Emotiva Audio Pro Airmotiv 4s powered loudspeaker Measurements

Sidebar 3: Measurements

I used DRA Labs' MLSSA system and a calibrated DPA 4006 microphone to measure the Emotiva Pro Airmotiv 4s's frequency response in the farfield, and an Earthworks QTC-40, with its small, ¼"-diameter capsule, for the nearfield responses. As the Pro Airmotiv 4s is a powered speaker, I can't publish a conventional sensitivity measurement. However, presenting 330mV of pink noise to the speaker's input and setting its level control to "50" gave an SPL on the tweeter axis of 84dB(B) at 1 meter.

The Airmotiv's small enclosure was impressively rigid, with just a few low-level vibrational modes apparent. Fig.1 is a waterfall plot calculated from the output of an accelerometer fastened to the center of one of the sidewalls. The highest-level mode lay at 340Hz, but its level was still very low in absolute terms. A slightly stronger mode, at 254Hz, could be found on the top panel, but the radiating area of the top panel is very small; this mode should have no audible consequences.

Fig.1 Emotiva Pro Airmotiv 4s, cumulative spectral-decay plot calculated from output of accelerometer fastened to center of side panel (MLS driving voltage to speaker, 1V; measurement bandwidth, 2kHz).

Fig.2 shows the Airmotiv 4s's response above 300Hz on its tweeter axis, averaged across a 30° horizontal window, and with the nearfield responses of the woofer (blue trace) plotted below 300Hz, and that of the port (red) plotted below 1kHz. The treble and bass switches were each set to "0" for these measurements; the complex sum of the nearfield outputs is shown as the black trace below 300Hz. The peak in the upper bass is almost entirely an artifact of the nearfield measurement technique, and the overall high-pass rolloff is much faster than a conventional reflex design's 24dB/octave, suggesting that the Emotiva's bass alignment is sixth-order, to prevent its small woofer from being driven to its excursion limit by infrasonic signals. The port has a sharply defined peak in its output just below 1kHz and peaks between 50 and 80Hz, while the woofer's minimum-motion notch occurs at 60.5Hz. This is the frequency where all the output comes from the port and suggests modest low-frequency extension.

Fig.2 Emotiva Pro Airmotiv 4s, anechoic response on tweeter axis at 50", averaged across 30° horizontal window and corrected for microphone response, with nearfield responses of woofer (blue), port (red), and their complex sum (black), respectively plotted below 300Hz, 1kHz, 300Hz.

The Emotiva's farfield response is smooth and even, if with a slight rising trend from the midrange through the high treble. Fig.3 shows the effect on this response of switching the speaker's treble control to "+2" and "–2": the range covered by the tweeter can be seen to hinge up and down by 2dB at 10kHz. Switching the bass control from "0" to +2" raised the woofer's output by 1dB at 100Hz, and the port's by 2dB at 60Hz. Switching the control to "+4" raised these levels by another 1 and 2dB, respectively.

Fig.3 Emotiva Pro Airmotiv 4s, effect of treble switch on HF-axis response (5dB/vertical div.).

The Airmotiv 4s's lateral dispersion, referenced to its tweeter-axis response, is shown in fig.4. Though there is a slight flare off axis at the bottom of the region covered by the tweeter, the radiation pattern is otherwise wide and even below 10kHz, suggesting accurate, stable stereo imaging. In the vertical plane (fig.5), a deep suckout develops in the crossover region more than 5° above the tweeter axis, suggesting that high stands will work best with this speaker. The Airmotiv 4s maintains its treble balance up to 15° below the tweeter axis, suggesting that this speaker will work well as a studio monitor when mounted on the mixing console's meter bridge.

Fig.4 Emotiva Pro Airmotiv 4s, lateral response family at 50", normalized to response on tweeter axis, from back to front: differences in response 90–5° off axis, reference response, differences in response 5–90° off axis.

Fig.5 Emotiva Pro Airmotiv 4s, vertical response family at 50", normalized to response on tweeter axis, from back to front: differences in response 45–5° above axis, reference response, differences in response 5–45° below axis.

In the time domain, the Emotiva's step response (fig.6) indicates that the tweeter is connected in inverted acoustic polarity, the woofer in positive polarity. The cumulative spectral-decay plot (fig.7) is impressively clean, other than a slight degree of delayed energy in the low treble.

Fig.6 Emotiva Pro Airmotiv 4s, step response on tweeter axis at 50" (5ms time window, 30kHz bandwidth).

Fig.7 Emotiva Pro Airmotiv 4s, cumulative spectral-decay plot on tweeter axis at 50" (0.15ms risetime).

Overall, Emotiva Audio's Pro Airmotiv 4s offers impressive measured performance, especially when you consider that it costs just $299/pair.—John Atkinson

Emotiva Audio Corporation
135 SE Parkway Court
Franklin, TN 37064
(877) 366-8324

drblank's picture

because they have no dealer network, which marks up the product. So, they are the low cost leader by selling direct. I think they are also made in China. At least that's what I've read about all of their other products.

To me the name kind of sounds like those cheap stereos people would sell out of the trunk of their car or out of a van near a gas station, even though they aren't. :-)

I personally just can't get past the name. :-)

tonykaz's picture

They have a wonderful little desktop volume control for $50 and a nice DAC for around $500.

You discovered a secret.

Start using Actives like this and you may not be able to return to Passive Speakers (starting at $2,000) & proper Amps (starting up round $1,500+).

All these little Actives are category crushers when it comes to performance and price.

So, why would someone buy a Magico? if they had one listen to any of the Professional Nearfield of Midfield Monitors from : Emotiva, Focal or Genelec?

Tony in Michigan

ps. of course this stuff is Professional Grade, not pretty enough to show off, maybe.

ps.2 Nice to see Stereophile doing a reality check like this.

la musique's picture

I agree with the show off.
It looks to me that the real' Hi Fi/musique lovers 'entousiast don't care about gliter etc...
What counts is the sound experience.

tnargs's picture

Nice enough but nothing that a Behringer can't do for a bit less, and certainly not delivering what the JBL LSR305 does. There's your category leader. Street price $240 a pair too.

Rick Tomaszewicz's picture

Nice to see increasing coverage of active monitors. I'd love to see a review of Emotiva's top active monitor, Stealth 8 ($749). Or a review of their top mono block power amp, XPR-1 ($1699). Neither are audio jewelry, but are reputed to be category crushers and highest value/$. Such reviews may not sit well with main stream manufacturers and advertisers, or with people who suffer from upgradeitis.

Sister site Audiostream's Michael Lavorgna loves studio grade Adam and Focal active monitors. I remember Paradigm's Reference Active 40 got rave reviews as a category crusher years ago.

Perhaps active monitors will become more popular as people demand better desktop performance and then experiment with them in their main audio systems. Makes sense in terms of value/$, amp/speaker optimization, fewer cables and less space.

Mike Rubin's picture

I still have a pair of NHT M-00 actives that I purchased after reading a Stereophile review in which Wes Phillips, I believe, declared them to be the best small speakers you could buy. This must have been around 2005 or so. I believe I paid about $400 or so for the pair.

ashutoshp's picture

Would having amplifiers built in to the speaker cabinet improve damping of resonances?
I am currently the proud owner of a pair of Emotiva's Stealth 6s (with 200 watt amps)....ruggedly handsome at a staggering 26 lbs. My wife's frequent banishing has fewer consequences because I can now simply carry my stereo to the time-out room. I have them mated to their DC-1 DAC/preamp and the combo is just fantastic... very balanced and smooth. Thankfully, 1 less component to match!
The downside to Emotiva's speakers is the rear port but compared to the Airmotiv's, the Stealth's give you an extra option (bass roll-off) for accommodating room accosutics. It appears subtle at first but fiddling with the controls REALLY helps with the bass response.
I should also add that the price-to-performance ratio is very linear when it comes to powered monitors. And unlike years past, there is a good market for re-selling so even those with upgradeitis can apply ;) The Stereophile crew should look at more powered monitors/speakers and if they want high end, in addition to the usual suspects from the likes of Focal, Genelec and Adam, I think the Event Opals at <$3000 a pair are a proper bargain. I have heard a lot of awesome speakers but nothing quite like the Opals.