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Quick measurements of Behringer Ultracurve DEQ2496

xr100

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#21
Here's the compressor set to 2.5 ratio, -10dB gain, -10dB threshold, 1ms attack, 20ms release (at 24/44.1k):
View attachment 49630

Nasty, but I guess I'm not sure why you'd expect a compressed waveform to look pretty :)
Ouch! Thanks for that. :) Does the compressor not operate at 96kHz?

"Compressed" waveforms can look much better than that... I'll expand (pun not intended) later.
 
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pkane

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pkane

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Ouch! Thanks for that. :) Does the compressor not operate at 96kHz?

"Compressed" waveforms can look much better than that... I'll expand (pun not intended) later.
It does, I just had everything set to 44.1k to measure jitter, and so left it this way for compressor test.
 
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pkane

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Ouch! Thanks for that. :) Does the compressor not operate at 96kHz?

"Compressed" waveforms can look much better than that... I'll expand (pun not intended) later.
I can play with compressors too, except this is a simulated one, built into my DISTORT app. Here's an example simulating a tube preamp transfer function. Nice, no? ;)

1581394765593.png
 

xr100

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#25
Let me know where I can get one of these driverack units for $100 and I'll buy one just to play with it! Looks like it was released at least 5-6 years after the Behringer unit and seems to copy most of the functions, although improving on many of the specs.
I wouldn't necessarily count on the DriveRack series having any better DSP performance than the Behringer. ;-)

"PC"-based software can definitely yield better results than the Behringer, although the PEQ seems to perform well enough.
 

xr100

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#26
I can play with compressors too, except this is a simulated one, built into my DISTORT app. Here's an example simulating a tube preamp transfer function. Nice, no? ;)

View attachment 49634
That's a static waveshaper, not a dynamics process! Compression generates harmonics as a result of "riding" the waveform, i.e. the waveform modulates the compressor's action. It is dependent on the time constants, detection mode (RMS vs. peak, etc.) and so on.

Zzz… more to follow. Oh, and if you want to use waveshapers etc., it's best to oversample or at least not be running at "base rates" (44.1/48kHz) in the first place, otherwise... aliasing galore...
 
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pkane

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Thread Starter #27
That's a static waveshaper, not a dynamics process! Compression generates harmonics as a result of "riding" the waveform, i.e. the waveform modulates the compressor's action. It is dependent on the time constants, detection mode (RMS vs. peak, etc.) and so on.

Zzz… more to follow. Oh, and if you want to use waveshapers etc., it's best to oversample or at least not be running at "base rates" (44.1/48kHz) in the first place, otherwise... aliasing galore...
Picky, picky! Here's the oversampled version and extended to 192kHz. And yes, this is a static waveshaper, sorry.

1581395355324.png
 
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pkane

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Thread Starter #28
Ouch! Thanks for that. :) Does the compressor not operate at 96kHz?

"Compressed" waveforms can look much better than that... I'll expand (pun not intended) later.
Here are the same compressor settings at 96kHz with DEQ (2.5 ratio, -10dB threshold, -10dB gain, 1ms attack/20ms release):
1581395868414.png
 

xr100

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#30
I figured it was, so more likely that they did it right. It's the only DEQ2496 feature I need or use. Even though the DEQ2496 does a lot more, its PEQ is very flexible and it's worth the price for that alone.
I know the main interest in this thread incl. the OP is the PEQ, but the creation of this thread was prompted by another thread in which the query was about dynamic EQ. :) And yes, c.f. the competition, it is indeed fabulous value as an off-the-shelf digital PEQ box.
 

xr100

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#31
Here are the same compressor settings at 96kHz with DEQ (2.5 ratio, -10dB threshold, -10dB gain, 1ms attack/20ms release):
Thank you, that looks much cleaner. I should really have suggested to try it at a frequency slightly off 1kHz given the 96kHz sample rate...
 
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pkane

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Thank you, that looks much cleaner. I should really have suggested to try it at a frequency slightly off 1kHz given the 96kHz sample rate...
REW locks the generator frequency to the correct rate for the FFT size, so it wasn't exactly 1kHz, maybe just a tad higher. (looking at some other charts, I think it was 1000.1Hz :))
 
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xr100

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#33
REW locks the generator frequency to the correct rate for the FFT size, so it wasn't exactly 1kHz, maybe just a tad higher. (looking at some other charts, I think it was 1000.1Hz :))
Ah! :)

Most compressors (whether in the analogue or digital domains) will generate harmonics when acting on a sine wave, it all depends on how aggressive the attack/release times are, peak vs. RMS detection, sidechain rectification, etc. Obviously, the digital domain has nasties ready and waiting to appear, aliasing etc. ;-)

(Albeit the analogue world, e.g. VCA's, can have their own problems, too.)

The 96kHz plot for the Behringer compressor looks fine. Of course, the spectral plot tells you nothing much about whether it sounds good or not, because that depends on the compressor's action, e.g. pumping etc. It can "match" what happens in the ear and then the "nasty stuff" gets thrown out by the ear-brain system, or masked, anyway.

I did try using the iZotope Dynamic EQ plug-in, that looks very clean. So it would be interesting to see how the Behringer's Dynamic EQ performs.

So far, though, I have to say that, notwithstanding higher performance digital processes are available, in SPDIF I/O mode at 96kHz, the Behringer is looking pretty darned good. :)
 
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#34
Yes, by modern standards the DAC part (at least) isn't all that good. The digital/DSP portion, on the other hand, is exceptional, IMHO.
Wow, thanks for checking this out. Like I said in the other thread I only use the PEQ....optical in, optical out to an external DAC and I dig it. Wouldn't want to go without it. This confirms why I like it.

I was thinking about it and I think I've had this unit a lot longer than I thought. Probably about nine years now without a hiccup. Although, it sat in my basement for the first two because I knew nothing about digital audio and this unit was a little intimidating in that regard.

Then one day I just hooked it up and dove right in. It's a bit cumbersome but in no time at all you get familiar with it and it's no big deal.

Years ago I had read about how it would get hot and how the DAC in it really sucked. An external DAC solves that and my unit never gets anywhere near hot.

Gotta go.....I think I see flames shooting out the side of it. Thanks again for the testing!
 
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#35
I figured it was, so more likely that they did it right. It's the only DEQ2496 feature I need or use. Even though the DEQ2496 does a lot more, its PEQ is very flexible and it's worth the price for that alone.
Right on.
 

stevenswall

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#36
Is there any audible hiss using analogue outputs?
 

AnalogSteph

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#38
Distortion vs. Frequency shows some increasing distortion (up to THD+N of -83dB at about 14kHz):
View attachment 49524

CCIF signal shows a high level of IMD components:
View attachment 49525
It be noted that THD(f) doesn't actually drop again after 7 kHz, this is purely a measurement artifact (<22 kHz lowpass filtering simply eliminates the 3rd harmonic). You can also clearly see how nasty the CCIF intermod looks.

As mentioned earlier, the DAC section of these is littered with high-K ceramic capacitors for some reason (very small, so possibly as bad as Y or Z class). Their H3 is swamping opamp distortion by about an order of magnitude. The worst offenders, I suspect, may be the handful with values well in the nFs.
 

A800

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#39
I love mine even when using the analog part.
 
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