DSP Xover project (part 2)

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#3,084
>>I've used IR :ROHM RPM7138

Thanks for the tip - in the end using new batteries in my remote did the trick, the IR receiver of the control kit is fine 🙂

>> Does anyone know if and when a fully boxed Najda with balanced outputs will be available?

The WAF website shows the boxed version, and when I recently bought my Najda kit, Nick mentioned the boxed version. How much it will cost, and when it is ready to ship will be interesting though.
 
#3,085
Enclosure

Hi all,

so, now i made a nice enclosure for my Najda, with a plotted layout-film and an acrylic glass. Looks fine.
But I need some help with speaker (I mean chassis) correction. Shell I use ARTA or RePhase or ??? and how ???

LG, Rainair
 

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#3,087
My question is similar to Raiders I think, unless he is not talking about room correction. I see ARTA can be used for room correction, which relates to my query.

I do room correction using the free REW program, though would like to hear how others do it.

After the measurement process, REW produces a txt file which I upload into Najda easily enough. I am using the NanoAVR setting since it seems to have filters near the Najda limit. Some equalizers are too big it seems.

Would love to hear if there is a better way.

I expect DIRAC would work, at a cost. Sounds very effective as it should for the money.

EDIT: Don't mean to make this a room correction thread, rather interested in what programs are compatible with Najda, and what settings are recommended. For example, I am right to use the nanoAVR setting in REW?
 
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#3,090
DRC FIR is a good free alternative to dirac etc.

DRC: Digital Room Correction

There is a thread with information here

http://www.diyaudio.com/forums/full-range/275730-convolution-based-alternative-electrical-loudspeaker-correction-networks.html

I don't know if the FIR files that are created will be compatible with Najda but if you use a computer as a source then it is easy to add a convolution plugin to do it.

This is a fairly difficult program to use but also very powerful, used carefully it can do some very clever things. You can do a simple measure and fix type of arrangement but most seem to have got better results from manual settings.

In IIR mode Najda can use up to 15 biquads per channel so it seems unlikely that it can't run what you need from REW. If you post the text file maybe we can see what sort of EQ REW is suggesting and the best way for Najda to reproduce it.
 
#3,091
Have downloaded DRC. Will see if the filters load to the Najda.

REW certainly works. In fact, I realized there is now the miniDSP 2x4HD option, so will use that with the mic pointing to between the two speakers (nanoAVR meant for mic at ceiling for surround sound system).
 
#3,092
Deas any one use JL sound USB to I2S on Najda ?
http://jlsounds.com/uploads/Specifications.pdf

I have problem configurating it

I have connect

USB/I2S------------NAJDA
11 - GND --------- 26 GND
13 - LRCH---------- 25 FSR
14 - DATA----------1 I2S LINE1
15 - BCLK/CLK ----- 23 CKR

also have connected on USB to I2S board as I'm using only USB power
PIN 1 to PIN 12 5V+
PIN 2 to PIN 11 GND

have connect PIN 1 and PIN6 with 4.7kOhm resistor for left justified ?
as Najda uses (quote from NAJDA MANUAL ) ;
''Data format is the most common, i.e. 64 bit clocks per sample period in 32-bit time-slots, with data aligned to the left''

any way, if someone is using JLsounds USB to I2S card, please post your setup which works with Najda...

thanks
 
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#3,093
Your connections look to be correct, have you connected a jumper from pin13 to ground on the Najda expansion port? This allows external i2s, without the jumper no external i2s will work. Labelled as Detect expansion board in Najda manual.

Also double check that you have the correct pins on Najda as it is easy to misread the pinout for that connector.
 
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#3,094
fluid said:
Your connections look to be correct, have you connected a jumper from pin13 to ground on the Najda expansion port? This allows external i2s, without the jumper no external i2s will work. Labelled as Detect expansion board in Najda manual.

Also double check that you have the correct pins on Najda as it is easy to misread the pinout for that connector.
Click to expand...

fluid thanks for replay
I have place jumper at that position...
I used to use Najda with rPi via I2S, and it work, but use to have problems...
(I have used to lose, I believe, synchronization be twin Najda and rPi, which would peek Najda into red...needing to reset everything to get it bect to work)
so now I will try to use USB/I2S board to avoid that...

I'm just not shure did I set everything right on JLsound USB card 😀

I have check, does Najda work, and it works with analog inputs
So I believe that I didn't setup USB card on the way that Najda need it to be recognized...
i hope 😀
 
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#3,095
If you have another DAC that can take i2s input test the JLsounds board with that to see if it works, there is a thread at diyaudio for that board maybe post on there to see if anyone can identify what the configuration problem is.

Can you select i2s as an input in Najda but just get no sound?
 
#3,096
fluid said:
If you have another DAC that can take i2s input test the JLsounds board with that to see if it works, there is a thread at diyaudio for that board maybe post on there to see if anyone can identify what the configuration problem is.

Can you select i2s as an input in Najda but just get no sound?
Click to expand...

I can borrow another DAC with I2S input but it's not a guarantee that if it works on it that it work on Najda (it mide have different I2S protocol)

Yes, I can select I2S input, but don't get any signal at the input (input volume meter is dead silent 😉)

I think I have to figure JLsound card for proper setup to work with Najda

will look for JLsound tread and try there...
thanks
 
#3,098
fluid said:
This is the thread

http://www.diyaudio.com/forums/digital-source/236028-xmos-dsd-384-khz-32bit-usb.html

All the new AKM and ESS chips use the same protocol as Najda, so it shouldn't be that hard to get to work...
Click to expand...

I tought it would be simple plug and play 😀
(inside USB/I2S card manual there is a table 1 for ESS (DATA_L DSD) and AKM (DATA_R DSD) compatibile DAC...which state to connect Pin 1 to Pin 5 via 4.7kOhm...but I think it's just for DSD materials)
It state;
- no connection for DATA_R DSD
- 4.7kOhm for DATA_L DSD

And there is table 2
- I2S no connection to PIN4,PIN6 (THIS WAS DEFOLT - DIDN'T WORK)
- LJ PIN6 to PIN1 via 4.7kOhm - THAT'S HOW IS NOW CONNECTED
- RJ 24bit PIN4 to PIN1
- RJ 16bit PIN4 and PIN6 to PIN1 via 4.7kOhm


have send email to JLsound and post a replay inside the XMOS tread
thanks
:cheers:
 
#3,099
Rainair said:
Hi all,

so, now i made a nice enclosure for my Najda, with a plotted layout-film and an acrylic glass. Looks fine.
But I need some help with speaker (I mean chassis) correction. Shell I use ARTA or RePhase or ??? and how ???

LG, Rainair
Click to expand...

The enclosure looks beautiful, hope I can get something decent looking in my own build!

Regarding chassis correction: the previous posts have looked at correction of the whole speaker in the room. If I understand correctly that you want to measure individual chassis and correct them, I would suggest the classic IIR filters of Najda, because you can get a lot of filters also at lower frequencies at 96 kHz and, more importantly, many chassis resonances are minimum phase which means they should also be corrected with a minimum phase (that is IIR) filter. I also find REW (Room EQ Wizard) the easiest but very powerful program for measurements. I like the webpage of Siegfried Linkwitz (Linkwitz Lab - Loudspeaker Design) as one of the best freely accessible resources for measurement, how to measure individual drivers, windowing, etc, because he is a true expert and explains a lot. Would be interested to learn the workflow you use in the end - quite often some of the "trivial" export steps etc are not well documented, so a post here would help.
 
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