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Discussion Starter · #1 ·
I am considering adding some amplifier(s) to my set up. I currently run UMC-1 and Sunfire TGA400 into JTR Noesis 212HT (101db/w/m) for LCR and two Def Tech BP1 (I think that is the model, small bipolars) as surrounds. Just for reference I also have 1 JTR OS and 1 Epik Empire and two Velodyne SC 12 subs.


The main reason I would add additional amplifiers if for music listening. The bass output is matched very well right now for my current set up and I do run the bass about 6db hot. It is quite possible I will add another JTR OS if I am able to get much higher clean SPL with an additional amp on the front stage.


Anyways I notice at very high spl (I'll take measurements tmrw) from 25 ft away in my 14x33x8 room the sunfire can be brought to a point where it loses a little control of the music and then any more volume and you get noticeable distortion. Now granted these levels are very high and I don't listen that loud for sustained times (no more than one song at a time with a break), but I want to take it to another level and I may move the rig outside in my backyard for a party or two in the summertime.


Does anyone one have opinion on what option might be better for the amplification. I am considering either a Lab Gruppen FP10000Q (not a clone, the real deal) for $3700 or 3 brand new Crown XLS 2500's for about $1800. Will the Crowns come close to the LG?
 

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Discussion Starter · #2 ·
those look like nice amps too. I am not too worried about the 30a requirement of the LG because I can have that run easily in my system. I just really question whether 3 crowns at $500 a piece will deliver like a LG FP10000Q, which costs of $6000. I know the old saying you get what you pay for definitely does not apply in audiophile equipment but I would think pro audio is more no nonsense. I only need 3 channels so the crowns seem like less waste of a channel. Just hoping someone has experience with both. May have to visit the pro boards.
 

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I know this is an old thread... but I just want to chime in since I have both of these brands running in my home theater.

The PLM 10000Q version of the Lab Gruppen that I own will eat the Crowns for breakfast in terms of overall power without even breaking a sweat. With the "all-in-one" box however comes SUBSTANTIAL power draw if you are doing a massive subwoofer setup. The unit actually requires a 30amp or more breaker setup. The multiple Crowns would not have this problem since you could run the amps on separate 20amp breaker circuits (which many home theaters have already).

The PLM's PEQ is downright excellent and wouldn't surprise me if it was "best in class". It is impressive and is laptop controlled using the software that the company provides. Unfortunately they don't have an IPAD app for the PLM class amps like they do for some of their other installed amps. This is a definite oversight considering the price of these amps.

Ebay seems to consistently have Lab Gruppen amps at good prices which I would strongly consider for home theater enthusiasts.


Having said all this, some issues to consider:

1. if you have outboard PEQ which is very good for subwoofer adjustments, then skip the PLM.
2. If you don't have enough power out of the wall, skip the 4 channel Lab Gruppen amps... go for the 2 channel lower powered ones.
3. the Crowns are very easy to offload on ebay compared to the lesser known Lab's. I know this since I watch ebay listings and these move substantially slower. Crowns are also easy to find on ebay as well at used prices.
4. If you use your subs very modestly and don't need high power, then the crowns will often be sufficient.

My Lab Gruppen amplifier is likely running at about 20% of max capability even during movie subwoofer duties. I am running 4 channels at 2ohms each, with each subwoofer box containing two 15" drivers in a sealed box.

I wanted an amp that would NEVER falter in peak output and likely never fail. I wanted my speakers to be the potential weak link if there was ever going to be a weak link... I wanted to never require an amp "upgrade" EVER again for subwoofers.

The PEQ in the PLM, once dialed in for my 4 in-wall subwoofers, NEVER HAS TO BE ADJUSTED AGAIN... even when I get a new surround processor. The subwoofers are dialed in FOR GOOD and don't have to be adjusted for new main speakers or anything else. Once the PEQ is setup on these subs, any new processor's room correction software barely has to do anything and simply has to adjust crossover points. Even a new owner of my home theater room would not need to make any other adjustments ... they are saved "For good" as long as nobody messes with the software.

The Lab Gruppen is worth every penny of the approx $4500 price tag I paid in the used market for it. It BLOWS AWAY the build quality of any junk you might buy from Denon, Marantz, Integra, Onkyo, etc. as well as 90% of the crap you find in a "high end" audio store. This thing will power concerts in the biggest stadiums in the world and will put most pro amps to shame with few exceptions. It will EASILY handle your "home theater" subwoofers.

Having said all that, it is NOT perfect for pure stereo playback or surround speaker duties. My high sensitivity 109db horns hiss BIGTIME when connected to this amp. This amp is made for PURE POWER and not necessarily critical listening. The noise floor is not sufficiently low for high sensitivity speakers in a highly noise controlled environment. I DO NOT advocate this amp for routine music or surround sound use ... besides, the power is tenfold excess SERIOUS OVERKILL for any typical speakers in a normal room.

Lab Gruppen's PLM 10000Q might be the last rack mountable subwoofer amplifier you will ever buy for any sane subwoofer setup that most folks have. If you need EVEN MORE power, go for the FP 7000 series for each pair of subwoofer speakers that you own or the PLM 20000Q with a 40amp breaker circuit.
 

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I forgot to mention, the Lab Gruppen has another "flaw" in that it is designed to run with fans and therefore is not silent by any stretch of the imagination. It isn't even silent by projector standards.

You definitely don't want to use the Lab Gruppen or Crown amplifiers inside the listening room.

There is also no 12volt trigger or any way to automate their on/off (except for Crestron owners apparently). I end up leaving mine on and wasting power. The downside to that is the fan keeps running and making noise regardless of the apparent temperature of the thing. Eventually dust clogs the dust filters on the front of the device and they need to be cleaned.

Amplifiers made for "home theater" don't really reach these power levels without paying even more per channel. The Speakerpower rack mount amplifiers are sufficiently or more powerful but also don't seem to have 12volt triggers. They also having fans. Eventually the fans on the Speakerpower will likely clog with dust due to the lack of filters unless these fans only turn on during overheating. The Speakerpower amps also look kinda downright ugly unless you are into that sort of thing.

If anyone else has any other suggestions for high power home theater subwoofer amps, I am all ears. Powersoft products are also very high wattage but also lack home theater on/off capabilities as they are also pro-amps.
 

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Discussion Starter · #5 ·
I did end up going with Lab Gruppen. I may not have been very clear but I was asking for use with my mains (LCR). My subs are horn subs by JTR and they already have the Speakpower amps integrated in the design. I ended up getting a LG10000Q for use with my mains which are JTR 212HT's which I use for 80hz and up. They are rated at 101db sensitivity but other have measure and find them closer to 104. I have a dedicated 30amp line for the amp and it is almost dead silent even at the +35dB gain setting (I actually lowered it to the 32dB gain setting). Great amp as long as you run in a separate room, does not have the same features as the PLM but I am using other PEQ and Dirac room correction so not really needed.
 

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I did end up going with Lab Gruppen.........


Congrats on the new amp.

I'm confused though. You must have the most sound absorbent room ever created. Those JTRs with 101db sensitivity running off that Sunfire should be able to make your ears bleed and it wasn't loud enough for you? WOW. You must really like some serious SPL! :)
 

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Yeah really... The lab gruppen 10000 is WAAAAY overkill for home theater for main speakers at that sensitivity!

In a home theater setup i can only imagine using that amp for subwoofers.

That amp will probabaly destroy the speakers sooner than your ears can bleed... It is meant for a stadium... Lol
 

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Yeah really... The lab gruppen 10000 is WAAAAY overkill for home theater for main speakers at that sensitivity!

In a home theater setup i can only imagine using that amp for subwoofers.

That amp will probabaly destroy the speakers sooner than your ears can bleed... It is meant for a stadium... Lol
So what amp would you recommend for those speakers? (something not overkill)
 

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Sorry for the late reply, but I would say that speakers above 100db sensitivity really depend on very quiet noise floor amps. This can be hard to judge based on marketing paperwork from the manufacturers.

Very good brands such as Parasound and Pass Labs will do a great job in having a low noise floor and excellent sonic properties overall. You probably only need around 100-200 watts for a home environment for speakers of that sensitivity.

I am seriously considering going with a Hypex Ncore based class D amp with my speakers soon to try out how well it works. NAD is one company makes Ncore based amps that you can buy. The reviews on these amps are really great.

There are many different applications where different amps might be used ... it kinda depends on your setup. I really don't think Pro amps are that great for ultra-high sensitivity speakers due to their ambient hiss... its quite annoying. Perhaps people that work in stadiums and nightclubs won't notice the hiss. At home the hiss is definitely noticable from lab gruppen's amps as well as Crown amps that I have at home.

My Pass Labs amp, while expensive, is straight up excellent with high sensitivity speakers. They make class A amps less than 100 watts that work really well with high sensitivity speakers.

Unfortuntately most amps will give you a signal to noise ratio stat but this often does not accurately reflect the amp's baseline hiss in my experience. This is true for pre-amps also. My Marantz 8801 pre-amp for example REQUIRES XLR attenuation pads in-line with the amp or the hiss and hum from the pre-amp is quite loud with my 109db sensitivity speakers.

Horn loaded speakers are efficient (don't require much power usually) but also are very revealing of defects in amps and pre-amps. I suspect this is at least part of the reason people have a crappy experience with horn loaded or compression driver horn loaded designs.
 

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Discussion Starter · #10 ·
the lab gruppen on a dedicated line is dead silent on my JTR's even when the gain is at 35dB. Much quieter than my Sunfire TGA7400. The lab is a great choice for mains. Porbably more power than anyone would use in HT (except a few):)
 
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