I started with one pair of AVAA C214s on the front wall, one in the left corner (where the resonances are loudest) and one in the right corner, and re-ran the test tones. When playing the 63Hz and 125Hz pulsating test tone with the C214s switched off, I heard it as an almost continuous tone with just a small amount of modulation. There it was: my room’s biggest issues, clearly identified. However, there seemed to be no improvement, as the tones remained more or less continuous. I heard barely any difference when switching one or two C214s on or off, even though I had made sure to try all the positions where this resonance was loudest.
Then, I discovered that it made a huge difference when I moved my head all the way forward while remaining seated. This indicated that the back portion of the room was affecting the results, contributing to room resonances at the same 63Hz frequency. This made me think I might need three or four C214S in this complex space, but before giving that more thought, it motivated me to find an even better position for the listening sofa. Via incremental steps, I settled on a sofa position 60 cm more forward, now 150 cm from the back wall. Sure enough, with the sofa in the newly optimized position, the difference between having the C214s switched on or off was now night and day! The left unit made the largest difference, but the right one sure helped as well. With two AVAA C214s switched on, I immediately heard crisp, staccato, clearly intermittent tones, rather than an almost continuous tone. There and then, the C214s proved themselves beyond any doubt.
As a quick side note, I want to add that before this test, I was pretty sure that I had already found the ideal listening position using a calibrated measurement microphone with standard test tones and lots of listening to music. But thanks to the pulsating test tones and procedures carried out for this review, I discovered that the circumstances could be further improved.
Motivated by the fantastic results, I felt compelled to reconsider the placement of the speakers as well. With the listening sofa “locked” in the position where the distinction between pulses was most pronounced, I continued looking for even more optimized speaker positions. Sure enough, I was able to find an even better balance with the speakers a little further back, where the low bass was stronger, and although not uniform in decay, the low bass response was now essentially flat down to 30Hz. On the other hand, the room-induced bass blur persisted, and the coloration was now worse than in the previous setup I arrived at using music and normal test tones. Essentially, I now had the perfect testing bed for the AVAA C214s!
With great anticipation, I queued the test tones and sat down in the listening spot, ready to hear how much more improvement could be achieved with the speakers in their newly refined positions. Sure enough, there was excellent differentiation when playing the pulsating test tones at all frequencies, but to my surprise, this was the case whether the C214s were switched on or off. I could no longer reliably tell whether the units were on or off. For a moment, I wondered whether the AVAAs might not be able to further improve the already pretty good situation.
But as soon as I started listening to music, I noticed a significant improvement with both units on. Sure, it was not night and day as it had been before, with a less ideal speaker and sofa placement, but it was unmistakable.
Because the AVAA system does not affect the music signal itself and only affects how the room responds, its effect does not necessarily slap you in the face. But sure enough, whenever I switched the units off, it was abundantly clear how much they cleaned up the sound. Even if the bass was pretty even-handed before, and the test tones did not unveil a difference, the articulation and differentiation in low bass notes when playing music had significantly increased. Moreover, even though the C214s do not operate above 160Hz, I’d swear the soundstage was now better organized, with improved focus and increased clarity, allowing all the little sounds to be more distinctly separated. I kept switching the units on and off, and indeed, transient behavior was snappier, dynamics increased, and the entire performance was now more solid, exciting, and realistic with the C214s switched on. Then, there was one more surprise…
When I stood up while the music was still playing, and without using the C214s, I was unpleasantly surprised by some bass notes playing much louder than others and also lingering on for much longer. In that listening location, it was almost as if I had returned to the old speaker- and sofa positions! Then, I switched the units on, and lo and behold, the sound immediately snapped back into focus! All the bass notes were now evenly loud, and the reverb was gone. Now I knew why the sound still improved so much, despite the absence of obvious effects using the test tones.
Above and below: Placement matters, but it is not highly critical.
Next, I experimented with the precise positioning of the two C214s, and I soon learned that this is not very critical. Whether they are stacked high up in the untreated left and right corners, in front of passive bass traps, or closer together on the floor, the improvements as described are consistent and vary very little. Heck, they even worked well when positioned right behind the speakers. While efficiency varied slightly, and the best performance was achieved in empty corners, the difference was far smaller than I had anticipated. Implementation really could not be any easier.
I did hear a very worthwhile difference between using one or two. Although my left front corner produces the biggest resonance, and a C214 placed there helps most, I found that a symmetrically placed C214 in the right corner helps immensely in balancing the soundstage and focus. In this space, the second unit is less critical and could be considered dotting the i’s, but every time I re-test it by switching the right unit off, I find the blur increases, and I quickly switch it back on. Honestly, I’d have loved it if all I needed was one C214, but alas, two yield a better result.
I also tried a single C214 in the middle of the front wall for good measure. While this still worked to a not inconsiderable extent, the result was less pronounced than with one in the left corner, and with a smaller beneficial effect on focus and soundstage clarity.
Next: Listening Continued, Wrapping Up, Value, and Conclusion
