Digital crossover with an AES in & out for 4-way loudspeaker management?

Jump to Latest
#41
Machismo said:
Minidsp of course does not have such AES equipped 4-way product available, otherwise I just might buy that one. 2-way they do have though.
Click to expand...

They have 3 products that can do this.

1) DDRC-88D, 8 ch AES in / 8 ch AES out
2) U-DIO8, 8 ch AES in / 8 ch AES out, no built-in processing but this plus a raspberry pi running CamillaDSP would work great
3) miniSHARC, 2 ch AES input / 8 ch I2S output, unfortunately they no longer sell the miniSHARC as a DIY board but the OpenDRC-DI is a miniSHARC + DIGI-FP + VOL-FP, it has 8 channels of I2S output so you would need to add I2S to AES boards

Michael
 
#42
Sorry! My mistake, I did not explain the reasons why I abandoned the DDR-88D option already long time ago. I excluded it, because It has 48khz internal processing, which is too low since 96khz is routinely available too by other manufacturers. And while high quality 48 khz music material is still ok for listening, 48 is not anymore optimal for processing. Also I can't say I prefer that pigtail wiring, it is not the most professional thing, but of course works just the same. But perhaps for someone else might find the 88D useful.

U DIO8 I am not familiar with, that probably has higher internal processing rate? Then it would be a good option, since it does not cost very much.

miniSHARC, is quite different than the device I was looking for, since I wanted something I can buy completely ready. Good to mention it anyway.

The thing also with any Minidsp is that after using their products since 2011 I have noticed some problems. First of all, most devices have an external power supply with flimsy connector to the board. Sometimes that thin wire backed out in the middle of playing, cutting power and some Minidsp devices at that situation made a loud BANG to the outputs which might easily damage the speakers. So now because I have so much invested in the sound system, I am only purchasing devices with internal power supply. Also I will not tolerate any bang sounds in any situations. Also Minidsp has had quite a few bugs over the years, I installed their car crossover and suddenly in the middle of driving it went completely crazy putting self generated huge noise at maximum output (without filtering) to all outputs burning mids and tweeters. NICE! And what I red, some other people had the same thing happen too.
Then there is the Minidsp SHD Studio which I have been using, after latest firmware update it started to sometimes make loud bangs to outputs when I changed the crossover frequency. It did not do that before.

So yeah, Minidsp is ok, but I personally now want to avoid them for the sake of security of my system, unless they start to improve their quality to a more professional level.

But to say something positive to the end, I really like the integrated Dirac of the SHD Studio.
 
Last edited:
#43
ErnieM said:
Have you tried the LIR filters?

Thanks.
Click to expand...
No not yet, I wanted to first evaluate it with the same settings I have used before with other crossovers, (4th order L-R). I did try the beta version of the control software, which is version 8 but that was way too buggy since it is still being developed, but luckily the standard version 7 did not seem to have any bugs. What is an improvement compared to Minidsp that you can slide the crossover frequency slider in realtime and hear the sound change immediately. That helps when you are trying to decide where to put the crossover frequency point and you want to get it just right. More fluent that way.
 
  • Like
Reactions: Hydrogen Alex and ErnieM
#45
Machismo said:
Hi,

Yes that one was missing from the list too, thanks. Truly is one of the most affordable options, only some hundreds of bucks. How has it worked for you and how is the sound?

https://en.nuoxun.com/?list_123/
Click to expand...
Hi
According to me the sound is very good . I use it coupled to a miniDSP SHD studio . I had it recently and did not really play with it . As a DAC , without any PEQ or filter , i love it . For now EQs and filters are in the SHD but i have a project of 3 way CBT line array . In France this product could be sold 4 or 5 times that price .
 
#46
bushmeister said:
I have been using a miniDSP 4x10HD for many years, but am looking for an upgrade.
My one concern with this device: https://linea-research.co.uk/asc48/
Is how do you control your volume?
I have a Turntable source as well as USB streaming and HD storage, so would need an easy to use global volume control - I can't see that his crossover has one?
Thanks
Click to expand...
I think it does not have a remote volume control possibility , that would be handy for sure. So far I have been using Minidsp SHD in series with the crossover without any filters or settings to add different inputs options and as a volume control. Or if I use a mixer connected directly to the crossover, the mixer has a master output volume control also in it.

I also have the ethernet cable always connected to the device so I can adjust, with a computer, the input gain that way. (Ethernet remote control via Linea’s System Engineer PC application)

Front panel buttons - I have not yet had time to study what is possible to do with those. One thing I did notice, the lights on the buttons are super bright, that might not be optimal for home use.

I almost forgot, if and when I use amplifiers with balanced analog inputs, then I route the signal through Okto to perform DAC, and Okto has a volume control knob and a remote control too. That might work for some non-compromise-sound quality people. Linea also has analog outputs, just have not tried those yet.

https://www.oktoresearch.com/dac8pro.htm
 
Last edited:
#47
Of course the most desired gain structure and overall sound quality of the signal chain becomes quite optimal when the volume control is done at the DAC just before the power amplifiers. At the same time the amplifier gains are set as low as possible.
Just wanted to add that, since it is so important to understand.
 
#50
Very good processors ( Marani).
I've seen and heard them used in large PA system. Sounded good.

To the OP, an 'original' Lake could be an option ( Lp4D). There was some without expansion cards for analog i/o. They are rare but exist.
That said i still use mine through it's AD/DA, they were pretty clean.
 
  • Like
Reactions: ErnieM
#51
I would like to suggest something different. Since you have the OktoPro8 you could hook up an RPi4 through USB and use HQPlayer software to do the crossover. HQPlayer will do DSP filters and Convolution and you can run it on a powerful remote computer. Signalyst, the developer of HQPlayer makes available NAA (Network Audio Appliance) software for RPi.

I have been using HQPlayer for some time in a 2 channel system using an analogue crossover. Thinking seriously of purchasing the OktoPro8 and trying the digital approach.
 
  • Like
Reactions: mdsimon2
#52
Why not build a system based on:

(half straight forward)
  • A mac mini (or pc)
  • ... running CamillaDSP
  • RME Digiface USB Toslink
  • 4 DACs

(or a little more twiddling)
  • a Pi 5
  • Picore player inc CamillaDSP (or Modee which has Camilla bult in)
  • USB isolator
  • XMOS multi channel i2s or s/pdif
  • 4 DACs

Both the above systems can do high Fs and many 100000 taps FIR and will be tight synchronous on all 8 out channels. Camilla supports both PEQ and FIR convolution - I can't see any limits really.

And.. why AES?

//
 
#53
#54
ErnieM said:
https://www.marani-proaudio.com/prodotti-Professional_Audio_Processor/31_3/eng/

I've been looking at these along with the Linea Research ASC48.

Any experience with Marani?
Click to expand...
Seems to be relased about 3 years ago. At first I got excited since it seems to have the most amazing crossover linear phase filters, that are unusually nice and steep:
"The newly added MIR linear phase crossover filter has the filter shape of the traditional IIR filter(4th/8th order Linkwitz-Riley), but does not produce any phase shift, and the resulting delay is about 50% of the FIR filter."

But then I noticed that it apparently only has analog xlr outputs, no digital AES! AES is only at the input. So it does not qualify for the criteria I had. But for someone who wants analog outputs, that might be the best option regarding the filters.
 
  • Like
Reactions: ErnieM
#56
And for the Linea Research ASC48 that I have been using now quite a while, I tested the linear phase filters it has, and they sounded very good, like they indeed would be perfectly in the correct phase. However, they only are half as steep compared to normal 48db filter = 24db, which was not enough for me, for example tweeter sounds were "leaking" in to my midrange line array creating problems and of course tweeter got too much power for high volume playing since midrange was also leaking in to that. Also for bass/midrange crossover point, steeper seemed to work better. So for my purpose, it didn't work out.

So my search is still on and while ASC48 is a very nice device, and I am currently using it with eighth-order Linkwitz–Riley, but I would want something like that Marani, that has steep and linear crossover, but that would also have the digital AES outputs. If you see one, let me know.
 
  • Like
Reactions: ErnieM
#57
Then i repeat what i said in message #50:
Take a look for a Dolby Lake processor LPD ( before Lab Gruppen bought Lake).
It have 48db/octave linear phase filter and steeper one too ( depend of xover freq, the higher the steeper, in 4 way linear phase mode). It works at 96khz and accept higher sample rate at input ( downsampled to 96khz internally), aes in out (16),... and it sound pristine.
 
#58
Yes, good that you reminded. Indeed it has:

The Lake Technology​

"Linear phase crossovers are another feature separating Lake Processing technology from ordinary processors. Linear phase crossovers can match traditional crossover slopes, such as 24 dB per octave and 48 dB per octave, when desired. But they are also capable of transition slopes exceeding 180 dB per octave."

That device was my original "dream" but at some point I noticed it has fan noise, which is not ideal for living rooms. "Cooling 2x fans, front-to-rear airflow"
https://mediadl.musictribe.com/media/PLM/data/docs/LMX/M_LA_0825-AAN_LMX 48-88_EN.pdf

And I know why, "Power consumption 75 W maximum" I guess lots of processing takes its toll. Just to compared the always completely silent ASC48: "Mains power 30w".

This being only 20w (quiet?) and about the same price level as the LMX it interests me,

https://nstaudio.com/wp-content/uploads/2023/01/D48X-Datasheet-V1p1-1.pdf

But there is no mention if it offers the linear crossover filters, maybe it does not... I will send them an email.

We will see, perhaps I should buy the LMX and just stash it away if it makes noise.
 
#59
Machismo said:
And for the Linea Research ASC48 that I have been using now quite a while, I tested the linear phase filters it has, and they sounded very good, like they indeed would be perfectly in the correct phase. However, they only are half as steep compared to normal 48db filter = 24db, which was not enough for me, for example tweeter sounds were "leaking" in to my midrange line array creating problems and of course tweeter got too much power for high volume playing since midrange was also leaking in to that. Also for bass/midrange crossover point, steeper seemed to work better. So for my purpose, it didn't work out.

So my search is still on and while ASC48 is a very nice device, and I am currently using it with eighth-order Linkwitz–Riley, but I would want something like that Marani, that has steep and linear crossover, but that would also have the digital AES outputs. If you see one, let me know.
Click to expand...

A RPi4 running CamillaDSP attached to your Okto can easily do this. Are you familiar with the USB/AES mode of the Okto?

I would even bet the CamillaDSP filters are objectively lower noise and distortion than almost any commercial hardware DSP.

Michael
 
#60
The one you link are from Lab Gruppen. I don't talk about this one, but the 'original' Dolby unit:
https://pa-audio.eu/product/dolby-lake-lp4d12/

Mine just spin up at start for something like 10 second and remain silent then after. I don't think i ever heard it's fan when in operation but it have space above and below into the rack, so it doesn't suffer from heat.
Sure it's an 'older' unit but... i don't care, it does what i ask, even have Dante! ( limited but still...)

D48 does fir but it's limited and dependent of number of chanel: 1024 tap for 2 chanel, 256 for 8...
Taps define the steepness of filter...

I quickly read your first post but i will do it again. I think i don't get what you want to do exactly.

If it's a digital box with FIR capability then all you need is... a pc with digital input soundcard. This is the hardware part. For software there is a bunch of possible options... depend what you want to achieve, your budget,etc,etc,...
 
Last edited:
You must log in or register to reply here.
Top Bottom