What is the advantage, and also the disadvantage, of a digital active crossover?

0 Members and 1 Guest are viewing this topic. Read 844 times.

Sandbakk

  • Jr. Member
  • Posts: 67
  • Dipole is my choice of speaker construction.
I'm very sorry if this has been brought up before, which I'm sure it has been, I just haven't been able to find it:

What is the advantage, and also the disadvantage, of a digital active crossover, connected just before the power amplifier? It will then be a digital source (in my case) - DA converter - preamplifier - AD converter/DA converter (in the crossover) - power amplifier.

Will there be any advantage at all in buying a $5000-$10000 DAC when connecting an ADC/DAC later in the chain?

Would it be an advantage to have a passive preamplifier before the digital crossover?

brj

Just to be clear, are you asking about the advantage/disadvantage of an active line-level crossover in general (vs a passive crossover) and just assuming that such a crossover has to be digital, or are you aware of the tradeoffs in active vs passive crossovers, but are specifically asking about analog vs. digital implementations of an active line-level crossover?

(I split the difference myself by using digital EQ before my DAC but an analog line-level crossover between my pre-amp and amps - see this post.)

You might also want to characterize the room and type of speaker that you're considering, as the balance of trade-offs will change a bit depending on those answers.  (If the drivers in your speakers require very steep crossover slopes, for example, it is easier to manage that digitally than analog.  But if your drivers don't need steep slopes, then it's not a constraint and that particular differentiation becomes moot.)

Sandbakk

  • Jr. Member
  • Posts: 67
  • Dipole is my choice of speaker construction.
My question is probably a bit simpler than that, what I really wonder about, in all its simplicity, is why someone would insert an AD/DA converter after a DA converter.  :D

And will there be any advantage at all in buying a $5000-$10000 DAC when connecting an ADC/DAC later in the chain?

The reason I ask is because I consider buying something like this: https://www.german-physiks.com/emperor-dsp-x-digital-electronic-crossover

WGH

And will there be any advantage at all in buying a $5000-$10000 DAC when connecting an ADC/DAC later in the chain?

Definitely yes. The DAC and digital crossover functions are completely different.

An expensive DAC inputs a digital signal, have better filters [than a cheap DAC] to remove noise above 20kHz without affecting frequencies below 20kHz, it might convert all PCM to DSD which is easier to convert to an analog signal like the PS Audio DirectStream DAC, and other tricks that make music more enjoyable.

The Emperor inputs an analog signal and splits it into three parts, there are plenty of electronics that do that.

Doublej

  • Full Member
  • Posts: 2687
The follow on question is who makes digital crossovers that accept digital inputs and do their products support hi-res digital?

Jon L

The follow on question is who makes digital crossovers that accept digital inputs and do their products support hi-res digital?

Unfortunately, most of these LMS/digital crossovers do not offer digital inputs.  The workhorse dsp crossovers such as Behringer Ultradrive DCX2496 and dbx DriveRack PA2 do not offer digital inputs and are getting VERY long in the tooth. 

The German Physiks Emperor Extreme DSP X-Over mentioned is >$30K and still does not offer digital input.  What's surprising is it does not even offer room correction, which most cheap pro units offer. 

A more reasonably-priced, high-quality digital x-over is Bryston BAX-1, which also does not offer digital input or room correction.

https://www.moon-audio.com/bryston-bax-1-digital-crossover.html?sku=Bryston-BAX-1&gclid=CjwKCAjwhNWZBhB_EiwAPzlhNvqWOmLojet-xxNybrqAUJYiPBuLIWac_598dg1Z8DDxxOjRNJX9cBoC3S4QAvD_BwE

For digital input, one would have to look at:

miniDSP SHD

https://deercreekaudio.com/products/ols/products/minidsp-shd?gclid=CjwKCAjwhNWZBhB_EiwAPzlhNuYzLHlziTh59NKQ_lWN4TmNp24ocSpQFxtJW0pm4ihXcvjOPy4ZGxoCWBoQAvD_BwE

Speedskater

  • Full Member
  • Posts: 2672
  • Kevin
For the loudspeaker designer, voicing a speaker there are a great number of advantages. The high cost of passive parts and the options of a DSP crossover have changed some designers minds.
The one disadvantage for new products is that old-school audiophiles still want to mix and match.
Now retro fitting isn't an easy task. You can't just plug in a few numbers from the speaker's brochure and expect great results. A passive crossover does a lot of things that don't show-up in the schematic.
 

Rusty Jefferson

  • Full Member
  • Posts: 867
Avoid the extra d/a conversion. The best active systems I've heard are DEQX based. You have to give up some control however as it's essential you let their technician remotely tune the system. It doesn't matter how much you think you know about doing it, you won't do it right.

I'd have to look at what the new models will be doing but the ones I'm familiar with have usb digital input and upsample everything to 24/96.

You get perfect time and phase alignment, and all the passive parts out of the system. Source > crossover > amplifiers > drivers.

HAL

  • Industry Contributor
  • Posts: 5180
If you look at the upcoming Danville Signal dspNexus 2x8 digital crossover at their webpage, they support USB Async and S/PDIF style digital input and outputs.  They process internally at 32bit/192KHz for the DSP crossover and use AKM A/D and D/A converters with 24bit/192KHz conversion for the system. 

The prices is supposed to be $3000.00 when released.  Best info I have at this point.

Here is the website:
https://danvillesignal.com/dspnexus-dsp-audio-processor

Hope that helps.

Jon L

If you look at the upcoming Danville Signal dspNexus 2x8 digital crossover at their webpage, they support USB Async and S/PDIF style digital input and outputs.  They process internally at 32bit/192KHz for the DSP crossover and use AKM A/D and D/A converters with 24bit/192KHz conversion for the system. 

The prices is supposed to be $3000.00 when released.  Best info I have at this point.

Here is the website:
https://danvillesignal.com/dspnexus-dsp-audio-processor

Hope that helps.

"The design of the crossover does not take special programming skills, We supply the dspNexus 2/8 with a licensed version of DSP Concepts' Audio Weaver. This is a graphical design tool that lets you create production quality crossovers tailored to the specific requirements of your target loudspeaker system. We provide training to use this tool effectively or in some cases, can connect you with a crossover specialist to help you."

This sounds too good to be true!!  I sure hope the DSP is low noise and clean, and if the DAC section is good, heck, I'll buy one  :thumb:

Sandbakk

  • Jr. Member
  • Posts: 67
  • Dipole is my choice of speaker construction.
Avoid the extra d/a conversion. The best active systems I've heard are DEQX based.

Thank's for the info about the DEQX prosessors. I'll wait for the new DEQX Pre-8 and see what it can give.