Lab.Gruppen E 4:2 Pro Amplifier Review

[amirm]

manual is here: http://www.marketing.labgruppen.com/webservices/dh.ashx?t=qv&v=8798

View attachment 70025

Power = I * I * R. Using 14 amps per channel we get 784 watts so that is not the limit.

 

[amirm]

Just found those measurements of 1200w E12:2 model.
Same conclusion than @amirm.
A lot of additional explanation, though, as this is written for pro users.

But bottom line is clear:
"The E 12:2 is marketed as a “1200 watt” amplifier. With regard to the “heating power” of the amplifier (the best measure of output power when driving a resistive load), it’s no where near that. It’s more realistic to think of it as a 50 V or 70 V amplifier designed for use with high crest factor signals. The limiting circuitry prevents an overload condition that could damage the amplifier. The matrix makes it clear that it is still better to not load the amplifier below 8 ohms if one requires high fidelity for low crest factor signals, especially at low frequencies with both channels driven. This is not a subwoofer amplifier."

Now that is really bad. Even consumer gear puts some disclaimer in there like "peak power" and such. Lost a lot of respect for the company just now. It is not like this is a $199 amplifier.

 

[Rja4000]

Never heard of a Swedish company with audio expertise.

You may have been listening live music through one of those without knowing though.

Last time I've been listening to Norah Jones live, they were using Lab Gruppen amps.
And, I can tell you (I was sitting 3 meters behind the FOH mixing desk), the sound was really amazing.

 

[Rja4000]

Now that is really bad. Even consumer gear puts some disclaimer in there like "peak power" and such. Lost a lot of respect for the company just now. It is not like this is a $199 amplifier.

Well, thank you again Amir.
We learned something today.

 

[Vini darko]

Skytec Watts strikes again.

 

[carlob]

Power = I * I * R. Using 14 amps per channel we get 784 watts so that is not the limit.

yup, can't be that.

 

[Rja4000]

Now that is really bad. Even consumer gear puts some disclaimer in there like "peak power" and such. Lost a lot of respect for the company just now. It is not like this is a $199 amplifier.

At least, in the manual, the power consumption table is clear.
Can we expect 400w continuous power for an amp consuming 90W from the mains ?

 

[Vini darko]

At least, in the manual, the power consumption table is clear.
Can we expect 400w continuous power for an amp consuming 90W from the mains ?
View attachment 70029

That table doesn't paint a pretty picture of efficiency for class D design. How old is this amp?

 

[amirm]

At least, in the manual, the power consumption table is clear.
Can we expect 400w continuous power for an amp consuming 90W from the mains ?
View attachment 70029

That's another confusing chart. It says you only get 50 watts out per channel with 4 ohm load! This thing is a disaster with documentation and performance.

 

[Rja4000]

That table doesn't paint a pretty picture of efficiency for class D design. How old is this amp?

Fans are also consuming power.

 

[GXAlan]

Now that is really bad. Even consumer gear puts some disclaimer in there like "peak power" and such. Lost a lot of respect for the company just now. It is not like this is a $199 amplifier.

Disappointing, indeed. This was also a 2011 introduction so one cannot blame “new owners” either.

I think there has been so much turnover in the audio electronics industry and margins that are razor thin such that you no longer have preservation of an engineering culture in many larger companies producing high power

You have Benchmark.

Accuphase is one of the few companies that seems to have preserved an engineering culture. They like to brag that their company has about the same number of engineers since they started and even though their products have not been recommended here, they are very honest and reported that balanced SNR is worse than unbalanced SNR.

If you ignore their tube line, McIntosh’s core solid state amplification line does seem to be consistent and Stereophile reviews have been pretty good. But they do have their tube line.

Parasound and Bryston may also be good companies to look at.

It would be interesting to see how different Crown amplifiers fare, and if the new “budget” Mark Levinson Amps are good.

 

[turbotuff]

I keep hoping to see a test of an older Crown AB amp, such as a Macrotech. I would send mine in, but shipping would cost more than the amp is worth lol.

 

[Vini darko]

Fans are also consuming power.

Ah yes I hadn't thought about the fan.

 

[GXAlan]

Ok. Lab Gruppen is officially on my do-not-buy list.

https://cc.bingj.com/cache.aspx?q=l...lang=en-US&w=i7ky-mYrlFUJ8X7iVwNYrXZCoLpYjGuR

If you search lab gruppen caution, you will see someone posting on the official forums that the E series seems underpowered for their JBL M2. That post is removed from the forums and you can only find it through a cached copy...

 

[amirm]

Wow, it goes from bad to worse...

 

[F1308]

You may have been listening live music through one of those without knowing though.

Last time I've been listening to Norah Jones live, they were using Lab Gruppen amps.
And, I can tell you (I was sitting 3 meters behind the FOH mixing desk), the sound was really amazing.

That might turn out to be the final measurement: you like it, let it be.

 

[pozz]

Ok. Lab Gruppen is officially on my do-not-buy list.

https://cc.bingj.com/cache.aspx?q=l...lang=en-US&w=i7ky-mYrlFUJ8X7iVwNYrXZCoLpYjGuR

If you search lab gruppen caution, you will see someone posting on the official forums that the E series seems underpowered for their JBL M2. That post is removed from the forums and you can only find it through a cached copy...

To quote in case it goes missing:

2020-04-24 11:38 AM

Lab Gruppen E Series Caution

Recently I purchased three JBL M2 Master Reference Monitors for L-C-R in my 5.2 mixing room. The M2s are typically packaged with a single Crown iTech HD5000 amp for each loudspeaker- one channel for the tweeter, one for the woofer. These amps contain presets for crossover and speaker tuning with onboard DSP, as the M2s have no internal electronics. I use a JBL Intonato monitor controller which has the DSP presets for the M2s as well. That allowed me to choose different amplifiers. After a lot of Internet research I settled on the Lab Gruppen E 12:2 amps. Bridged they are rated almost the same (1200W vs 1250W) as the Crowns. They are quiet and efficient and carry the Lab Gruppen reputation- exactly what I was looking for. I bought six- one for each driver. I soon realized though that even at 1200 watts per driver, the M2s felt underpowered. I visited another studio outfitted with the same speakers but also with the Crown amps. Something was definitely diferent. I searched the web again and *finally* found an explanation in a SynAudCon white paper (https://www.prosoundtraining.com/2019/09/27/common-amplifier-format-lab-gruppen-e122/) dealing with the E 12:2s. Measuring the amps, they found that the 1200watt power rating was more than a little misleading. They can output their rated power only for a matter of microseconds! They conclude:

"Given the above two scenarios, is this a 600 W amplifier that limits on a sine wave, or is it a 125 W amplifier with 4 dB of “dynamic headroom?” One could make a case for either. I guess it depends on whether one is selling it or using it. "

Well I'm using it. Actually, I'm using a half dozen of them. Lab Gruppen has a great reputation for building high quality, reliable amplifiers. It's too bad the marketing department doesn't live up to the same. I'm going to replace them in the very near future, but I'm hoping someone has a recommendation for amplifiers that provide similar power to the Crown iTech HD 5000 (1250 wpch @8 ohms) without the added expense of the DSP which is redundant to me. Do all Lab Gruppen amps have misleading specifications, or are the E series the only ones claiming nearly six times their actual output?

 

[boXem]

Ah yes I hadn't thought about the fan.

Boh, in this case there would be a constant offset appearing at some point. And the losses would not be *that* big. I would more look on the power supply side.

 

[Rja4000]

Disappointing, indeed. This was also a 2011 introduction so one cannot blame “new owners” either.

I think there has been so much turnover in the audio electronics industry and margins that are razor thin such that you no longer have preservation of an engineering culture in many larger companies producing high power

You have Benchmark.

Accuphase is one of the few companies that seems to have preserved an engineering culture. They like to brag that their company has about the same number of engineers since they started and even though their products have not been recommended here, they are very honest and reported that balanced SNR is worse than unbalanced SNR.

If you ignore their tube line, McIntosh’s core solid state amplification line does seem to be consistent and Stereophile reviews have been pretty good. But they do have their tube line.

Parasound and Bryston may also be good companies to look at.

It would be interesting to see how different Crown amplifiers fare, and if the new “budget” Mark Levinson Amps are good.

You can't really compare.

The amp under review here is a pro installed sound amp.
As I explained above, the goals and priorities for such a use case are light year away from HiFi.

That doesn't excuse the lack of transparency regarding the actual output power of the amp.
But that's about all that could be put on the negative side here.
(And, even if that's important, to be fair, the pro users have a tendency to NOT trust specs anyway, and to try some samples in real life before committing to any serious investment. So they probably do care less.)

So, in short, you can't compare that to the amplifiers you are listing.
First they couldn't drive 70V or 100V lines. Second they most probably wouldn't survive half of what the typical "installed sound" amp will have to survive during its (long) career.

We're all p... off by the lack of transparency.
But let's not confuse things.

 

[Rja4000]

Boh, in this case there would be a constant offset appearing at some point. And the losses would not be *that* big. I would more look on the power supply side.

I don't know.
The more power you have to produce, the more heat you'll have to dissipate. So the more power would be needed for fans.
If you look at Purifi specs, the yield is lower for 4 ohms. So you need more heat dissipation.

Remember those beasts are supposed to be stacked and to run continuously (potentially 24x7), probably with highly compressed music content, so ALL heat will have to get out through the fans.
I remember something like power consumed by the fan % of cube of flow speed...

That's very different than a typical HiFi amplifier.