Behringer DEQ2496 Ultracurve Pro DSP Review

[SpaceMonkey]

I have 2 of these working in digital domain (dig in/dig out) for years. All good, can't complain, knock wood.

 

[sergeauckland]

With modified analog output stage it seems that is possible to reach much better performance. About 10dB less THD.
https://www.behringermods.com/proof.html
https://www.diyaudio.com/forums/dig...improvement-stock-dcx2496-13.html#post4424612

Behringermods also can modify the ADC inputs to provide much better analogue performance. Simon at Behringermods did mine for free as an exercise, as I wanted to be able to use it as a pure ADC for live recordings. His mods certainly improved the measured performance, but didn't make any audible difference as far as I could tell.

S

 

[A800]

I own one of those.
Sound is pretty good.
Even analog.

 

[LTig]

Mine runs cool. Maybe that's because I use it as digital SPDIF in & out without the A/D or D/A converters.

Same here. The DEQ runs cool whatever I do with it.

 

[AnalogSteph]

1. Current production 2496 series units have switched over to CS5381 as an ADC as AK5393 has been discontinued.
2. The main culprits in terms of distortion are a number of tiny ceramic caps in the signal path - no NP0 in sight even down in the hundreds of pF (a puzzling design decision), though the ones in the nFs are the most critical ones. Some further improvement can be achieved thereafter by upgrading the NJM2068s. Also, the output stage is a single-ended impedance-balanced job stock, so one opamp is seeing very high levels. Some have entirely replaced the analog stages, which is one way of dealing with the issue I guess.

 

[LearningToSmile]

Can't recommend these, it's an analog crossover and mine was noticeably noisy. Would work for a subwoofer but not for high efficiency speakers.

Thanks, that's good to know - I was mostly hoping to get a performance on par with something like a dbx 223xs for a bit less money but if it's audibly noisy then I'll just spend the extra few bucks. It's also not perfect but should be good enough for me.

 

[LTig]

I own one of those.
Sound is pretty good.
Even analog.

Agreed. With my cloth ears I couldn't tell a difference between bypass and plain ADC/DAC without any processing.

 

[audio_tony]

Is that a bit of phase lag between channels?

 

[Ron Texas]

Something like the DCX2496 would be more interesting to this group as it provides subwoofer integration with crossovers and delay. Thank you for another detailed set of measurements @amirm

 

[Robbo99999]

So far maybe get a feel its probably not any better or below these so it could be a pure >24bit headless panther in that race game ..

Amir's previous AP unit: https://www.audiosciencereview.com/...urements-and-minidsp-2x4-hd-dsp-and-dac.2674/

Amir's current AP unit: https://www.audiosciencereview.com/...8-8-channel-usb-dac-review.10123/#post-275814

Tom Christansen (Neurochrome): https://neurochrome.com/pages/minidsp-4x10hd

Ha, yeah, good point! Yeah, I remember looking at those miniDSP reviews before here, and so if Amir did test the cheapest miniDSP (the plain old 2x4, not the HD version) then I would expect it to be no better than those reviews you linked. However, I'd be curious to know for sure, and given it's perhaps the cheapest 2 channel standalone DSP solution I think it would be worth testing. I wouldn't mind if it got a headless panther, I wouldn't get rid of it, as I only use it for TV & movies, and for that it's good enough quality to my ears - I don't use it for music listening. For music listening I use Laptop PC -> Equaliser APO -> E30 DAC -> JBL 308p Mkii, whereas my TV goes like TV -> miniDSP 2x4 -> JBL 308p Mkii....I got a simple switch box to switch between the two different streams.

 

[Francis Vaughan]

TV -> miniDSP 2x4 -> JBL 308p Mkii...

The thing about this is that the 308p mk II almost certainly has a ADC/DAC performance that is vastly worse than any of the gear we are discussing. The DACs are really part of the power amps, and have, at best, dubious performance. Which goes to underline the fact that as much as we like to obsess about the ultimate performance of our DACs, it is mostly empty specmanship.
I've just bought a MiniDSP 2x4 HD to run the bass management in my HT. IMHO a perfect match. I get individual control of four subwoofers in the room. The performance of the ADC/DAC chain will be simply not an issue. The next project after that is using four Khadas tone boards and probably a miniDSP digital-digital dsp crossover (nano or hopefully a rumoured new miniSharc.) That almost certainly has over the top performance, but it isn't expensive, so why not?

 

[martin900]

Thanks, that's good to know - I was mostly hoping to get a performance on par with something like a dbx 223xs for a bit less money but if it's audibly noisy then I'll just spend the extra few bucks. It's also not perfect but should be good enough for me.

JBL M552 maybe? Unless you're looking for new.
There is also the BSS FDS360 that works with pre-set frequencies and slopes by replacing resistors and caps on the add-in cards. The op-amps are socketed so it might be worth a shot.
The absolute best active xover I've owned is Bryston 10B.

 

[Tips]

I was thinking of using it as a DAC fed with optical out of my Macbook Pro with optical out miniToslink (as I don't have the money to get RME ADI 2 DAC hehe).
The thing is that DEQ2496 has no volume control so I am wondering if I feed it with optical from Macbook with MacOS if MacOS will allow me to adjust the volume in the OS?
Has anyone tried it or could try it for me please and let me know please?

Currently I am using currently Hifime UAE23HD

 

[JeffS7444]

Can anyone provide a schematic for the DEQ2496? I want to try a mod I read about which modifies the analog i/o by replacing feedback loop ceramic capacitors with C0G types. The author of the article (actually about the DCX2494, and sorry I can no longer find that article) measured something like a 10x improvement in THD once this was done with no other changes, just those capacitors.

I purchased mine a number of years ago and it's worked great. But at the time, people were complaining about failing electrolytic capacitors, so I replaced them all with 105-degree parts rated for high ripple current. Temperature rating was probably overkill, as the unit doesn't generate much heat.

 

[phoenixdogfan]

Sure it's twice as expensive and less flexible, but if I was only looking for EQ/RC in the digital domain I'd definitely drop the extra coin on the minidsp SHD Studio over something like this. Nice to know it is at least competent for it's price-range and intended application however.

SHD Studio unfortunately had no A to D converter. Strictly digital I/O. Even the 2 X 4 HD does A to D.

As I've written before, it seem miniDSP always either gives you something you don't need that you have to pay through the nose for, or leave something out that you really want. They never just give you the full suite of I/O ports. The 2 x 4 HD with spidf outs and Dirac Live would be perfect, but they won't release one that way without charging $1K.

 

[xykreinov]

I have one, and use it for digital S/PDIF input/output.

Never even tried the analog section.

The price has gone up a bit, $100 or so.

It's an old device, Maybe as old as 2003:

https://www.google.com/search?q=Behringer+DeQ2496&rlz=1C1CHBF_enUS778US778&biw=1045&bih=954&sxsrf=ALeKk02Yi76WA4mDOAwR0_BCYb-oWLs02Q:1603490388513&source=lnt&tbs=cdr:1,cd_min:,cd_max:12/31/2004&tbm=

Mine wouldn't save settings, when I got it, later, Audio Buddy bought one and it would restart randomly.

Both required reseating the antique ROM chip - bent legs on mine, don't know on his.

Stable ever since, like 8 years ago.

Wow, very impressive measurements for 2003

 

[sam_adams]

There are two sites that I know of for those wanting to modify their Behringer devices:

https://www.behringermods.com/index.html

and Jan Didden's Linear Audio site:

https://linearaudio.nl/

 

[Robbo99999]

The thing about this is that the 308p mk II almost certainly has a ADC/DAC performance that is vastly worse than any of the gear we are discussing. The DACs are really part of the power amps, and have, at best, dubious performance. Which goes to underline the fact that as much as we like to obsess about the ultimate performance of our DACs, it is mostly empty specmanship.
I've just bought a MiniDSP 2x4 HD to run the bass management in my HT. IMHO a perfect match. I get individual control of four subwoofers in the room. The performance of the ADC/DAC chain will be simply not an issue. The next project after that is using four Khadas tone boards and probably a miniDSP digital-digital dsp crossover (nano or hopefully a rumoured new miniSharc.) That almost certainly has over the top performance, but it isn't expensive, so why not?

Yes, I previously remember a discussion related to this where there was an online calculator where you could add SINAD's together as if they were in an audio chain, and thereby you could work out what the combined effect would be. I tried googling it just now but didn't really come up with a definitive source. Well, let's say miniDSP 2x4 is 70dB SINAD, and what do you reckon SINAD would be of the ADC/DAC within the JBL 308, say 60 dB SINAD? What would happen if we combined a state of the art DSP solution of 114dB with said 60dB JBL 308. If we compared the result of the two scenarios how would the overall SINADs of the audio chain compare?

 

[amirm]

Yes, I previously remember a discussion related to this where there was an online calculator where you could add SINAD's together as if they were in an audio chain, and thereby you could work out what the combined effect would be. I tried googling it just now but didn't really come up with a definitive source. Well, let's say miniDSP 2x4 is 70dB SINAD, and what do you reckon SINAD would be of the ADC/DAC within the JBL 308, say 60 dB SINAD? What would happen if we combined a state of the art DSP solution of 114dB with said 60dB JBL 308. If we compared the result of the two scenarios how would the overall SINADs of the audio chain compare?

Simple rule to remember is: if your upstream device has 10 dB better performance, the effect on lowering the downstream device is 0.5 dB or negligible.

 

[Ron Texas]

Yes, I previously remember a discussion related to this where there was an online calculator where you could add SINAD's together as if they were in an audio chain, and thereby you could work out what the combined effect would be. I tried googling it just now but didn't really come up with a definitive source. Well, let's say miniDSP 2x4 is 70dB SINAD, and what do you reckon SINAD would be of the ADC/DAC within the JBL 308, say 60 dB SINAD? What would happen if we combined a state of the art DSP solution of 114dB with said 60dB JBL 308. If we compared the result of the two scenarios how would the overall SINADs of the audio chain compare?

A minidsp 2x4 HD has a SINAD in the neighborhood of 86 to 90db depending on who is measuring it. It hasn't been measured here with the latest instruments and methods.