[earfonia]

 
 
 
Sections:
Introduction and Summary
Sound Quality
Op-Amp Rolling
Control Panel
Features & Measurements
 

Review of Creative E-MU XM7

 
 
Sound Blaster X7 is an impressive multi-platform, all-in-one solution for music, movie, and gaming. As a USB DAC, X7 works with most of today's operating system, Windows, Mac OS, and newer version of Android, & iOS. But what makes X7 stands out from the USB DAC's crowd is the SB-Axx1™ multi-core Digital Signal Processor (DSP) that adds many unique audio processing features to the Sound Blaster X7.

The SB-Axx1™ DSP is a multi-channel digital audio mixer and signal processor, capable of processing up to 32 concurrent audio channels, at up to 24 bit 96 kHz per channel. Not only for mixing, but also audio effects such as equalizer, compressor, and other customized effects. If Creative would make a professional digital mixing console based on SB-Axx1™ DSP alone, it would probably cost around $ 1k or more. SB-Axx1™ is a powerful audio DSP.

Sound Blaster X7 has a very unique triangular shape, nice looking, and attention grabbing design for a desktop component. Though for practical purpose, I prefer the conventional rectangular box shape for easy stacking and transport-ability.

I bought SB X7 standard edition in November 2014 during the launch in Singapore Expo. And many thanks to Joseph from Creative Singapore, for the loan of SB X7 Limited Edition, to be reviewed together with the standard edition. The differences of the SB X7 Limited Edition to the standard edition are:
1. Approximately 1 ohm headphone output impedance. Lower output impedance than the 2.2 ohm on the standard SB X7.
2. High power, 144 watts power adapter, while the standard edition comes with the 69.84 watts power adapter.
3. White color.
 

 

I'm more of an audiophile, and not a gamer, so I won't review X7 from the gaming perspective, but more on SB X7 overall sound quality and main features. And 5.1 configuration was not tested either since I don't have 5.1 receiver and speaker setup.

Purist audiophile probably considers the audio processing features in X7 are not necessary features. The fact is, Sound Blaster X7 is not only designed with gaming and movie in mind, but also has included some important features for audiophile, such as:
USB asynchronous data transfer protocol.
USB and SPDIF Direct Mode that bypasses the SB-Axx1™ DSP for bit perfect digital audio conversion.
Audiophile-grade Components like the Nichicon “Fine Gold” capacitors.
Swappable op-amps on the DAC output stage, to fine tune the sonic character.

Sound Blaster X7 adopt asynchronous USB transfer mode, relying more on its internal low jitter clock, rather than the signal clock from USB / SPDIF. The asynchronous USB transfer mode is probably not mentioned in the X7 webpage and manual, but it is an important feature to be mentioned, and was informed to me by Creative.

Creative have pushed the limit of a multi-function audio interface that excels in all aspects. And I would say they have done it really well! Sound Blaster X7 delivers. A very unique one box solution with superb sound quality and tons of features. And very reasonably priced!



Pros:
Multi-platform & multi-function audio interface, with USB host function to interface with Android and iOS platform through USB connection.
Tons of features in such a small package, with extensive connectivity options.
Asynchronous USB data transfer protocol
Very good sound quality headphone output and line output, with pretty good speaker amplifier.
High power headphone output (measured approximately 1200 mW @ 32ohm).
Convenience 3.5 mm and 1/4" headphone socket.
Very good sound quality Bluetooth audio with easy NFC pairing.
Rich audio processing features for gaming, movies, and music, with smart equalizer.
5.1 outputs with speaker calibration.
Standalone operation.
Swappable op-amps.
 

Cons:
High dependency to Sound Blaster Control Panel, minimal dedicated buttons for important features for standalone operation.
No default start up volume for hearing safety.
No volume level indicator.
No DAC operating sampling rate indicator.
Bluetooth connection announcement, "Device connected" & "Device disconnected" can be too loud and annoying. There should be an option to disable it, or replace it with a simple soft sounding tone.
 

Suggestions For Improvement:
Volume level indicator. Even a simple 4 LEDs indicator is sufficient.
Option for default start up volume feature for hearing safety.
DAC sampling rate frequency indicator.
Dedicated button for DAC input selector. Toggle switch to switch between: USB Direct - SPDIF-In Direct - DSP Playback Mix (Default).
Dedicated button for profile selection.
Bluetooth transmitter / Bluetooth 4.0 adapter function, to pair Bluetooth headphones to SB X7.
Better quality microphone input to accommodate good quality microphone (for recording, karaoke, etc.).
Option to bypass line input gain.
Icon to launch the X7 control panel from the Android notification panel.
Enable bass management in Stereo 2.0/2.1 speaker configuration, to use the subwoofer channel when required.
HDMI input.
 
 
 

 


In summary, Sound Blaster X7 is really a High-End Sound Blaster that successfully integrates Gaming, Movies, and Music into one unique and innovative product. Superb sound quality with tons of features. Kudos to Creative!

 

[earfonia]

Sound Quality
 

The sound quality test was done mostly using Sound Blaster X7 standard edition, with stock Op-Amps NJM2114D & LME49710, and Direct Mode set to ON (checked). Direct Mode sounds cleaner & more transparent than DSP Mode. Other setup / condition will be clearly indicated. Please take note that further sonic tuning can be done by op-amp rolling and the rich feature of DSP audio processing when preferred.
 

 
 

Headphone Output
4.5 stars for the headphone output sound quality.

Clear, clean, detailed, smooth, and powerful. Very open and transparent sounding. Leaning slightly toward analytic, but in a good way, no harshness, and does not cause listening fatigue over long period. Bass is very tight, punchy and well textured. Bass is a tad leaner compared to my Yulong DA8 headphone output. Personally I do prefer for a slightly thicker and fuller mids and bass, but X7 sonic signature would match nicely with some warmer sounding headphones, such as my Philips Fidelio X1, Audio-Technica M50, & Yamaha HPH-200.
 

 

Detail and transient are excellent, music feel snappy and lively, very clear and detailed. I guess the high level of detail and clarity probably useful for gaming. Overall the tonal balance is very natural with great clarity and transparency.

With around 1200 mW power output @ 32 ohm, SB X7 headphone output practically drives any headphone. Headphone matching in this case is not about power, but more on the sound signature. My headphones preferences for SB X7 are toward natural to warm sounding headphones, and I prefer not to use analytical sounding headphones, especially when using stock op-amps. For analytical headphones, I recommend to replace the stock LME49710 with warmer sounding op-amp such as AD8597 or OPA827. See Op-Amp Rolling section for more detail.
 
 
Comparison with Sound Blaster X7 Limited Edition
In comparison to the Sound Blaster X7 Limited Edition, the standard X7 has 2.2 ohm output impedance, while the X7 Limited Edition has around 1 ohm output impedance. High output impedance amplifier mostly affecting multi-way / multi-driver IEM, due to the crossover circuit, and some impedance differences between the drivers. But single driver headphones and IEMs are not prone to a few ohms differences in the output impedance.
 

 

From my observation, standard edition X7 and X7 limited edition headphone output sound practically quite similar in tonality, especially when driving headphones and single driver IEM. I tried to distinguish the differences between the two, using headphones, I could only hear a very2 small insignificant differences, the X7 limited edition being a tad more open and transparent. IMHO, tonality wise only a very slight differences over the standard edition, not something significant.

Even when using multi-driver IEMs such my Ultimate Ears TripleFi 10, DUNU DN-1000 and DN-2000, that supposedly should be easier to hear the difference, the sonic differences is still very small. UE TF10 gets muddy and dull on high output impedance amplifier, but that is starting slowly from 5 ohms and above. The 2.2 ohm output impedance of the standard edition is practically low enough to get great sound from TF10, and other multi-driver IEMs.


Comparison with Yulong DA8
Yulong DA8 is my reference DAC+Amp. DA8 has fuller midrange and bass, more body and weight to the music. Yulong DA8 also slightly smoother and warmer sounding. SB X7 has higher perceived detail and clarity, though Yulong DA8 also has high level of detail and clarity. SB X7 sounds a little analytic when compared to Yulong DA8. Imaging and spaciousness are comparable. I would say for long period of music listening with my reference headphone, Beyerdynamic T1 & Sennheiser HD800, I prefer the Yulong DA8 headphone output. But for warmer headphones such as Audio-Technica M50, I prefer the Sound Blaster X7.
 

 

Comparison with ifi micro iDSD & ifi micro iCan
Similar to the SB X7, my ifi stack: ifi micro iDSD & ifi micro iCan, also use TPA6120A2 on their headphone output. Comparing to the ifi stack, SB X7 headphone output does have some similarities in sonic signature to the ifi micro iDSD & ifi micro iCan headphone output signature. They don't sound the same, but share some similarities. All have the clean, transparent, and clear sounding type of signature. Quite different than the warmer sounding amplifier or source that I have, like the Centrance DAPport, Yulong Sabre A28, and Audio-Technica AT-HA22TUBE. My Yulong Sabre A28 balanced headphone amplifier for example, is too warm for many of my headphones, and SB X7 headphone output is more natural sounding in comparison to the Sabre A28 warm signature. It is more about mix and match, and personal preference. Not about which one is the best.
 

 

Coming back to the comparison with the ifi stack:
Sound Blaster X7 with stock Op-Amps. Volume set to 30% at normal gain.
ifi micro iDSD, Filter: Bit-Perfect, Power mode: Normal, iEMatch: High Sensitivity. Line Out: Direct.
ifi micro iCan, Gain: 0 dB, line input connected to micro iDSD line output using ‘Better Cables RCA’ cable - Silver Serpent Anniversary Edition (6 inch).
Headphone for this comparison: Audio-Technica MSR7LTD
All headphone outputs have been matched to around 0.25 Vrms at 0 dBFS (measured using 50Hz sine wave).

On the above setup, Sound Blaster X7 headphone output sound signature is approximately in between micro iCAN and micro iDSD, closer to the micro iCan sound signature than the micro iDSD headphone output.

Bass level is more or less comparable between the 3, but on micro iDSD headphone output, bass sounds dryer and harder with short decay, therefore bass doesn't sound as full & pleasant as the micro iCAN and SB X7 headphone output. Both micro iCAN and SB X7 have more pleasant bass decay, more natural sounding bass rumble and vibration without sacrificing bass texture. But both micro iDSD headphone output and SB X7 have slightly punchier and tighter bass than the micro iCAN. So for bass, I do slightly prefer SB X7 bass over the ifis, combining the punchy and tight bass with natural decay.

Micro iCAN has the smoothest treble among the 3, and SB X7 treble smoothness is somewhere in between micro iCAN and micro iDSD headphone output. SB X7 treble is smoother then micro iDSD, less edgy, but micro iCAN is smoother.

For midrange and vocal, SB X7 sound signature is again, in between micro iCAN and micro iDSD. micro iCAN vocal sounds smoother while micro iDSD leans to analytic.

Dynamic performance is quite similar between the 3, they all have good dynamic, musically engaging and they never sounded lazy.

The level of clarity, detail retrieval, spacious imaging, clear instrument separation, are all pretty close. Practically, the differences between the 3 headphone outputs are small, and require revealing headphone to distinguish the differences. With warm sounding headphones it will be difficult to distinguish the differences. All 3 headphone outputs have excellent sound quality, with micro iCan and Sound Blaster X7 are preferable over the 'rather dry' micro iDSD headphone output. And please take note, that the Sound Blaster X7 sound signature can be tweaked further by Op-Amp rolling.

SB E5 and SB X7, though using the same headphone amplifier chip, but their sound signature is day and night, quite different. E5 is warmer with strong bass. X7 sounds more neutral, cleaner, more refined and spacious, slightly towards analytic with excellent clarity and detail. Bass and mids are leaner on X7 in comparison to E5, and overall slightly brighter. Hiss noise also much lower on X7 (especially standard edition), almost pitch black.


IEM Friendly Headphone Output
2 things are important for a desktop DAC+Amp to be IEM friendly:
1. Low gain setting is available to give sufficient useful range of volume control.
2. Low noise output for sensitive IEM.
 

 

SB X7 has 2 gain settings, normal gain and high gain. At normal gain, the maximum output voltage is approximately 2.1 Vrms, and 6.6 Vrms at high gain. With the IEMs I use for testing, useful range of volume control is up to around 40%, which is quite sufficient.

Noise floor on SB X7 standard edition headphone output is very2 low. hiss noise during silent is almost inaudible even with sensitive IEM such as DUNU DN-1000 and DN-2000. Noise floor is much lower than Sound Blaster E5 headphone output. I found the headphone output noise floor on the SB X7 standard edition is actually slightly lower than the X7 Limited Edition. But there is nothing to worry about, hiss noise is still very low on SB X7 LE, still far from being easily audible. The SB X7 LE headphone output hiss noise level is about the same as the level of hiss noise I hear from ifi micro iCan, which is very low. While the X7 standard edition is surprisingly even lower, almost pitch black even with sensitive IEM. Please take note, the hiss noise is practically very2 low, and only slightly audible with very sensitive IEMs. In my case I can only detect it using DUNU DN-1000 and DN-2000. With other less sensitive IEMs in my collection, as well as headphones, no hiss noise is heard. Sound Blaster X7 is definitely an IEM friendly desktop DAC+Amp.



Speaker Output
3 stars for the speaker output sound quality using the standard 69.84 watts power adapter, and 4 stars when using the high power 144 watts power adapter.
 

 

The speaker amplifier is using TPA3116D2, high efficiency class D amplifier. With the standard 69.84 Watts adapter, SB X7 is able to drive my bookshelf speaker the older version of B&W Matrix 805 pretty loud. I would say the sound quality is decent, but not great. Clean, a bit dry, decent enough for music and movie. With the standard 69.84 watts adapter, I consider the speaker amplifier in SB X7 as a bonus feature, good to have, useful when we need it. For the price, I don't ask for more, the speaker amplifier is simply a useful feature, but most probably will not replace your high end receiver or stereo power amplifier.

When using the 144 watts power adapter from the SB X7 Limited Edition, it is a different story. The extra power improves the detail and dynamic significantly. Tonality is still the same, but level of detail and dynamic improved. Music sounds more realistic & enjoyable with the 144 watts power adapter. If you need to use the speaker output, consider to upgrade the power adapter for better driving and handling capability of the speaker amplifier.

Out of curiosity, I cut my stock of Mogami Neglex 2534 cable, and made a cable adapter, from the speaker output binding post to 4 pin female XLR, to connect my Hifiman HE5-LE orthodynamic headphone to the speaker amplifier of SB X7. Hifiman HE5-LE and HE6 are known to be power hungry, and perform well when driven by speaker amplifier. But the downside of using speaker amplifier to drive those headphones is the relatively higher noise floor of speaker amps will be easily heard on headphones. To my surprise, SB X7 speaker amp is dead quite on HE5-LE, and it drives HE5-LE effortlessly. It sounds very clean, and also a bit dry when compared to the warm sounding Yulong A28 balanced headphone amp that I use to drive HE5-LE. Overall, SB X7 speaker amp is pretty good for HE5-LE, though a little too bright for me. Compared to the headphone output, the speaker amplifier sounds a little edgy on the treble, but with better dynamic. But overall quite acceptable, and can be improved by op-amp rolling. Now I found the speaker amplifier of SB X7 to be a nice feature for driving my Orthodynamic headphone.
 

 

 
 

Line Output
4.5 stars for the line output sound quality. 

Main stereo line output is using Burr-Brown PCM1794, while the surround channels are using 2x Burr-Brown PCM1793. I didn't test the surround channels, only the stereo line output from the Burr-Brown PCM1794.

Line output level is adjusted by the main digital volume. Maximum output level is the standard 2.0 Vrms. In this test, I used ifi micro iCan headphone amplifier connected to the line out of SB X7, comparing it with the sound quality of ifi micro iDSD line out. SB X7 volume was set to 100%.

ifi micro iDSD is a highly sophisticated DAC, and currently my portable reference DAC. Using Dual-Core Burr-Brown native DSD/PCM chipset, the micro iDSD is capable of True Native PCM768 and Octa-Speed DSD512. Surprisingly, SB X7 DAC section, being not as sophisticated as the micro iDSD, the sound quality of the line output is not far behind the micro iDSD. In fact, by using only the stock op-amps, the sound quality is actually pretty close.

Tonal balance, clarity, perceived detail and dynamic are excellent, and pretty close with the micro iDSD performance. The difference is more on the imaging & micro detail, where iDSD sounds a little more spacious with better layering and instrument separation. The treble is also slightly smoother on the iDSD, and overall slightly more refined. But overall perceived sound quality is pretty close. Considering that ifi micro iDSD is a very sophisticated audiophile oriented DAC, for the Sound Blaster X7 as an all-in-one solution, to achieve line output sound quality that is pretty close to ifi micro iDSD performance is quite a remarkable achievement. And the tonality can even be tuned further by Op-Amp rolling.

I also did a comparison between SB X7 and SB X7 LE line output, they are practically sound the same, and I couldn't hear any differences. But the RMAA loop test measurement shown some differences between SB X7 and SB X7 LE on the very high frequency response (on the Features & Measurement section below). But RMAA test is dependent to the line input used to measure / record the line output. In this case, I don't know if the difference is due to the different frequency response of the line output or the line input. To my ears, both SB X7 and SB X7 LE line output sound practically the same.



Line Input
Line input uses Burr-Brown PCM4220 ADC, supporting audio recording of up to 24-bit/192kHz in Direct mode, and up to 24-bit/96kHz in DSP mode. The same AD converter chip as the one used in high-end audio interface TASCAM UH-7000. From my observation, it seems there is a +6 dB adjustable input gain at the line input. Frankly, I didn't expect this, as I prefer to have line input that is directly goes to ADC input without additional input gain.

Standard unbalanced line input maximum input voltage is 2 Vrms. SB X7 line input can only take 2 Vrms without clipping when the input volume is set to 50%. At 100% input volume, maximum input voltage is only 1 Vrms. I guess the extra 6 dB input gain is to accommodate some low output sources. Anyway, what's important is the sound quality.
 

 

 

I don't have precision measurement instrument to test the line input quality, so I just did a simple regeneration test, to record the line output of SB X7 using the line input. I use short 6 inches long RCA cable (Better Cables - Silver Serpent) to connect the line output to the line input. Setup:
Sound Blaster X7 LE with stock Op-Amps
Direct Mode selected
Line Output volume set to 100%
Line Input volume set to 50%
Playback and recording using Reaper 4.7.7 (Digital Audio Workstation).
Reaper device setup : WASAPI
Project setting : 24 bit - 96 kHz.
 

 

Thanks to my friend Leonard Cucos, he composed for me a simple drum track using Logic Pro, that I can use for testing. I did 5 regeneration recording. Generation 1 recorded from the playback of the original file. Generation 2 recorded from the playback of generation 1 playback, and so on, until generation 5. The recording is done without any effect or additional processing. No normalization, no compressor and limiter, no equalizer, no other processing.

The original file of the drum track and all the recorded files from generation 1 to generation 5 can be downloaded here:
https://mega.co.nz/#!uZd2XJpQ!VBl_qodc2qr0bZ-QZD3vrEnW62EZdygQlihaFlyPRMI

Please don't use those files for any other purpose than for your own observation. Please don't upload, post, or publish it elsewhere. If you need to use those files, please ask permission from me and Leonard. Thanks for your cooperation!
 

 

 

 

 
The 35 ms delay on the recorded tracks is caused by playback to recording latency. With ASIO driver this latency could be greatly minimized. But for this test, I didn't need low latency.

We can hear and see the different of the generation 5 file to the original file. It sounds like there is a mild compression in the process that makes the recorded file sounds slightly louder without increasing the level of the maximum peak. Generation 5 file sounds slightly louder than the original file. Especially the bass and midrange sound fuller on the generation 5 file. We can see the changes of the waveform on some close-ups below. Clearly shown that the waveform density gets thicker on subsequent recorded file. I couldn't verify that the changes of the waveform are mostly caused by the line output or the line input. But listening to the recorded file, the line input sound quality is surely very good, very low noise, and good enough to convert analog sources into high quality digital format. But I do prefer that the input gain can be bypassed, for the analog signal to go straight to the ADC input.



Bluetooth
I'm quite impressed with the Bluetooth sound quality. Roughly comparable to wired connection playing 96 kbps MP3 / AAC files, which is good enough for casual listening or background music. Bluetooth sound quality is still behind CD quality, mainly in detail, transient, and bass impact. But it is practical, useful, and quite enjoyable.

1 thing that I found annoying is the Bluetooth connection announcement, "Device connected" & "Device disconnected". I really wish there is an option to disable it.

1 thing that I found inconvenience when streaming music through Bluetooth connection from my phone is, there is no shortcut to launch the X7 control panel from the Android notification panel. It would be nice if I can quickly launch the X7 control panel from the notification panel, rather than looking for the control panel icon on the apps drawer.
 
It would be great if SB X7 can also transmit music from Bluetooth interface, so when we connect it to Blu Ray player through SPDIF, we can use bluetooth headphone to watch movie. Hopefully it will be one of the feature in the next model.

 

[earfonia]

Op-Amp Rolling
 
 
Op-Amp rolling can be a long topic by itself, we can try hundreds of op-amps resulting endless of combinations. So I will limit to some op-amps that I'm familiar with, and available in my inventory.
 

 

The stock op-amps combination perform really well, very transparent, clean and clear sounding, matching very well with natural to warmer sounding headphone or speaker. So replacing the stock op-amps is not a necessity. Only when the default sound signature felt rather too analytical with your headphone or speaker setup, then op-amp rolling will probably help to optimize the setup.
 
 

 
The first pair of op-amps, shown on the left side on the picture above, are the op-amps for the current to voltage conversion stage, requires low noise op-amps. So choose for low noise op-amps, that either has similar or lower noise than the stock NJM2114D. I found the NJM2114D performs really well on the I/V stage, so I prefer to keep NJM2114D on the I/V stage and only change the next stage of op-amp, LME49710, which is the differential to single conversion stage. I did change the NJM2441D with one of my favourite low noise op-amp, AD8599, but after sometime I feel NJM2114D sounds better on the I/V stage. When I use AD8066 to replace NJM2114D the output DC offset was rather high. Also tried LME49860, not much different than NJM2114D, very transparent sounding, slightly brighter and the mid to bass sound slightly thinner. So for the op-amp rolling, I will use the stock NJM2114D on the I/V stage, and only replace the LME49710 with other op-amps.
 

Please be careful when doing op-amp rolling, and take note of the following:

1. On Sound Blaster X7, the supply voltage for the 4 replaceable op-amps is 22.3 volt (V- to V+). Only use op-amp that is rated with higher maximum supply voltage than 22.3 volt.
2. NJM2114D is dual channels op-amp, and LME49710 is single channel op-amp. Choose appropriate op-amp for proper replacement.
3. Always switch off SB X7 before replacing op-amp.
4. Be really careful when unplugging the op-amp. Op-amp pins / legs are easily bent when we are not careful.
5. After replacing the stock op-amp, always test the headphone output with voltmeter to test the AC and DC output without music, to make sure there is no harmful voltage on the output. Then start with low volume, and test it using a cheap earphone first, before using your favourite earphone / headphone. I ever blew my Shure SRH840 in the past, due to faulty op-amp when doing op-amp rolling. Don't blow your headphone; take the lesson from my experience.
 
 

 
 
Below is the list of op-amps (in no particular order) I tested to replace the LME49710. Please take note, that op-amp performance is system specific. The impression below is specific for Sound Blaster X7. The op-amps below might perform differently on different system.
 

 
 
OPA604
Famous op-amp for intimate vocal. OPA604 has a very unique sound signature that is probably the closest to tube sound signature among other op-amps I ever tested. Vocal is what OPA604 does best. Smooth warm and a bit mellow sounding. Vocal presentation is slightly forward, brings the singer closer to the audience. It is not the best choice for clarity, transparency, and spaciousness. It is not as transparent as the LME49710, kind of the opposite of the LME49710 fast and transparent sound signature, OPA604 is leaning towards the warm and slightly dark sound signature. Midrange sound thicker and fuller. Imaging is not as spacious as LME49710, and may sound a bit narrow. But I enjoy vocal better on OPA604. It removes most of sibilant and edgy treble. While LME49710 is more natural sounding, better for other recordings that good with transparency and spaciousness. I do recommend to try OPA604 since it has the opposite sound signature of the LME49710, to give the idea how much op-amp rolling may change the overall sound signature.
 

AD8597
Very effective to smoothen edgy treble without losing too much transparency. AD8597 sounds silky smooth and organic, and a touch warm. Not as warm and thick as the OPA604, and relatively sounds more natural than OPA604. AD8597 also has better spaciousness and treble extension than OPA604. One of my favourite op-amp for some bright sounding headphones. Bass and midrange is good, smooth and organic with good detail. Vocal sounds silky smooth and intimate, but not as intimate as OPA604. A good option to tame analytic sounding setup, and yet keeping the whole tonality relatively neutral and spacious. But not a good option for the warm sounding setup, as it might sounds a bit dull on warm sounding system. In simple comparison, AD8597 is somewhere in between LME49710 and OPA604.
 

OPA827
One of the top picks op-amp from the list. Overall tonality is neutral. Bass and mids sound fuller and stronger than LME49710, with good dynamic. Vocal is smooth, thick and full bodied like OPA604, but clearer with better detail. While treble is quite extended and transparent, yet slightly darker and smoother than LME49710. Treble is more sparkling and transparent than OPA604, and pretty close to AD8597. Imaging and spaciousness is very good, but LME49710 is slightly more spacious & transparent sounding, with slightly better instrument separation. OPA827 is a full and lively sounding op-amp with excellent bass & dynamic. A very good choice to improve bass and midrange body, when LME49710 sounds thin with the existing setup or headphone. OPA827 is one of my favourite op-amp for my Beyerdynamic T1.
 

OPA627
OPA627 is a very famous op-amp, known for its flat tonality. On SB X7, it sounds really neutral, tonality is perceived like a perfect flat, with excellent low bass and upper treble extension. It is less analytic, with smoother treble than the LME49710, while LME49710 sounds slightly more transparent and spacious. It's good to use OPA627 as a reference op-amp to compare tonality of other op-amps. Imaging and instrument separation are excellent, very good 3D imaging. Not very spacious but accurate. What OPA627 is slightly lacking is dynamic, not as dynamic and lively sounding as the OPA827. When the headphone or speaker is also lacking in dynamic, the result could be a dull sounding setup. But if the rest of the component have good dynamic, OPA627 shines. The plain vanilla OPA627 is a reference op-amp for tonality, but might not always musically engaging. As for myself, though I like the OPA627 tonality, I do prefer something with better dynamic like OPA827. And I often find LME49710 transparency and spaciousness are quite addictive.
 

AD797
Probably as famous as the OPA627, AD797 is a very well-known op-amp. The speed, detail, transparency and liveliness of AD797 are impressive. One of the most open and transparent sounding op-amp I ever tried. The level of detail, transparency and spaciousness are slightly higher than LME49710. AD797 tonality has some similarity to transparent sounding LME49710. The different is more on the bass, where AD797 sounds slightly fuller and hits slightly harder. Although the level of detail and clarity is high, AD797 is still musical and doesn't sound sterile. Comparing to OPA627, OPA627 is more sweet and polite sounding, while AD797 sounds livelier, and may sound a bit aggressive. If OPA627 considered flat sounding, AD797 is perceived as mildly V shape. OPA827 sounds slightly smoother and better for vocal than AD797, while AD797 sounds more lively and transparent. The difference is not much; basically both are excellent op-amps. Not for those who are looking for warm sounding sound signature, but mostly for setup that sounds too mellow and lazy, AD797 is probably the magic pill to wake it up and make it sounds more energetic and transparent.
 

OPA228
Snappy and lively sounding with forward presentation. I would say OPA228 is fun sounding, but not the V shape type. Low bass extension & treble transparency don't sound as extended as the stock LME49710. Mid bass is slightly more emphasized than the low bass, as well as lower treble sounds more emphasized than the upper treble. On SB X7, OPA228 sounds natural, but doesn't really improve anything from the LME49710.
 

AD8065
Another op-amp with unique sonic flavour that I like, especially for vocal. It sounds like an improved OPA228, with better detail, transparency and spaciousness that are close to LME49710, but with smoother treble than LME49710. If you like OPA228 sound signature, I would say try AD8065. It has mild emphasize on low midrange to mid bass area that help to add body to vocal and improve bass punch. Bass sounds punchy and lively, but not as full and powerful as OPA827. Dynamic is good, pretty close to OPA827. AD8065 has pretty good chemistry with SB X7. Vocal doesn't sound warm or mellow, but well defined, smooth, with good texture. Vocal is a little forward in presentation. I prefer AD8065 for vocal as compared to OPA604. Comparing AD8065 to the stock LME49170, what I consider improvement is the smoother treble while retaining the level of detail, transparency and spaciousness. Slightly fuller vocal and punchier bass. Recommended!
 

OPA1641
Natural sounding, but a bit grainy, not as smooth as the other op-amps in the list. There is nothing bad about it, it sounds more neutral than OPA604, but also nothing special. More or less comparable to OPA228, slightly more neutral. I still prefer the stock LME49710 in comparison to OPA1641, at least for Sound Blaster X7.
 
 

Depending on the system matching and individual preferences, my top picks from the list would be: the stock LME49710, AD797, OPA827, & OPA627. Beside those AD8597 and AD8065 also perform beautifully on Sound Blaster X7.

 

[earfonia]

Control Panel
 

The Sound Blaster X7 Control Panel so far has been quite stable, and bug free, running on Windows 7 SP1 64 bit, and also on Android 4.4. Sound Blaster X7 has tons of features for such a compact box. But in order to use them properly, we need to understand a little bit of its architecture and signal routing. 
 


DAC Input Selection
 

 
 
Imagine there is an input selector for the DAC, with 3 input selections:
1. Direct Mode: Audio signal directly from USB input (computer); up to 24bit - 192kHz.
2. SPDIF-In Direct: Audio signal directly from SPDIF input; up to 24bit - 192kHz.
3. SB-Axx1™ DSP Playback Mix: Audio signal from the DSP playback mix; up to 24bit - 96kHz.

The input selector is on the control panel, 'Speakers / Headphones' configuration tab:

 

1. USB Direct Mode is selected when we check the 'Direct Mode' check box.

 

 

2. SPDIF-In Direct is selected when we check the 'SPDIF-In Direct' check box, and unchecked the 'Direct Mode' check box. If the 'Direct Mode' check box is still checked, it will override other selection, and USB Direct Mode is selected.

 

3. SB-Axx1™ DSP Playback Mix, the default mode, is selected when both 'Direct Mode' and 'SPDIF-In Direct' are not selected / unchecked.

 

When one of the input is selected, the rest are disconnected. There is actually a mechanical relay for those inputs, and we can hear the relay 'click' sound when we switch the input selection. So for example, if we happen to play music using Bluetooth streaming from our phone, and then we check the 'Direct Mode' check box, the music from Bluetooth will stop (Bluetooth control will remain). Bluetooth & other inputs are all connected to the SB-Axx1™ DSP, and playable only when the SB-Axx1™ DSP playback mix is selected, by deselecting both 'Direct Mode' & 'SPDIF-In Direct'.

The DAC input selection will remain as long as SB X7 connected to power. That means the power adapter is kept ON, and connected to SB X7. When power is off, input selection goes to default, which is the SB-Axx1™ DSP Playback Mix.

Please take note that 24bit - 192kHz playback is only through USB 'Direct Mode' & 'SPDIF-In Direct'. Although in the SB X7 User Guide page 30, it is mentioned the following:
"SPDIF-In Direct allows bit-to-bit input stream of up to 24-bit 96kHz signals without processing."
I did test and confirm that the 'SPDIF-In Direct' accepts and plays SPDIF optical signal with sampling rate all the way up to 24bit - 192kHz, including 88.2kHz & 176.4kHz. For the test, I use my RME HDSP Hammerfall sound card in my desktop PC that is able to output SPDIF optical signal up to 24bit - 192kHz, connected to SB X7 optical input.
As for the SB-Axx1™ DSP, it works in 24bit - 96kHz, so playback mix is only up to 24bit - 96kHz.
 

 

I strongly suggest to have a dedicated button for this DAC Input Selector, so we don't have to rely too much on the Control Panel. For example, when we want to listen to our old cassette tape deck or probably vinyl turntable that is connected to the SB X7 line input, and there is no sound because previously we use 'Direct Mode', we can simply deactivate the 'Direct Mode' by a simple switch rather than to start our laptop or pairing our smartphone to access the control panel. Or probably the not so elegant way, to unplug the power and to plug it back to return to the DSP playback mix input. A dedicated button for DAC input selector will improve SB X7 standalone operation greatly.
 


Playback Mix and Recording Channels
 

 
 
After the 3 input selections for the DAC, the next important feature is the inputs and outputs of the SB-Axx1™ DSP. The SB-Axx1™ DSP is a digital mixer with rich audio processing features. All available inputs are connected to the SB-Axx1™ DSP. In stereo mode it mixes all the inputs channels into playback stereo mix. While for recording, SB-Axx1™ DSP routes all the input streams to the USB interface, and all the input channels can be recorded individually, including the playback mix ('What U Hear' channel).
 

 

 

Output of the playback mix is set on the Mixer tab. We can enable all the inputs, stream music signal from all inputs, and we will hear the entire different music signal from all the inputs mixed together.
 

 
 
Beside the stereo mix, SB X7 also capable to playback 5.1 surround channels from both USB and SPDIF input. I don't have any 5.1 setup, so I cannot test the 5.1 feature. I did test playing 5.1 surround recording from 2L free high resolution sampler, using foobar, and I connected a headphone amplifier to the Rear channels output, I can hear the rear surround channels. So surround 5.1 music playback using foobar seems to work without any additional setup. 5.1 setup equipped with 5.1 speaker test, and calibration for speakers distance (up to 5m) and level (+/- 20 dB).
 

 


Sound Effects and Enhancements
Beside the main features of the input selections, playback mix, and recording channels, SB-Axx1™ DSP provides many customized sound effects for music, movie, and gaming. Please take note, that all sound effects and enhancements are only effective for signal that is processed by SB-Axx1™ DSP, and not applicable for 'Direct Mode' and 'SPDIF-In Direct'. I'm not going to discuss in detail all the sound effects one by one, just some of them that I found useful for my applications.

Bass enhancement sounds good and probably the most useful feature. The range of bass frequency to be boosted is adjustable by the setting of the low pass filter, in the range of 10Hz to 500Hz.
 

 

Smart Volume seems to be a combination of compressor & equalizer to adjust overall loudness. For me the night mode is useful when listening music at night when I just want to listen to music softly on speaker, but still want to feel the bass. It sounds different then listening with low volume. Bass is more present with smart volume night mode.

I like Dialog Plus for movie. Tried to watch a full movie with it, really effective to make the dialog sounds clearer.

CrystalVoice processes the sound from the microphone. It can change our voice to for example Alien voice (never heard one before), or kids voice, when using the mic for communication or gaming. I do feel to improve the microphone pre-amplifier is more important than processing the sound quality digitally. The mono microphone pre-amplifier is rather noisy when we use high gain with external microphone.

Scout Mode is for gaming, which is basically reducing some mid bass area to improve overall clarity.

Cinematic seems to be a kind of compressor to adjust dynamic, but I didn't test it. Seems only work for Dolby encoded signal.

Profile is a really smart feature from the control panel, and I think it will be very useful when there is a dedicated button for switching between profiles at the front panel of the SB X7. We have a dedicated button for SBX, why not one more for switching profiles? Or probably profiles data is not stored in the SB X7 memory? Not necessary all the profiles, but let say the top 3 or 4 profiles are selectable from the front panel. I suggest Creative to consider a dedicated profile selector button for the next model of SB X series.
 

 

The following is example of the profile script that we can save as xml file. It gives us the info of what is stored in the profile, and what is not:
 

 
 

Smart Digital Equalizer
The equalizer is a smart digital equalizer. Digital equalizer that smartly calculate the available headroom for frequency adjustment, and automatically adjust the whole spectrum, not only the adjusted frequency, to get optimum result and avoid clipping when there is no more headroom available.

The equalizer is a feature of the SB-Axx1 DSP. The DSP integrates the calculation of both the digital volume control and the digital equalizer for optimum result. For example, when there is no more headroom for boosting the frequency, the DSP decreases the rest of the spectrum for optimum loudness ratio between the boosted frequency and the rest of the spectrum. So the equalizer will remain effective in any given condition and will never cause clipping.

I notice that in normal gain of the headphone amplifier, SB X7 spares extra headroom for the equalizer. Maximum headphone output at Normal gain without equalizer is around 2 Vrms. But when the equalizer is used to boost, the maximum output can reach up to 3.65 Vrms. But at high gain, no extra headroom for equalizer, so at maximum volume, equalizer boost is done by reducing the rest of the spectrum that is not boosted.

To test the equalizer, I generated a stereo file with 50 Hz sine wave on the left channel and 250 Hz sine wave on the right channel. Both frequencies are at 0 dB Full Scale. The following screenshots show some scenarios of how the DSP integrates the digital volume and the digital equalizer to produce optimum result at any given setting. 

High gain - volume 100% - eq 0 dB:

 
High gain - volume 66% - eq 0 dB:


High gain - volume 66% - eq +7 dB @ 250 Hz:


High gain - volume 66% - eq +12 dB @ 250 Hz (50 Hz automatically reduced for optimum loudness ratio to 250 Hz):


Low gain - volume 100% - eq 0 dB:


Low gain - volume 66% - eq 0 dB:


Low gain - volume 66% - eq +12 dB @ 250 Hz (Extra headroom up to 3.65 Vrms):


Low gain - volume 100% - eq +6 dB @ 250 Hz:


Low gain - volume 100% - eq +12 dB @ 250 Hz (50 Hz automatically reduced for optimum loudness ratio to 250 Hz):

 

The implementation of the digital equalizer is really smart indeed. Impressive!

 

[earfonia]

Features & Measurements
 
 

Volume Control
Sound Blaster X7 utilizing digital volume control in 100 steps. Volume setting follows the PC volume setting. However, in standalone operation, the start-up volume retain the previous volume setting stored in SB X7. To me this is sometime quite problematic. Often I connect the line output of the SB X7 to my headphone amplifier, and set the X7 digital volume at 100% for optimum audio quality, and set volume using the external headphone amplifier volume control. But sometime I use the SB X7 build-in headphone output directly in standalone operation, for example Bluetooth streaming from smartphone. If I don't remember to turn down the volume before playing music, the previous volume setting at 100% will simply blast off my ears and headphone. Therefore, for hearing safety, I strongly suggest to Creative to include 'Default Start-up Volume' feature on the next firmware upgrade, and to all future models of sound blaster. So user can set start-up volume at 0% or probably around 10%-20% for hearing safety.

Another suggestion is to put volume indicator on the front panel. It will help to remind user if volume was set too loud before starting to play music. A simple 4 LEDs indicator would be sufficient, and in my opinion is very important. The lack of volume indicator is often quite annoying, especially in standalone operation.
 

USB Host
This is a very nice feature of SB X7. USB Host feature allows high resolution digital streaming from Android and iOS devices through the USB interface. On android, Sound Blaster Services is required to use USB Host feature. I don't have any iOS device, so I tested the USB Host feature only on Android devices, Samsung Galaxy S4 (KitKat 4.4.2) and Teclast X89 tablet (KitKat 4.4.4). Sound Blaster X7 uses 'Android Open Accessory' protocol for USB Host interface with Android devices, and by the AOA requirement, SB X7 will also charge the Android device connected to the USB Host port.
 

 

The control panel is smart enough to detect when there is music streaming from USB Host port, to automatically disable the 'Direct Mode'. USB Host port connected to the SB-Axx1™ DSP inputs, therefore will be disconnected when Direct Mode or SPDIF-In Direct is selected. But the control panel only disable Direct Mode, and not the SPDIF-In Direct. When SPDIF-In Direct is selected, the music streaming from USB Host port will be disconnected.

What I observed, playing the same songs, streaming from Android (Samsung Galaxy S4, PowerAmp player 2.0.10, equalizer, tone control, & limiter off) through USB Host port, and PC (foobar v1.3.3) through USB port, non-Direct Mode:

1. Overall sound quality from PC is better, better detail and dynamic. Bass is stronger and midrange sound fuller when playing from PC.
2. Different volume, PC is louder, even if the Android phone volume control is set to max, and also on the mixer of SB X7 control panel the USB Host volume is set to max. The difference is quite a lot. Using Beyerdynamic T1, playing from PC, I set the SB X7 volume to 40% (high gain), while for the same song streaming from Android, I set the SB X7 volume to around 55%.
3. As expected, SB-Axx1™ DSP is a digital mixer, therefore when playing from both Android and PC, music from both will be mixed and we can hear both at the same time.
 

Microphone Input
The microphone input is mono. Quality is just average and rather noisy when using mic boost. Stereo microphone input with better quality microphone pre-amplifier is recommended to be the future improvement in the next model of Sound Blaster X series.
 

Headphone Output
Although there are 2 headphone outputs, 1/4" and 3.5mm sockets, but there is actually only 1 pair of headphone amplifier. Those 2 sockets are in parallel connection. But with 1200 mW @ 32 ohms, SB X7 has plenty of power to drive 2 headphones at the same time for convenience. The headphone amplifier is using the well-known high power amp chip TPA6120A2. Using some simple setup and USB oscilloscope, I did some measurement to check the headphone output parameters. I don't have high grade precision measurement instrument, so the measurement result below is not highly accurate and should only be used as estimated figures. Below is the result of my measurement, pretty similar result between the SB X7 standard and SB X7 Limited Edition.

SB X7 Standard Edition
Measured Output Impedance: 2.11
Normal Gain Maximum output voltage at 600 ohm load: 2.08 Vrms
High Gain Maximum output voltage at 600 ohm load: 6.52 Vrms
Maximum output current at 15 ohm load: 277 mA
Calculated power rating:
Max power output at 32 ohms: 1,328 mW
Max power output at 50 ohms: 850 mW
Max power output at 300 ohms: 142 mW
Max power output at 600 ohms: 71 mW

SB X7 Limited Edition
Measured Output Impedance: 1.51 ohm
Normal Gain Maximum output voltage at 600 ohm load: 1.94 Vrms
High Gain Maximum output voltage at 600 ohm load: 6.36 Vrms
Maximum output current at 15 ohm load: 271 mA
Calculated power rating:
Max power output at 32 ohms: 1,264 mW
Max power output at 50 ohms: 809 mW
Max power output at 300 ohms: 135 mW
Max power output at 600 ohms: 67 mW
 
The headphone sockets have jack detection feature to disconnect the speaker amplifier when any headphone jack detected in either 6.5 mm or 3.5 mm socket.


Speaker Output
The speaker amplifier is utilizing high efficiency TPA3116D2 Class-D audio amplifier. The maximum output power is 2 x 50W @ 4Ω, but also depends on the type of power adapter. Sound Blaster X7 has 2 types of AC-DC power adapter:
Standard: 69.84 Watts AC-DC adapter (24V - 2.91A) - bundled with standard SB X7
High Power: 144 Watts AC-DC adapter (24V - 6A) - bundled with the white 'Limited Edition' SB X7
 

 

 

 

The power adapter is using the standard DC connector, with 5.5 mm (0.22 in) in outside diameter and 2.1 mm inner diameter. The outer cylinder approximately 11 mm long. The high power adapter is available as an optional upgrade kit for the standard X7, at approximately $ 110.-.

Maximum output power from the specification:
50W + 50W (4Ω, 1kHz, 10% THD) - using high-power 144W adapter
38W + 38W (4Ω, 1kHz, 10% THD) - using standard 69.84W adapter
27W + 27W (8Ω, 1kHz, 10% THD) - using standard 69.84W adapter
 

Line Output and Line Input
Line Output Full Scale Sensitivity: 2 Vrms.
Line Input Full Scale Sensitivity: 2 Vrms @ 50% input volume.

To estimate the quality of the line output and line input, I did RMAA loop test, connecting the line output to the line input using a very short (6 inches) good quality RCA cable. For all the RMAA test below, line output volume was set to 98% (to avoid clipping at line input), and line input volume was set to 50% (from my observation, probably the 0 dB input gain).

Please take note:
RMAA test is only as good as the quality of the audio interface used for the measurement. And in most cases, only useful for verification purpose of the audio quality within the 20Hz to 20 kHz range. For example, most audio interface line input only have linear frequency response up to around 20 kHz, or probably up to 50 kHz at higher sampling rate. So if I measure an amplifier with flat frequency response up to 100 kHz (which is common), RMAA test result using the 50 kHz audio interface, will only shows frequency response up to 50 kHz. So in this case RMAA test result doesn't reflect the frequency response of the amplifier under test, but the frequency response of the line input of the audio interface. Once again, please take note, RMAA test is only for verification purpose, and not accurately reflecting the real specification of the equipment.

Measurement is done using RMAA 6.4.0, in 24 bit - 192 kHz.

Below is the summary of both SB X7 and SB X7 LE, in Direct mode and DSP Playback mode.
Direct Mode is clearly cleaner than the DSP playback mix, lower overall noise and more linear frequency response. In Direct mode, both SB X7 and SB X7 LE frequency response is flat from 20 Hz - 20 kHz. SB X7 LE has better roll off curve at high frequency beyond 20 kHz, probably they have slightly different ADC low pass filter characteristic, but I'm not sure about that.
 
 
RightMark Audio Analyzer test
 
Testing chain: External loopback (line-out - line-in)
Sampling mode: 24-bit, 192 kHz
 
Comparison of Sound Blaster X7 & X7 LE in Direct and DSP Mode.

 

Summary

Test	[MME] Sound Blaster X7 - Direct - Out98-In50 - 24-192	[MME] Sound Blaster X7 - DSP - Out98-In50 - 24-192	[MME] Sound Blaster X7 LE - Direct - Out98-In50 - 24-192	[MME] Sound Blaster X7 LE - DSP - Out98-In50 - 24-192
Frequency response (from 40 Hz to 15 kHz), dB:	-0.06, -0.20	+0.25, -0.27	-0.12, -0.24	+0.28, -0.32
Noise level, dB (A):	-117.7	-106.7	-116.8	-88.7
Dynamic range, dB (A):	117.6	106.5	116.8	88.9
THD, %:	0.0026	0.0020	0.0048	0.0028
IMD + Noise, %:	0.0029	0.0034	0.0057	0.0085
Stereo crosstalk, dB:	-113.1	-102.4	-112.0	-85.4

 

Frequency response

 
 

Noise level

 
 
 
SPDIF Input
Supported sampling rates: 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz, 176.4 kHz, 192 kHz.


SPDIF Output
Supported sampling rates: 44.1 kHz, 48 kHz, 96 kHz.
In the default DSP playback mode, not in the USB to SPDIF converter mode, the SPDIF output is operating at 48 kHz. The reason is Dolby compliance, to support 5.1 output through SPDIF optical. SPDIF optical bandwidth is limited to 2x 192 kHz, or equal to 8x 48 kHz. 5.1 output at 48 kHz is equal to 6 channels of 48 kHz, which is still within the maximum bandwidth. 5.1 output at 96 kHz will be beyond the SPDIF optical bandwidth limitation.


USB to SPDIF Converter
Sound Blaster X7 has a unique feature to function as a USB to SPDIF converter.
In the list of playback devices, Sound Blaster X7 shown as 2 devices:
Sound Blaster X7
Sound Blaster X7 SPDIF Out
 

 

When 'Sound Blaster X7 SPDIF Out' is selected as playback device, music signal from USB is connected directly to the Optical SPDIF output, and disconnected from the DAC and SB-Axx1™ DSP. Digital signal from USB then converted to digital optical SPDIF signal. Since it bypasses the SB-Axx1™ DSP, equalizer and other sound enhancement are not applicable. If 'Direct Mode' is selected, signal from USB will be disconnected from the SPDIF output, so 'Direct Mode' should be unchecked to use this feature. The supported optical SPDIF sampling rates are: 44.1, 48, and 96 kHz.

Using foobar WASAPI driver, the sampling rate of the optical SPDIF output will be adjusted accordingly to the sampling rate of the played file. Only song files with 44.1, 48, and 96 kHz sampling rate are supported.

The following scenario is possible:
Foobar playing music using 'Sound Blaster X7 SPDIF Out', output to optical SPDIF output.
At the same time, smartphone playing music through Bluetooth connection to SB X7, or a portable player connected to SB X7 line input, output to headphone or speaker.
This is just to show the power of Sound Blaster X7 handling multiple music streams at the same time, and output it to different outputs.
 

Dolby digital
If Dolby Digital signal is detected, the Sound Blaster X7 is able to decode it. It will display a solid white LED on the Dolby Digital indicator. There is calibration option for the 5.1 speaker setup. I didn't test this feature as I don't have any 5.1 setup.


Headphone Stand
Smart design and quite useful for earphone and light weight headphone. Too flimsy for large and heavier headphones.


 
 
 
 

Useful Tips:

Firmware Upgrade in Force Mode by @Mad Lust Envy:
http://www.head-fi.org/t/756102/creative-sound-blaster-x7-detailed-review-impressions/645#post_11765134
 
 


Feature Highlights:
Asynchronous USB data transfer protocol
SB-Axx1 multi-core audio processor
Main Stereo DAC: 1x Burr-Brown PCM1794 (127dB Dynamic Range)
Surround Channels DAC: 2x Burr-Brown PCM1793 (113dB Dynamic Range)
ADC: Burr-Brown PCM4220 (123dB SNR)
TPA6120A2 for the headphone amplifier
TPA3116D2 for the speaker amplifier
DAC output I to V stage: 2x NJM2114D (one for each channel)
Differential to Single conversion stage: 2x LME49710 (one for each channel)
Bluetooth 4.1 Low Energy connectivity
apt-X Low Latency and AAC are supported for quality wireless connections
PCM stereo up to 24 bit - 192 kHz (including 88.2 kHz and 176.4 kHz)
5.1 channels up to 24 bit - 96 kHz
USB to SPDIF converter
 

Specifications:
Output : Stereo and 5.1 Channels
Audio Processor : SB-Axx1™
Connectivity Options (Main):
microUSB
Microphone : 
Built-in Stereo Mic
1 x 1/8" (3.5mm) Mic In
Line / Optical :
1 x RCA Aux/Line In
1 x TOSLINK Optical In
1 x TOSLINK Optical Out
Speaker : 
2 x Binding Post Passive Speaker Out (L/R)
1 x RCA Line/Front Speaker Out
1 x 1/8" (3.5mm) Rear Speaker Out
1 x 1/8" (3.5mm) Centre/Sub Speaker Out
Headphone :
1 x 1/8" (3.5mm)Headphone Out
1 x 1/4" (6.3mm)Headphone Out
USB HOST :
1 x Type A USB Host Port - Device Audio Stream & Charging
Headphone Amp
Up to 600 Ohms
Max Channel Output
5.1 Channels, Stereo Amplified
 
Updated 24 Feb 2015:
Dimension:
Width : 15 cm
Height : 13 cm
Depth : 15.9 cm (including Binding Post terminal)
Weight : < 800 grams (unit only excluding headphone stand)


Unboxing & Accessories

 

 

 

 
 
 
Equipment used in this review:
 
Headphones:
Audio-Technica MSR7LTD (second headphone after T1 for sound analysis)
Audio-Technica M50
Beyerdynamic T1 (main headphone for sound analysis)
Hifiman HE5-LE
Philips Fidelio X1
Sennheiser HD 800
Yamaha HPH-200
 
IEMs:
Audio-Technica ATH-IM50
Audio-Technica ATH-IM70
DUNU DN-1000 with JVC EP-FX8M-B eartips (main IEM for sound analysis)
DUNU DN-2000
Ultimate Ears Triple-Fi 10
 
DACs:
ifi micro iDSD
Yulong DA8
 
ADC:
Creative Sound Blaster X7
 
Headphone Amplifiers:
ifi micro iCAN
 
Cables:
Anker® 6ft / 1.8m Micro USB to USB A Cable
Pangea Audio - USB cable - PCOCC & 4% silver - 2 Meter
Better Cables RCA cable - Silver Serpent Anniversary Edition (6 inch)
 
Computer & Player:
DIY Desktop PC: Gigabyte GA-H77-D3H-MVP motherboard, Intel i7-3770, 16 GB RAM, Windows 7 Home Premium 64 bit SP1.
foobar2000 v1.3.3 (ASIO Proxy 0.7.1.2)
 
 
 
Some recordings used in this review:
 

 

[inseconds99]

Awesome review!

 

[Fegefeuer]

Damn, this needs to be featured on the starting page and throughout the web. 10/10 stars, man. Wel done

 

[Mad Lust Envy]

That is simply the best review of a piece of gear that I have ever seen. Thanks for the incredibly informative review.

 

[lenroot77]

Wow this is superb! Excellent work my friend!

 

[Spamateur]

Unbelievably good review. Excellent work!

 

[earfonia]

Thanks guys!


10 May 2015 Update
I would like to use this space for mini review of Creative E-MU XM7 speaker.
 
 
Many thanks to Creative Singapore, on 6 May 2015, I had an opportunity to compare Creative E-MU XM7 speaker with other well-known speakers within the price bracket, Pioneer SP-BS22-LR and Chane A1rx-c.

 



From left to right: Pioneer SP-BS22-LR, E-MU XM7, & Chane A1rx-c.
 
 

The Setup

 
 

The 3 pairs of speaker were setup in a 4x7 meters meeting room. The floor was carpeted, and some part of the walls covered with thin sound absorbing material. The room was not totally damped or dry, but acoustically less reflective. There was a large glass panel behind the speakers that normally used as whiteboard.
 


 
We setup 2 units of Sound Blaster X7, one connected to a Windows 7 laptop and the other X7 connected to a Windows 8.1 tablet. Both using the same version of SB X7 Control Panel version 2.17.12. All tests were on 'USB Direct Mode' (No DSP & EQ). Both SB X7 speaker impedance setting were set to 8 ohms. With 2 units of SB X7 we can switch between 2 pair of speakers much quicker.  

To equalize the loudness, we play pink noise, and measure it using Dayton Audio iMM-6 calibrated microphone and AudioTool application on Samsung Galaxy S4. First we play music on E-MU XM7 and adjust the volume to comfortable listening volume, and then we play 0 dBFS pink noise. Measured pink noise was around 79 dB (flat, no weighting).
 



 
Volume settings on SB X7 for the 3 pairs of speaker were as the following:
Creative E-MU XM7 : 35
Chane : 32
Pioneer BS22 : 30  

I also setup Zoom H6 with MS capsule, and binaural microphone MS-TFB-2-11847 Master Series by Sound Professionals. The binaural microphones were connected to mic input 1 & 2 of Zoom H6, using a DIY cable. Input 1 & 2 phantom powers set to 12 VDC. The binaural mics were positioned in my ears during recording.
In general, the MS capsule of Zoom H6 sounds brighter than the binaural mics, most probably due to the distance and the proximity effect of the cardioid mic in the MS capsule. The result of the binaural mics recording is actually translates better to what I heard directly from the speakers, the tonality is closer to the speakers sound. The binaural mics are omni directional mics, therefore they don't suffer from proximity effect. The result from MS mics sounds brighter than the real tonality of the speakers. So, please take note of that.
 



 
One more thing, performance of those speakers is depending on the quality of the amplifier. Therefore result of this test is limited to pairing with Sound Blaster X7. Those speakers may sound better or worse with other amplifiers.  

 

Sound Quality

 

Creative E-MU XM7

I'm quite surprised by how smooth & balanced the XM7 sounds. I couldn't describe it as warm, bright, mid-centric, or 'V' shape. The tonality has good balanced without any emphasize or de-emphasized on any frequency region. Overall sound quality is very musical and pleasing. Slightly more laid back than the forward sounding Pioneer BS22. Better low bass and upper treble extension than Pioneer BS22. Overall tonality sounds more balance and more linear than Pioneer BS22.
 

Don't expect XM7 bass like from larger speaker, but I don't feel the bass is lacking at all. Especially for small to medium room, bass is quite full with good low bass extension. From the 3 pairs of speaker tested, XM7 has the best bass. Low bass extension is better than Pioneer BS22, about the same as Chane A1rx-c. Overall bass quality is cleaner, fuller, with better texture than the BS22. BS22 emphasized on mid-bass punch, and might sounds a little punchier, but XM7 bass has better quality, extends lower, at about the same level. So overall, XM7 bass sounds fuller than BS22. Thanks to the bigger 5" XM7 woofer (4" woofer on BS22). Chane A1rx-c bass (5" woofer) has about the same quality as XM7, but slightly less in power. XM7 bass sounds more powerful than Chane A1rx-c.  

I created bass test track using Audacity Risset Drum. It is series of bass pulses starting from 20 Hz to 60 Hz, in 10 Hz increament. 4 Pulses for each frequency. This test track is very useful to check bass quality, especially when testing IEM with BA drivers. Even some high-end IEMs fail to produce clean bass from 20 Hz. The Risset Drum track file can be downloaded together with the rest of the recorded files.  

As you can see from the recording analysis below (binaural mic - left channel), both E-MU XM7 and Chane A1rx-c (2nd & 3rd tracks) produced all the bass pulses relatively well. But Pioneer BS22 (1st track) bass is not linear, and fail to produce clean 20, 40, & 50 hertz pulses. You can download and hear the recordings. Scroll down for the download link at 'Recordings' section.  

 
 

E-MU XM7 midrange and treble sound smooth and balanced. The treble is not as transparent and airy as the Chane A1rx-c ribbon tweeter, but still has good upper treble extension. Vocal sounds full and natural. I really like vocal sound from XM7, smooth, full bodied with good detail and clarity.  

E-MU XM7 might not perform classical as airy and transparent as Chane A1rx-c, but with better bass XM7 sounds more engaging and fun for modern genres. In my opinion XM7 could be the better all-rounder from the 3. Chane A1rx-c sounds a little more refined, with more emphasize on clarity and transparency, but the bass is slightly less powerful. Personally I like both E-MU XM7 and Chane A1rx-c equally.  

 

Pioneer SP-BS22-LR

 
Slightly less extension on both low bass and upper treble, slightly punchier bass, but doesn't go as deep as XM7. More forward presentation, and also less expansive soundstage. Tonality doesn't sound as linear as XM7, slightly lacking in depth.
 

When not compared, IMHO Pioneer BS22 is a good sounding speaker. Especially for the price, I don't really have anything to complain. Probably I would like to hear better bass, but probably that's all a pair of 4 inches woofers can do. But when compared to E-MU XM7, I prefer the XM7 over BS22 for better sound quality as described previously.  

 

Chane A1rx-c

I really love the transparency & clarity of Chane A1rx-c. The treble from ribbon tweeters sounds really impressive. Overall tonality is quite linear; bass is a little shy as compared to XM7 and BS22, but treble is more transparent with better overall clarity. A little sibilant revealing for bright recording, but not really prone to sibilant. Chane A1rx-c really shines on Classical music.
 
The recordings didn't do justice for Chane A1rx-c. In reality the brightness is silky transparent, not like what you hear from the recordings. In reality Chane A1rx-c sounds much better than the recordings.
 

Comparing E-MU XM7 and Chane A1rx-c is a matter of personal preferences. E-MU XM7 is slightly less transparent with more bass; Chane A1rx-c is more transparent with slightly less bass. Both are excellent sounding speakers.  

 

 

Recordings

 

As mentioned, I made some recording during the test, with both Zoom H6 MS capsule, and MS-TFB-2-11847 binaural microphones. You can download the recordings for your observation, but please don't use it for other purposes. The position of the MS mics was approximately 2 meters from the speakers. While I sat right behind the MS mics, with the binaural mics on my head. The only post processing I did on the recording is level adjustment, to correct and equalize the loudness. No equalizer or other post processing is applied on the recordings. All recordings is done in 24 bit - 96 kHz. All files are in FLAC format. Here is the download link (225 MB):
http://www.mediafire.com/download/87fqme3lbdxcdqd/2015-05-06_Creative_E-MU_XM7.zip
 



 
 

Please take note of the following:
We cannot judge speaker sound quality from the recorded sound of the speaker!
It is logically and theoretically wrong to observe speaker sound quality from the recorded speaker sound. There is no recording system accurate enough to do that. As you can hear from recordings made by MS mics and binaural mics, those already sound very different. None is accurate. Also speakers are highly dependent on room acoustic. Recording made in other room will sound different. The reason I share this recordings is only to estimate the differences between the speakers. Not to estimate the sound of any particular pair, but to hear the differences between them. Though far from accurate, but still can give some rough idea of how the 3 pairs sound differently from one to the other.  

 

There are 13 tracks in the zip file:

 

Track 01-07: Jazz Track - Merlion Lounge
A good friend of mine, Leonard Cucos, helped me to compose a short light jazz track using Logic Pro. The first track is the original file that we played through SB X7. Track 02-04 are recorded sounds of the 3 pairs of speaker using Zoom H6 MS microphones. Track 05-07 are recorded with binaural microphones, with my head became the 'smart' head for the binaural microphones.  

Track 08-10: Risset Drum Test - Using Binaural Microphones
Started from 20 Hz pulses, increasing to 60 Hz, in 10 Hz increament. 4 pulses per frequency.  

Track 11-12: E-MU XM7 - 29 seconds YouTube playback through Bluetooth
Before we finish, we tested E-MU XM7 for YouTube. YouTube video played on iPhone, audio was streamed to SB X7 using Bluetooth, played on E-MU XM7, recorded on both MS and binaural as indicated in the file name. This is just to give an idea of vocal recording from playing YouTube, and also the different sound characteristic of both MS and binaural mics. Here is the YouTube link:
http://youtu.be/p1gbyKj-aLI
The clip is from minute 1:25 to 1:54.
 

 

 

I was really impressed with the performance of E-MU XM7. It has natural, studio monitoring quality sound characteristic. Being physically the smallest in the group, it offers the best bass quality & quantity. I found detail and clarity from all the 3 speakers are really good, with Chane A1rx-c is slightly better from the rest. Dynamic wise, all 3 have sufficient dynamic for music to sound lively, with E-MU XM7 is probably the better choice for modern genres. Kudos to Creative and E-MU R&D group!
 
 
 

 

[thatBeatsguy]

This is, by far, the most comprehensive review I have ever read. Amazing job, @earfonia!

 

[igndenny]

Well written review. Bravo earfonia

 

[cdsa35000]

Features & Measurements
...
Comparison of Sound Blaster X7 & X7 LE in Direct and DSP Mode. 

Summary

Test	[MME] Sound Blaster X7 - Direct - Out98-In50 - 24-192	[MME] Sound Blaster X7 - DSP - Out98-In50 - 24-192	[MME] Sound Blaster X7 LE - Direct - Out98-In50 - 24-192	[MME] Sound Blaster X7 LE - DSP - Out98-In50 - 24-192
Frequency response (from 40 Hz to 15 kHz), dB:	-0.06, -0.20	+0.25, -0.27	-0.12, -0.24	+0.28, -0.32
Noise level, dB (A):	-117.7	-106.7	-116.8	-88.7
Dynamic range, dB (A):	117.6	106.5	116.8	88.9
THD, %:	0.0026	0.0020	0.0048	0.0028
IMD + Noise, %:	0.0029	0.0034	0.0057	0.0085
Stereo crosstalk, dB:	-113.1	-102.4	-112.0	-85.4

 

Frequency response

Noise level

...

Well done!

But you didn't explain why X7 LE in DSP mode is Lo-Fi Dynamics with overall 18dB higher Noiselevel/Crosstalk and higher Distortion than X7 standard?
It should be easily fast distinguishable with that hell of a noise!

 

[earfonia]

Well done!

But you didn't explain why X7 LE DSP is Lo-Fi with overall 18dB higher Noiselevel/Crosstalk and higher Distortion than X7 standard?
It should be easily fast distinguishable with that hell of a noise!

 
Please take note, that the RMAA test showing higher noise on X7 LE, only on DSP mode, not on Direct mode.
I honestly don't know the reason why X7 LE DSP mode has higher noise than standard X7 DSP mode. If I know the reason I would have explained it.
I seldom use DSP mode, only 'Direct Mode' most of the time (clearly mentioned in the 'Sound Quality' section), so I didn't hear any annoying noise during the test.