Testing & Results
As I mentioned in the introduction, I used my own voice and the voice of a well-known volunteer to test the Blue Microphones Digital Spark. They are repeatable, I know them both extremely well, and it covers what I think at least half of the target market will be doing with this microphone; recording themselves. I used several professional-quality microphones that I am very familiar with as a reference. The main difference they have compared to the Spark Digital is that they are all analog, and need the addition of a microphone preamp and an A/D convertor to be able to create digital recordings. That’s standard practice, and I chose a good, but reasonably inexpensive two-channel mic preamp to partner with the analog mics I used for comparison. I also used what I feel most people would use for A/D conversion, which is a dedicated sound card inside the computer. I need to mention that the combination of these two items can easily cost $2-300, if you don’t have them already. Here’s a picture of the mic preamp that I used (courtesy of the manufacturer). It’s out of production now, but there are others available now, that offer similar performance at a similar price.
Computing requirements for the Spark Digital are quite low, so I used my daily driver PC for the majority of the testing. It’s nothing special, just an old AMD Phenom BE, but it has a good 24bit/96kHz discrete sound card in it because I like to listen to music while I’m at my desk. The line output feeds a modified Dynaco tube amplifier and a pair of Celestion F1 speakers situated on the desk. This setup is not the ultimate in audio quality, but it has a very natural sound and is better than 99% of the “computer speakers” on the market. For critical monitoring tasks, headphones are almost always the go to solution, as they provide much higher resolution than most speakers. I use a couple of different headphones, depending on the mood and the application.
The Audio-Technica ATH-AD700 phones have the most natural sound and are the most comfortable. If I’m watching a movie, they’re the best choice by far. The Grado SR125 phones are the most illuminating, especially in the midband, and are also pretty comfortable. They’re just a bit too revealing for casual use, when I need to focus on more than what is in my ears. Both of them feature semi-open construction and as a result, don’t offer full isolation from the sounds around you. The JVC HA-RX900 headphones are what I normally use for live mixing, because they do offer excellent isolation. Partly because of their closed-back construction, they offer the best bass response and they have a solid midrange. The highs are a little closed in, compared to the best headphones, but they’re still there. These are the type of headphones that are best to use for monitoring during the recording process. You only want to hear the signal that’s being sent to the recorder, and you don’t want any of the ambient sound being mixed in with your monitor feed. Later, when playing back the recording, the open or semi-open back headphones are OK, and their increased resolution is useful in spotting possible issues with the recording.
Testing and scoring was somewhat subjective, in that I used my own ears as measuring instruments, but I’ll also claim that my assessments are somewhat objective. As a DIY builder of audio equipment, and as an audio engineer focused on live sound performances, I have a well-trained set of ears, and a mature characterization framework that I can draw upon. I’ve used dozens of different microphones in a variety of settings and I always try to integrate independent assessments into my own evaluations. Each of the microphones was scored on a number of qualities that I find useful in differentiating both loudspeakers and microphones. In no particular order, they are: Softness/Hardness, Tone realism, Dynamics, Definition/Resolution, Bass response, Midrange response, Treble response, and Spatial clarity. For each microphone, I read an identical script and adjusted the microphone location and attitude to get the most natural sound. I then did a final take and recorded that signal for further comparison. I scored each unit while listening to playback through the Grado SR125 headphones, as they are the most revealing of the bunch that I normally use. I also listened through the other headphones that were available, just to see if there was some positive or negative synergy that was impacting the results. I used Exact Audio Copy V1.0 beta 3 software for the recording process, and foobar2000 v1.3.2 for playback.
- Motherboard: ASUS M4A88TD-V EVO/USB3 (1308 BIOS)
- System Memory: 4 x 2GB OCZ, AMD Black Edition OCZ3BE1600C8LV4GK
- Processor: AMD Phenom II X2 555 Black Edition Callisto 3.2GHz Socket AM3
- CPU Cooler: Cooler master Z600
- Video: ATI Radeon HD 5670 512MBB GDDR5 (Catalyst 8.801.0.0)
- Drive 1:Corsair F100 SSD 100GB (CSSD-F100GB2)
- Drive 2: Western Digital Velociraptor 300GB Drive WD3000HLFS
- Enclosure: SilverStone Fortress FT01 SST-FT01B-W Gaming Case
- PSU: OCZ ModXStream Pro 500 Modular ATX12V V2.2, OCZ500MXSP
- Operating System: Windows 7 Home Premium SP1
- AKG C 1000 S Microphone
- AKG C 3000 Microphone
- AKG C 3000 B Microphone
- Audio-Technica AT3035 Microphone
- Presonus BlueTube Microphone Preamp
- Grado SR125 Headphones
- Audio-Technica ATH-AD700 Headphones
- JVC HA-RX900 Headphones
- Creative Labs X-Fi XtremeMusic Sound card
- foobar2000 v1.3.2
- Exact Audio Copy V1.0 beta 3
Most people have had exposure to a wide variety of audio loudspeakers. From the lo-fi junk that comes bundled with entry-level computers and the incredibly tiny versions that are jammed into the corner of their laptops, to the towering racks of pro-audio drivers at a live concert, everybody knows that different speakers all sound different. Not that many people understand that microphones are exactly the same way. The tiny microphone on your smartphone has a diaphragm that’s scarcely bigger than the period at the end of this sentence. A high end studio quality condenser mic, used to record those hot vocals from your favorite star, has a gold-sputtered, hand tuned diaphragm that’s roughly one inch in diameter. It also costs somewhere between $1,000 and $20,000, and it’s probably a 1950’s vintage tube version, to boot.
Based on extended listening to the various tracks that were recorded with a number of microphones that I’m familiar with, I gave each one a rating for the eight different characteristics I mentioned in the methodology section. Just like the revised rules for figure skating, there are no tens, as that implies that there is nothing better. Remember, these are all very affordable, entry level products, in the grand scheme of professional recording tools.
C 1000 S
C 3000 B
Two things pop out at me after compiling the results. One is that the Spark Digital really hung in there with a group of microphones that I like and respect, and that generally cost more than the Digital Spark. Secondly, it had a very even performance across the whole spectrum of important characteristics, and didn’t have any significant failings. If I had to guess how the manufacturer accomplished that, I’d say that the opportunity to design the whole signal chain at once probably allowed a high level of optimization. All of the low scores (if you can call a 7 low…) have to do with the way the Spark Digital handles treble. This is always a high wire act for microphones, as an accurate, extended high frequency response will often cause problems downstream. Even though the mic was just capturing the sound honestly, the microphone always gets blamed for any harshness that comes out at the end of the signal chain. It’s a common problem; everyone wants detail, more detail, until their brain says, “STOP, ITS TOO BRIGHT!” In this case, the Spark Digital commits a minor sin of omission in order to save the user from the annoying pops, screeches, and whistles that often detract from an otherwise good recording.
What does this mean for the end user? It means you have to treat this microphone the same way you would any other microphone. You have to play to its strengths and compensate for its weaknesses; there are no perfect microphones. For instance, the acoustic guitar that is accompanying the singer is not going to have the same snap that you would get if you had a separate, small diaphragm condenser pointed right at the player’s fingers. Compensate by using steel strings, instead of Nylon. OTOH, you aren’t going to get any of those annoying, harsh sibilants from the singer. It’s always a compromise, which is why audio engineers tend to throw seven mics at a trio of folk singers. They want to be able to mix and match the signals later, in the quiet leisure of their mixing room. With one microphone and a single USB connection, you don’t have that luxury, so spend a lot of time trying different microphone placements. Sometimes a couple inches one way or another will make a big difference.
If I had to sum up the performance of the Digital Spark, I would have to couch it in terms of two things; suitability for use, and value. Everything I experienced with this latest model from Blue Microphones was just right for what I see as the most compelling use case. Podcasts and video voice-overs are a growing application for a much larger group of users than ever before. Almost all of them are amateurs, and don’t have a background in audio engineering. The Spark Digital gives them the means to produce professional quality sound with very little knowledge or effort. I give it a 10 for this application. Musicians are going to have a harder time of it, unless they’re singing a cappella. Trying to record an instrument and voice with one microphone is going to mean some compromises will have to be made. If you’re serious about your music, I suggest buying a small mixer with at least four mic preamps, and a couple good analog microphones. You’ll have a lot more flexibility, including the ability to record in Stereo. Here’s where the value part comes in. For the podcaster, the musician’s rig used to be the only game in town and it was overkill for voice-over duty. The Spark Digital gives you everything you need to get very high quality audio into your computer, for less than 200 bucks. You can do it for less (…see the Yeti and Snowball models from Blue Microphones), but you can’t get the same audio quality for less money.
Let’s move on to some Final Thoughts and then, my Conclusions about the Digital Spark and how I think it fared when benchmarked against some industry standards.