A few observations regarding NlightN loudspeakers
Pete W., CTS
Content: October-2003, updated: April-2005

I recently received and offered to evaluate a pair of NlightN brand loudspeakers, manufactured by Carlsbro, U.K. under license from NXT. They are a rectangular, flat panel design with rigid frame, using six voice-coil driver motors to energize a rectangular, low mass diaphragm.

Cut to the chase:

  • The NlightN loudspeakers fared quite poorly for recorded music playback due to poor low frequency response.
  • The loudspeakers sound very good for vocal reinforcement, but only when listened to in a relatively near-field environment.
  • The loudspeakers sound very good for acoustic guitar amplification, but are sensitive with regards to room placement.

Preliminary description-1
Preliminary description-2
I am very familiar with line of flat panel loudspeakers manufactured for many years by Sound Advance Systems, particularly their two-driver BT-82. I found the general construction to be similar, with the exception of the six NXT drivers, and I have been eager to compare the two brands. The listening tests below are entirely subjective and entirely too verbose.

General Observations: Construction

The NlightN loudspeakers appear to be physically well designed. In handling these loudspeakers quite a bit over the last couple of weeks, I really appreciated the front steel grille for handling protection and wish that Sound Advance had a similar grille available as well. I recommend that protective grilles should be made available for the rear of the loudspeakers as well to completely cover the flat diaphragm.

If I had to nit-pick, there are only a couple of things which stood out:

1. Both the front perforated front metal grille and the cover for the driver assemblies on the rear of the loudspeaker have a particularly strong metallic ring when tapped. I don’t know how this could be mitigated, but in my brief tests they did not add any coloration to the sound that we were aware of.

2. When received, a couple of the voice coil leads were hanging in contact with the diaphragm, as shown below. I gently pushed them back out of contact.

Side view of the motor

The six little NXT motors (comment received: "Aren't those precious?!") are mounted in a cluster toward the center of the diaphragm and appear to be wired in a series/parallel arrangement. The claimed power handling capability of the loudspeaker is “100 Watts,” but I am still awaiting real (RMS) test specifications from the distributor. In my opinion, the motors do not appear to be capable of significant power handling capability—either thermally, or in what little magnet structure I could observe. There is no discernable heat sink or metalic substrate provided on the voice coil/diaphragm side of the motors, shown at the bottom of the image above. I am sure this is why the frequency response has been rolled off below 100 Hz.

I am disappointed at the lack true engineering specifications for these loudspeakers as are available for the Sound Advance products. In spite of the preliminary sales literature, these loudspeakers are not able to defy the laws of physics.

General Observations: Listening

Use test #1 was in a 25’ x 35’ room with all hard, reflective surfaces. The speaker was mounted on a tripod about six feet from a wall. We used a TOA 60 Watt integrated amplifier, Shure SM57 microphone and CD player for the test.

Amplified speech was well balanced, requiring no equalization. However, in this hard acoustic environment, the omni-directional nature of these loudspeakers causes sound to reflected everywhere. In many listening locations in the room, perhaps only 12 feet from the loudspeakers, the apparent point of sound origination was completely cancelled out, leaving a broad, diffuse sound source. This is probably nirvana for brainwashed fans of Bose music systems, but for vocal reinforcement this is quite problematic.

Please refer to an excellent article published in Sound & Video Contractor: A World of Reflections.

The frequency response of the loudspeakers for voice reproduction is very good. The frequency response of the loudspeakers for recorded music reproduction was unacceptable due to the dreaded 100 Hz roll off. The loudspeaker did appear to be less prone to feedback with a mic in close proximity.

Use test #2 was at a large M.I. store having an open, 20-foot ceiling. The speaker was again tested on a stand about 12 feet from the nearest wall, with powered mixer, SM-58 and CD player.

Vocal performance was quite articulate and balanced, with no EQ required, up to about 20 feet. Past that point, direct sound became much too diffuse for adequate vocal sound reinforcement.

Music playback was again a disappointment due to the 100 Hz roll-off, and deemed unacceptable without additional low frequency help. Earth to Marketing: Having to drag an auxiliary subwoofer around absolutely kills any portability benefits of the NlightN loudspeakers.

We then tested acoustic guitar. On the stand, the loudspeaker sounded quite good and the transient response was outstanding. The 100 Hz roll-off was not noticeable, but was perceived as a "lack of power" or effiency. When the loudspeaker was taken off of the stand and placed on the ground, there was a perceived increase in low frequency extension which made the instrument really sound great. The manager of the store said they "kicked butt" on his various brands of so-called acoustic guitar amplifiers, but he was concerned about the aggregate cost for that application (I am, too).

Use test #3 was at a local 300-seat church which offers contemporary acoustic and electric music styles. The speaker was initially set up on a stand centered on the raised stage, around 8 feet from the rear wall, and 20 feet from side walls. There is 2" of Fiberglas acoustic treatment on all walls surrounding the stage area. We initially tried a Shure M-58 mic with no equalization, Soundcraft mixer and Crown amp.

Since the reflections from the rear of the loudspeaker were greatly absorbed by the acoustic treatment, the direct sound "throw" of the loudspeakers was significantly increased, to around 40 feet. The loudspeaker was essentially made directional by the absorption of the sound from the rear of the loudspeaker! Again, I liked the vocal balance, but it did not particularly suit the musicians and singers present.
Pick it, Daniel.

We then took the loudspeaker off of the stand and placed it in various placed around the stage for use as acoustic instrument amplification. Here, it is shown on the floor about three feet from the rear wall. It sounded good and was very well received.

When placed at floor level in front of the musicians and vocalists, it excelled as a vocal stage monitor, as the vocalists could be significantly off axis without losing high frequency response. This is also the most problematic location, because the strong, direct sound from the rear of the loudspeaker competed with the house loudspeakers. The vocalists wanted to keep the NlightN's. I declined.

Use test #4 took place briefly at a local fine acoustic instrument store. We used a Yamaha amplifier with a variety of instruments, including a Gretsch jazz electric.

The Godin and Taylor guitars sounded very good amplified; and again the loudspeaker positioning within the room was critical to the perceived sound balance. The Gretsch electric caused various mechanical buzzes and rattles from the frame and grille of the NlightN loudspeaker, due to the significant low frequency energy. It was worth a try. I also discovered that the K&M Heli guitar stands worked great to hold the NlightN's at floor level.

Conclusion

Those of us who have had a chance to evaluate the NlightN loudspeakers have been attempting to determine exactly what applications these loudspeakers were actually designed for--separating hype from reality--and where they could be considered a valid alternative to a conventional loudspeaker. Discarding what I found to be unacceptable uses in my brief tests leaves a couple of scenarios:

In a fixed installation with additional subwoofer(s), the NlightN loudspeakers would probably be a great sounding, albeit novelty, foreground music system. Without knowing the MSRP of the NlightN's, I suspect the installed cost would be somewhat higher than conventional loudspeakers.

Specifically as the loudspeaker component of an acoustic guitar amplifer, these loudspeakers would probably be very well received. Until another music source is played back through the system.

After carting these loudspeakers around for a couple of weeks, I truly grew weary of apologizing for the "lack of bass." Nevertheless, as a semi-professional musician I see the promise before me of a lightweight and accurate stereo sound reinforcement system which would fit entirely in the rear of a PT Cruiser. Unfortunately, the NlightN loudspeakers do not fulfill that promise. Fortunately, Sound Advance loudspeakers do.

You can read more of the promotional material at the NlightN website.

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