Crown XLS1002 Pro Amplifier Review

[maverickronin]

What’s the purpose of measuring anything above 20kHz? (Assuming it’s not a broken AM transmitter, of course), especially in combination with the audible frequency range and metrics?

IIRC, @amirm usually runs that test on class D amps because they often have higher distortion at higher frequencies.

The ultrasonic harmonics won't be audible directly, but that nonlinearity at high frequencies will also cause IMD at audible frequencies.

The multi tone or a 19+20KHz CCIF IMD test would might make potentially audible issues more obvious.

 

[MediumRare]

IIRC, @amirm usually runs that test on class D amps because they often have higher distortion at higher frequencies.

The ultrasonic harmonics won't be audible directly, but that nonlinearity at high frequencies will also cause IMD at audible frequencies.

The multi tone or a 19+20KHz CCIF IMD test would might make potentially audible issues more obvious.

@amirm can you post the IMD and the 32 tone chart?

 

[cistercian]

IIRC, @amirm usually runs that test on class D amps because they often have higher distortion at higher frequencies.

The ultrasonic harmonics won't be audible directly, but that nonlinearity at high frequencies will also cause IMD at audible

@amirm can you post the IMD and the 32 tone chart?

I want to compare the 32 tone chart to the 2502.

 

[Asinus]

He is using it on a subwoofer (as am I). So you don’t want highs in that. My point was that setting a low pass (no matter it’s value, but not too low that it interferes with other crossover settings and create phase issues) helps with the noise.

the crown has a max of 3000hz for this setting...what low pass ever has an ability to set it at 300khz?

I have a 1502 (bridged and lowpassed) driving a sub. The amp itself emits a low level hiss when it is on, no matter if it is connected via XLR/RCA or speakon/posts on the other end. Even when there is no load connected it hisses. It is barely audible beyond 1m though.

 

[Jdunk54nl]

I have a 1502 (bridged and lowpassed) driving a sub. The amp itself emits a low level hiss when it is on, no matter if it is connected via XLR/RCA or speakon/posts on the other end. Even when there is no load connected it hisses. It is barely audible beyond 1m though.

Mine is definitely connection related between the amp and my AVR. Without the cable plugged into the AVR it is near dead silent. I can hear a very minor hiss if the amp is turned all the way up and I put my ear right next to the tweeter, but it literally has to be nearly touching the tweeter.
Plug in any other source and the amp is silent. I tried a couple other options as stated above.
Once an rca cable is plugged in to the AVR preout, there is a buzz/hum that starts coming out. It seems/sounds like a ground loop between the amp and the AVR.

Again this isn't a real issue on the sub, I can hear it if the amp is again turned all the way up and my head is right next to the sub, but turn on a low pass filter and then I can't hear it at all on the sub. If I connect the speaker cables to my towers, I can hear it but it is faint.

My issue now is my OCD knowing that there is a hum...I can't not attempt to fix it....

 

[Panelhead]

Is frustrating.
Worry about Sound Quality and know there is noise and distortions.
All signals pass though zero volts output. That hum, hiss, or whatever is riding along with the music.

 

[PeteL]

He is using it on a subwoofer (as am I). So you don’t want highs in that. My point was that setting a low pass (no matter it’s value, but not too low that it interferes with other crossover settings and create phase issues) helps with the noise.

the crown has a max of 3000hz for this setting...what low pass ever has an ability to set it at 300khz?

Some may argue that it's desirable to remove the SMPS switching frequency induced noise, not audible obviously, but for exemple Amir here use a low order/High cuttoff filter for it's measurments I tought you could have meant something like that but that has nothing to do with DSP, I was just trying to understand the 3000 Hz value.

 

[Asinus]

Is frustrating.
Worry about Sound Quality and know there is noise and distortions.
All signals pass though zero volts output. That hum, hiss, or whatever is riding along with the music.

As long as electrons are moving there is going to be thermal noise, the catch is if you are able to hear it. The review conclusions are spot on, it is a good amp for subs or non-critical listening (e.g. surround or height speakers on HT).
I used a 1502 for a time driving F208s and the signal hiss was only noticeable with the ear next to the tweeter, overall not drastically worse than the class G amp that replaced it. The hiss coming from the amp case I mentioned before is also not noticeable if you can stash the amp behind furniture or have a hidden rack.

 

[Asinus]

Some may argue that it's desirable to remove the SMPS switching frequency induced noise, not audible obviously, but for exemple Amir here use a low order/High cuttoff filter for it's measurments I tought you could have meant something like that but that has nothing to do with DSP, I was just trying to understand the 3000 Hz value.

AudioPrecision themselves argue that:
https://www.ap.com/analyzers-access...mily-switching-amplifier-measurement-filters/
although for review purposes filtering in SW is probably close enough to get a good picture of the performance.

 

[Jdunk54nl]

Mine is definitely connection related between the amp and my AVR. Without the cable plugged into the AVR it is near dead silent. I can hear a very minor hiss if the amp is turned all the way up and I put my ear right next to the tweeter, but it literally has to be nearly touching the tweeter.
Plug in any other source and the amp is silent. I tried a couple other options as stated above.
Once an rca cable is plugged in to the AVR preout, there is a buzz/hum that starts coming out. It seems/sounds like a ground loop between the amp and the AVR.

Again this isn't a real issue on the sub, I can hear it if the amp is again turned all the way up and my head is right next to the sub, but turn on a low pass filter and then I can't hear it at all on the sub. If I connect the speaker cables to my towers, I can hear it but it is faint.

My issue now is my OCD knowing that there is a hum...I can't not attempt to fix it....

I posted this in another thread but will update here too. My Hum/buzz was caused by my coax OTA antenna cable screw part being transmitted through the tv HDMI out to AVR preouts to Amp.

Fun time chasing that source of hum/buzz.

 

[pma]

The distortion produced by this amp is close, in spectral content, to crossover distortion of underbiased classB. Crossover distortion is the only kind of distortion where we have general agreement about its audibility and negative affect to sound. In poorly designed classD amplifiers, this kind of distortion is a result of too long dead time in the output transistor switches.

 

[BAMCIS]

This is a review and detailed measurements of the Crown XLS 1002 rack mounted pro amplifier. It was kindly purchased new by a member and drop shipped to me. The 1002 costs US $339 including Prime shipping from Amazon.

Note: our company, Madrona Digital, is a dealer for Harman and hence Crown products. We use fair bit of Crown amps in custom installs usually to power in-ceiling speakers and such. Member wanted to buy it through us but the margin on it was no more than a cup of coffee (relative to online sites) so I suggested he buy it elsewhere which he did.

Not sure what to say about the look other than it is made to have some style while being rugged:

View attachment 84694

The LCD with bluish backlight reminds me of displays on electronics back in 1980s. I guess at this price they had to cut every penny.

I was relieved to see binding posts besides speakon connectors:

View attachment 84695

Now don't laugh but I could not figure out how to pull out the safety plugs they put in the darn binding posts! There is no way to grab then and I did not want to put a mark on them by using a sharp tool. The manual says only European units have it but clearly that is not correct. Anyway, I resorted to using the SpeakOn connectors for my testing. For input I focused on XLR inputs.

I set the gain to max to get the nominal 29 dB I have standardized on for testing amplifiers.

There is a fan in the back and some inside. But none came on that I could hear above the sound of my PC during testing. Nothing shut down even when the amp was pushed into clipping. Some kind of limiter would kick in after short period to keep the power level at max. Temperature of the case didn't even rise above room temp.

Amplifier Audio Measurements
Performance was stable during a 5 minute warm up time so I ran with them:

View attachment 84696

Strange to see higher order harmonics dominating the distortion profile (FFT to the right). Ratio of noise+distortion to signal as expressed in SINAD is what I expect decent pro amps to produce:
View attachment 84697

Slightly below the average of all amps tested.

Signal to noise ratio is in the same range:
View attachment 84698

Crosstalk is reasonable:
View attachment 84699

Frequency response test shows that everything is digitized due to inclusion of DSP functionality in this amp:

View attachment 84700

Power into 4 ohm is healthy as is the case with most pro amps:
View attachment 84701

I was disappointed to see one channel be much worse than the other though.

Letting distortion go higher we get higher power output:

View attachment 84702

The burst/peak power is not higher because of the limiter I mentioned in the intro.

Using 8 ohm load gives a more behaved response than 4:
View attachment 84703

This indicates the one channel is starving for current than the other (likely longer path to the power supply).

I was unhappy to see distortion shoot up at higher frequencies:
View attachment 84704

Fortunately in practice there is not much energy up there so you will be operating in low wattage area where distortion is quite a bit lower.

Finally, I removed my AES filter to get the spectrum:

View attachment 84705

Switching frequency is around 380 kHz and decently attenuated.

Conclusions
Competent pro amplifiers target for good enough noise and distortion. The Crown XLS 1002 falls in that category so if you were expecting to have anything better for so little money and so much power, you would be disappointed. But otherwise the amp does what it targets to do.

I am going to put the Crown XLS1002 on my recommended list for non-critical applications or for driving subwoofers and such.

------------
As always, questions, comments, recommendations, etc. are welcome.

The job last night after helping my wife can more tomatoes was to dehydrate these beauties:

View attachment 84706

They are called "blush" tomatoes and were invented in San Francisco in 2011! They are oval with the most beautiful coloration as if they are peaches. Once ripe, they have an incredible sweet and slightly sour taste. Once dried, they become like slightly sour and sweet candy. The rains are attacking them right now aiming to kill what is left of the plants but I picked another 10 pounds or so today.

You came here to learn about audio but you are also learning about gardening and preserving food as well. Surely that deservers a raise for me in the form of additional donations using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

Use a drywall or similar screw to remove the safety plugs. Just insert into the center of the plug and turn a half turn. Slowly pull the screw out and you will remove the plugs without marking the terminals. You can also put the plugs back in if you need to

 

[livesound2]

Few thoughts to offer to this thread about pro amps. I have A/B tested my Maggies with my Bryston 4B and then a QSC CX900. The most noticeable difference was the increased headroom and tighter / punch in lower midrange 80 - 250 hz area. The QSC amp is rated at 450W @ 8 ohms. Spec sheet available on QSC.com discontinued products. The Maggies love the power and I was very surprised it surpassed the Bryston in sound quality.
I use another CX 900 for the center channel Maggie and rear sub. Bryston moved to power the ELAC BS243.4 rear surrounds. My preferred source for critical listening is my oppo and DVD-A's.
If Amir is interested I have a Crown MacroTech MA5002VLZ to send him but it is quite a beast. Not a bear but a beast.

 

[MediumRare]

Deal Alert: $50 off with no tax or shipping - I just bought 2 for $289 each!

https://www.audiosavings.com/crown-...j-pa-power-amplifier-amp-only-8-lbs-dsp-54243

 

[nniemiec]

Just here to say after finally installing my speakers c/o of the neutrik connections w/ this amp - that this amp really woke up. Highly recommended to anyone who hasn't tried it.

 

[Wolf]

Anyone needing to pull out those plugs in the binding posts:
Just drive a small screw into them and pull out the screw with pliers. The plug will come with the screw.

 

[hyfynut]

1002 has lower specs than 1502. Reviews are now more realistic.

The story online is that the amplifiers above the entry 1002 are cleaner for some reason.

 

[JeffGB]

The story online is that the amplifiers above the entry 1002 are cleaner for some reason.

I read through some service information from Crown on the XLS amplifiers and the xls1002 is different from the others in that it uses the AD-DA that is in their proprietary RUBY chip (designed for the XLS series by TI) and the higher models use an outboard AD-DA (cs4272) that results in lower noise.

 

[hyfynut]

I read through some service information from Crown on the XLS amplifiers and the xls1002 is different from the others in that it uses the AD-DA that is in their proprietary RUBY chip (designed for the XLS series by TI) and the higher models use an outboard AD-DA (cs4272) that results in lower noise.

That tracks. I've never taken the time to learn why it was so. Makes perfect sense

 

[guenthi_r]

Got an brand new XLS 1002 for 200 bucks.
Connected to my hard to drive 2 Ohm speakers (92dB sensitiv) direct from my SMSL SU-9n i got very few hiss, i must put my ear very close to the AMT tweeter to hear it.
Good!
Soundwise, i am not sure if the XLS sounds "better" ore not compared to my previous amp (Yamaha A-S 700)...
So far so good!
One question: Does the XLS has an "Auto-Standby"?

As always, thanks to @amirm for the review!