# Results of a digital active crossover unit comparison



## paulspencer (May 11, 2007)

Normally if you want to hear an active crossover, you have to buy it and set it up in your system and you probably won't get the chance to compare. Well, a chance came up to get together with some others and do some comparisons. Thought you guys might be interested in the results.

We compared
Behringer Ultradrive DCX
Behringer Ultradrive DCX with the Pilgrim audio mods
MiniDSP
DEQX

We did two tests:
1. digital conversions
2. digital active crossovers

We used an instant switching level match box that switches both inputs and outputs. For the first test, we let the units simply act as digital converters of an analogue input - ADC then DAC. We compared to a loop through wire.

For the second, we set up with the same settings and measured to ensure we were comparing level matched and with the filters doing the same thing. It's quite time consuming to set up an event like this, so it was not the last word on perfect accuracy. We did not match to within 0.1 db but we took a decent stab at matching.

We didn't do the test blind. While this may disappoint some, but I felt that using instant switching would be revealing enough. We did this test for our own curiosity, but no one had a point to prove. In a previous informal comparison, I found that was enough even with levels obviously not matched. No one in that test could hear a difference with the digital conversions vs a loop through wire, not even one person there who was certain a difference would be heard.

Our extended tests did show differences, but I'd call them subtle. At certain times, I noticed a difference in imaging where there was a small shift. The instant switch during a sustained note is quite revealing. MiniDSP appeared to have increased treble detail compared to DCX, despite mreasurements showing that it rolls off more above 20k. The measurements from what I recall didn't seem to reveal why that might be the case.

The full write up is here in my blog:
http://redspade-audio.blogspot.com/2010/12/active-crossover-listening-tests.html
and there are more comments in the linked SNA thread.

My findings if I can sum it up in a nutshell?
MiniDSP is the first one you want to try out of these.

DEQX sadly didn't quite get a fair trial, we had time limits and something wasn't quite right.


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## Anthony (Oct 5, 2006)

Thanks for posting the results! I wanted to get into active crossovers back when I was building speakers a lot. Closest I got was an analog crossover from Behringer for prototyping passive networks (getting slope and f correct).

But if I ever get time again, I'll have to look at that MiniDSP.

Thanks for the writeup!


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## paulspencer (May 11, 2007)

Even for the non-DIY crowd, MiniDSP could be very useful for things like bass EQ. People are still spending 10x as much on a Velodyne EQ unit or even more on some other options. Or for those building a diy sub with a pro amp, it could also be handy for the crossover, just as long as they can sort out the gain structure.


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## zero the hero (Feb 24, 2008)

Yeah that looks like a fascinating product! It's reassuring to hear it actually sounds good too.


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## Trick McKaha (Oct 7, 2009)

It is this kind of objective report that I value most about this site. Not that I don't also like the good old subjective debate, but I sure appreciate the work that went behind this thread.


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