This is third unit I spotted during last years but first one I spotted before it was sold or expired.
I have been looking for a replacement solution for the Najda.
PC + dac8pro have more EQ power. But usability in home environment with need for multiple source connection can not be solved with a PC.
So Najda is still the got to the solution.
I use FIR filters on Hi and Mid drivers. Base and subs are fed straight true to a MiniDSP 2/4 unit where I EQ the bass. This gives much flexibility and solves some of the lacking computing power.
PC + dac8pro have more EQ power. But usability in home environment with need for multiple source connection can not be solved with a PC.
So Najda is still the got to the solution.
I use FIR filters on Hi and Mid drivers. Base and subs are fed straight true to a MiniDSP 2/4 unit where I EQ the bass. This gives much flexibility and solves some of the lacking computing power.
Attachments
I guess same thing can be done with two Najdas, one for FIRs and other one with normal PEQ for lower part (so long awaited mixed mode but with two devices). If they will be stacked, one remote could be used to control volume on both.
On the other topic. Am I wrong or this could be used to make Najda 8 channel sound card with volume control?
XMOS Multichannel high-quality USB to/from I2S/DSD SPDIF PCB 3W - DIYINHK
On the other topic. Am I wrong or this could be used to make Najda 8 channel sound card with volume control?
XMOS Multichannel high-quality USB to/from I2S/DSD SPDIF PCB 3W - DIYINHK
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Nicolas was ready for an EQ + FIR config. Sadly he never released it. (You can find some trace of discussion in this thread and in config files or if you use a binary decompiler)
Sure but today I need at least 2x5 with attenuation support and this is not possible with snigle Najda. When using two of them I can do mixed mode by myself using one Najda for FIR filters and other for IIR filtering.
There is a french projet for Octa dacs where the developper have enabled an internal DSP feature (In coopoeration with Okto) 🙂
<<extension DSP pour DAC OKTO Research>> - 30102466 - sur le forum <<Sources et DAC>> - 1057 - du site Homecinema-fr.com
<<extension DSP pour DAC OKTO Research>> - 30102466 - sur le forum <<Sources et DAC>> - 1057 - du site Homecinema-fr.com
I'd quite like to try FIR on my sub tapped horns left and right channels, but never got my head around it. 20Hz to 100Hz.
I have no correction on the other channels, just X/O and time alignment.
Still not enough horsepower?
I have 2 Najda units, use I2S input.
How to dual them and use only one volume control?
The only way I could see to do it was to use the 4th pair of outputs as inputs to the 2nd Najda.
Sub-optimal I would have thought.
Is there another way?
For those frequencies Najda will not be enough, even if all taps could be dedicated to single channel (and it's impossible anyway), or maybe only in this case.
As for volume, if two Najda's see same remote controller they will both change volume according. Of course first you need to set same level on both.
It's not perfect but at least it's something.
FIR asks for much calculating power. But if the topic is interesting then read Mitch's writings. He is one who has much knowledge and has published articles and at least one book about speaker EQ with FIR filters.
Integrating Subwoofers with Stereo Mains using Audiolense
Fit filter development can be done using REW and rephase programs. You can find tutorials on rephase homepage.
This is a good tutorial where you first use REW auto EQ. Then move the corrected measurement to rephase wherefrom you can save FIR filters.
Jusing REW and rephase to generate amplitude and time domain corrections/
This is a good tutorial where you first use REW auto EQ. Then move the corrected measurement to rephase wherefrom you can save FIR filters.
Jusing REW and rephase to generate amplitude and time domain corrections/
I was not following this thread too closely. I did no realized that Nicolas went missing during his South America trip.
Looks like official search was called off this year.
RTL Today - Public prosecutor's office: Search for Nicolas Holzem officially called off
It's really sad news.
Looks like official search was called off this year.
RTL Today - Public prosecutor's office: Search for Nicolas Holzem officially called off
It's really sad news.
Thanks.
I'll stay as I am - unless something new comes along that is as user friendly!
Could be interesting to do a reverse engineering, just to give more life to this project.
The multichannel fir mode with txt import are almost unique on the market
Hi all,
I also searched a lot to optimize 2 Najda in FIR, finally I use them in I2S only inputs / outputs with DAC ESS9018 for low medium, medium, treble, left / right for Najda 1, and DAC ESS9028 for bass, left right for Najda 2.
Samples for Najda 1 are limited to 512 (per channel) on the 6 channels, for a use of approximately 80% of the 2 processors. (with detected instabilities ...)
For Najda 2, 1023 samples on each left / right channel.
The problem with all this "beautiful" organization (with a common clock of course) is the random phase drifts between the channels, detected at the outputs of the DACs, (measured on the audio bench) which are due to the 2 DSP56725s.
It is indeed stupid to seek a good temporal alignment of the different loudspeakers using FIRs, if the source itself, which best guarantees this alignment, drifts ... especially when starting the DSPs.
I have not yet found the time to analyze the problem, and especially to find the solution, linked I think to the time of the reset on the DSPs, and to the arrival of the tops of the master clock ...
To complete my configuration, I use a Metronome Twisted I2S input which reclokes all the files in 96KHz, (the FIR Rephase files are created in 96KHz), the Metronome clock replaces the 2 quartz (not very precise ...) of the 2 Najda.
The I2S output of the Metronome enters the I2S ports of the Najda.
I use the excellent USB / IS2 XCore 208 interface card which fits into I2S on the Metronome. (I use Audirvana on Mac as a player)
Last precision, there is a bug on Najda, the I2S outputs are reversed, (measurement made on my I2S Tektronic MDO3014 analyzer),
the left channel entering, exits on the right when exiting ..., but becomes OK again when you connect a PC to Najda, I had already indicated to our dear Nicolas another bug on Najda that he had corrected in 1 hour, unfortunately it will be impossible for that one.
In conclusion, the sound result is very satisfactory on a large high efficiency horn system, with emotion (finally!) Restored, when everything is well started and in phase !, So it's quite experimental, I only use them. DSP from Najda, and the difference is huge in terms of quality compared to the basic version.
I also searched a lot to optimize 2 Najda in FIR, finally I use them in I2S only inputs / outputs with DAC ESS9018 for low medium, medium, treble, left / right for Najda 1, and DAC ESS9028 for bass, left right for Najda 2.
Samples for Najda 1 are limited to 512 (per channel) on the 6 channels, for a use of approximately 80% of the 2 processors. (with detected instabilities ...)
For Najda 2, 1023 samples on each left / right channel.
The problem with all this "beautiful" organization (with a common clock of course) is the random phase drifts between the channels, detected at the outputs of the DACs, (measured on the audio bench) which are due to the 2 DSP56725s.
It is indeed stupid to seek a good temporal alignment of the different loudspeakers using FIRs, if the source itself, which best guarantees this alignment, drifts ... especially when starting the DSPs.
I have not yet found the time to analyze the problem, and especially to find the solution, linked I think to the time of the reset on the DSPs, and to the arrival of the tops of the master clock ...
To complete my configuration, I use a Metronome Twisted I2S input which reclokes all the files in 96KHz, (the FIR Rephase files are created in 96KHz), the Metronome clock replaces the 2 quartz (not very precise ...) of the 2 Najda.
The I2S output of the Metronome enters the I2S ports of the Najda.
I use the excellent USB / IS2 XCore 208 interface card which fits into I2S on the Metronome. (I use Audirvana on Mac as a player)
Last precision, there is a bug on Najda, the I2S outputs are reversed, (measurement made on my I2S Tektronic MDO3014 analyzer),
the left channel entering, exits on the right when exiting ..., but becomes OK again when you connect a PC to Najda, I had already indicated to our dear Nicolas another bug on Najda that he had corrected in 1 hour, unfortunately it will be impossible for that one.
In conclusion, the sound result is very satisfactory on a large high efficiency horn system, with emotion (finally!) Restored, when everything is well started and in phase !, So it's quite experimental, I only use them. DSP from Najda, and the difference is huge in terms of quality compared to the basic version.
Sadly item I bought has CS3318 fried. Channels 1 and 2 are distorted others are muted and there is no reaction to any attenuation actions. Fortunately sound before CS is fine. This week I should get new CS3318 for replacement.
You are right there is not any other product on the market that can do FIR and still can be used as a preamp in a family environment.
I don't know have I found the same instability but I can hear that something is wrong when running a measurement with REW. It sounds like Najda is producing lots of harmonics at the end of the signal sweep.
This is not always present and can be cured by rebooting Najd.
I also get (sometimes) distortion in one FIR channel that I am able to cure by switching off some of the other channals.
But then again after rebooting I don't get that same problem.
When trying to analyze the problem I find that these seams to occur
in winter when the air is very dry inside as a result form heating. This generates static electricity that can be felt.
I have also felt charged from Najda when hooking up amplifiers or such. So I feel that there might be some leaking from the PSU. My Najda is a Boxed unit that Nick did build.
When one Leeds to another then there might be some instability issues with the Najda design that we now can sense and maybe even measure.
Analyzing CS3318 datasheet I found info that max output capacitance is 100pF. Above that it can gat unstable or needs additional output/buffer stage that can drive higher capacitance.
Maybe that is your issue, long or hi capacitance IC's.
On the other topic, had some najda charge issues when there was TV in my audio loop drough dvd player. TV was connected to other power line/power socket (but still same phase). Got read of this part and powered all devices from single line/power strip.
Maybe that is your issue, long or hi capacitance IC's.
On the other topic, had some najda charge issues when there was TV in my audio loop drough dvd player. TV was connected to other power line/power socket (but still same phase). Got read of this part and powered all devices from single line/power strip.
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