NF-1A Monitor Review

ã 2001 by Eddie Ciletti

On first listen the Fostex NF-1A sounds different from most monitors. Many have a smiley-faced EQ curve with lots of boom and sizzle to make things sound good. If your critical listening needs have not yet been met, check out the Fostex NF-1A. You’ll find it provides more midrange detail where the ear is most sensitive than the current trend of monitors.

The Fostex NF-1A is a bi-amped two-way monitor system that lists for about $1800. Rear panel balanced inputs appear as both XLR and ¼-inch connectors. In addition to tweeter level, +/- 3dB trims provide gentle manipulation of both low and high frequency slopes plus a special "mid-dip" switch — centered at 3kHz — reducing that area by 3dB. The NF-1A features a 6.5-inch woofer with a cone design Fostex calls a "hyperbolic paraboloid." The unique shape keeps the low-mass cone rigid to minimize distortion and extend its useful response — the cross-over is at 5kHz — with a sculpted edge-surround designed to control resonance. Fostex claims the soft dome tweeter is capable of reproducing 40kHz. Our independent lab tests concluded the tweeter continued to deliver useful information well beyond 20khz, exceeding the standard window of concern for monitor testing.

No speaker system is perfect and it may take a few listens before you become comfortable with the NF-1A. That’s not a bad thing. There are engineers who still prefer Tannoy and Altec coaxial monitors and even the Yamaha NS-10, because each "makes them work harder." A Control Room Monitor should be like a dominatrix that "encourages" discipline and restraint, revealing excessive or deficient EQ, poor mic choice or placement. I think the NF-1A has a midrange clarity that is reminiscent of these "classics" while being more articulate, less fatiguing and with better imaging. 


Two identical monitors placed side-by-side will sound different because of the distance between each and the listener plus the interaction of cabinet geometry. Note that some monitors have rounded edges, some are square boxes and others are sculpted into shapes that seem to have been inspired by aircraft design. Location and cabinet geometry affects the sonic fingerprint and imaging of a single monitor as well as whatever neighboring alternative system you may have.

That said, my experiments ended with the now discontinued Yamaha NS-10 on the "inside" and the Fostex NF-1A on the outside. Many people are intimately familiar with the Yamaha NS-10, comparing the two suits the purpose of this evaluation as you will soon see. Figure-1 shows three frequency response measurements made by Michael Shields, a custom electronics engineer who doubles as a monitor system specialist. 

Listen to the Fostex NF-1A and you may notice a hint of the Yamaha NS-10 in the midrange, confirmed after taking a close look at the region between 600Hz and 3.5kHz in Figure-1. The blue bump in the middle is a stock NS-10. The similarly shaped, but less exaggerated green below is the Fostex NF-1A. Red is the same NS-10 with a crossover modification. Between 600Hz and 6kHz the NF-1A is smoother than the NS-10 providing a level of clarity that was most helpful when re-mastering 78RPM recordings. Other monitors that are "soft" in this region would have exaggerated the rumble and surface noise that remained — after using Cedar De-Click, De-crackle and De-Hiss hardware — serving more as distraction than assistance.See the Sidebar "Sans Chemicals" for the spicy romance novel details.

Figure-1: Comparison of Fostex NF-1A with stock and modified Yamaha NS-10.


Michael Shields tested the Fostex NF-1A via Bruel&Kjaer 2010 analyzer and the 4440 gating system using a Bruel&Kjaer 4134 / 2619 microphone. The analyzer generates a sweep-able tone burst that was designed both to improve measurement accuracy as well as to reveal system resonance. This was most apparent between 600Hz and 800Hz, an area that previously confused other reviewers. Taking notice of the product literature, Michael and I removed the woofer to evaluate the two internal hyperbolic reflectors. Tapping on them revealed resonance in the aforementioned region although their intended purpose is to break up standing waves within the cabinet. The resonance was greatly reduced after wrapping each in Thinsulate, a 3M product distributed by Lester Acoustics.

There is notable peak between 8kHz and 9kHz that is more pronounced than I’d like, but it can be tamed a bit by the controls provided and it does provide a crisp image. For this reason, the 3khz mid-dip switch might better serve the NF-1A either if centered at 8.5kHz. (Fostex is allowing me to make some tweaks that I will share with them and users if successful.) 


Mr. Shields posited that achieving "measurement flat" response is not necessarily musically appealing and suggested that all monitor systems should allow an optional roll-off starting at 2 kHz with a 3dB / octave slope. Working as lab assistant to such a knowledgeable person — rather than just being handed a response chart — helped to confirm what I’ve come to instinctively feel, that most monitors are too bright AND that the available controls do not provide a suitable degree of flexibility. Out of the lab, I only attempted to match the Fostex NF-1A with the Yamaha NS-10 for the sake of comparison — both being a little bright for my taste — yet the NF-1A is more engaging than many and not fatiguing like the NS-10. 

Above 300Hz, our measurements were basically in agreement with the published response chart for the Fostex NF-1A. Measurement below 300 Hz requires a modification to the test procedure, an area we did not concentrate on because in the real world, I didn’t find the NF-1A to be lacking warmth as the graph might suggest. Again, our "lab" tests were more for the purpose of comparative analysis using a known reference. The combination of a self-powered monitor, a unique "low" frequency driver and a ported cabinet gives the Fostex NF-1A a tighter and more extended bottom, albeit less pronounced than the upper bass / lower mid region of the NS-10.


This background information is for those who may not realize that Fostex has been in the loudspeaker as well as the hard disk recorder business far longer than most, if not all, of its competition. These are my words, not theirs. Other companies market products for the sake of catching a trendy wave. Fostex products sometimes go unnoticed for being ahead of the curve. I think the NF-1A self-powered monitoring system deserves a listen. 

The parent company of Fostex is Foster Electric, a designer of loudspeaker components and systems. I have always considered "them" to be pioneers, taking chances and applying new technological developments to ideas that were ahead of their time. One look at the NF-1A woofer and you’ll seem what I mean. Foster was applying Ribbon-Transducer technology — to headphones, coaxial speakers and microphones — back in the eighties during the explosion of narrow-format analog tape machines. Look at how popular ribbon technology is today!


One day long ago I had the good fortune to hear an analog safety copy of the Beatles "ABBEY ROAD" through a pair of Altec 604 monitors. Having grown up with the vinyl being played on less than studio quality systems, the experience transported me back into time and was deeply moving. When evaluating the Fostex NF-1A, I listened to an assortment of CDs as well as some vinyl ending up with a Capitol-era Sinatra compilation that, then as now, is still a great example of recording technique. Those who are vintage crazed might have a romantic attachment to the equipment, but I place importance on performance talent first and then the ability to make technology work for you.

That said, the Fostex NF-1A made excesses of EQ seem obvious, but not painful. (Some "good-sounding" monitors can cross the threshold of pain all too quickly.) When it was time to put the Fostex NF-1A to work, I was in the process of compiling the recordings of Art Lund, a 1940’s vocalist who sang with Benny Goodman (on Columbia) and later had his own career on MGM. These were all 78 RPM records that I had transferred, de-clicked and de-crackled using CEDAR hardware. In those days, recording equalization was not standardized amongst the various record companies. That occurred later, when the RIAA actually served a useful purpose by setting the standards for the LP and 45. (Unlike now when no one seems to be able to come up with an acceptable compromise between FREE and ROBBERY.)

The lack of an equalization standard combined with the recording equipment of that pre-HiFi era plus the challenge of playing 78RPM records now made me thankful that the Fostex monitors were available at this stage of the compilation. As suspected, the more pronounced midrange of the Fostex NF-1A forced me to reconcile the sonic discrepancies from tune to tune. I could really hear stylii characteristics — various dimensional variations are available to archivists in order to extract the most from these aged grooves. 

After tackling the major issues, I burned a reference CD and transported it to my various alternate systems. Perhaps not surprisingly, everything seemed to be coming from the "same place" as it should be. I was actually able to enjoy the music and nearly forgot about the struggle to get all the stuff to that magic place.

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