Fried Transmission Line Satellite and Subwoofer Design.

Discussion in 'Speakers' started by Salectric, Apr 18, 2018.

  1. JimPA

    JimPA Junior Member

    No he didn't use the B110 in a transmission line. enclosure.
    If one would build a scaled down version of the C3L I am sure they would work fine.
  2. Jim,

    What type of wood did Fried recommend for the satellites?

    Which 6.5" driver and which tweeter do you recommend of the units still available? Perhaps you will be coming to that when you get to the crossovers.
  3. JimPA

    JimPA Junior Member

    Back then he stated 3/4 flake board for the C3L and O4 enclosures.

    I used 1" industrial grade for the subwoofers which is primarily used for countertops.
    For constructing the transmission line of the O4 and C3L enclosures 3/4" for the interior pieces.

    For the satellites 1" for the front baffle and back of the enclosure.
    He stated to use 3/4" for the sides pieces for the C3L transmission line.
    Making the enclosures wider would affect imaging.

    I have always used the 3/4" particle board with the small flakes compared to the less expensive 3/4" with the larger flakes.
    I found that cutting precise 7.5 degree angles is easier with the 3/4" particle board compared to using mdf.
    The 1" industrial grade is listed as mdf in the the lumber yard catalog even though it isn't really mdf.

    Both the C3L and O4 are so well braced with the interior pieces of the transmission line enclosure resonances
    shouldn't be an issue.

    I would use the Hiquphon tweeters.
    scanspeak-classic-p17wj00-6.5-woofer or the
    One of the previous owners of Fried Products was selling the Silver Flute 6.5" as replacement drivers for the C3L with a new series crossover design.

    The Gefco drivers are not available anymore a photo of the 6.5" model below.
    The Silver Flute have wool in their cones to dampen resonances like the Gefco models made for Fried.
  4. Which Hiquphon? The OW1 perhaps?
  5. JimPA

    JimPA Junior Member

    Here is the link to Ellis Audio.
    The OW2-92FS has ferrofluid and the sensitivity is 90db.
  6. JimPA

    JimPA Junior Member

    I have listened to the Totem Hawk that use the 15w Scan Speak woofer and preferred it's midrange over some of their other models.

    Also the Scan Speak 7" would be a little to large in Sd. for the C3L enclosures.
    It's disappointing that don't make a 6.5" version of their revelator line.
    IMHO it's because they use the metric system.

    Once I heard the Scan Speak carbon fiber 17w model in a pair of Merlin speakers with the Dynaudio Esotar tweeters and really liked their performance.
  7. JimPA

    JimPA Junior Member

    These are some of the Fried crossover plans.
    These are for the C2 satellite and either O2 or SM2 subwoofers.
    The SM2 use a 12" subwoofer.
    The first one use a parallel crossover design.
    Fried parallel.jpg
    The below schematic is a series crossover design.
    This is when Fried finally switched to all series resonant crossover circuits.

    You can see that the exact same crossover values are used but the layout was changed.
    The subwoofer use a 12 mh 14 gauge air core inductor.
    The mid bass driver us a .5 mh 18 gauge air core inductor.
    Fried always choose 18 gauge for the mid bass driver.
    No zobel is required for the subwoofer crossover in a series design.


    There were a few versions of the C3L crossover.
    The original C3L crossover is a pdf file.
    Also included is a new crossover for the C3L enclosure using the Hiquphon tweeters and Silver Flute 6.5" driver. DSC_0161.JPG
    The below schematic has the C3L values crossed out and the C6 and O6 values hand.written.
    I was told the values and had to right them down LOL.

    The schematic below has the C5 crossover that use the Hiquphon tweeters and Focal 6K412 driver. DSC_0161.JPG

    Attached Files:

    Salectric likes this.
  8. JimPA

    JimPA Junior Member

    Some might wonder what a series resonant circuit is.
    A resonant circuit is a circuit where the inductive reactance of the coil is equal to the capacitive reactance of the capacitor.
    You have a resonance point in the frequency response where both the inductor and cap cancel each other out.
    This is determined by the values of L and C.
    At this resonant impedance will be at it's lowest and current will be at it's highest.
    On either side of this point voltage will be higher.
    With a parallel resonant circuit all of these attributes are exactly opposite.
    At resonance the only opposition to the current is the resistance of the inductor.
    When you have a resonance in a series circuit you get a step up in voltage.
    The opposite happens in parallel in that you get a step up in current.
    For every halving of resistance in the circuit you get a doubling of current and voltage.
    This is why it's important to use air core inductors instead of iron core in the Fried designs.
    Last edited: May 10, 2018
    MikeyFresh and Salectric like this.
  9. Jim,

    So in terms of drivers that are currently available, you would recommend the ScanSpeak P17WJOO and the Hiquphon OW2-92FS? And perhaps the series crossover shown as “C-6” on your pdf file? I realize the attenuation network might need to be tweaked but it would appear this crossover should be ok otherwise. Do you agree?

    I have an old Fried C brochure that makes a big deal about the rounded edges of the front baffle. Yet the later C models seem to have gone back to right-angle edges. Is that correct?
  10. JimPA

    JimPA Junior Member

    The C models are all rounded.
    I used a sander to round mine off a bit.
    The first C3L crossover would be a better choice for the P17WJOO having a 2 ohm Re in series with Hiquphon tweeters with a 18 gauge .5mh air core inductor.
    All that would be needed to change is the zobel and possibly the Re value in series with the tweeter if the 2 ohms wasn't flat.

    Fried tried to eliminate any resistor in series with the Hiquphon tweeter.
    The later crossover used a 30 ohm Re in parallel of the tweeter but he went back to the earlier design I was told.

    You might recognize Trelja from Audiogon.
    i have never met him but he thinks the Silver Flute driver might be better then the P17WJOO.
    The Silver Flute is a paper wool composite cone.

    The C6 and O6 Gefco composite cones have a very low voice coil inductance.
    Fried used these with his MARS ambience recovery circuit.
    Each speaker had the 6.5" and 10" drivers playing both channels.
    One voice coil played the left channel and the other voice coil played the right channel in each speaker.
    I am not sure why he abandoned the use of the MARS circuit.

    i have enclosed the Studio V brochure,
    These use the Gefco 6.5" and 8" drivers with the Hiquphon tweeters on a flat baffle.
    After Fried discontinued the Mars circuit each 6.5" and 10" driver had both 10 ohm voice coils wired in parallel.
    This lowered the voice coil inductance in each driver.

    Another thing Fried did he used the voice coil inductance of his 6.5" drivers as the inductor value in his series satellite crossovers.
    The Gefco 6.5" have a voice coil inductance of .35mh when both voice coils are wired in parallel of each other.

    Attached Files:

  11. JimPA

    JimPA Junior Member

    This Scan Speak driver would work in the O4 enclosures.
    The Vas is a little higher then my Dalesford and Gefco 10" drivers.
    Fried used highly compliant drivers in all of his transmission lines.
    My Fried Dalesford 6.5" Vas are 35 liters the Gefco 6.5" Vas are 30 liters.

    Look at the reviews of the Silver Flute 6.5"
    Most drivers are not suited for a series crossover design.
    One needs a driver with a smooth roll off when crossed over to the tweeter.
    This is why Dr. Raines choose the Silver Flute when he owned Fried Products after Fried passed away.

    Neither Joe Trelja or Dr. Raines have ever heard any of the old Dalesford that I have.
    I haven't emailed Joe in a long time.
    He does live in my county closer to Philly than me.
    Salectric likes this.
  12. Excellent information. Thanks again for sharing all this.
  13. JimPA

    JimPA Junior Member

    Salectric I found another thread about some of the drivers that have been used in the Fried designs on Audiogon.
    One thing about the P17WJOO driver is that it's a stock unit.
    PSB used an oem model if this driver that have a longer xmax.
    These were used in the 90's with a two way model.
    I read a review of this model in the former Speaker Builder publication.

    Fried claimed all of his oem 6.5" drivers were a duo cone design.
    The dust cap shape help extend the response resulting in a low mh.
    All of the 6.5" drivers Fried used had a 1" voice coil diameter.

    Poly cones are going to have a different sound then a paper composite cone sound.
  14. JimPA

    JimPA Junior Member

    Here are some videos of my speakers done with a cellphone.

    My son took this video about 25 feet away from the speakers.
    The highs and lows were diminished due to close miking.
    Last edited: Jul 4, 2018
    airdronian likes this.
  15. JimPA,

    I just won an auction for a NOS pair of KEF B200 SP1022 woofers which, as you know, are the woofers used in the Fried H and M speakers. I am not totally sure what I will do with them just yet but this was too good a deal for me to pass up. The SP1022 has tight, detailed bass and it goes very deep in the H transmission line. The downside is its limited power handling.
  16. I too, keep an extra pair of the SP1022's on hand; just in case I overdrive my model H.

    I have only recently begun to follow this thread and I feel such a loss over what might have been, concerning the sharing of knowledge and talent had we met years ago, as I lived in Bucks County for several decades.
    My father knew Bud during my college days but I never had the chance to meet him. My father and I designed and built many speakers over the years and I have continued on with that hobby.

    Interesting thread.
    JimPA likes this.

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