know you don't have to bypass the great features of your player to use DSP.

You are correct and I have thought about this because it seems like a good option when you consider cost/ benefit. I will never argue the benefits of room correcting <300Hz. The difference there is night and day in your average room unless you can tolorate very large bass traps and room treatments.

[James Romeyn]

Thanks for this thread.  I found it fun & invigorating to read.  

Regarding the above post: I have the equivalent of the largest diameter 4' tall ASC Tube Trap cylinder in one corner of my room.  The room has two huge modes, aprox 32 & 80Hz.  The trap helped but by no means cured them.  The trap is big.  The fully automated EQ in my Sunfire True Sub Sig EQ totally eliminated the two modes.  I could never consider for one minute listening to a non-EQd sub in this room again.  

PS, high Eric!

[Rick Craig]

I want to thank John Ashman for his support of the DEQX and bearing with me during my many emails to him. Timing is everything and it seems each time I was ready to pull the trigger John had already sold the DEQX unit that he had available for me  

The good news is that I did find a unit available elsewhere and have ordered it. I already have some ideas of how I would like to use it and look forward to doing some new designs.

[gme109]

Anyone try one of these? I know this unit doesn't replace  crossovers, but it's a cheap ($380) and well received room correction device.

http://www.enjoythemusic.com/magazine/equipment/0705/behringerultracurve2496.htm

[drubrew]

Brian,
I can probably do a demo on a Passive Crossover vs DEQX real soon. I finally got my Verestarr 6 channel amp in, which I will use to Triamp my speakers. While I can offer a demo with passives on the 2 way monitors, I can not do it between my bass cabinets and monitors. As from the beginning of my design the goal was to always have an electronic crossover between the monitors and bass cabinets.
The speakers I'm talking about are located here:
http://www.moon-audio.com/DIY.htm
The passive crossovers were designed by me and QC'd by Per Skanning. Who I trust more than anyone on the planet when it comes to speakers. Especially since he started Skanspeak and now runs Skanning aka Audio Technology.
Anyway we carry DEQX and are pretty versed in it's workings and can provide a good test platform. I'm a little busy right now with the business but hopefully soon I can clear some time for personal pleasure.

[Bingenito]

Sounds like a plan just let me know when you are ready.

[timbley]

Anyone try one of these? I know this unit doesn't replace  crossovers, but it's a cheap ($380) and well received room correction device.

http://www.enjoythemusic.com/magazine/equipment/0705/behringerultracurve2496.htm

You can get one for as little as $250.00 I have been using one of these with some Klipsch RF-7s to bring them and my room  under control. Very effective. I'm also using the Behringer DCX2496 active crossover, and building a pair of 5 way speakers that will require two of the DCX's.
I've sold the RF-7s to fund my new 5 way project. While I wait for the drivers I ordered, I've done a little test making some 3 ways out of a pair of Radio Shack Linaeum tweetered speakers and some 1.75" Apple computer monitors. I've got the crossover points at 5K and 1.25K, 48db/octave to simulate the effect of having the highs and upper mids on drivers restricted to two octave ranges as all the drivers will be with my 5 ways. Despite the cheap quality of the drivers, and the lack of any substantial bass with the poor 4" driver having to cover everything below 1.25k, the mids and highs are wonderously beautiful.
If you ask me, typical 2 and to a lesser degree 3 way speakers, even high priced, are loaded with massive compromises. The drivers, no matter how good, are being pushed to the limit and well out of their optimal ranges. The passive circuits introduce more problems.
Digital active crossovers can significantly surpass anything that can be reasonably done with a passive circuit in a very meaningful and audible way.  I think the future will bring us amps and speakers and digital crossovers that are designed together, and they will sound wonderful and completely unfatiguing, even when listening to MP3s.  And they won't have to be all that expensive.
The future's looking good! (at least for audio)

[Rick Craig]

Now that I have my DEQX up and running I'm kicking myself for not buying one a long time ago  

And yes Mr. Ashman, it works very well with line arrays. Come to Denver later this month and you'll hear it for yourself  

[goon-heaven]

Rick: How does the DEQX compare against your passive crossovers? Pros & Cons?

[ekovalsky]

Now that I have my DEQX up and running I'm kicking myself for not buying one a long time ago  

And yes Mr. Ashman, it works very well with line arrays. Come to Denver later this month and you'll hear it for yourself  

Told you so  

I'm sure you'll find it a great crossover design tool at the least.  You may also find the steep slopes allow you to widen the frequency range of the tweeter safely.   Whether the tweaked DEQX system can surpass a great passive crossover remains to be seen.  Along with many others here, I am definitely curious to see where you and other designers go with this technology.

[Rick Craig]

Rick: How does the DEQX compare against your passive crossovers? Pros & Cons?

Actually the array I'm working on is different than the standard XT8 so I don't have a passive crossover to compare to. The DEQX is superior for line arrays though, no question about that. The steep slopes and digital filters are a real advantage for arrays. I have to say I was skeptical but the DEQX takes them to another level and has made me a believer.

[Rick Craig]

Told you so  

I'm sure you'll find it a great crossover design tool at the least.  You may also find the steep slopes allow you to widen the frequency range of the tweeter safely.   Whether the tweaked DEQX system can surpass a great passive crossover remains to be seen.  Along with many others here, I am definitely curious to see where you and other designers go with this technology.

For a point source I'm sure it can surpass anything that you can do with a passive filter (linearity,lower distortion, wider dispersion, no insertion loss) if you spend enough time with it. In some cases the difference may not be great enough to warrant the extra cost.

 Line arrays are a different beast and will benefit more in some ways than a point source. Dipole designs are perfect for the DEQX because in order to be optimized they need some active equalization.

[goskers]

Hmmm, dipoles and arrays are both ideal for a DEQX.  I guess that's a good sign as this is what I am building.  

[Rick Craig]

Hmmm, dipoles and arrays are both ideal for a DEQX.  I guess that's a good sign as this is what I am building.  

Have fun and be prepared to take many measurements  

[goskers]

Yep, measurements are my friend.