Deqx digital feed 3 Nuforce DDA-100s

[closenplay]

My build is a 3-way dipole WMTMW using AMT (various) tweeters, BG neo10s, AE Dipole15s. The plan is to use the digital outputs of a Deqx HDP-4 to feed the inputs of three Nuforce DDA-100s, digitally processing/crossing over and triamping while keeping the signal all digital until the power amp output. Music source will be computer. For HT use I am using 8 AE IB15s for subs (well......maybe for 2 channel listening as well).
Would welcome any thoughts/concerns/ideas. Thanks.

 

[thierry38]

hi,

why not using the computer for crossover/EQ and send the multichannel digital output to the nuforce ?

you can save the cost of the Deqx Hdp-4,a computer is more powerful.
a correct sound card allow FIR crossover/EQ with a large flexibility.
need only 2 spdif repeater if you want to use digital output to drive the 3 power amps.

and you can add DRC process.

 

[closenplay]

Thank you for the reply. I am not very familiar with using the computer for crossover and processing duties. Are the available programs able to meet the performance specs of the HDP-4? ( up to 300db slopes, virtually zero phase filters, no group delay, extremely low distortion figures) If there is a product that comes close in performance I would certainly consider it. Also--do you use the same computer that you are sourcing material from or are there better results if you build a separate dedicated computer for this. Is there a tutorial website describing how to construct and use a computer in this way. Might you be able to use a large amount of RAM and no hard drive for a dedicated computer? If you needed "hard drive" space would solid state memory yield better sonics? I think this option opens up a wold of new possibilities that I would like to learn about. All helpful suggestions are welcome. Thanks. ( I think we are all into saving money while learning or is it learning to save money?)

 

[thierry38]

Are the available programs able to meet the performance specs of the HDP-4? ( up to 300db slopes, virtually zero phase filters, no group delay, extremely low distortion figures) If there is a product that comes close in performance I would certainly consider it

programs are convolution engine ,most of them are free.
and rephase to generate impulse response.(freeware too )
till 1000 db/oct FIR crossover/FIR EQ and DRC (all in linear phase )
a netbook can do the job with usb soundcard.

JRiver media jukebox or any vst host to play music (freeware too ).

the topic beside.a full tutorial
http://www.diyaudio.com/forums/pc-based/223805-easy-fir-crossover-pc-based-drc.html

 

[bohdan1232000]

Hi,

If you are interested in convenience of a HTPC audio server coupled with powerful loudspeaker management system - you could be interested in Ultimate Equalizer shown on Bodzio Software website.

Major characteristics of Ultimate Equalizer system are:

• Active system – allows amplifiers to exert maximum control over loudspeaker driver and makes crossover characteristics independent of driver loading.
• DSP crossover and voicing – maintains crossover and voicing characteristics with mathematical precision.
• Amplitude and phase HBT equalization – results in flat amplitude and phase responses and extends bass response.
• Linear phase – maintains 0deg acoustical phase response of each driver, which results in transient-perfect system for correct spatial imaging (realism, depth, resolution, ambience) for multi-channel sound reproduction. Also removes “flabby bass”.
• Minimum-phase/Linear-phase room EQ – removes most obnoxious room modes.
• Remote control – via 2.4GHz wireless keyboard and mouse.
• Use Windows Media Player, or install JRivers Player – to create audio server and state-of-the-art loudspeaker management system (user-friendliness, power, flexibility, cost efficiency and sound quality) on one HTPC.

Best Regards,
Bohdan

 

[closenplay]

Thank you Bohdan and Thierry. I read through most of the info/links that you both sent to me. I did not see in either program the ability to have the output of the computer's multiple channels be digital. That is the design and advantage of the Nuforce DDA-100, the ability to be driven directly by a digital signal. Are there sound cards available that will output each individual channel for each driver digitally?

 

[thierry38]

Hi,

i've just understood what you want to do.
driving 3 stereo nuforce da100 with stereo spdif.(power amp do not convert digital to analog,the nuforce is working in full digital mode ).

maybe RME or LYNX pro soundcard,it gonna be overkill to drive a home stereo system.

deqx is a good (expensive ) choice,seems to be easy to setting up.

 

[Thierryj]

@closenplay: I am considering something similar , based on 3 DDA-100. How do you intend to manage the global volume ? (from within Deqx, physical link between the 3 knobs, one remote for all . . . )
Other point : are you sure adjusting the gains within Deqx does not degrades the resolution ?
In my case , at this stage, I will investigate first the solution suggested by thierry38efd with additional sound cards to have 3 S/PDIF stereo output channels (but then I have the gain/volume problems quoted above)

 

[pos]

My build is a 3-way dipole WMTMW

Hi closenplay,

If you are planning on doing a WMTMW you should take a look at the Horbach-Keele filter implementation.
You can generate these filters with rePhase, but you will still have to calculate the proper critical frequencies and filter "R" coefficient using the formulas in this presentation:
http://www.linkwitzlab.com/Horbach-Keele Presentation Part 2 V4.pdf

I think Acourate and UE also implement them, maybe in a more user-friendly manner (automatic parameters calculations using the target beamwidth and spacing, etc.).

Still, it is adviced that you read and understand the above presentation if you want to undergo such a project, and calculating these parameters is quite straightforward.

To apply the convolution you can also look at the miniSHARC solutions if you want to avoid having a PC in the loop.

 

[closenplay]

Thierryj- Sorry for not responding until now--I have not checked this thread for a long time, especially since I wasn't getting alerts regarding responses. I have the speakers up and running w/ the deqx. Haven't finalized eq and crossovers yet, but sounds fantastic! Feeding the deqx from either computer or oppo bdp-105 via s/pdif. Then s/pdif x3 from deqx to the dda-100s. Volume control via the deqx. How is your project coming along?