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Emotiva XPR-1 Mono Amplifier Power and Distortion Measurements

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All measurements were conducted using our Audio Precision APx585 8 Channel HDMI Audio Analyzer following our rigid Amplifier Measurement Test Protocol.  It is recommended that the reader reference our Amplifier Measurement Protocol to gain a better understanding of meaning of our measurements and jargon used in the test portion of the review.

XPR-1 tests.JPG

High Power 8 Ohm Test Loads

Before getting into all of the power tests, I did a quick check to see how green friendly the XPR-1 amp was.  I measured roughly 50 watts idle power consumption which is very low for an amplifier of this power capability.  Even with almost 10 watts of pure class A bias, this amp is efficient! 

I did some quick spot-checking on the Emotiva XPR-1 amplifier gain structure to ensure it could be properly driven with a wide assortment of preamps or receivers.  Normally I’d prefer to see amplifiers hit their max gain with a 2Vrms input signal but the Emotiva XPR-1 had a higher than usual input sensitivity.  This is understandable given the huge amount of power and gain this amplifier has.  It takes about 3.5Vrms to hit the max output of this baby so make sure you chose a preamp that has clean output drive to 4Vrms.    I measured 29.5dB gain with an 8 ohm load attached using the balanced inputs.  Emotiva specifies 29dB gain which is very close to what I measured. 

Signal to Noise Ratio

 

XPR-1_snr.jpg

 XPR-1_snr-1kwatt.jpg

Emotiva XPR-1 SNR (A-wt) @ 1 watt (top pic) and 1kwatt (bottom pic)

The XPR-1 exhibited a very good low noise floor.  At 1 watt I measured 91.6dB (A-wt) and 89dB with only a 20kHz filter engaged.  Emotiva specifies 93dB (A-wt) which is close to my measurement.  The small improvement with A-wt filtering engaged indicated this amp exhibited a very low out of band residual noise.  At rated power (1kwatt), I measured 122dB (A-wt) which is significantly better than Emotiva’s published 118dB figure. 

Frequency Response

 

XPR-1_freq.jpg

Emotiva XPR-1 Frequency Response @ 450 Watts

The frequency response of the XPR-1 is ruler flat at virtually every power level from 10Hz to the limit of my measurement system (80kHz).  This measurement was taken at 450 watts into an 8 ohm load!   No slew-rate induced distortion was present here.

Power Measurements

Using our Audio Precision APx585 8-channel HDMI analyzer, I conducted a full barrage of power tests on the Emotiva XPR-1. The XPR-1 was tested on a dedicated 120V / 20A line.  It’s important to note that the XPR-1 can also accommodate 220V and likely would have produced significantly higher power figures under 4 ohm loads if tested at that voltage.

We tested power using three methods all of which were taken at < 0.1% THD + N:

  • Continuous Full Power Bandwidth (CFP-BW) from 20Hz to 20Khz into 8 and 4-ohm loads
  • 1kHz Power Sweep vs Distortion (1kHz PSweep) - popularized by the print magazines, this is an instantaneous power vs. distortion test at 1kHz. The problem with this test is it often masks slew related and or frequency response problems some amplifiers exhibit at the frequency extremes, and thus inflates the measured power results. It does provide instant gratification # for consumers to argue over on the forums, so we are now incorporating this test to please the masses.
  • Dynamic PWR - 1kHz CEA-2006 Burst Method testing. This is a dynamic power measurement adopted from the car industry similar to IHF method, only a bit more difficult for an amplifier and more representative of real musical content.

Keep in mind most review publications don't do continuous power measurements and they usually publish power measurements into clipping at 1% THD + N. Our measurements are very conservative as we use a dedicated 20A line with no Variac to regulate line voltage.  We constantly monitor the line to ensure it never drops more than 2Vrms from nominal which in our case was 120Vrms. 

For more info on amplifier measurements, see:  The All Channels Driven (ACD) Test

 

 XPR-1-freq-1kwatt.jpg

Emotiva XPR-1 Full Power Bandwidth Continuous Sweep (1 kwatt, 8 ohms)

The Emotiva XPR-1 ripped through the 10Hz to 20kHz power sweep at 1 kilowatt like nobody’s business.  I’ve never measured an amplifier that could produce 1 kilowatt full bandwidth before.  Impressive, most impressive!

 

 XPR-1_Psweep_8ohm.jpg

XPR-1_Psweep_4ohm.jpg

Emotiva XPR-1 1kHz Power Test
Top Pic: 8 ohm load;  Bottom Pic:  4 ohm load

The power sweep tests revealed the Emotiva XPR-1 to be the most powerful amplifier we’ve ever reviewed to date!  The XPR-1 maintains Class A/B operation right up to the Class H switch point which can be seen as a bump in the above 1kHz power sweep tests at about 340 watts (8 ohms) and 500 watts (4 ohms).  The XPR-1 is essentially identical in performance to their Class A/B XPA-1 amplifier below these switch points. The modest rise in distortion once engaged in Class H is a small trade off to pay for doubling available amplifier power.

 

 Emotiva XPR-1 CEA 2006 Burst (8 ohm).jpg

Emotiva XPR-1 CEA 2006 Burst (4 ohm).jpg 

Emotiva XPR-1 Dynamic Power Test (1kHz)
Top Pic: 8 ohm load;  Bottom Pic: 4 ohm load
 

The CEA-2006 burst tests simulate musical program material.  The power levels achieved by the XPR-1 for these tests are legendary.  Into 8 ohms, the XPR-1 produced over 1.7 dB of dynamic headroom for 8 ohm loads and 2.13 dB for 4 ohm loads.  A large power supply, lots of output devices and most importantly a very robust design really pulls off wonders here.

# of CH Test Type Power Load THD + N
1 CFP-BW 1 kwatt 8 ohms 0.1%
1 CFP-BW * 1.7k watt 4 ohms 0.1%
1 1kHz Psweep 1.25 kwatt 8 ohms 1%
1 1kHz Psweep 1.35 kwatt 8 ohms %
1 1kHz Psweep 2.03 kwatt 4 ohms 0.1%
1 1kHz Psweep 2.19 kwatt 4 ohms 1%
1 Dynamic PWR 1.5 kwatt 8 ohms 1%
1 Dynamic PWR 2.86 kwatt 4 ohms 1%

Emotiva XPR-1 Power Measurement Table

* 4 ohm CPF-BW:

I was unable to spot check rated power at 20kHz without it tripping the XPR-1’s fault protection. I suspect the line sag was too much causing the amp to run out of voltage and distort excessively. 

Emotiva rates the XPR-1 as follows:

  • 1 kilowatt < 0.1% ; 8 ohm load
  • 1.75 kilowatt < 0.1% ; 4 ohm load

Because the Emotive XPR-1 is such a massively powerful amplifier, it makes testing its maximum output capability very challenging.  Without holding the line voltage constant with a VARIAC, we were unable to hit all of the manufacturer’s specifications without causing severe line sag (4 ohm power testing) and corrupting the distortion measurements which sometimes lead to lower power measurements or causing the amplifier protection circuits to activate.

FFT Distortion Analysis

 

XPR-1_fft-1watt.jpg

XPR-1_fft-1kwatt.jpg

Emotiva XPR-1 FFT Distortion Analysis
(Top pic: @ 1 watt ; Bottom pic: @ full power

I ran FFT distortion plots at 1 watt (top pic) and at 1.1 kilowatt (bottom pic) to determine how clean this amplifier really is. 

At 1 watt, the spectral distortion was below the noise floor of my measurement equipment which is another way of saying “awesome”!  I did detect some residual noise -80dB down at 63kHz but not even you dog would be able to hear that.

At 1.1 kilowatts the XPR-1’s odd order harmonics dominated with the 3rd harmonic still being an impressive 80.1dB below the fundamental.  I spot checked lower power levels (where the amp spends most of its time). I found the 3rd harmonic at 115 watts to be 97dB below the fundamental and at 300 watts the 3rd order harmonic was -91.7dB.  This is darn good performance and really illustrates the distortion reducing benefits of a fully differential circuit topology.

Downside

What could be the downside of a nearly 2 kilowatt mono-block amp that delivers promised power and fidelity and a very reasonable price?  Well, if I must pick nits, they are mostly cosmetic.  I would have liked a thicker top plate, locking balanced connectors and a beefier toggle switch on the backpanel to give the product a more high end feel to it. 

A Big ol’ analog VU meter like the much more expensive McIntosh amplifiers sport would have scored big points with audiophiles.  In fact I must confess to be one of those audiophiles that would have preferred the VU meter over the LED display. It just seems to be such a waste of so much gorgeous glass space to only have a single LED display centered in the glass.  Perhaps Emotiva can consider offering a Special Anniversary edition of this amp in the near future with VU meters for a small premium in price.  It would add such a nice touch of class to a product of this caliber of performance.

Operationally the XPR-1 was flawless. The only minor issue to note was that the XPR-1 was the second review product from Emotiva that I experienced with a loose top plate chassis screw.  I informed the manufacture about this and they are looking at lengthening the screws in future production builds to prevent this from happening.

Recommendations

The Emotiva XPR-1 is not the type of aglass.jpgmplifier most audio enthusiasts will need for their systems.  Before putting the XPR-1 on your shopping list as your next amplifier, ask yourself the following questions:

  • Do you have the type of loudspeakers that could appreciate the raw unadulterated power of this behemoth?
  • Do you have the rack space to house two of these gargantuan sized power amps?
  • Do you have access to dedicated 20A power outlets?

If you answered “yes” to the above three questions, than you’d be hard pressed to find a better mono-block solution at anywhere near this price.  The XPR-1 runs cool and quiet so you don’t need a lot of ventilation. Emotiva claims space conscious customers can even stack the pair if you don’t have the space to place them side by side or on separate shelves.  I have no reason to doubt this recommendation as no matter how hard I drove the amps, they only got comfortably warm to the touch.  These amps will definitely earn points with green conscious consumers.

Feed these babies a high quality, fully differential signal path from source to preamp and be prepared to be rewarded with hulk like dynamics and Swiss watch precision.

 

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Recent Forum Posts:

Lvnsnfnatk posts on October 17, 2015 13:23
I'm grateful to have found this website! You guys review great gear that is priced resonably. These Emotiva Monoblocks appear to be well made and have good sound. They also make a pure class A amp. Is there a dealer where I can hear this gear A/B'd ?

I'm a power junkie for sure and am so relieved I changed out the 15A crap that was there prior. My room is wired by 3 separate 20A recepticles with my amp getting its own line. I just assumed these lines are 220V as you recommend, but i'm not sure. How can I tell?

Can I somehow wire in a 30A line for the amp? I realize the recepticle and plug is different as on a clothes dryer, but the temptation to get more power has me contemplating it. I wonder if it's possible? Just a thought.
AUTOBOT posts on April 18, 2015 12:10
Please do a youtube video on this amp.
I have a pair of these with dedicated 20 amp circuits for each amp hospital grade isolated ground receptacles.
Love them.
sharkman posts on July 27, 2014 10:47
I stand corrected on McIntosh amps, I didn't realize they made a 2000 watt mono. I think that's way beyond the needs of 99.9% of audio owners as well, and I'd wager they don't sell as well as their 600 watt mono.
gene posts on July 27, 2014 00:30
Macintosh amps are more realistic in the power department. 99.9% of audio owners don't need 1000 watts per channel, and no house is built with 20 amp dedicated lines,

Maybe the meaning of your message was lost in cyberspace but I fail to see how Mcintosh amps are more “realistic” in the power department. Last time I checked McIntosh also builds 2kwatt Monobloc amplifiers.

McIntosh MC2KW Amplifier, 1 Channel 2000 Watts McIntosh MC2KW Amplifier

You're not getting that kind of power from 120Vac/15A circuit.

Need that much power, get a dedicated 20A line or 220V or both. Don't need it? Get a smaller amp.
sharkman posts on July 26, 2014 02:40
Where did I fault Emotiva? I simply said most owners don't need 1000 watts per channel. You characterize something I said wrongly, then attack me for it. Weird.
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