# New Equip: Lab Gruppen PLM10000Q with Lake Processing



## Chester (Feb 19, 2007)

Hey, I believe I am the only person who has ever mentioned the Lab Gruppen PLM10000Q on here; probably most people do not know about the existence of this amp, which is easiest to describe as a Crown I-Tech HD amp on steroids  Basically it is 4x 2350 watt amps (@ 2 Ohms), with 96kHz Dolby Lake processing integrated into the box... the analog inputs have a dynamic range of >114 db; the digital In's are >116 db... but the truly great thing is that EVERYTHING (after the ADC conversion, assuming you run analog) is digital; my prior amps were 2 Crown K2's (this amp is ~4 K2's in wattage), processed by a Crown USM-810 (24 bit, 48kHz signal path on USM)
To look at more specs check out their site: http://labgruppen.com/products/plm_series_touring/

I HIGHLY recommend this amp to anyone, even without EQ (after I setup only the crossover) the stereo field is now incredibly precise, vocals sound like they are coming from dead center between the speakers, cymbals and other high frequency sounds are also much better 'placed' in the stereo field. I really could have run everything without a house curve or any EQ at all! I had been using an amplifier per channel with the K2's so I attribute the improvement largely to the entirely digital nature of the signal path in the amp (though I am running analog inputs right now). The Lake processing is FIR processing, so you can add up to 256 filters to each (input) channel, and the software takes the overall response of the filters and makes "one eq curve" which is applied to the sound, you can also implement linear-phase crossovers (there is some delay with the linear phase crossover... I am running one at 80 Hz (48 db/oct) and it requires a 20 ms delay, at 125 hz I could move to a 10 ms delay...) however I look at this as 1.2 'frames' of a 60 hz video display... not too bad  There are also IIR (traditional) parametric eq filters [with nonlinear phase characteristics] that can be placed on each of the outputs, ~20 between the high and low outputs (for each input channel), depending on the types of crossovers you have running.

Be sure to look into the Raised cosine EQ, and the Mesa EQ filters (available on the Input EQ, applied to both channels of crossed over audio) which are quite cool, basically they [raised cosine] are a little different than a 'typical' parametric eq due to their ability to precisely control one frequency region... they do not have the "tail" on either side of a typical parametric EQ's response. Here are some images to give you an idea of the Lake processing (these images are from a control program for a Mackie DSP card that uses Lake so the software is slightly different than what the Lab Gruppen amp uses:








The above image shows the 'speaker' Output EQ, the parametric filters are the 'typical' variety (IIR Bi-Quad), note the 'tails'








This shows the Mesa EQ functionality, the filter at 406.5 Hz is a 'Raised cosine' filter, note how its response is much more limited to near the center frequency (no 'tails')








Here is what Lake calls the "Ideal Graphic EQ", this is a good example of the raised cosine filters also, typically in (most) graphic Eq's, a the response will not follow the peaks of the filters, with the raised cosine filters (that affect only the specified bandwidth) this does not happen, the grayish line showing the actual response passes through the peaks of each filter.

I have found that a VST plugin I use (Electri-Q) at www.aixcoustic.com is very useful for 'converting' the response of a bunch of traditional parametric filters to 'raised cosine' filters if anyone would have the desire to do so, basically you input (with traditional filters) the response you want, then use a bunch of what Electri-Q calls Sine^2 filters to cancel the response... just 'swap' the gains on the Sine^2 filters to get the values for the Lake software  Another cool thing is that the Lake software allows for EQ filters from 15.63 Hz through 40.3 kHz, so you can EQ your sub and speakers very precisely 

There are lots of monitoring features built in, I believe there are between 6 and 10 temperature sensors inside the unit; with data on the speakers being used, the amp will predict the voice coil and magnet temperature to keep from burning out speakers; pretty much every protection I can think of, it has...

If anyone has questions about the PLM10000Q or Lake processing, let me know and I will do my best to explain, Lab Gruppen (who recently bought the rights to Lake from Dolby) is soon coming out with a processor called the LM 26, a 2x6 1U rack-space unit that will preform Lake processing, I was told by a dealer that they will be MSRP ~$3k

I do need some help though... the amp has fans that constantly run (though they are variable speed and are relatively quiet), if anyone has any ideas/suggestions for building a box (I am thinking Plexiglas) with sound adsorption in it (but separate in/out airflow sides) to adsorb the fan noise, I would appreciate your input 
Here are my pics so far, it was difficult to get a good picture of the screen...


----------



## recruit (May 9, 2009)

Wow matt some serious processing going on with Dolby Lake and some serious $$$ also, have heard great things about the EQ of Dolby Lake and believe they use this technology in most theatres, I bet sounds it awsome :T


----------



## Chester (Feb 19, 2007)

The lake processing is awesome, I have been running a linear phase crossover for the past few days and notice that the mid-bass is much 'tighter' (I hate using subjective terms like that) and the stereo imaging, even on 'lows' is much better... The sound is incredible  I still need to figure out the whole amp silencing thing though


----------



## Ricci (May 23, 2007)

I'm glad you like the amp. Looks nice. I suspect that there isn't as much talk about the LG, Powersoft, or Hoellstern amps due to the $$$$ involved. A little too rich for me and most others to justify spending on one for home use.


----------



## Chester (Feb 19, 2007)

I can understand what your getting at with the price issue; I have found that when I am really "into" something (a hobby/subject) my goal always ends up being to do/create/build *the best*, usually that is achieved through countless small upgrades 'to the next level' for different components... 

-Initially I was just using as many computer speakers as I could hook up and splice into my source channel... I had a lot to learn at that point 
-first it was using my computer (kX drivers) as a crossover for a pair of car audio amps powered by 2 radioshack 25 amp (13.8 volt) power supplies, powering a pair of 6x9 (car audio) speakers and a pair of 15" car audio subs in a sealed box
-then I built a sonosub of 10.63 cubic ft, tuned to 22 hz (I believe that was the tuning frequency)
-then I got some klipsch synergy sb-1's
-then I got crown k2 amps
-around the same time i added a dbx driverack pa (crossover/processor)
-then I got/built a JL audio 13w7 subwoofer
-then I upgraded the processing to a USM-810 (lots of parametric eq's and crossover functionality)
-built a pair of Lorelei (DC Gold audio) prototype speakers
-built the DC Gold N7R speakers (the steel enclosure ones)
-Lab Gruppen PLM10000Q (processing/amp all in one)

The more I advance my knowledge, the more I end up 'upgrading', which is what made the PLM10000Q an easy choice: it is *the best* amp and processing I could find, around the USM-810 area in the 'timeline' is when I realized it would be a lot cheaper in the long run to just get what I consider to be *the best* right off the bat instead of upgrading, since (eventually) I would probably upgrade in the future anyways  This way, more of my life is spent using *the best* and being content, instead of obsessing with making things 'that much better'. I realize that most people do not necessarily share my philosophy...

The PLM came out to market in September 2007, which is about the Lorelei build in the the time line, so even if I wanted to I could not have gotten it when I started out; plus I had not heard of Lake processing till 2007 anyways 

Anyways, the only other changes/upgrades I can conceive of doing in the future are maybe building a sub with a TC Sounds LMS Ultra subwoofer, and changing my adsorption on the walls to rockwool panels (and thinking the adsorption placement/room acoustics through a lot more): I have a relatively good understanding of room acoustics however I have not yet made as great an effort (as with the system) to tune the room. After that things will be what I consider to be 'the best'... then I will need to find a new hobby I guess :/ 

I am all for saving money though, I got the amp at ~60% the MSRP (new), and if I could have built one myself to save even more I would have, but I am not and electrical engineer and highly doubt I would be able to singlehandedly build something comparable (all the same functionality) within 10 years time


----------

