The latest entry in the Kali Audio line of affordable, powered studio monitors is the IN-8 three-way speaker, expanding on the Kali two-way LP-6 and LP-8 powered models.
The IN-8 has an 8-inch woofer, a single 4-inch midrange driver and a 1-inch tweeter, making use of the same woofer, tweeter and front port shape/design as the Kali LP-8 monitor. However, the two monitors differ significantly with the LP-8’s large, oblate waveguide surrounding its tweeter replaced by the IN-8’s coaxial, or coincident, midrange/tweeter transducer and integrated waveguide.
COAXIAL (COINCIDENT) SPEAKERS
In the past, coaxial speaker designs like the famous Altec Lansing 604E placed a midrange/treble horn driver in the center of the woofer. Another popular method used in compact car stereo speakers is to mount the tweeter on a perforated plate in front of the woofer. In both examples, the midrange/tweeter assembly is not physically attached to the woofer and is, for the most part, (acoustically) transparent to the woofer’s bass frequencies.
Drivers with coaxial designs share the same acoustic center and produce a single, coherent acoustic point source. When monitors with physically separated midrange and tweeter drivers (like most two-ways) reproduce the same frequencies, two or more wave lobes are created that will interfere with each other; i.e., add or subtract from each other. Acoustic off-axis “lobing” is most problematic at or near the crossover frequency between the two drivers.
With the Kali Audio IN-8, the woofer is mounted in the cabinet just below the midrange/tweeter transducer—a concentric driver that has a dome tweeter placed where normally the dust cap of the midrange driver would fit. There is a small plastic trim ring outside the tweeter’s edge and then a small air gap physically separating it from the midrange cone itself. There is no inner suspension between the midrange cone and the tweeter. The circular driver’s midrange cone acts as the waveguide for the coaxially mounted tweeter.
But using a vibrating midrange cone for the tweeter’s waveguide will result in tweeter/midrange inter-modulation distortion (IMD) if the design is poor. To prevent IMD, the total amount of peak excursion allowable for the midrange cone has to be under 1 mm. Excursion is constrained by the driver’s electro-mechanical limits, including damping, maintaining a predictable SPL output and, most importantly, the chosen crossover frequency. Back and forth cone travel is a function of frequency, with more excursion at lower frequencies.
Using a second-order filter, the crossover frequency is 330 Hz between the woofer and the midrange/tweeter driver. Furthermore, the woofer and midrange/tweeter drivers are mounted close together in the cabinet, within a quarter-wavelength of each other (quarter wavelength of 330 Hz is 26 cm), so the two effectively act together to produce a single point source.
The IN-8 monitor cabinet is made from MDF and uses three separate Class-D power amplifiers, with 40 watts for the tweeter (the midrange-to-tweeter crossover uses a fourth-order filter at 3000 Hz), 40 watts for the midrange and 60 watts for the woofer. All three amplifiers have protective peak limiters to guard against accidents. The tweeter has a 1-inch textile dome, while the midrange uses a poly-coated paper cone.
As compared to Kali Audio’s LP-8, the IN-8 is taller at 17.7 inches, but retains the same footprint with a depth of 11 inches and a width at 10 inches. The IN-8 also weighs a bit more at about 30 pounds.
The IN-8’s frequency range (±3 dB) is specified at 45 Hz to 21 kHz, and max SPL is 114 dB at 1 meter. The IN-8 measures 85 dB continuous SPL with 20 dB dynamic headroom at 2.8 meters away.
Rear panel connections have both unbalanced RCA, balanced XLR and TRS input jacks, standard world IEC/power on/off switch connector, and a ±6 dB volume control knob with center-detent. There are the same eight DIP-switches as on the LP series. Switches 1 to 3 offer eight different boundary curves for low-frequency rolloff filters to compensate for where you place the monitor in your room. Switches 4 through 7 are for ±2 dB low-and high-frequency shelving filters with 0.7 dB/octave from 800 Hz down to 100 Hz (LF) and from 1.25 kHz to 10 kHz (HF). Switch 8 turns the RCA input on/off.
The Kali Audio IN-8 also conforms to the new EU regulations regarding power consumption, standby and off modes. The monitor uses 20 watts while in use and 0.5 watts in standby/sleep mode. When no audio is present on the input of the monitor for 20 minutes (green LED), it will go into sleep mode (orange LED). It takes about 3 to 6 seconds of audio input to wake the monitors from sleep mode.
WHAT DO THEY SOUND LIKE?
I placed my pair of IN-8s on a pair of IsoAcoustics Aperta 200 Speaker stands on top of my Sound Anchor monitor stands. That puts the IN-8s 48 inches from the floor (measured to the center of the woofer), and I angled them downward (using the Apertas) to aim directly at the listening position. The monitors were set up 56 inches apart, measured from the center of each woofer, and that worked out great for my listening position in front of my desktop, out front at the third corner of the equilateral triangle.
Because of its small size, my mix room (2.9 meters wide) has to be on the dry side (non-reflective), but it’s not acoustically dead. It is acoustically treated with bass trapping, a combination of diffusion and absorption for the ceiling cloud, and there are no reflections coming from the left and right side walls on either side of the IN-8s.
For my first tests, I used the AES/EBU digital input on my Cranesong Avocet IIa monitor controller to play mastered CDs I know well, as I had a hand in engineering and/or mixing them.
RESETTING MY EXPECTATIONS
I’ve never had monitors with concentric drivers in my room before, and I was immediately impressed. To be certain for this review, I rechecked everything, established the IN-8’s symmetrical setup, and measured and calibrated the output from the Avocet IIa.
I’m still getting used to these new main monitors, but I found the stereo imaging and center soundstage locked, consistent and solid. The stereo field is wide—it sounds wider than the actual physical distance between monitors! The center image also does not move as I move about the listening position. I got a full and natural sound without overkilling and beaming high frequencies or a hyped-up bass. I found it very easy to hear deep into these mixes; low-level dynamic passages and subtle details such as reverb tails and other effects were heard exactly as intended.
I pulled up a Pro Tools session to mix a song I had not heard in a while to see how mixing goes using the IN-8s. I wanted to do a fresh mix to hear how it “translated” to my various playback devices I use for checking mixes: CLA-10s, IK iLoud MTMs, iTunes, iPhone, headphones, in-ears, in L+R mono on a cheap speaker.
While mixing, I was amazed at how well the IN-8s tracked musical dynamics with open and good reproduction of both transients and low-frequency, EDM-style “pumps.” The recorded dynamics from kick drum punches, snare drum accents and bass guitar “pops” are heard accurately, with some of the unprocessed, natural transients hitting too hard or not hard enough.
I started with the default DIP-switch positions: all down, or flat, but that would soon change. In my room, the monitors are 0.45 meters from the wall behind them and 0.6 meters from the walls on either side. I found the IN-8s just slightly bass heavy and a touch bright for me in this room. I changed Switch 1 to the “up” position (as recommended for speaker stand placement less than 0.5 meters from the rear wall) and also Switch 6 to roll off high frequencies. I’m using these settings for now, and I’ve found them to work just like the HF and LF trims on the LP-6 and LP-8 models; ±2 dB tilt EQs centered at 1 kHz.
I started mixing a soulful R&B tune with very percussive drums and spikey electric guitars. While getting pan positioning and basic levels, EQs and compressors set, I would go back and forth between the IN-8s and a couple of pairs of different headphones. I could hear and set pan positioning and EQ on them just as easily as I usually do on headphones.
The mix’s vocal production was massive, with many tracks of singers panned about the stereo field. The final mix level of the individual harmony parts was easy to attain, and that balance held up on the alternate speaker checks later on.
I also noticed that the IN-8s were less fatiguing than the two-way monitors they replaced. Sitting back on the couch 3 meters away, where a lot of my clients like to sit and listen, the sound was more even than before, and that is good thing!
I finished the mix and checked it on all my usual listening touchstones, and I had no surprises. I’m recommending the IN-8s as an excellent yet inexpensive studio monitor for small mixing spaces. You’ll have crystal clear stereo imaging, along with a truthful and accurate representation of what you have recorded and mixed immediately.
COMPANY: Kali Audio
PRODUCT: Kali Audio IN-8 Three-Way Coincident Studio Monitor
PROS: Amazing and realistic sound; low price