by Andrew Brandon
This is my third "fullrange driver" project within the last year or so. The first was the "Afterburner" which I did a write up of and James kindly published. Since the Afterburner I also built a pair of Jerico Horns which after disappointing results at first showed their strength after some trial and error stuffing of the compression chamber. The Afterburner was to my ears truly a Fullrange Speaker, a bass reflex cabinet; it used two drivers, a wide range 12" speaker and a Radio Shack tweeter to fill out the highs. The Jerico on the other hand uses a single fullrange driver, the Fostex 208 Sigma which is a 8" driver with a whizzer cone. The Jerico after the aforementioned stuffing episode became my reference, not very low bass but what was there was good with the highs rolled off but nevertheless a wonderful sounding speaker with a tone like no other, the closest I had come to "faithful" sound reproduction, not the real thing but good enough for me. So why the Zigmahornet after the Jerico Horn?
Well, nothing being perfect besides perhaps you and I, I had to try to improve upon the sound of the Jericos. Actually nothing could be further from the truth, it has nothing to do with the Jericos or trying to improve on anything else, its just that I had this sheet of half inch plywood that just kept calling me and telling me that it wanted me to put it on the table saw and shape it anyway I liked and then caress it with some sandpaper and….
Okay back to reality. I first saw the Zigmahornet approximately 2 years ago on a Swedish (I believe) website and it simply appealed to me. I did not pay much attention to it then, after all it was only a 4" driver, the cabinet was nice though, tall and slim, driver at about ear height and slim so it should be a great imaging speaker but I knew that real speakers used real drivers, as in large drivers. Fast forward 2 years and my thinking has taken a 180-degree turn. You know, I read too much. I have been fooling around this stereo hobby for about 27 years and am now "discovering" fullrange drivers. I am either a slow learner or have been reading the wrong things or maybe just reading in the wrong places. Huumm maybe all three? Now I'm thinking too much.
On my travels through the W.W.W, I was looking for other implementations of the Fostex 208 Sigma, after all it's a Japanese speaker so who better to learn from but the makers themselves. I came across several designs for many of the Fostex range of speakers, with the 208's being always used in horns but relatively small horns. I also noticed many designs based around 4" drivers and further to that I would estimate that there were more speakers designed around 4" drivers than any other sized driver. Now I know that Japanese homes tend to be smaller than those in the West and in Japan real estate is extremely expensive so I first thought that it was a size issue but as I read more, a word kept repeating itself on these Japanese speaker sites over and over again……… Tone. The more I read the more I saw it. Tone.
There were two sites in particular that went into some details of a 4" speaker driver, speaking about the compliance of the suspension, the cone, and listing the changes that had been made to the speaker since its inception and the fact that its still available and very popular. The writer even went on to say that at one stage of its life it was changed for the worse many felt, there was an "outcry by hobbyists" and after several years the speaker was changed to its former state. Apparently this design had been around for decades and the justly famous 108 series is based from this speaker and they finished by saying that it is considered by some to be a "high end" speaker. This was the Fostex FE-103. Well after reading all that I just had to part with some of my money!
I realized that tone is what is more important to me and why I preferred the Jerico horn to any other speaker I had heard to date. It was closest to the real thing, no the Jerico did not do everything but what it does right it does wonderfully. So I thought to myself if the FE-103 driver is so popular and many speak highly of it especially about the tone then let me give it a try. Then I remembered the Zigmahornet.
Now, being a computer person I have enough intelligence (read experience but intelligence sounds more impressive) to know not to trust computers so I always print what I consider to be of value and file it away, yup, me who used to work for a company that sold computer imaging solutions and promised quick, easy and reliable file retrieval using our system. Plus I always thought it's easier to take paper rather than a pc to the john to read and you never know, you might need some extra.
Back to the Zigmahornet. I got out the file and took a quick look, real simple and not much wood BUT, I had a hard time figuring out the plan, some of the measurements in the port area simply did not make any sense to me. So to the Full Range Forum I went and asked for help deciphering the plan. A few hours later I got the first of several responses and eventually figured out what was where on the plan. The only "problem" I could see was that the Zigmahornet called for a Fostex 103 Sigma and I found only two places on the WWW who sold same, one in Italy and one in Germany. So, I decided to try the Fostex FE-103. Not the Sigma, and not any of the other 103 series, just the plain Fostex FE-103. I went to the Fostex website to order same but lets just say don't hold your breath. Again I went to the F.R. Forum and again my question was answered, Madisound sells them. So, I called up Madisound and after about 5 minutes and about US$65.00 from my credit card balance they were on the way. Of course I had already started the cabinets and when the building phase was completed I stuck a pair of 40-1197's in. They had been used before in a Buschorn that I had modified to use them so they had been broken in already. So I hooked them up and fired up the amp, not bad, pretty nice actually, they imaged really well as I thought they would but overall nothing to write home about, certainly worth the effort and price but that's about it. A good sounding speaker at a bargain price and it takes up precious little room. The next day the FE-103 speakers arrived. I put them in that same evening and noticed immediately a difference, much clearer but certainly brighter, more tone?
By the way, the R.S. 40-1197 is NOT a Fostex FE-103, not even a kissing cousin. There are similarities yes but that's it, some similarties.
I let them play that evening to break in and also the next evening. After about 7 or 8 hours I noticed the sound changing, smoothing out and a little more bass as well.
Well, it's been several weeks now and I am still in awe with these speakers. The bass is not bad, it does not shake the walls but it does impress for a 4" inch driver. Actually I do not consider them to be 4" drivers, 3 inch would be more realistic. The suspension takes up approximately 1" inch of the diameter. I have yet to start measuring them, I plan to but really am in no hurry. I have always preferred music to test tones but that's just me.
When I refer to bass below I mean upper bass, none of these speakers has true bass.
The Jericos have more bass maybe, yes maybe, I would have to listen to them side by side with the levels equal. The thing is with the Jerico as you play music you usually have some bass, not a lot but you can hear some lows with the music. The Zigmahornets are not like that, a lot of the time you do not notice the bass but when a bass note comes around its suddenly there. I thought that maybe its just the Zigmahornet, after all it is a resonant pipe but when listening to the bass its very tuneful, not a one note bass at all, in fact the bass maybe the most tuneful and articulate. Want to hear a Cello or Standing Bass? This is your speaker.
I do have a sub connected, a 5 cubic foot sealed 12" unit that I also built but do not use very often and find that I leave it off most of the time. I have found that the Zigmahornet is the only speaker that I have successfully integrated with the sub though. Truly the only speaker that the sub "extends", the others I have tried never could integrate properly.
A few things I did with my implementation. I routed out the back of speaker hole so as to allow the speaker to "breathe" more easily. The speaker is mounted on the front so the inside of the cabinet was routed at the rear of the speaker cutout. I also used my Dremel tool to cut 6 "channels" from the routed area approximately 3 inches away, 3 at the top of the speaker and three at the bottom to also aid getting air to the driver. I have placed a square of 1-inch polyester batting approx 6 inches long by the width of the cabinet behind the speaker as damping material. I will try other stuffing at sometime to see what the effect is but for now am leaving the stuffing as is. I also made the port or maybe I should say the block of wood that creates the port removable so I can try other port lengths. The speaker connections are simple brass screws. I used 4 screws to hold on the base of the speaker, the base being another piece of plywood but I am thinking about changing the base to tile or a heavier piece of material because the speaker being so tall and slim is easily knocked over but more importantly, I think it is too light and needs to be coupled to the floor in a more substantial manner. I did put some homemade spikes on the bottom of the speaker to couple with the floor.
I have yet to put a finish on the speaker, it's built with Brazilian 1/2 inch plywood. One of these days I will get around to it.
So that's it, a 4" driver that impresses me no end, it is true and coherent I will not say it's the driver that is the magic, the lack of a whizzer, the small area of the cone or the suspension, neither will I say that the cabinet is what makes this speaker so special. I can only say it's a wonderful combination that must be heard to be believed. I can without hesitation say that every speaker project I do seems to be better than the one before. This combination of the Fostex FE-103 and the Zigmahornet is no exception. It's a combination that the 208 Sigma and Jerico Horn can only dream of.
|You can never have enough clamps !
|So small, you can build two at a time !
| This picture shows the kitchen window in the background. Little did I know at the time that open kitchen windows work as sawdust attraction channels. Even with the wind blowing away from the house the channel attraction is stronger. I spent a lot of time in the kitchen shortly after this picture was taken and have since been banned from the back patio when sawing wood. I am still trying to get back into the wife's good graces so as to have my wood shop returned to me. No luck so far.
To date everyone who has seen them has commented favorably on their unusual looks.
| When I grow up I want to be a Zigmahornet !
The Music I listen to mostly is Jazz,"World Music", Motown from the "60's up and Reggae. Here are my "favorite five" seedee's.
- Beethoven or Bust - Telarc CD-80153 also used for testing.
- Chesky 10th Anniversary Special Edition - Chesky CHE10 also used for testing.
- below the bassline - Ernest Ranglin Island Jamaica Jazz 314-524299-2
- …all this time - Sting AM Records 0694931692
And my all time favorite
- NOVABOSSA:RED HOT ON VERVE - VERVE 314 535 884 -2