Microphone Input Performance

The Creative Sound Blaster X4 is equipped with a combined line/optical input and a microphone input. Creative again doesn't mention the exact ADC chips they use, but they do give us their specifications. Both inputs support a 24-bit/192 kHz bit depth/sample rate. The ADC chip has a dynamic range of 104 dB and total harmonic distortion of 0.0017%. To test the microphone input of the Sound Blaster X4, I used the Drop + Sennheiser PC38X analog headset.

The following sample was recorded after I set the microphone gain to 100% and left all of its other features (SmartComms Kit, Acoustic Echo Cancellation, Smart Volume, Voice Morph, and Microphone Equalizer) off.



Here's the same microphone recorded on two different sound cards: the EVGA NU Audio Pro, a beast of a PCI Express sound card, and an integrated sound card using the ASUS SupremeFX S1220 audio codec.





The microphone input sounds clean and natural, and it effectively manages to bring the best out of a connected microphone. It's a bit quieter than expected, even at maximum gain, but there's a simple solution for that. In the Creative app, go to Mixer > Recording, find the Microphone entry, click on the three dots next to it, and check the "Microphone Boost" option. Once done, lower the microphone sensitivity to around 60%, and below is what you'd get.



My voice is now significantly louder while remaining as clear as before without introducing excessive background noise. There's plenty of room left for further gain adjustments in either direction. Another option is to use the Smart Volume feature offered within the CrystalVoice section of the Creative app. My previous experiences with this feature have been bad, as it introduced significant compression, but in its current form, it seems to be greatly improved. Here's a sample of the microphone with the sensitivity set to 100%, and the Smart Volume feature activated.



In this sample, my voice is pretty much as loud as when I was using microphone boost. However, quiet parts of the sample suffer from some static noise, and it is impossible to use the Smart Volume feature when the sound card is set to Direct Mode, which is why I strongly suggest you stick with microphone boost and 60% sensitivity instead.

Creative apparently implemented massive improvements to the Microphone Equalizer feature found within the CrystalVoice section of the Creative app. Take a listen to the following sample demonstrating a couple of different available microphone equalizer presets.



When I was testing the microphone equalizer presets on the more expensive Sound Blaster GC7, they did change the timbre of my voice but added copious amounts of compression, which rendered them unusable. That's not the case with the Sound Blaster X4. Here, the microphone equalizer presets actually do what they're supposed to without ruining voice quality in the process. 11 of these are available, so there's plenty of room for experimentation. I only wish creating our own microphone equalizer profiles would be possible. Perhaps an idea for a future update, Creative?

The Sound Blaster X4 supports the microphone monitoring feature, which works great, with next to no perceivable delay. You can turn it on in the Mixer section of Creative App.


Finally, we have SmartComms Kit, a "suite of smart communication features that helps to simplify the way you communicate during online calls", as Creative describes it. SmartComms Kit consists of three features: VoiceDetect, NoiseClean-out, and NoiseClean-in.

When activated, the VoiceDetect feature automatically mutes the microphone when you're not speaking, and activates it when you are. The idea is obvious: to make you dead silent whenever you're just listening and remove the necessity of manually muting the microphone. You can set VoiceDetect to Auto Adjust or play with the voice level and environmental noise sliders on your own. Here's a demonstration of the VoiceDetect feature at work, first in a fairly quiet room and then in a noisy office.




As you can hear, the VoiceDetect feature does what it promises. In both environments, it successfully managed to mute my microphone when I wasn't talking, and it activated it when I was without cutting me off at the start or end of my sentences. Both samples were recorded with the VoiceDetect feature in Auto Adjust mode. If your environment is exceptionally noisy, you can set the voice level and environmental noise sliders to "Loud" and still have the microphone muting successfully, although with a higher chance of being slightly cut off when you start talking. It is even possible for the microphone to stay muted in extreme scenarios; for example, when your dog starts barking in the background, but this will also depend on microphone quality and your sensitivity settings. Overall, the VoiceDetect feature is completely usable, and a welcome addition to the Sound Blaster X4.

As for the NoiseClean-out and NoiseClean-in features of the SmartComms Kit, they're basically noise canceling filters applied to outgoing (your voice) or incoming comms (voices of the people you talk to). Here's a demonstration of the NoiseClean-out feature, recorded in a fairly noisy environment. The sample opens with NoiseClean-out deactivated, just so you can better hear what it actually does once it's on.



As far as background noise filtering goes, the NoiseClean-out feature of the Sound Blaster X4 performs admirably. It manages to silence my environment without adding any audible compression to my voice. Some slight artifacting can be heard in the background, but that's just the noise-canceling filter doing its thing. In a normal online conversation, details like that would likely go completely unnoticed.

The NoiseClean-in feature behaves similarly, but it's safe to assume it's not going to get used nearly as much, simply because it is applied to all incoming audio, including your Spotify music, YouTube clips, games, and everything in between. In other words, you have to turn it on and off manually when having online meetings, and at a certain point, that becomes a hassle. I only used it in extreme cases, when the person I talked to had an unbearably bad microphone. Too bad there isn't a way to bind the NoiseClean-in feature to one of the buttons on the Sound Blaster X4, as that would make this feature much more useful.