Crown Xti4002 Pro Stereo Amplifier Review

[fpitas]

Packaging is a limitation if you want to run much above silicon temperatures. SiC has been demonstrated up to 500C but comercialy available power devices have simlar temp ratings to silicon due to the packaging.

Yes, true. I'm used to the packaging that the microwave stuff has, which may be too rich for regular switching use.

 

[kipman725]

Incidently on the power required for pro drivers front, we are currently using 4000W/ch and 4ohm drivers to achieve that (nominal) power output but don't reach objectionable levels of driver distortion before clip. So even higher power amplifiers would be useful.

 

[JimWeir]

This is a review and detailed measurements of the Crown XTi 4002 DSP stereo professional amplifier. It is on kind loan from a member and costs US $1,345.
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The design wants to look fancy and it kind of gets there with those vents. The segmented LCD and menu navigation is serviceable but the amplifier is really designed to be configured and managed using JB HiQnet software. There are no network connections so you use USB for that purpose:

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Yes, the sample is pretty beat up physically but what makes these amplifiers "professional" is to take that kind of use and keep going. I like that standard binding posts are provided in addition to SpeakOn. The former is more likely to be usable in a home hi-fi scenario.

I was pleased to see multiple settings for the fan. Alas, as you see later, even at lower power usage the fan comes up and makes fair bit of racket. This is aggravated by major whining from internal transformer(s) when pushed to max power. So really not that usable in a standard hi-fi cabinet.

Note: our company, Madrona Digital is a dealer for Harman products and we are a heavy customer of Crown Amplifiers (for custom installs, not consumer). So feel free to read any level of bias into my subjective remarks.

If you are new to my testing, please watch this video on understanding amplifier measurements.

Crown XTi4002 Amplifier Measurements
I usually post the warm up at the end of the review but it is an interesting graph so let's look at it first:
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I usually see amplifiers stabilize after a few minutes but the 4002 kept improving so I let it run for some 18 minutes (1100 second) where performance suddenly worsened. I was wearing headphones so I took them off only to hear pretty annoying whine from the fan going to full power even though total power being produces was just 10 watts. Clearly the amplifier wants to run warmer for optimal performance but priority is given to reliability. To that end, the design should have been optimized for a lower temperature. Fortunately we are talking about just 1 or 2 dBs.

Here is our standard dashboard:
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We don't expect a whole lot from pro amps and that is where we are with the 4002:
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I should probably create a separate set of graphs for pro amps. Noise performance is not great:

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Not good numbers for any kind close in listening like in hi-fi applications.

Frequency response is flat and load independent which is good:
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Looks like input is digitized at 48 kHz sampling rate. Distortion is naturally high by consumer amplifier standards:

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Crosstalk was just "OK"

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These amplifiers are sold almost completely on the basis of how much power they produce. As such, a lot of exaggeration goes on when it comes to that. Let's see how the 4002 does:
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Considering that I am using a shared household outlet (12 gauge feed but 15 amp rating) this is impressive amount of power and consistent with company specs more or less.

Switching to 8 ohm load we still get plenty of power:
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I then threw the PowerCube at it to see how well it does with both reactive and loads going down to 2 ohm. As if to to say, "come on, give me all you have" the amplifier made all kinds of noises and lit up its red LEDs in protest. But still managed to produce numbers that are just unbelievable:
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Yes, the amplifier produced nearly 90 volts out of its speaker terminals (both channels driven). And didn't care one bit what load I fed it! To put this in context, this is how much power we have:
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Stunning! Note that the measurement only lasts long enough for the analyzer to capture it so likely less than a second. But still, the amplifier robustly fought the difficult load and peaked to nearly 8 kilowatts at 2 ohm load!!! It never went into any kind of protection and just ran.

Varying frequencies doesn't seem to change the response much:
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Finally, you are likely going to hear the amplifier powering down:
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Conclusions
By consumer hi-fi standards, the noise and distortion is quite high. That is not the target of this amplifier class though. It is meant to produce a lot of power and do it day in and day out. And provide in-built DSP to handle jobs like crossover, delay, etc. To that end, the XTi 4002 delivers on its promise in an impressively way -- better than any amplifier I have tested to date. Even using 15/20 amp rated 120 volt supply we have in US, we get copious amount of power.

Noise is a major issue for home use though so only proper application is in a remote location or at least locked up in a cabinet.

I am going to recommend the Crown XTi4002 based on its intended market, or home use for driving subwoofers and such.

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I have been using my crown XTI 2000 amplifiers in my mean system to power my very inefficient magnepan MMG’s’s‘s for 15 years. I’ve been able to pull a measured peak voltage equivalent to over 1 kW at the input terminals to my loudspeaker. Producing a peak, sound pressure level of over 111 dB

Regarding the fans, I have modified the fans to a quieter model and with music listening they rarely come on, unless I’m playing above average levels, ideally they reside in an instrument cabinet so you wouldn’t hear the fans come on board I do not hear any electrical noise from these amplifiers. I also like how I can use the DSP to optimize the response of my loud speakers and crossovers.

 

[JayGilb]

If my stick welder ever dies, this may be a suitable replacement.

 

[dlaloum]

Is it possible for class D amps to be able to reach such power figures in a reliable way? Most completed amps that I’ve seen are very lacking in heat sinking and even fans (if needed). I know that the pro amp companies use class D solutions, but last I looked it was for (relatively) lower power applications.

I see one can get 2k/channel with an Ice power module. I haven’t heard good things about their reliability, however.

This Crown amp really “doubles down” to 2 ohms, unlike other amps that just lower their reported 8 ohm measurement to make it seem that way.

Crown has the XLS2500/XLS2502 as the ClassD equivalent - very similar functionality including the DSP, and very similar power levels - better SINAD, and no issue with fan noise (at least on my exemplars) - also I believe the MSRP is substantially lower... (I purchased mine used, after an initial lifetime in pro use... they bear the scars of their first life, but I have always found the performance excellent)

 

[GGroch]

.......Crown- Competently engineered and fully fit for purpose.
........Thanks to @amirm for characterizing this.

Right! Remarks that Crown is crap and needs to learn from home HiFi mfg. miss the point. Specs are extremely important to successful pro manufacturers like Crown; I would guess they are more important than they are to most consumer mfg. The specs important to Crown are totally different from those important to home HiFi.

If the XTi4002's fan is as loud as the fan on my class D Behringer NX1000D pro amp; the S/N spec is not the biggest noise barrier for home use. It is likely suitable for homes only when located in a separate equipment room. In the case of the Behringer, switching to a quiet fan was easy to do.

The fact is, Crown just did not care about high S/N or low fan noise for its intended use.

 

[fpitas]

Yes, the realities of professional use are very different than the typical front room.

 

[JayGilb]

Yes, the realities of professional use are very different than the typical front room.

Yes, this amp is generally used in a fixed installation environment where fan noise is just part of the background.

 

[Spkrdctr]

I was surprised that the fan came on at 10 watts. I would have called Crown to see if that is in need of repair. I have never heard of any Crown amp ever turning on a fan at 10 watts. If the fan came on at 75 watts it would have given us better numbers. It could be what the factory wants, but it is a first for me. 10 watts is so low it seems the fan would just come on at startup! I might have to call Crown and get the info to post here. I just can't believe 10 watts is right.........

 

[jhaider]

Crown has the XLS2500/XLS2502 as the ClassD equivalent - very similar functionality including the DSP…,

This core design of this line is quite a bit older than DriveCore, but the signal processing capabilities are superior to XLS. PEQ and so on.

XLS are fine sub amps as well, but need upstream signal processing.

 

[Gorgonzola]

This Crown amp is worthless as a home hi-fi amp, and I rated as if I were considering it for that purpose. (Personally have no application for an amp to suitable to power a shopping mall sound system.)

This amp will sound bad to anyone who listens compared to the latest Purifi, Hypex, or ICEpower amps -- or even those made in the last decade. Sound difference deniers are going to have a hard time with this one.

 

[fpitas]

This Crown amp is worthless as a home hi-fi amp, and I rated as if I were considering it for that purpose. (Personally have no application for an amp to suitable to power a shopping mall sound system.)

This amp will sound bad to anyone who listens compared to the latest Purifi, Hypex, or ICEpower amps -- or even those made in the last decade. Sound difference deniers are going to have a hard time with this one.

I don't understand the reasoning behind that statement. Your ears can hear SINAD beyond 70dB?

 

[Waxx]

This Crown amp is worthless as a home hi-fi amp, and I rated as if I were considering it for that purpose. (Personally have no application for an amp to suitable to power a shopping mall sound system.)

This amp will sound bad to anyone who listens compared to the latest Purifi, Hypex, or ICEpower amps -- or even those made in the last decade. Sound difference deniers are going to have a hard time with this one.

I have both NCore amps and a Crown XLS amp in my house, and the difference is not that big as you say. Off course the NCore is better, but the Crown is still good enough to sound good and not disturb the music. That XTi is only slightly worse... The biggest issue is the fan, not the sound of the amplifier. And that with the fan can be solved easely when used in a hifi system (this amp i have here is for outside use, but i'm still setting up the diy system.).

And for pro use (the primary target) it's more than fit for midsize systems of decent quality, and that for a relative cheap price. An Ncore or Purifi amp, even of equal power can't do that, it's not build for that. The Crown is not toplevel, then you need amps from Powersoft, Labgruppen and some other brands. But it does the job for a lot of cases for a fraction of the price of those.

 

[pseudoid]

I can't buy and return if you are asking that. But you all are welcome to do that. If they rent it, then it is not an ethical issue at all.

Would it be worthwhile to start a new thread discussing how this can be achieved with the help of members chipping in for such rental$?

Similar to your "What *electronic audio products you want tested most" thread. (*replace "electronic" with "rental"?)
There maybe some big implications for this effort that can be discussed in such a thread.
Rental timing/period/price will require much coordination.
.....

 

[JeremyFife]

Voted 'fine' for the elevated noise (fan too) but I hope I haven't done this workhorse a disservice.
Outside my area of knowledge and pretty useless to me - but it's not made for me!
It'd fry my dog and my speakers, and I'd have to build a cabinet for it in another room ... and I'd never be able to turn it up.
Not for me, but I can still appreciate the robustness and the power at a reasonable price.

 

[amirm]

I was surprised that the fan came on at 10 watts. I would have called Crown to see if that is in need of repair. I have never heard of any Crown amp ever turning on a fan at 10 watts. If the fan came on at 75 watts it would have given us better numbers. It could be what the factory wants, but it is a first for me. 10 watts is so low it seems the fan would just come on at startup! I might have to call Crown and get the info to post here. I just can't believe 10 watts is right.........

This is 10 watts continuous for > 15 minutes. It didn't come on at the start.

 

[amirm]

What supply voltage did you use, @amirm ? Looks like the unit accepts up to 240.

Nominal 120 volts.

 

[IAmAlwaysSerious]

I don't understand the reasoning behind that statement. Your ears can hear SINAD beyond 70dB?

I expect I could hear the noise floor on this thing with any speakers I own, though I spend most of my speaker listening time a meter away from the drivers.

I wouldn't hold it against this amp though, personally.
I rarely need more than ten watts and maybe 100 watts per channel at the absolute most. Well, not counting the subwoofer...
Four kilowatts could launch all my cones into orbit.

This would be a kinda crap amp for me. It'd be fun to have a use for it though.

 

[Gorgonzola]

I don't understand the reasoning behind that statement. Your ears can hear SINAD beyond 70dB?

Apparently.

 

[pseudoid]

I don't understand the reasoning behind that statement. Your ears can hear SINAD beyond 70dB?

Honest Q: How many active stages with SINAD of -71dB can your audio-chain handle before it becomes audible to you?