Axiom Home Page Forums General Discussion Home Theater External Amps - Crown XLS1000 Class Amps

I recently read an M80 review where the reviewer employed Crown XLS1000 amps (200+ watts) to power them. A few readers questioned the logic of using commercial/DJ/nightclub amps for home theater applications due to concerns over noise/hum/less shielding... a little over my head...

I'm currently running a Pioneer Elite SC-35 to power an all Axiom 7.1 set-up, which seems fine, but if I upgrade to a VP180 and add height speakers, should I be looking at separates now? I'm not a fan of Motive but do like Oulaws and wonder if Crown is a decent alternative? Thoughts?

i think the people that down talking the pro amps are doing it either out of ignorance, or snobbery. If you go to crowns website, there are a couple video's of them torture testing a certain line of their amps, every amp goes through the same test, if i remember correctly, each amp goes though 4 or 6 different tests before it is allowed to be sold. One of these tests is a signal to noise test.. i do think that this line is their most expensive amps though.

I would say, if you are not driving your receiver into clipping, then realistically you do not need more power.

So, does your system currently play loud enough for you? have you ever driven the Pioneer into clipping on several channels?

if your answers are yes and no. Then i would tell you to save your money.

However, If you want to i would say there is absolutely nothing wrong with using a pro amp. I also think that going this route is the most cost efficient way to get more power.

There are lots of people using pro amps from Crown,Yamaha, Behringer, Peavey etc etc very successfully with all sorts of speakers. In fact its quite a popular route to go. It is true that fan noise might be an issue, however depending on the popularity of the unit in question you choose they are a lot of DIY guides about replacing the fans on many of them.

If you have the M80's and thinking about the VP180, if there are any speakers that can take advantage of more power it would be them. A well designed pro amp will be able handle low impedance speakers like the 80's and VP180 at high output levels with plenty of headroom to spare unlike a receiver.

I agree with Dakkon and it is a very cost efficient way to get lots of power not just a measly 100 watts more.

Add QSC to the Doc's suggestions above, they too may/may not need a quieter fan mod. Keep in mind, you'd likely void your warranty once you open up the unit. the GX5 was used by a member who used to frequent the boards not too long ago(with a combo of PSB/Axiom speakers).

You may want to contact QSC directly and ask them about such a mod. I'm sure I read somewhere on another forum that they did this for someone who wanted a quieter fan for HT use.

TJ, welcome. No, it's highly unlikely that there's a good reason to be looking at other amplification, including a separate amplifier. Your SC-35 has quite a powerful amplifier. The VP180 is slightly above average in sensitivity and should cause no problems. Height speakers operate at relatively low levels and are easily powered by what you have.

I agree with JohnK and the others, your Pioneer is a top notch avr and is more than capable of driving the M80s and a VP180. There are some gains to be had by going to an external amp whether or not you feel it is worth the added expense is up to you.

in my case, my pro amp has all the same qualities as a good audiophile amp, i.e. it is transparent and makes no hum or noise of any kind, except the fan which i hear only when there is no signal coming out of the speakers.
i thought about replacing the fan, but as i never hear it when something is playing, i thought it would not be worth the time and effort. also, this would most probably void the warranty.

mine is built like a tank and costs very little for it's output capacity.

I keep getting tempted to buy a pro amp, remove it's case, and buy or build a new case that is HT-friendly with a bigger, but slower fan.

How many people would pay $200 more than the cost of one of the pro amps to get the same reliability & hundreds and hundreds of WPC output, but in a "normal" looking case with no fan noise?

$200 more? Hmm. Maybe $100.

You'd still be getting a nice looking, reliable amp that might be rated for 400 WPC for maybe $700....

Would you go $175?

You know how cheap I am. $125.

That's a very interesting idea, Mark.

It's funny that you guys are talking about this.

A few days earlier, Chris and I had the same discussion at lunch. The watt/$$ ration is absurd, therefore, what? I don't' know.

We were thinking we should audition one and see how we feel.

There are a lot of competeing brands out there, most with similarly low prices. Oh, I'm sorry, the new, more complicated term for "prices" is, of course, "pricepoints." Duh.

It's not like they've been a secret. However, if listeners like us would be happy with them, then zillions of other people would have already found that out and whoosh!-- no more Outlaw, no more Emotiva. Right?

I am still really interested in finding out. However, it would be dangerous for me to go into a Guitar Center without buying a new keyboard and a Hi-Watt stack.

I know those amps are commonly used by large venues to power stage monitors and the like, but they don't have to be that clean to do that well enough. Hmmmm?

Like the vast majority of this equipment nowadays, it is manufactured in totality or at least the innards at a minimum, are from China. I think one would also have to take in to account that Crown is part of the JBL/Harmon conglomerate so there is a long history there. Yamaha, for example has a separate professional division with power amp models, however, it would be interesting to know whether or not there is any direct or indirect design connection between these units and their AVRs because, unlike the Crown stuff, their power amps certainly aren't cheap.

As an old guitar player myself, like Bob, my only concern would be in using such equipment in an A/V application, is how would the noise floor compare to a quality A/V amp? Used in a professional/live application, realistically, noise nor extended frequency range is of much importance especially when cranked up. One is certainly not going to connect their system to a Hi-Watt stack and expect it to sound any good.

Having said all that, I have never tried one, so in all honesty, I wouldn't know until I connected one to hear if there is any meaningful difference and how it would compare to electronics designed specifically for A/V use.

I've been tempted to buy a "pro" amp a number of times, but have wondered about the noise floor, etc... as well.

If the "specs" of that "pro" amp are equal to an HT amp, then what allows it to be SO much less expensive? Manufacturing volume? Competitive market? Lower markup?

This is the Crown that I keep going back to: 775WPC, Stereo, @ 4 Ohms and 440WPC, Stereo, @ 8 Ohms. I mean, if you're going to see if increased power makes a difference, why only go a bit above my Denon Receiver? I also like that it has RCA inputs and can take banana plugs on the outputs for convenience. $600 with a full, 3-year warranty. How can you go wrong?

As much as I like the idea of the Outlaw monoblocks, for the same cost, they only offer me 200 WPC at my 8 Ohms... not a huge difference from what my Denon is giving me now.

Now, take that Crown amps' specs and stick it in this case. NOW how many people would pay $800 for that product?

one of my amps is a proamp: QSC GX5, and at full gain, there is a bit of noise IF one puts his ear near the speaker; when i lower the gain (sensitivity) by about 6 dB, then it's totally quiet.
My other amp, a Hafler 500 was a proamp; those sold for house use did not have any sensitivity pots, but the pro ones did. That was the only difference between the two.

one only has to check specs to see that they're as good quality as excellent home audio amps and, for the price, they're a bargain.

a plus is the fact that the standard warranty is 3 years, and if you register your new amp at QSC, you get a 3 year extension.

if you have a question about using the QSC amps, usually it's the chief engineer who answers you on their forum.

Exactly.

JB: Quebec isn't that far from Concord, NH.
If I do my part by sending you a nice blanket to wrap it in, can you drive it down to Mark's for us to hear?

Mark, you free tomorrow?

sorry, but i don't have a car...but i do have blankets.

the amp has no sound of its own (it sounds exactly the same as my other amp), but it's a perfect feed for M80's, specially in my small room, where only a fraction of the potential power is used.

It really makes you wonder how they can do it? Just looking at the amp you provided the link to, you can't even buy an HT amp at any price that comes anywhere near that type of power yet alone for $500 bucks and its Class D configuration which is generally much more expensive and only 10 pounds!

I would love to have an experienced electronic engineering type who has expertise in this area offer an explanation for the BIG difference in price.

I think that audiopiles will tell you that Class D amplification isn't as creamy as Class AB. Or something.

The engineer would be as puzzled as you. You should probably talk to the marketing guy.

No, but these days, it seems they are.

The amp I have most recently seen bench tested was the new Peavey IPR 1600 and it plays clean. Fan noise when not playing program material was the only issue. Well, there were the screaming blue LEDs on the front panel, but electrical tape would take care of those nicely.

The Peavey is a solid amp.





To the OP here is a master list of pro amps that have been put on the bench.

http://www.avsforum.com/avs-vb/showthread.php?t=855865

1% distortion is pushing the limit of being audible and many of the 'pro' amps are spec'd out with higher distortion levels than this 1%. I have seen a few as high as 3% and a few more higher than that so you have to be careful and watch those little details.

most of the time, if one decreases the signal level by 1 dB or less, the distortion then decreases in dramatic fashion.
amps can produce 10% distortion easily by overdriving them.

when i was shopping for a proamp, this Crown XLS2500 amp was in my (very) short list. I opted to buy the QSC GX5 instead, mostly because of the price difference.

i totally agree with you, big and heavy and stylish costs huge amounts of money to produce, and audiophiles are ready to spend much more on distortion numbers that are 0.0001% less than the competition, or on class A amps that heat your house, or just on style.
check on the Musical Fidelity AMS100 amp, a huge 110 Watt/8 Ohm beast that's 1 meter deep and weighs around 100 kg. and, sitting idle, comsumes 1000 Watts; for the weight and size and price, it should put all other amps to shame sound wise.
on those kind of products, the marketing guys get a high fever.

what happens is, i think, that those pieces of equipment sell in so limited quantities that the prices must be very high to compensate.

it so happens that engineers know how to make excellent amps since the 70's, when Otala found the solution to TIM, and nobody can tell if one is better than the other in double blind tests.

I looked at the QSC as well, but the fact that they spec the power @ 1kHz (only) bothers me:

QSC power rating:

8 ohms / both channels driven / 1 kHz: 500 W

4 ohms / both channels driven / 1 kHz; 700 W

2 ohms / both channels driven / 1 kHz: 350 W


The Crown is rated for 440 WPC, both channels, 20Hz-20kHz, while the QSC is rated @ 500 watts at 1kHz. For all practical purposes, I'm sure they put out the same power.

But I'm bothered by the non-standard way QSC specs it out. It reminds me of the old days of hugely inflated power ratings in car audio because they weren't given in standard terms.

It doesn't mean the QSC is bad, I just don't like their deceitful (IMHO) marketing of the power.

why not go on their forum (http://forum.qscaudio.com/forum/) and ask for clarification.
they don't have PR's giving the answers, but an engineer; then you should be able to make a better decision.

Mark, you might also check out the QSC RMX2450 currently at $600 on AMZ(with 15% promo included). It specs out very well down to 2 ohms....aparently this is the amp that Behringer copied on their EP4000 at around $300-400USD.

All those in favour of Mark buying a Pro Amp say "Chowdah"!

BTW, connectivity is an issue on some pro amps and should be considered too.

Look at the Behringer EP2500 into a 2 ohm load!

Yes, if you can believe those specs posted at AVS (and I see no reason NOT to), those amps seem capable.

Chowdah.

The guy that does those amp measurements on AVS I think was a Crown technician at one point?

The methodology seemed sound. I thought the data was pretty compelling, and I appreciated the referral. I can't handle spending time on AVS, so it's great when someone actually identifies the relevant stuff that I can cherry-pick. That Behringer sure seems like a good value and a solid performer.

Great looking specs but wasn't there some sort of issue with those Behringer amps a few years ago?

I don't remember if that is one of them. That model number is different than what they are currently selling today. We (myself included) like to bash Behringer because of their reverse engineering but I can't deny they put out some unbelievable value products.

Their highly touted Behringer 2030 speakers are said to be a ripoff of some Mackie monitors.

Not the EP4000/2500. It was the smallest amp in that series that had some issues in the mid range.

Tom only likes the Behringer, 'cause it's the fake last name he's gonna start using when he's through with "Tuttle."

Funny, I was going to choose Parasound as my fake last name.

That's odd. I was going to go with Goobersnitt.

Unfortunately, Ken, Tom appears to be a star-effer, so if you want him to still be your friend, I'd go with Burns or "And Barbie."

I will hunt you down like a dog and stab you in the face.

I didn't get it at first, but now I think I do. You simply want to hunt me down like a dog and stab me in the face.

I guess I was reading into to it too deeply.

I promise not to do that to any of your posts again. Sorry.

Edit: I'm kidding. I got it. I'm printing it out and putting on the fridge door, about 24" off the floor, so MR. Watson can have a snortle whenever he trots by and reads it.

Bob, . Thanks.

It may have actually been my review on Home Theater Shack. Since the M-80's and VP180 are 4 Ohms the Crown actually pushes 350 watts per channel at 4 ohms. At $300 new there really isn't a less expensive solution for pushing a lot of power and the Class-D runs cool with no audible fan noise or hum. I have tried a lot of different power amps from Emotiva, Wyred4Sound and Outlaw and while there may be some measurable difference, not that I have found any myself, it really came down to a matter of cost. I love the Class-D sound and liked the Wyred4Sound amp a little more than the Crown XLS1000, but not $1100 more....

Very glad to have read your response,and original review!

I didn't see much benefit in moving from a 140 watt/channel receiver to separate amp offering 200 watt/channel but I forgot the ohm difference. 350+/channel at 4 ohm would be noticeable. Silly question though, was that Crown XLS1000 amp one channel or two channel???

it's a 2 channel amp.

you can see the specs here: http://www.crownaudio.com/amp_htm/xls_drivecore.htm

TJ, 350 watts wouldn't be "noticeable" unless they were actually being used by playing louder. Since it's highly likely that the present amplification can already easily handle all safe(to your hearing)sound levels, playing even louder wouldn't be a good idea. Also keep in mind that the 140 watts would also see an increase into 4ohms to something over 200 watts.

My Denon 3808 pushes about 240W into 4 ohms according to a lab test that was done when it was first released, where is that link.........

Was that with one channel driven or both, Jay?

Both. Still looking for that site.

Found it here