ProSoundWeb Community

Please login or register.

Login with username, password and session length
Advanced search  
Pages: 1 [2]  All   Go Down

Author Topic: Lab.Gruppen Lake LM26 Processor  (Read 17790 times)

Mac Kerr

  • SR Forums
  • Hero Member
  • *
  • Offline Offline
  • Posts: 10223
Re: Lab.Gruppen Lake LM26 Processor
« Reply #10 on: August 06, 2010, 12:45:02 pm »

Andy Peters wrote on Fri, 06 August 2010 00:22

Ryan Garnett wrote on Thu, 22 July 2010 06:48

Looking at that PCB, one has to wonder if they couldn't make the thing a quarter of the size?


Because if the PCB was a quarter of the size, it'd likely have eight layers, and that's a lot more expensive than a larger four-layer board.

A larger PCB with the parts spread out doesn't get as hot as one with everything crammed all together.

Also, the stuff in the lower center/right are all parts of a switch-mode power supply, and they kept that stuff away from the analog electronics (top to the right). All of the digital stuff (the DSP, and FPGA, the Ethernet, their associated power supplies) and the mains power supply are on the other side of the PCB from the analog. Keeps everything quiet.

-a


I addition to Andy's very real technical reasons, what would be the point? It is already a 1RU device, the box isn't going to get any smaller. Making the box shallow makes it hard to reach the connectors when it is mounted is a rack with other gear.

Mac
Logged

John Roberts {JR}

  • Newbie
  • *
  • Offline Offline
  • Posts: 0
Re: Lab.Gruppen Lake LM26 Processor
« Reply #11 on: August 06, 2010, 02:21:59 pm »

Mac Kerr wrote on Fri, 06 August 2010 11:45

Andy Peters wrote on Fri, 06 August 2010 00:22

Ryan Garnett wrote on Thu, 22 July 2010 06:48

Looking at that PCB, one has to wonder if they couldn't make the thing a quarter of the size?


Because if the PCB was a quarter of the size, it'd likely have eight layers, and that's a lot more expensive than a larger four-layer board.

A larger PCB with the parts spread out doesn't get as hot as one with everything crammed all together.

Also, the stuff in the lower center/right are all parts of a switch-mode power supply, and they kept that stuff away from the analog electronics (top to the right). All of the digital stuff (the DSP, and FPGA, the Ethernet, their associated power supplies) and the mains power supply are on the other side of the PCB from the analog. Keeps everything quiet.

-a


I addition to Andy's very real technical reasons, what would be the point? It is already a 1RU device, the box isn't going to get any smaller. Making the box shallow makes it hard to reach the connectors when it is mounted is a rack with other gear.

Mac



Yup there is no single best answer, and it would probably be somewhat cheaper to use 2 sided PCB for rear jacks, maybe as many as 4 separate different technology and physically smaller PCB, connected together with a bunch of ribbon cables... What could possibly go wrong with ribbon cables?  Laughing

While a single large board may cost a little more, it pays dividends in reducing point to point wiring, increased reliability, etc.  

I doubt this sku is that much of a sharp pencil exercise and there is perceived value in the deeper/heavier chassis.

JR
Logged
 https://www.resotune.com/


Tune it, or don't play it...
-----

Bennett Prescott

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 8924
    • http://www.adraudio.com
Re: Lab.Gruppen Lake LM26 Processor
« Reply #12 on: August 11, 2010, 05:08:38 pm »

Over the weekend I had a chance to run some critical audio through the LM26. Long story short, I used it to run one half of the PA system, and I was unable to hear any sonic difference one side or the other, which is excellent.

About that daylight viewable screen... seems about at good as the DLP, which is to say passable. Mostly it's just so small that you have to get real close to tell what it's saying, but the meaningful front panel level indicators tell you most of what you need to know and can be seen easily except in direct sunlight.

index.php/fa/31986/0/

Before I ran a show on it, however, I measured it.
Logged
-- Bennett Prescott
Director of North American Sales
ADRaudio d.o.o.
Cell: (518) 488-7190

"Give me 6dB and I shall move the world." -Archimedes

Bennett Prescott

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 8924
    • http://www.adraudio.com
Re: Lab.Gruppen Lake LM26 Processor
« Reply #13 on: August 11, 2010, 05:18:00 pm »

Here is a screen shot of a measurement of the processing applied to what happens to be the middle section of my line array. The LM26 is the purple trace. As you can see, the two processor provide exactly the same processing for identical settings. The deviation in the phase trace is due to half a sample of difference in the delay times and doesn't actually exist.

This is pretty interesting given that the audio comes into the DLP over analog, arrives at the LM26 over an ethernet cable via the Dante protocol, and comes out just the same! Modern technology never ceases to amaze me.

index.php/fa/31987/0/

P.S. Smaart 7 really is fantastic, I've used it to make several measurements over the last few days and it makes getting the data I need to see much easier.
Logged
-- Bennett Prescott
Director of North American Sales
ADRaudio d.o.o.
Cell: (518) 488-7190

"Give me 6dB and I shall move the world." -Archimedes

John Roberts {JR}

  • Newbie
  • *
  • Offline Offline
  • Posts: 0
Re: Lab.Gruppen Lake LM26 Processor
« Reply #14 on: August 11, 2010, 05:31:33 pm »

Bennett Prescott wrote on Wed, 11 August 2010 16:18



This is pretty interesting given that the audio comes into the DLP over analog, arrives at the LM26 over an ethernet cable via the Dante protocol, and comes out just the same! Modern technology never ceases to amaze me.



P.S. Smaart 7 really is fantastic, I've used it to make several measurements over the last few days and it makes getting the data I need to see much easier.


Repeatability is an under appreciated benefit of DSP. I recall the blood sweat and tears of trying to make a 4 pole analog crossover adjustable over a reasonable range and accurate enough between HP and LP to be usable.

Even using high quality parts (alps potentiometers) we had to manually measure and tweak the ganged pots at mid rotation.  I don't miss those good old days.


JR
Logged
 https://www.resotune.com/


Tune it, or don't play it...
-----

Bennett Prescott

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 8924
    • http://www.adraudio.com
Re: Lab.Gruppen Lake LM26 Processor
« Reply #15 on: August 11, 2010, 05:43:23 pm »

What I found more interesting is that the latency through these two processors is not the same.

Base latency, analog in to analog out, of the DLP is 1.1ms. For the LM26 it is 1.02ms.
If I turn on "Latency Matching" both processors exhibit a latency of 2.02ms analog in to analog out.

Things get tricky when I use Dante, however. "Latency Matching" does not account for the latency of this interface, so even with it off the DLP is still exhibiting 1.1ms while audio from LM26's analog outputs arrives after 2.69ms. Activate latency matching on both processors and the spread seems to increase to 1.65ms. That may be meaningless in some circumstances, but in many you must be very careful to account for it, and interestingly enough it is twice what Dante indicates to me its latency should be... hopefully it is not variable! I am not using any FIR filters in either processor, so I do not know if latency matching accounts for them as well.

For an exciting visual example of this, here are two traces. This is the same magnitude response as in my post above. The purpleish trace is the phase shift due to the differing delay through each processor, analog in to analog out on both (.08ms). The greenish trace is the phase shift due to latency induced through the Dante interface (about 1.6ms). It gets much worse if latency matching is enabled on the LM26 and not on the DLP, but that would be a stupid thing to do so I certainly didn't do it.

index.php/fa/31988/0/

The good news is I had a great conversation with Josh Evans this morning about these issues, and he has promised to talk to the head honchos about allowing latency matching over Dante, as well as allowing aux outputs to be grouped, and perhaps some other things that would be handy. Until a solution appears, he has told me to "use AES to link Lake processors". I therefore pass this advice on to you.

Oh, also he taught me about how to create modules with variable numbers of aux outputs, which eliminates half of my problems with the Lake processing. I should have figured this out, but this is why it's good to have friends in high places.
Logged
-- Bennett Prescott
Director of North American Sales
ADRaudio d.o.o.
Cell: (518) 488-7190

"Give me 6dB and I shall move the world." -Archimedes

Bennett Prescott

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 8924
    • http://www.adraudio.com
Re: Lab.Gruppen Lake LM26 Processor
« Reply #16 on: August 11, 2010, 05:50:07 pm »

 One final point of interest, here is a screenshot of what the Lake control software says it is doing to my audio. Close... but not quite. I suppose using it as a guesstimate of the -6dB points on my butterworth crossovers isn't as reasonable as I'd hoped. What it's doing in the HF as well is a mystery to me, since the measurement is reasonable while the display is not. Perhaps I need to measure at 96K to really see what's going on in the HF, but I don't have an interface that can do that, and the Lake display sure looks like it's behaving funny before that point.

index.php/fa/31989/0/
Logged
-- Bennett Prescott
Director of North American Sales
ADRaudio d.o.o.
Cell: (518) 488-7190

"Give me 6dB and I shall move the world." -Archimedes

Dan Brown

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 1450
    • http://www.reachcomm.net
Re: Lab.Gruppen Lake LM26 Processor
« Reply #17 on: September 16, 2010, 12:16:20 am »

I should have a pair of them in tomorrow.
Looking forward to it.

I loved my original Lake Contour Pro26 and am sure the LM26 will be every bit as good.
I am glad LabGruppen has picked these up and is supporting the product

The new digital input options are certainly going to be a plus over the original

db
Logged

Franz Francis

  • Full Member
  • ***
  • Offline Offline
  • Posts: 183
Re: Lab.Gruppen Lake LM26 Processor
« Reply #18 on: September 16, 2010, 09:03:52 am »

There are also some training videos on theis website, which can only be accesed by a registered user.

http://training.labgruppen.com/videos/

Franz
Logged

Moritz Nasterlack

  • Newbie
  • *
  • Offline Offline
  • Posts: 4
Re: Lab.Gruppen Lake LM26 Processor
« Reply #19 on: December 09, 2010, 08:00:27 am »

Hello Bennett  Smile

At first, big "Thank You" for your postings about the Lake products! They are VERY interesting and informative!

Short, easy question about the Lake Control software.
Which tablet-PC you are using to control the parameters?
I'm looking for a cheap one  Cool
You have new informations about your HF-"problem"?

Greetings from Germany,
Moritz
Logged
Pages: 1 [2]  All   Go Up
 

Page created in 0.023 seconds with 21 queries.