You know, it really pleases me to see all of the reviews that have been listed here regarding the old legendary, if you will, Ohm Walsh F's. While I have never heard the F's, I have heard a set of A's a number of years ago in the living room of my uncle, Bob Ajaye. From what I remember, the A's were substantial in everything they did. i mean, big heavy speaker in a rather large cabinet and sound for days! Also, completely unconventional when you consider it on construction and functionality alone.
I'll be sure to pass along this pages URL to my uncle the next time that I speak with him about how his A's are and have been holding up over the years. You know, I might even get him to participate in few of the forums. Time will definitely tell.
These speakers are simply among the finest speakers in the world. If they are in good condition they will rival any current speaker by any manufacturer at any cost. HHRExotic speakers are the ONLY knowledgeable source that is rebuilding/remaking these speakers.
I have 2 pair of the original speakers, one HHR Exotic repro and one of the newer Walsh Ohm Acoustics models. The best sounding speakers are the HHR's followed very closely by the older OHM F's. Which are in good shape.
No other speaker at any cost can rival a good pair of these. Period.
Introduced to Ohm Acoustics by another friend who had bought Ohm A's, the only speaker that made my head turn to look for at the singer. I attended the "world premier" of the Ohm A in the early 1970's, extremely impressed with the sound, and wanted a Ohm Walsh speaker.
First hear the F's when introduced in 1973. Bought them from a friend a few years later. Then upgraded to the Walsh 5's in the mid-'90s. I write here, less of a review and more of what I experienced as an owner for 19 years, perhaps helping the current owners enjoy it more. Other reviewers have more than covered the great sound of these classic speakers.
The F's has a silky high end, when new. It changes slowly over a long time as the "putty" like coating dried, in the titanium, gray-colored upper section. I didn't notice the gradual change, but the highs were different. Thought of fixing it, but Ohm no longer repaired them. The shiny middle section is aluminum with a foam backing. That foam deteriorates over time, and is nearly impossible to replace correctly. The edge surrounds at the bottom of the cone also rots over time. I read that Ohm has better foams now that last 20-30 years.
Despite the aging of the drivers, the sound remained good and clear, even the sibilant 's' on vocals was still clearly heard. I assume that this is because the foam did not fall off the inside of the cone yet, although it was crumbly when touched. I bought a kit and replaced the bottom cone surround foam that finally fell apart, and the speakers regained some lost bass and worked fine again. Critical that you center the surround properly, or the voice coil will run against the magnet and can cause failure of the speaker.
Used a 60 W/ch amp at first, and the sound was very good. But when I turned up the volume, the sound became distorted. Not enough power to run these F's.
Next got a direct-coupled amp that puts out 300 W/ch into 4 ohms. Wow! It brought the speakers alive. the amp has high damping factor, nearly 500 at mid frequencies into 4 ohms. Get an amp with power and damping for these. Normal listening does not require much more than 1-10 watts, so these amps work fine for music peaks of 100-200 watts. Much louder, you need a bigger amp, but the speaker can't take continuously high power. Look into recent Walsh speakers that can take more power.
One reviewer metioned the binding posts, and another the fuses. Recommended were GBB-4-amp from the factory. I tried various fuses and found all of them affected the sound, especially the faster-blowing kind, like the GBB. Be careful with higher than 3 amp fuses. Good if you want to replace the binding posts; I did not find the need to do so, but wired larger 12-gauge cable directly to the post, bypassing the smaller wire internal to the box.
The F's also had different supports over time. The very first ones had a flat steel bar with a small slat of wood glued to it. Later there was more wood and even later, a metal channel support. Either way, I wrapped black felt around the bars, and that improved the sound by absorbing some of the diffraction and reflections from the support members. Do the same for the wood inside surfaces in the grille cloth frame, and the black wood surface that the driver is bolted to, overlapping the felt onto the metal rim. It's best to listen without the grill frame anyway for the best sound, although the sound is still good with grilles on.
The F projected a very wide stereo image, that sometimes went beyond the left and right speaker. The focus of soloists was remarkably good. I did not try to verify the phase coherency with measurements, but could hear effects that demand good coherency, and phase coherency match between the two speakers. I was able to hear surround signals on video recordings coming from behind me that went overhead toward the front center as the source moved in that direction, using only a single pair of F's in the front. Some signals sourced at the side of the listener, were placed there, again with two F's speakers only, no other speakers used.
I had these speakers on vinyl tile over concrete floor and they sounded great. In a room with carpet over foam padding, the sound muddied a slight bit. That was improved by placing the speaker on supports that have points that connect the cabinet bottom through the carpet and pad to the wood floor. The most noticable change was improved bass.
Placement of these F's vary all over the room. They sound greatest in my room of about 17x25 when placed 2-3 feet from the long wall, and about 8-10 feet apart. The bass varies with the room, but is very powerful clear down to below 35 Hz, although the spec is 37 Hz. I also had no obstructions between them or in front of them to the listening area. Damping/absorbing material on the wall both behind and between these speakers can improve the image even more. Don't over do it, or the mids and highs get absorbed too much and you get over-bassed. Move these around to get the best overall sound and leave them there.
Other listeners visiting my home remark that the sound is so clear. I found the sound very smooth too. Listen to an instrument that runs up the scale from low to high and hear how even the sound is.
Those that have F's, try swapping the drivers from left to right and see if the sound improves or degrades. My pair sounded better in one configuration.
Overall, if you can still find these, get them. You can upgrade through Ohm later. They are large and take up room, and need space around them to sound their best.
In 1972 I worked as an Audio Consultant in Roanoke VA. Our store was an Ohm Acoustics dealer. We had just seen the Ohm A and the new and much smaller Ohm F at a show in Wash DC. The handmade, one-off Ohm A's were magnificent. Actually the pic you see above is the Ohm A, the commercial smaller Ohm F was about 2/3 the height and width of the A and its Walsh cone had the bottom 2/3 made from a paper composite material, while the top high frequency portion was of titanium foil. The Ohm A on the other hand was 100% metallic cone, 18" diameter at is base (the F was 12" I believe). The model A cone was heavy aluminum as its base which extended about 3/4 of the cone height to the transition to the titanium foil "tweeter". The aluminum and titanium portions had different conical angles also, while the F used a single cone angle. The tweeter designs were similar on the F anf the A, the midrange, woofer and the voice coils were very different however. Bob Ajaye of Ohm was the master builder and tuner of the A, while the F was an assembly line "mass produced" product. I used Dynaco ST400 power amps, strapped to mono (600W rms per channel) on the As. I had Dyna preamps to, the PAS3x and the PAT4 and PAT5. I listened mostly then to rock music, and eventually blew the A's voice coil after a particularly loud and out of control party one Saturday afternoon. After the voice coils melted on Lou Reed's Rock 'n Roll Animal , we dissasembled the driver from the base cabinet and I remember getting burned on the giant magnet assembly! Damn that hurt! Man, those were the days. But not to worry, Bob Ajaye rebuilt them for me (under warranty!!!) and I was back in business in about 10 days.
Sonically, the A had thunderously powerful bass response, but relatively clean, even with the (veiled sounding) Dyna equipment. Denon turntable, Formula 4 (Polk distributor) tone arm and Fidelity Research MkIII moving coil cartridge. dB Systems MC-preamp. Back to the A's sound: the midrange and high end was crystal clear with just a hint of a FR dip in the upper mids. Cymbals would actually shimmer and hang in 3-D relief in my room. Unbelievable realism. The stereo image was to die for as these speakers were completely cylindrical and thus nearly omni-directional as a result. We used a lot of room sound control as I remember but once the room was tuned, it was pretty amazing. Talk about getting involved with the music! I started my own audio store in Roanoke iVA in 1975 and lost touch with Ohm. I heard that Bob Ajaye had left the company and took a lot of the Walsh practical knowledge with him. In 1984 I was a grad student at Duke (MSEE) and I needed money - I sold the A's to an eager guy who drove down from Pennsylvania to pick them up. My loss, was his gain. As he left, he was grinning from ear to ear. I was too, since I knew all too well what he would experience when he got them home and all hooked up. Tha Ohm A magic. - David R Smith