Crown XLi 800 Power Amplifier Review

[PaulD]

I think either JBL has documented it or people have figured it out as I know some that are using it with their own DSP.

People figured it out, there is info on the net, but they also admit it's not perfect. I asked Harman and have a good relationship with them (I bought 2 sets of M2s and 24 of the 7 series), they will not release it...

 

[GrimSurfer]

I have a couple of similar amps, the Crown I-Tech 4x3500 in studios, and the fans are too loud even for isolation boxes in a studio and we had to relocate them out of the rooms. To be fair Crown do say this is the case, a point I overlooked . The fan noise of the Crown amps is one of the reasons that the JBL M2 is not suitable for home use, unless the amps can be put in another room, as the xover etc is all done in a Crown professional amp (and they will not release it for others to replicate in another way).

I liked your post, not because it supported my post but because it helps prevent somebody else finding this out the hard way.

Some people do have server/equipment rooms. For them, noise generation isn't a big deal. For folks using general purpose spaces, however, it can be.

It's good when manufacturers are up front about all of this. Crown has a very secure spot within the PA amp market, so I'm not surprised they make things clear for commercial users who tend to take a workman like approach to purchasing.

Many thanks for passing along this observation.

 

[GrimSurfer]

I found this picture of its guts:

I don't see a pot on it to adjust but it may be hidden.

You can see the transistors mounted on inward facing heat sinks, the twin fans behind to draw air across them.

The chassis on these PA amps are usually slim, leaving very little room for convective cooling. Pretty significant power densities too. Not surprising they use fans... likely withvariable speed control too.

 

[PaulD]

I liked your post, not because it supported my post but because it helps prevent somebody else finding this out the hard way.

Some people do have server/equipment rooms. For them, noise generation isn't a big deal. For folks using general purpose spaces, however, it can be.

It's good when manufacturers are up front about all of this. Crown has a very secure spot within the PA amp market, so I'm not surprised they make things clear for commercial users who tend to take a workman like approach to purchasing.

Many thanks for passing along this observation.

Thanks, that's why I posted it. We built new studios last year and as most equipment makes minimal noise now, we dumped the "machine room" that used to house tape machines, console power supplies and power amps. It worked fine except for the M2 amps - I found out the hard way. Fortunately we had corridors next to the rooms we could put the amps in relatively easily. While Crown do say the amps should be in another room, it was buried within the documentation, they assumed a more standard studio setup and we were caught out, fortunately it was a relatively easy fix for us.

 

[Wombat]

My Altecs(1 per side, used up to 500Hz) are spec'd as 98dB per watt @ 1metre.

My Yamaha XP1000 amp spec'd @ 100W per channel.

Active crossover.

I don't expect the fan to run with my use even when listening loudish - 101dB SPL @ 2W continuous per speaker @ 1metre(~93DB @ 3 metre).



Yamaha XP1000

 

[digicidal]

I purchased as few of the earlier generation XLS series for my theater originally. In HT use I didn't ever hear the fan come on - mostly because if it was working hard, that meant I was listening hard... however, you could hear hiss at the tweeters without signal. It was bad enough that I went back to my much lower powered and way less efficient Emotiva amps. I used one for awhile in my office in a cabinet with poor ventilation - and in that location I heard the fan come on several times - despite the case never getting even slightly warm (but it's not thermally coupled to the case so that's not surprising).

If I had a bar or restaurant, I'd happily run a rack of those and never worry about thermals or SQ - and I'd pat myself on the back as far as saving energy in the process. For listening in a quieter environment, I think it's worth a bit more cost to have a quieter, fanless amp - even if you have to give up some of that headroom to make it fit in the budget. The PA-1's I'm running in my office now certainly aren't the quietest amps either... but they are a significant improvement over the XLS (tiniest amout of hiss perceptible). To be fair they were also nearly twice as much cost-wise, despite being very affordable IMO (20% of the cost of a Benchmark AHB2 for the pair - shipped).

In both cases, I heard 99% speakers... the hiss being the only exception - so sound was great either way really.

 

[Xulonn]

This Crown XLi-800 with its massive toroidal transformer (linear PS) is definitely not an "Air Box" which is a descriptive term used starting in the 1970's when transistors allowed very "compact" audio component designs. The Crown is a very compact amplifier, especially considering its power rating and the fact that it is not a Class-D design.

Quite frankly, I think that the $270 Crown looks a terrific bargain for a very high-power stereo amplifier, and it could be a good choice for those on a very tight home-audio budget especially for those who listen to pop, rock or other highly compressed, limited dynamic range music.

When comparing the Crown with a couple of other mid-sized, higher-power amplifiers that were tested here at ASR, I thought of the Neurochrome 286, a $1,300 limited production 100wpc amplifier kit with a switching PS, extremely low noise and distortion, and a marketing target of home audio system use. The Neurochrome, like the Crown, is a "filled-up" chassis, but with lots of heat sinking rather than fans, and is obviously designed to be placed where convection can be effective. Notice the "wavy" profile of the cooling fins, which are tweaked for maximum solid>air heat transfer, apparently eliminating the need for "active" cooling (fans).

The other amp that came to mind was the $3,000 "high-end" high-fidelity "pro-audio" Class-AB amp - the AHB2 from Benchmark. In @amirm's review, he stated that "You get 500 watts of stunningly clean power." It is an "airbox," but unlike many of the larger Hypex and ICEpower amplifiers, the AHB2 has a reason for all of the empty space inside the chassis - the HUGE cooling fin area. I am guessing that the extra height is primarily to accommodate the fins and facilitate better convective (passive) cooling.

Unfortunately, even though I am supposed to be on a tight budget, I admire well-engineered audio gear, and am willing to spend a bit more than I probably should for lower power, noise, and distortion.

I gave up on cheap Chinese Class-D mini-amps after two Topping PA3s died on me, and I now have a Classé Model 70 in my system. Its in excellent condition, and is a 30 pound, 70wpc, balanced XLR input Class-AB amplifier from the early 1990's. I bought it for $400 from a New York dealer/engineer for $400, and it is used, and was thoroughly tested. It has a bit of barely audible toroidal transformer mechanical hum, but I can live with that. I should be completely happy, but since my audio curiosity occasionally overwhelmes my budget, I also purchased a Ghent Audio (China) case with balanced XLR inputs, and will be getting a couple of 70w ICEpower modules to install in it. I expect it to be equal to the Classé - and without the hum.

For me, at age 77, and fortunately still having decent hearing, I will play with audio until I go deaf, have to give up my independent living, or die and go to heaven. And in heaven, everyone's hearing is perfect, all audio systems have zero distortion, bit-perfect playback, full orchestral dynamic range - and everything is free - a socialist's dream and a capitalist's nightmare. (Unfortunately for those who are condemned go to the hot place down below, all recorded music is played backwards on Bose mini-cubes driven into severe distortion, and all hearing is plagued with terrible tinnitus and never-ending migraine headaches.)

 

[digicidal]

I always suspected that Fry's Electronics' audio department was hell. Thank you @Xulonn for confirming that fact.

 

[GrimSurfer]

This Crown XLi-800 with its massive toroidal transformer (linear PS) is definitely not an "Air Box" which is a descriptive term used starting in the 1970's when transistors allowed very "compact" audio component designs. The Crown is a very compact amplifier, especially considering its power rating and the fact that it is not a Class-D design.

Quite frankly, I think that the $270 Crown looks a terrific bargain for a very high-power stereo amplifier, and it could be a good choice for those on a very tight home-audio budget especially for those who listen to pop, rock or other highly compressed, limited dynamic range music.

When comparing the Crown with a couple of other mid-sized, higher-power amplifiers that were tested here at ASR, I thought of the Neurochrome 286, a $1,300 limited production 100wpc amplifier kit with a switching PS, extremely low noise and distortion, and a marketing target of home audio system use. The Neurochrome, like the Crown, is a "filled-up" chassis, but with lots of heat sinking rather than fans, and is obviously designed to be placed where convection can be effective. Notice the "wavy" profile of the cooling fins, which are tweaked for maximum solid>air heat transfer, apparently eliminating the need for "active" cooling (fans).

View attachment 36167

The other amp that came to mind was the $3,000 "high-end" high-fidelity "pro-audio" Class-AB amp - the AHB2 from Benchmark. In @amirm's review, he stated that "You get 500 watts of stunningly clean power." It is an "airbox," but unlike many of the larger Hypex and ICEpower amplifiers, the AHB2 has a reason for all of the empty space inside the chassis - the HUGE cooling fin area. I am guessing that the extra height is primarily to accommodate the fins and facilitate better convective (passive) cooling.

View attachment 36168

Unfortunately, even though I am supposed to be on a tight budget, I admire well-engineered audio gear, and am willing to spend a bit more than I probably should for lower power, noise, and distortion.

I gave up on cheap Chinese Class-D mini-amps after two Topping PA3s died on me, and I now have a Classé Model 70 in my system. Its in excellent condition, and is a 30 pound, 70wpc, balanced XLR input Class-AB amplifier from the early 1990's. I bought it for $400 from a New York dealer/engineer for $400, and it is used, and was thoroughly tested. It has a bit of barely audible toroidal transformer mechanical hum, but I can live with that. I should be completely happy, but since my audio curiosity occasionally overwhelmes my budget, I also purchased a Ghent Audio (China) case with balanced XLR inputs, and will be getting a couple of 70w ICEpower modules to install in it. I expect it to be equal to the Classé - and without the hum.

For me, at age 77, and fortunately still having decent hearing, I will play with audio until I go deaf, have to give up my independent living, or die and go to heaven. And in heaven, everyone's hearing is perfect, all audio systems have zero distortion, bit-perfect playback, full orchestral dynamic range - and everything is free - a socialist's dream and a capitalist's nightmare. (Unfortunately for those who are condemned go to the hot place down below, all recorded music is played backwards on Bose mini-cubes driven into severe distortion, and all hearing is plagued with terrible tinnitus and never-ending migraine headaches.)

Great post. Let's hope you don't have a chance to sample audio in heaven (or thru hearing aids) for some time yet. I'm pretty sure you won't be listening to Bose whenever you get to the other side.

As your post points out, much can be gleaned from architecture, chassis size, and a quick look at the cooling fins/fans. It's not hard figuring out what will run hot and what will not. Most of the time anyway.

The Benchmark shows a really good understanding of heat flow. Main board down low, heat sinks on the outside edges and standing vertically. The heat goes up and away from everything. Elegant.

The cheap, thin tinfoil like heatsinks (which can work well due to large surface area/low thermal mass) are always on the inside of the chassis to prevent handling damage. Unfortunately, the air in there doesn't move much and the louvred top/bottom are rarely "open" enough for reasons of safety and aesthetics.

 

[Ron Texas]

I don't know what people are trying to prove here. The Crown XLI 800 is not suitable for home HiFi use. I don't think it's a great amp for bands either because it is heavy. However, painting with a broad brush and saying all PA amps are crap for HiFi is not true. The question is how good is good enough when speakers have levels of distortion in their best range that are 100 times that of the best amps, and listening environments have noise levels that are also 100 times (or more) than the best measuring amps. Some of the worrying going on here isn't any more productive than trying to select expensive cables, except some members don't get it.

 

[RayDunzl]

the AHB2 has a reason for all of the empty space inside the chassis - the HUGE cooling fin area.

It's not empty...

The picture posted was missing the second story.

 

[GrimSurfer]

I don't know what people are trying to prove here. The Crown XLI 800 is not suitable for home HiFi use. I don't think it's a great amp for bands either because it is heavy. However, painting with a broad brush and saying all PA amps are crap for HiFi is not true. The question is how good is good enough when speakers have levels of distortion in their best range that are 100 times that of the best amps, and listening environments have noise levels that are also 100 times (or more) than the best measuring amps. Some of the worrying going on here isn't any more productive than trying to select expensive cables, except some members don't get it.

I think the reviews by @amirm and the post by @PaulD pretty much sum things up.

 

[GrimSurfer]

It's not empty...

View attachment 36171

The picture posted was missing the second story.

Second floor, top view, paints a different picture; one less crowded in the middle.

Looks like the rectified PS on the second deck, which would keep any of that heat away from the main board's SMDs.

 

[Xulonn]

It's not empty...

Aha! The scrutinizer lives up to his name! Must be the penetrating power of the Drag Queen glasses!

Edit: Definitely not an air box with all that stuff inside...perhaps this Denon tuner is a better example of an air box:

 

[mitchco]

People figured it out, there is info on the net, but they also admit it's not perfect. I asked Harman and have a good relationship with them (I bought 2 sets of M2s and 24 of the 7 series), they will not release it...

JBL M2 active XO settings

 

[PaulD]

JBL M2 active XO settings

Yep, that's the one I remember. I showed it to Harman and I'm told the engineering team claim it is not quite right... I can only report what I know. When I get time (Xmas?) I may get a chance to measure it for myself.

 

[RayDunzl]

.perhaps this Denon tuner is a better example of an air box:

That's empty.

Look's almost as empty as my Auvio HD Tuner, which has another air box inside it.

 

[KozmoNaut]

The ~45cm wide form factor for hifi gear is a bit superfluous now for most gear. It made sense in the days of turntables, reel-to-reel decks and amps built from chunky discrete components with large power transformers. And obviously it is the standard size in the pro audio segment, due to the ubiquity of 19" racks.

The only modern consumer devices that need this much space are A/V receivers, and mostly because of how much space their inputs/outputs take up on the back panel. There are a few slimline receivers out there, but they're usually pretty basic.

 

[RayDunzl]

My little Krells have a lot of air in them:

There's about sixty pounds that isn't air, though.

 

[Aap op Sokken]

I don't think that a little more bias current to push a class B amp into AB mode has any serious effect on the overall thermal dissipation. The highest dissipation is at much higher loads where the bias current definitely plays no role in the sum of all dissipated power.

Indeed under load the difference vanishes, i meant to point out the difference in power usage when idle. It's going to be low anyway, but class B will be even lower. This may be a consideration in always-on devices.