Behringer DCX2496 digital X-over

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JinMTVT

Member
Joined 2004
Does the REM stuff have proper surround decoder?
or can be setup within XP/VISTA to use channels for so?
if not...cna't use for HT setup

Aren't there digital volume controls on the DCX ??
aren't those loseless ??
i don't see why 1000 volume controls would be a bad thing ...
if it is loseless...more options is always a better solution than no options ..and one can always leave them all to 100% volume

If Vista has a loseless volume control, that would resolve the volume issue on the pc side
but what about if i want to use a PS3 ?
a standalone BR player ?? ( don't see why i woould do that since PC + PS3 already covers 100% of my intented use ...but some others might )


Can anyone point me to standalone surround decoders with digital outputs? haven't seen any yet
 
S

ScottGardner

Member
Joined 2008
JinMTVT said:
Does the REM stuff have proper surround decoder?
Click to expand...

No. Not that I'm aware of. Actually I don't think any sound cards do.
Generally the way this is handled is the decoder resides on the PC (ffdshow splitter->decoder).

Or you can stream digital to your external decoder and it does it, but in this case the receiver is also handling the D/A and probably won't give you multiple digital outs.
or can be setup within XP/VISTA to use channels for so?
Click to expand...
Yes. This is a two step process: First set-up the sound card driver to provide one big virtual device that has 6 (5.1) or 8(7.1) channels, then tell windows to use it.
Aren't there digital volume controls on the DCX ??
aren't those loseless ??
Click to expand...
Yes, Not sure. I think Jan already looked into this and solved it with his Active Output mod.
i don't see why 1000 volume controls would be a bad thing ...
if it is loseless...more options is always a better solution than no options ..and one can always leave them all to 100% volume
Click to expand...
True, but is kind of a hassle to manage them all
If Vista has a loseless volume control, that would resolve the volume issue on the pc side
but what about if i want to use a PS3 ?
Click to expand...
What output does it have? If it is sending seperate channels your OK (just re-route the in's to the Out's. This is done all the time in studio recording sessions for monitoring playback while laying down new tracks. My guess is that if you want digital, it will come encoded DTS/AC3 and this is a problem. You would need a realtime decoder on the PC and I don't know of one. Or an external decoder that handles all the decoding and provides digital outs but I have't seen one of those either.

You could also rip movies to the PC to play and just take analog game sounds and redirect to outputs.
a standalone BR player ?? ( don't see why i woould do that since
PC + PS3 already covers 100% of my intented use ...but some others might )
Click to expand...
?? BR player ??
Can anyone point me to standalone surround decoders with digital outputs? haven't seen any yet
Click to expand...

Yeeees, this would be helpful but I haven't seen one either.
 
S

ScottGardner

Member
Joined 2008
I think part of the problem is that there are so many different encoders that it is difficult for a standalone decoder to keep up.
It would ideally need to decode:

Surround
AC3
DTS
Dolby TrueHD
DTS-HD
SACD

Others?

2/4/6/8 or more channels.

If you found one that has digital outs it probably wouldn't support everything. Sony used to make an external decoder that had digital outs but I think it was limited to 5.1 AC3.
 
S

ScottGardner

Member
Joined 2008
Seems to me you want to start at your outputs and work backwards:

Speakers<-Amps<-DCXs<-(Device that has AES/EBU)<-PC
--------------------------------------------^MIX^)<- AES/EBU Converter <- DECODER <- PS3

Take a closer look at the RME Hammerfall DSP AES-32 about $500.
This card would give you at least 8 AES outs and ins. (7.1) this would allow you drive 4 DCXs.

PS3 outputs these formats encoded:
SACD
DTS
HDCD

You will need a Decoder/processor that outputs either AES/EBS (ideal) or s/pdif or analog.

If your decoder outputs AES/EBU hook them up to the RME inputs and skip 1 and 2
1.Feed the output of the decoder to 4 Behringer Ultramatches
2.Feed the outputs of the ultramatches to the inputs of the RME
3.Use TotalMix on the RME to redirect outputs to the DCXs.

This means the decoder controls the volume of the PS3 and The PC controls the volume of everything else. Or better yet use Jans Active output mod on all three DCXs and use one remote to control then all.

Jan can one remote control the volume on more than on DCX simultaneously
 
S

ScottGardner

Member
Joined 2008
Different caps for passive output mod?

I'm putting together Jan's passive output mod. I will be setting up the
crossover this way: LH LH LH.

The published mod assumes a setup of LMH LMH.

So, what would be better choices for the caps in my situation?

The specified EPCOS is now discontinued, what would be a good
replacement?

Are WIMA the best way to go?
Would Black Gates or some other exotics be worth it?

Any and all comments will be greatly appreciated.

Thanks,
Scott
 
AR2

AR2

Master Burner
Joined 2002
burningamp.com
Hello guys,

I do not know if any of you are planing to attend Burning Amp 2008
www.burningamp.com
I know that Jan will be there. :)

I am planing to bring my completely moded DCX and one pure stock DCX2496 for the listening evaluation. I hope that will put to rest all the questions if it is worth moding the DCX. It would be great if anyone visiting could bring any other active crossover so that we could have a full test.

AR2 :D
 
H

hep

Member
Joined 2004
Interesting article and viewpoint by Bill Wong from the Penton publication electronic design journal

Even in this age of tiny earbud music players, audiophiles want high-end stereo systems that provide perfect acoustics and fidelity— and technology is making these systems less expensive than ever. In fact, I recently received a letter from a reader asking about some of these developments:

“I heard that Emerald Physics has a set of $3500 speakers that outperforms more expensive, $20k to $50k systems using a DSP. Is this possible?” asked S. Brown.

DSP IN THE MIDDLE
To get the answer, I talked with Clayton Shaw, president of Emerald Physics. His company’s $3500 CS2 system includes a set of open-baffle speakers combined with a Behringer DCX2496 Ultradrive Pro that sits between your preamp and a set of four amplifiers that drive the speakers (see the figure).

The DCX2496’s 32-bit Sharc DSP from Analog Devices implements an eighth-order digital filter network that Emerald Physics uses for active crossover support in addition to adjusting frequency, phase and time linearization, and lowfrequency (LF) equalization to deliver optimum audio performance from 20 Hz to 22 kHz.

The DSP performs these tasks to make up for the differences in performance between all the components in the system. Each speaker has a pair of 4-O, 380-mm, low- to mid-frequency woofer drivers operating below 1 kHz to handle vocals and large instruments and an 8-O, 25-mm exit compression driver. The speakers are placed 3 to 7 ft from the wall because reflectivity plays an important part in audio quality.

The DCX2496’s algorithms account for the position information, the amplifier characteristics, and the speaker characteristics. This is more difficult than it sounds because different amplifier pairs may be used with the system, and each type of speaker has different response characteristics.

The non-linear characteristics and distortion that can be added would result in a lower-quality playback. Signals routed to the low-frequency and high-frequency speakers normally go through a crossover system. The crossover point is where the differences of the speakers and amplifiers have the most effect.

The active crossover is set at 1 kHz. The system employs a Linkwitz-Riley filter also known as a Butterworth squared filter. Presets allow easy configuration by even non-technical audiophiles, though techies are free to tweak parameters.

DOWN THE AUDIO STREAM
The audio stream passing through the DCX2496’s 24-bit analog-to-digital converters (ADCs) and digital-to-analog converters (DACs) is then modified so resulting wavefronts are in synch for the listener. This controlled directivity is harder to accomplish than you might think because of the nonlinearity of the components across the spectrum, including changes in dispersion patterns. For example, low-range output tends to be more omnidirectional while compression drivers and waveguides handling the upper end are more directional.

The precise reproduction of the original sound is why audiophiles will pay so much for speakers and amplifiers that can deliver this level of quality. It allows us to hear subtle nuances that would otherwise become background noise.

When it comes to manipulating the audio stream in the time domain, it’s easier to use the DSP than a passive crossover system. The DSP also allows a range of techniques to be applied to the stream so adjustments are made in a number of areas, delivering controlled directivity.

The CS2’s patent-pending controlled directivity applies to a wider range of speaker architectures. Its big advantage is its ability to provide consistent and realistic output regardless of room configuration. It also can deliver a binaural effect if the speakers are angled toward the center, though this can only be done with a very accurate tuned waveguide system.

In the future, a move to all-digital operation will eliminate the need for the DCX2496’s ADCs and DACs. However, systems will still require Emerald Physics’ compensation support because of the remaining components within the system. In any case, analog rules the high end where amplifiers use vacuum tubes because of distortion and stability issues.

ANALOG DEVICES • www.analog.com
BEHRINGER • www.behringer.com
EMERALD PHYSICS • www.emeraldphysics.com
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jan.didden

jan.didden

AX tech editor
Joined 2002
linearaudio.net
Paid Member
I am using my heavily modded DCX with a pair of CS2's, using Clayton's DCX correction settings. The sound is very, very good, considering the relatively simple speaker setup. The open baffle means you have no box coloration whatsoever and this makes a big difference. Yet, bass is strong and fast.

There is a further difference between the stock DCX and my mod (described on my web site) because I trew out all those opamps, electrolytic signal caps and muting transistors in the output stages. Added analog level control with remote control so the digital level control can remain at 0dB for maximum dynamic range and resolution.

I'll be attending RMAF as well; probably bring my modded DCX.

Why not have a diyaudio get-together at RMAF? Then we all move to BAF the weekend after ;)

Jan Didden
 
P

Pulse-R

Member
Joined 2005
This may work, but depending on the DAC may also not work.

if the Blu-Ray player converts multichannel audio into PCM bitsteam for the DAC, then there will be a 'S-clock','B-clock' and 4x 'Data' signals.
In this case, you would likely need to make 4x output SPDIF drivers to send the 2-channel data to each DCX.

or

In the case that the DAC directly decodes multichannel audio, you then need to 'split' the various signals (as per above) out of the multichannel bitstream (DOLBY OR DTS or DSD) using a decoder IC. This becomes very messy.
edit - one IC that works for this is the Yamaha YSS944 LSI
 
H

Horizons

Member
Joined 2004
janneman said:
I am using my heavily modded DCX with a pair of CS2's, using Clayton's DCX correction settings. The sound is very, very good, considering the relatively simple speaker setup. The open baffle means you have no box coloration whatsoever and this makes a big difference. Yet, bass is strong and fast.

There is a further difference between the stock DCX and my mod (described on my web site) because I trew out all those opamps, electrolytic signal caps and muting transistors in the output stages. Added analog level control with remote control so the digital level control can remain at 0dB for maximum dynamic range and resolution.
Click to expand...

Jan:

I am very interested in your mod for the DCX2496, do you have a web link for further information?

Also, has anyone documented the DCX settings for the CS2?
 
jan.didden

jan.didden

AX tech editor
Joined 2002
linearaudio.net
Paid Member
Horizons said:


Jan:

I am very interested in your mod for the DCX2496, do you have a web link for further information?

Also, has anyone documented the DCX settings for the CS2?
Click to expand...


Hi Horizons,

The design is documented on my site www.linearaudio.nl , and a kit is sold by Ward Maas of Pilgham Audio www.pilghamaudio.com .

The xover and eq settings for the CS2 can be read out from any DCX that is delivered with the speakers, through the serial PC interface, and can then be shared with others.

Let me know if I can be of further help.

Jan Didden
 
lawbadman

lawbadman

Member
Joined 2003
Hello Guys,

I am thinking about buying a DCX2496 as a christmas present for myself :)
For those of you who have been using it. Have you been happy with its performance?
Are there better (sonically) alternatives?
What mod made the most significant difference?
Has it been able to keep up with hi-fi equipment?
 
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