Digital Active Crossovers vs Passive Crossovers - is there a big difference?

I was wondering whether to buy a Tyler Acoustics Scan Speak system or do it myself with digital active crossovers and have someone help me.

Is there a big enough a difference between like a Behringer or DBX digital active crossovers and passive crossovers?

Is it worth it?

Thanks,
- Andy
 
I bought the Beringer, tested it, returned it. The crossover points didn't track well between the high and low pass. I can't recall what else was wrong, but either distortion or noise was also an issue. Next I bought the DBX analog 223XS. It works fine, but does not have any ability to compensate for anything, just straight crossover function. I now have three miniDSP 2x4HD boxes. The flexibility they give you covers most anything you will ever want to do. For instance with the miniDSP it is easy to high pass filter a driver using a Linkwitz transform to achieve perfect crossover slopes rather than just adding a filter to the existing driver high pass response. It also has delay values that can be adjusted for each channel. The FIR filter allows compensation of reflections . I'm droning on and on. Ha
 
Oh, the fine details. The fun thing to do when tuning crossover points is to use the miniDSP to compensate the drivers to have extended flat response (linkwitz transform on low end) and then use the DBX analog to provide the crossover function. The DBX allows adjusting the crossover point with an analog knob. So it allows slow smooth changes in crossover frequency while listening closely. Obviously the miniDSP allows adjustment, and you can save different crossover points to four remote control selected profiles, but there is a few seconds of silence when switching between the four saved profiles.
 
The main difference is in that (digital) DSP's are all converting the signal to digital (PCM sampling) and do the processing digital. This influences the sound on a very subtile way. Some people like it, some don't (like i).

But a digital crossover is way more flexibel than any analog crossover ever will be and often also include delay, eq and room correction, wich with an analog crossover is not doable or extremely expensive.

It's all in what your goal is, both have advantages and disadvantages and it's up to you to decide what is more important.

The behringer is crap on the analog side, and very mediocore on the digital sie, even the most basic minidsp is better. DBX is very mediocore but decent. Best deal is minidsp HD, best sounding (on any budget) that i heared is the Xilica XA rack module that is often used in pro audio but they cost a lot more than a miniDSP.

But for low power systems, that are not ment to be studio monitors (wich means total flat response), an analog passive crossover can be much better in my book. And Active analog crossovers (when done right) also as both lack the analog/digital/analog conversion and the digital processing.
 
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mortron

Member
2011-08-20 6:02 am
Town
Passive XO scares me. Lots of factors in their design that need to be considered, and have found trial and error can be a drawn out process. So it depends on your level of commitment and how much you like to tweak.

Used to use an Ashly XR2000 but decided that I wanted some EQ ability and found a used DBX Driverack 260. Was quite a game changer. Turned lifeless subs into house rattling beasts, and allowed me multiple settings with precision. On my analog, I could never keep settings matched etc. due to the knobs not being detented.
 

conanski

Member
2013-03-31 3:53 am
What kind of project are you working on, home audio or pro? Digital offers so much more functionality than analog it's not really a fair comparison and next to a passive crossover the advantages are numerous not the least of which is how easy it is to try out a hugh range of crossover options with a live system to see/hear what works best for your drivers. This requires more amplifier channels so it can be expensive to start but I think once you go down this route you won't likely go back to passive unless it is to deliberately simplify a system for a specific purpose. And if that is the case at least you have something to compare the passive network with to gauge the accuracy of your build.



The Berry DCX gets lots of abuse online but I can't figure out why, I have seen people complain about noise, distortion, or how bad the limiters sound but I can't replicate any of that with my copy. There are numerous mods available for it including complete circuit boards so it does have an enthusisatic following but even without any of that I think it is a lot better than the negative press would have you believe, it sounds noticably better than the DBX DRPA and has more flexible routing. I think some of the problems people experience with these processors is related to them being designed for professional signal levels, if you don't have any components with balanced outputs you may be better off with a home audio based solution like the mini DSP.
 
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AllenB

Moderator
Paid Member
2008-10-18 11:31 am
Passive XO scares me. Lots of factors in their design that need to be considered,
Knowledge of electronics can be an advantage here, DSP shields the user from this. However, the knowledge of AC theory, filters and acoustics leads to best results either way.

As a result of this I feel that DSP can get a person started more quickly, but some may then reach an impasse.
 
The Berry DCX gets lots of abuse online but I can't figure out why, I have seen people complain about noise, distortion, or how bad the limiters sound but I can't replicate any of that with my copy. There are numerous mods available for it including complete circuit boards so it does have an enthusisatic following but even without any of that I think it is a lot better than the negative press would have you believe, it sounds noticably better than the DBX DRPA and has more flexible routing. I think some of the problems people experience with these processors is related to them being designed for professional signal levels, if you don't have any components with balanced outputs you may be better off with a home audio based solution like the mini DSP.

Yup. Nothing wrong with the DCX(at least with my 2009) when properly driven. Very capable and a good value as well. There might be slighty more transparent devices but diminishing returns are in play.
 
I never even wanted to start learnig to design passive crossovers, but made several spekers designed by others and tried to learn the basics. Then I got the idea to make 4-way partly dipole speakers of my own design - and minidsp 4x10HD was only practical choice.

Despite I had been interested in audio for 40 years, I had a lot to learn about loudspeaker design. Radiation patterns, interferences, crossover types, phase matching, delays, etc. must be undestood with dsp too! Box construction is just the same.

Performing decent acoustic measurements at home is mandatory when we want to skip simulations and use trial-error-correction iterations. Without good measurements the project will definitely be a disaster. But still no test animals harmed etc. irreversible waste. Some tweeters most likely will get meltd, but start with cheap ones!
 
I have used ultracurve and dcx many years with no problems. Thing is to feed them digitally, so they get full signal level to work with. Now I have minidsp's nanodigi, and I'm enjoying it a lot. Reason to buy nanodigi is to have digital volumecontrol with remote. It's not too easy to find proper 6-ch analog volumecontrol with remote for dcx. I used just motorised potentiometer. Everything I listen is in digital format, so I like to keep signal in digital domain, and convert it to analog after nanodigi, so there is no unneccesary conversions. I do like these digital crossovers and peq's. Passives are fun to do, but with digital you don't have to buy many crossover components to play with. Laptop is enough.
 

Ugg10

Member
2017-11-18 9:59 am
UK
I am looking into a 3 way project using dsp.

My sources will all be digital so I intend on keeping the signal digital for as long as possible so the scheme I have is -

Digital source (streamer or cd) coax spdif > minidsp nanodigi coax Spdif > 4 x Khadas Tone Board Dac > analogue Rotel RMB1066 (6x60w, 8 ohms)

That way I can play around with crossover points, LR2 and LR4 slopes, overall frequency shape (smiley face, flat, 3dB slope, bbc dip etc), set delays to take into account speaker position on baffle and then add on top some room eq to take out any bass reflections.

Not sure I could do 10% of that in hardware from a standing start.

Once happy with the dsp crossover I may then try and replicate in hardware to see if there is a significant audible difference.

Just a few thoughts.

Edit - @Ferrofluid our posts crossed in the their, good to hear the nanodigi works well for you. Do you know if rephase work with it?
 
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Quite satisfied with Behringer...

I've had pretty good results with low-end Behringer (all of it? :D ) gear for years. My current use of them does not rely on any A/D conversion but yes D/A converters for active EQ system. Whether their analog section is "crap" I don't know, but I've detected no issues in my home system. With an all active system, perhaps the biggest issue will be residual noise (hiss) when quiet/no signal present. This seems a very small price to pay when you consider the power of shaping EQ and crossover any way you wish.

Behringer can't be all junk. Their DEQ2496 (I've owned but not currently) is popular enough that it is still sold, for nearly twenty years! That is an incredible life span for any electronic audio PA product.
 

Pano

Administrator
Paid Member
2004-10-07 6:05 am
Panama
I bought the Beringer, tested it, returned it. The crossover points didn't track well between the high and low pass. I can't recall what else was wrong, but either distortion or noise was also an issue.
Strange about the tracking. Did you have the link function turned on? I measured a couple of DCX and the crossover curves were perfect, as far as I could tell. Noise is an issue for consumer level signals because the DCX is set up for higher "pro" levels. That's all in the analog sections. Ditto distortion.
The ADC-DSP-DAC chain is fine. The analog sections need to be bypassed with better. The power supply can use a little help, too.