Fried Transmission Line Satellite and Subwoofer Design.

Salectric

Senior Member
Don't want to take this thread off track but curious about the large speakers that are under the speakers you are discussing. Love the look of them and am curious what they are.
The large speaker is simply the woofer section that supplements the satellite on top of it. In other words, it's a 3-way system but with the midrange/tweeter in a separate enclosure.

The speakers are not a real Fried design but a hodge podge of his ideas. The satellite is a Model H with homebuilt crossover using the Fried H values. The KEF B110 midrange runs full range on the bottom, i.e. no rolloff in the bass, which limits the power handling (theoretically) but enables a smooth, detailed response extending below 100Hz. The woofer cabinet follows the Model O plans but it uses a KEF B139 woofer instead of a Dalesford 10". It has a huge air core choke made with 12g magnet wire.
 

JimPA

Junior Member
It was brought to my attention by Dan Stanley that Shayne the former owner of Fried Products perfected another crossover for the C6 satellite model.'
Dan and I have had a bit of correspondence about the Fried designs.

The Zobel circuit was delighted.
The inductor value is still. 35mh and the inductor is a 12 gauge copper foil.
The cap value is 12.6 mfd.
The tweeter R1 is still 2 ohms as is the R2 resistor value is still 15 ohms.

Shayne basically changed the Zeta value of the crossover .
Increasing the cap value crosses over the 6.5 woofer at a lower frequency.
When it comes to a series crossover circuit the inductor shunts the tweeter as the cap shunts the woofer.
There are two crossover slopes for each driver by using just a cap and inductor.
With a parallel crossover the cap affects the tweeter and the inductor affects the woofer.
There is no interaction between both drivers like a series circuit.
This is one reason why they called not quite a first order and not quite a second order crossover in some of the AES papers.

If both drivers are at the same exact impedance at the crossover frequency the first octave is 12 db per octave and the following octaves are 6db by using first order Butterworth values.
This is why they are referred to as quasi second order series crossovers.

Another observation is that the R2 tweeter resistor does affect the woofer since this is a series circuit.
With a parallel crossover circuit the L pad or R1 and R2 resistors do not affect the woofer.

The tweeter R1 and R2 resistor values raise the Re to that of the woofer so both drivers have the same exact impedance at the crossover frequency.
Fried did a lot experimenting with the C3L model and tried eliminating the R1 resistor by increasing the R2 resistor value in parallel of the tweeter.
I have seen at least 3 different crossovers for the C3L models where he went back and forth with the resistor values.
Most of his series crossovers use a R2 15ohm value in parallel of the tweeter.
I have found this value works quite well building clones of the C3L model using completely different drivers.
 
JimPA, When I install the Gefco drivers in my C3L cabinets I'll need to change the crossovers to the C6L design. Do you recommend implementing the design you discussed above?

Just noticed it uses a different gauge and type conductor for the inductor. Is this an off the shelf item?
 

JimPA

Junior Member
JimPA, When I install the Gefco drivers in my C3L cabinets I'll need to change the crossovers to the C6L design. Do you recommend implementing the design you discussed above?

Just noticed it uses a different gauge and type conductor for the inductor. Is this an off the shelf item?
I have only used the original C6 crossover.
L1 18 gauge air core .35mh
C1 6.8 mfd cap.
Tweeter R1 2 ohms and R2 15 ohms.
Midbass Zobel 2 mfd cap 10 ohm resistor.

I have yet to try the later one Dan Stanley informed me about.
Knowing Shayne it probably sounds very good.
 
I have only used the original C6 crossover.
L1 18 gauge air core .35mh
C1 6.8 mfd cap.
Tweeter R1 2 ohms and R2 15 ohms.
Midbass Zobel 2 mfd cap 10 ohm resistor.

I have yet to try the later one Dan Stanley informed me about.
Knowing Shayne it probably sounds very good.

I finally installed the Gefco drivers. The drivers are dual voice coil and I assumed they needed to be connected parallel. I still need to modify the crossover. Audibly, the mid-range is way too prominent.
 

JimPA

Junior Member
I finally installed the Gefco drivers. The drivers are dual voice coil and I assumed they needed to be connected parallel. I still need to modify the crossover. Audibly, the mid-range is way too prominent.
Yes the voice coils have to be wired in parallel.


I noticed the eBay seller listing for the drivers has come to an end.
202668661385
 
Back in 1979 Fried was discontinuing his use of all the Kef drivers.
I have only seen photos of the Kef 8" driver used in the model H subwoofer.
When Fried came out with the B-2 satellites for use with the H subwoofer is when he switched to Dynaudio D-28h for the tweeter.

He also switched the 5.5" driver to the Dalesford.
He also made the H two separate units and used the Dalesford 10" which he called the model T.

I don't know of any source for new old stock anywhere.
Falcon Acoustics is making new Kef B110 units like the ones used in the Ls3/5a.
falcon-ls3-5a-b110-drive-units.html
The price is up there for the new drivers.

I do have plans for the Fried C3L transmission line model which I have built quite a few pairs of.
I also have the crossover plans for using the Silver Flute 6.5" with the Hiquphon tweeters hiquphon.htm if you wanted to build a pair.
Some people claim the Silver Flute 6.5" performs as well as the Vifa P17WJOO 6.5" woofer.
scanspeak-classic-p17wj00-6.5-woofer
The Vifa driver was renamed after Vifa was bought out by Scan Speak
Jim,
Could I get a copy of C3L Plans? I owned a pair of Qs from back in the day when they were the most I could afford. A few years ago I purchsed a set of Ms which is what I really wanted when I bought the Qs. (I gave the Qs to my daughter who is still enjoying them.) My M's have the original drivers in them and all work great except one tweeter which is a little flakely. The cabinets are starting to show the years in wear & tear, especially the top caps which were fragile to begin with (If anyone has plans for building replacement caps I would to have them.) The Ms may look a bit worn but they sound so good. Just about everything else I have auditioned made me walk away because they just didn't sound like real music like the Ms. I actually had the opportunity to enjoy a lengthly phone call with Bud many years ago. He was easy to talk to and very willling to take time to discuss his speakers and thoughts on design. I have some documentation on the Ms, (crossover schematic, M2 upgrades, although I hear the drivers are almost impossible to find) if anyone is interested.
 

Salectric

Senior Member
The drivers for the M can be found but they can be expensive. There is a company making the B110 and T27 again. I forget the name but it might be in this thread. The real problem would be the B200 SP1022 woofers. They weren’t easy to find even while they were still being made. But if you keep a Saved Search on eBay they will come up from time to time. I managed to snag a pair of NOS SP1022s still in the original KEF packaging. If your woofers haven’t been abused they should still be fine. Fortunately they don’t disintegrate like woofers with foam surrounds.
 

JimPA

Junior Member
Jim,
Could I get a copy of C3L Plans? I owned a pair of Qs from back in the day when they were the most I could afford. A few years ago I purchsed a set of Ms which is what I really wanted when I bought the Qs. (I gave the Qs to my daughter who is still enjoying them.) My M's have the original drivers in them and all work great except one tweeter which is a little flakely. The cabinets are starting to show the years in wear & tear, especially the top caps which were fragile to begin with (If anyone has plans for building replacement caps I would to have them.) The Ms may look a bit worn but they sound so good. Just about everything else I have auditioned made me walk away because they just didn't sound like real music like the Ms. I actually had the opportunity to enjoy a lengthly phone call with Bud many years ago. He was easy to talk to and very willling to take time to discuss his speakers and thoughts on design. I have some documentation on the Ms, (crossover schematic, M2 upgrades, although I hear the drivers are almost impossible to find) if anyone is interested.
The C3L plans are on post #19.
 
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