Fulton FMI 80

One evening, I spotted the above pair of speakers on FB marketplace. The description was plain and simple, "a pair of speakers in wooden cabinets for $30." Since the seller was less than an hour's drive away, I immediately sent a message expressing interest. I received a quick reply and set an appointment to pick up the following morning. 

Although Robert W. Fulton's FMI 80 speaker system developed a following in the mid 70s, my first exposure to his audio activities was via Fanfare magazine in the early 80s. He wrote the article "Prerequisites for Capturing the Musical Experience" for the same publication, extolling the virtues of directly heated triodes. Joe Roberts reprinted this on page 20 of the premiere issue of Sound Practices.

Fulton J Modular
Top to bottom = RTR electrostatic tweeter panels + FMI 80 + Bass Bin

Stereophile's J. Gordon Holt was an early champion of the Fulton FMI 80 and J Modular speaker system. Both models were also warmly received by the Boston Audio Society in December 1975.

According to Robert W. Fulton's bio notes, he was sort of a renaissance man who, aside from being an engineer, played the trumpet/cornet, listened to (and recorded) mostly classical music + some jazz. It's been proposed that he developed the FMI 80s as near-field monitors for his recording projects. As we get past computer simulations and edge towards the dawn of artificial intelligence, we need more audio engineers like him who are intimately familiar with live acoustic music, yet very well grounded technically.

Bob wired the 8" paper coned/alnico magnet ROLA (2203 24592) as a wide range driver in an acoustic suspension cabinet. Wide range is just how I like to use my Altec 414A, 756B and 406Z/-8Y. 👍

To compensate for the mechanical roll off of the ROLA 8" driver, 2 x Peerless MT225 2.25" paper cone/alnico magnet tweeters are blended in around 1500 Hz to augment upper harmonic overtones. The silky smooth and airy top end remind me of my favorite conical tipped phono cartridges. 

 

 

There is an official Fulton Musical Industries website. Unfortunately, it offers scant information about their legacy products. The above FMI 80 brochure and crossover schematic were taken from the Fulton FMI speakers - model and parts reference thread by Josh Hendi in Audio Karma. This is the most comprehensive source of information about Fulton speakers I've found to date.

Using a 1 kHz sine wave input and adjusting levels for 2.83 V rms at the speaker terminals, the needle in my Radio Shack SPL meter was hovering between 94-96 dB at 1 meter, which is pretty close to the figure claimed in the brochure.

Let's see how Bob Fulton's paper cones + alnico magnets + simple XO concoction in an acoustic suspension box deal with Julie London.

Since the FMI 80 was introduced to the market at the tail end of Altec 755E production, I can't help but wonder if Bob Fulton was familiar with any of the various permutations of the Altec 755. Why? Because its tonal balance, frequency range and dynamic abilities are closer in nature to the Altecs.

Back view of my FMI 80s

Based on the vintage looking L-Pad and barrier-type terminal block, my FMI 80s were modified early in their life. In spite of the mod, the wiring still corresponds exactly to Josh Hendi's XO diagram above. Perhaps the presence of an L-Pad had more to do with being able attenuate the top end rather than cap rolling or...? 

Fortunately, the original 6uf Callins cap was retained and both measured perfectly. The Callins acquitted itself remarkably well when compared to vintage paper in oil cans in my stash. I left them there for the rest of my listening evaluation since that was how Bob voiced it as suggested by Salectric (post #4) in this HiFi Haven cap discussion.

Prior to launching his own moving coil cartridge, this Vinyl Asylum discussion alluded to Fulton's preference for a Shure V15 Type IIIG with a simple stylus profile. Since an original VN3G are as rare as hen's teeth, I'm using a generic conical from Voice of Music attached to my V15-III body to play David Bowie + Pat Metheny Group. 

I've listened to the FMI 80s extensively with the tweeters fully attenuated by the L-Pads. The ROLA 8" driver is devoid of nasty upper midrange break up modes. That smoothness in response comes at the expense of snappy transient ability, which doesn't quite escalate heights achieved by the Altec 755E. With the help of dual Peerless MT225 tweeters, some may actually prefer the FMI 80. But it's best to hear them for yourself and decide.

This Donald Byrd + Booker Little track is traced by a Fulton RS-1 (Entré EC15 body) moving coil cartridge with conical stylus. In this video the FMI 80s is driven by a 1250 mWPC triode strapped choke-capacitance coupled SE46 amp.

It's clearly evident that this above 90 dB sensitive FMI 80 was designed by someone who's not only a highly competent engineer but more importantly, used his musically-trained ears! 

I was completely enthralled by the Fulton FMI 80's performance, but it fell just a bit short of the musical standards set by the Altec 755Cs and even more so, the Altec 755As.😉