Tweaking Home Theater Pt. 11 - Douglas Connection DCF-92 Speaker Cables

DarqueKnightDarqueKnight Posts: 6,603
edited August 2018 in Electronics
Introduction

My initial intent to downsize my home theater from 5.1 to 3.1 turned into a major upgrade cycle where the three power amplifiers, Blu-ray player, front, center, and surround speakers, preamp-processor, and interconnects were upgraded. All video media (DVDs and Blu-rays) were transferred from disc to a NAS server. The equipment cabinet was modified to accommodate a large center channel speaker. This project began in February of 2017 and recently concluded with the replacement of the Monster Cable Z3 Reference speaker cables used on the front and center channel speakers. The upgrade speaker cables were Douglas Connection DCF-92.

This is actually my second and third pair of DCF-92 speaker cables. I have a 25 foot pair in my rig at work.

bcwk5jcuq4bk.jpg
Figure 1. Life in audiophilia/videophilia -- a small downsizing project turned into a big upgrading project.

The Speaker Cables

oghn0pfqts12.jpg
Figure 2. Douglas Connection DCF-02 speaker cables for front and center channel speakers.

iyffxukdeydn.jpg
Figure 3. Douglass Connection DCF-92 on left, Monster Cable Z3 Reference on right.

Monster Cable Z3 Reference - This speaker cable was manufactured from the late 1990s to early 2000s. Monster no longer offers home speaker cables.
Features:
Time Correct windings for better imaging
Magnetic Flux Tube for less interference
PEX™ Dielectric for lower noise floor
MultiTwist Construction: tighter winding for enhanced clarity and inner detail
Duraflex jacket for long-lasting resistance to abrasion and chemicals
Incorporating Monster's patented Microfiber dielectric for faster transients and superior clarity.
Soldered gold plated brass terminations with gas-tight screw-on gold plated brass spade and banana connectors.
Oxygen free copper
Effective wire gauge: 10 AWG
Price: $350 for 10 foot pair.

Douglas Connection Furez DCF-92
Features:
Star Quad noise cancellation wire geometry
Foamed Polyethylene insulation (FPE)
High conductivity oxygen free copper
Solderless construction
Furutech 211 R solid copper spades with rhodium plating, vibration damped resin housing, and solderless set screw wire connectors
Effective wire gauge: 9 AWG
Price: $456 for 10 foot pair

Cable Conditioning (Break In)

Wire insulation has dielectric properties that can store and release energy similar to a capacitor. The release of energy by the insulation creates noise in the audio signal. Running a signal of sufficiently high current amplitude through the wire charges and polarizes the insulation so that its capacity to store and release energy is greatly diminished.

The Audiodharma Cable Cooker runs a high current, wide bandwidth conditioning signal through a cable and greatly shortens break in time. For speaker cables, the Cable Cooker's conditioning signal is a nominal 1.88 amperes at 12 volts, or 22.56 watts. The LSiM 707's sensitivity with 1 watt at 1 meter is 88 dB. An input signal of 22.56 watts would produce an output of 101.5 dB...very loud.

0lbr432pjrmr.jpg
Figure 4. Douglas Connection recommends a break in period of 60 to 100 hours. One hour on the Cable Cooker is approximately equal to three hours of ordinary play back time. I ran the Cooker on the DCF-92s for 25 hours. Cables were attached with the signal running in the direction of the logo lettering on the ends.

ra3g1mhxbxtz.jpg
Figure 5. Cables can be daisy chained on the Cooker with no loss of signal strength. I used some PS Audio locking banana connectors to join the spades of each pair of cables.

c5yz1hhw1ai6.jpg
Figure 6. A lab grade Agilent 34401A true RMS digital multimeter measured the Cooker's current amplitude at 1.906 amps.

7uudyl7axo13.jpg
Figure 7. A Tektronix TDS 2012 digital oscilloscope was used to measure and monitor the Cooker's signal throughout the conditioning process. This is the Cooker's signal with no cable load.

smbrq9gukwzr.jpg
Figure 8. This is the Cooker's signal immediately after the DCF-92 cables were installed.

zfffaeb7etuh.jpg
Figure 9. This is the Cooker's signal after 25 hours after the DCF-92 cables had processed for 25 hours. The amplitude of the ringing spikes at the rising and falling edges of the pulses had decreased by approximately 12%.

yjo2pwsgcq4b.jpg
Figure 10. Not fun - dealing with the jungle of wires behind the equipment cabinet. The DCF-92 cables are very flexible, and that helped a lot with reinstalling the amplifiers.

After installation, I heard the telltale signs of over cooking: smeared bass and diminished high frequency detail. This is a temporary effect that vanishes with either letting the cables rest for a few hours or playing music through the cables for a few hours. I chose the latter. I let music play for an additional 19 hours at a moderate level (70 dB-C). A brief listening session 6-1/2 hours later before going to work confirmed that the sonic deficiencies due to over cooking were gone. I did the first critical listening session later that evening.

Listening Evaluation

Critical listening was done after 25 hours on the Cable Cooker and after an additional 19 hours of music playback.

The first thing my ears were drawn to was the bass - it was more finely detailed, more articulate, faster, and more tactile.

With two channel music, multichannel music, and movie sound tracks, I heard details in the sound stage that I had not previously noticed. There was more image weight, more solidity and three dimensionality to voices and instruments, and more tactile sensation against my body and through the listening seat.

The surround speakers sounded louder and with clearer details, although no changes in wiring were done for them. There was tighter integration of all five speakers and subwoofer with an enhanced sense of being in the middle of a thick sound field.

There was an enhanced sense of depth by a foot forward. Sound stage width and height remained the same. However, images at the far sides of the sound stage were clearer and more detailed and had more weight.

"So hot it burns Mice!"~DK
"Polk SDA-SRSs are hopelessly out of date both sonically and technologically... I see no value whatsoever in older SDA speakers."~Audio Asylum Member
"Knowledge, without understanding, is a path to failure."~DK
"Those who irrationally rail against something or someone that is no threat to them, actually desire (or desire to be like) the thing or person they are railing against."~DK
Post edited by DarqueKnight on

Comments

  • DarqueKnightDarqueKnight Posts: 6,603
    Room Response Measurements

    Room response measurements were taken with the Dayton Audio OmniMic system. The room measures 15' wide x 18.5' long x 12' high.

    vcmmtgb3y2oj.jpg
    Figure 11. Room response with Monster Cable Z3 Reference speaker cable.

    tqghpqj34xzw.jpg
    Figure 12. Room response with Douglas Connection DCF-92 speaker cable.

    ba0foy1fvihh.jpg
    Figure 13. Comparison of room responses between Monster Cable Z3 Reference and Douglas Connection DCF-92 speaker cables.

    The color coded lines in the following harmonic distortion plots represent the following:

    Black - frequency response.
    Dark blue - sum of 2nd-5th harmonics.
    Red - 2nd harmonic.
    Purple - 3rd harmonic.
    Green - 4th harmonic.
    Light blue - 5th harmonic.

    kyh3f5suz9yf.jpg
    Figure 14. Harmonic distortion response of Monster Cable Z3 Reference speaker cable.

    ogxz0b31a0gz.jpg
    Figure 15. Harmonic distortion response of Douglas Connection DCF-92 speaker cable. From 30 Hz to 2.5 kHz, the DCF-92 had an average 3-5 dB lower harmonic distortion.

    Bass decay plots show how long it takes the sound to decay at each frequency. The ideal situation is flat response which means that some bass notes do not last much longer than others. Significant differences in decay times and very long decay times can cause a decrease in bass definition. Lower and flatter is better.

    7ysb9ga0bngn.jpg
    Figure 16. DCF-92 bass decay plot. Unfortunately, I neglected to do a bass decay plot for the Z3 Reference cable...and I couldn't bring myself to go to the trouble of reinstalling them just for that measurement.

    References

    How My LSiM 707s Sound To Me - A Review
    http://forum.polkaudio.com/discussion/182984/how-my-lsim-707s-sound-to-me-a-review

    Downsizing Home Theater - 5.1 To 3.1
    http://forum.polkaudio.com/discussion/176162/downsizing-home-theater-5-1-to-3-1/p1

    Digitizing My Movie Collection: Synology DS 918+ NAS Review
    http://forum.polkaudio.com/discussion/180783/digitizing-my-movie-collection-synology-ds-918-nas-review

    Douglas Connection Furez DCF92 Speaker Cables - ReviewDouglas Connection Furez DCF92 Speaker Cables - Review
    http://forum.polkaudio.com/discussion/168833/douglas-connection-furez-dcf92-speaker-cables-review

    "So hot it burns Mice!"~DK
    "Polk SDA-SRSs are hopelessly out of date both sonically and technologically... I see no value whatsoever in older SDA speakers."~Audio Asylum Member
    "Knowledge, without understanding, is a path to failure."~DK
    "Those who irrationally rail against something or someone that is no threat to them, actually desire (or desire to be like) the thing or person they are railing against."~DK
  • verbverb Posts: 8,010
    Well done analysis @DarqueKnight ! For me, this is the first time I've actually seen quantitative data showing the affects of cable conditioning. Very interesting. Thanks for taking the time to do this study and share.

    Question for you based on your hypothesis:
    lwibue8r212b.png

    Does this mean that the affects of conditioning diminish over time? And the cables must be reconditioned periodically?
    Basement: Polk SDA SRS, Cary SLP-05 Pre, Enlightened Audio Designs CD Transport, Northstar Designs Excelsio DAC, Silnote Morpheus Ref2 Digital Cable, Marantz SA-14 SACD, McIntosh MC300 Amp, Furman 15PFi Power Conditioner, Pangea Power Cables, Wireworld Oasis 8 RCA IC's, MIT Shotgun S3 IC's, MIT Shotgun S1 Bi-Wire speaker cables
    Office: PC, EAR Acute CD Player, EAR 834L Pre, PASS ACA Monoblocks, Denon UDR-F10 Cassette, Acoustic Technologies Classic FR Speakers, SVS SB12 Plus sub, MIT AVt2 speaker cables, IFI Purifier2, AQ Cinnamon USB cable, Groneberg Quatro Reference IC's
    Spare Room: , Antique Sound Labs Wave AV-8 Monoblocks, Tisbury Mini Passive Pre, Tjoeb 99 tube CD player (modified Marantz CD-38), Analysis Plus Oval 9's, Zu Jumpers, AudioEngine B1 Streamer, Klipsch RB-61 v2, SVS PB1000 sub, Blue Jeans RCA IC's
    Living Room: Peachtree Nova Integrated, Cambridge CXN v2 Streamer, Furman 15PFi Power Conditioner, Polk RT265 In Wall Speakers, Polk DSW Pro 660wi sub
  • DarqueKnightDarqueKnight Posts: 6,603
    verb wrote: »
    Does this mean that the affects of conditioning diminish over time? And the cables must be reconditioned periodically?

    It's possible depending on the dielectric properties of the insulation and how much the cables are used.

    This is from the Cable Cooker website:

    "Unless cabling is completely disconnected for a long period of time, we don’t think they completely revert back to their original, raw state. However, in our experience, all cables retrograde in performance over time. Break-in or conditioning is a long-term, but not permanent phenomenon. Cabling performance improves (as does one’s system) with a periodic “recharge” of 24 to 36 hours every few months, and many long-time Cooker owners continue to enjoy this benefit."

    https://www.thecablecooker.com/faqs/

    AudioQuest's Dielectric Bias System uses a 72 volt battery pack to maintain a conditioning charge on their cables' dielectric material.

    https://www.audioquest.com/content/aq/pdf/DBS.pdf

    This is a review of my Cable Cooker shortly after purchase in 2009:

    http://forum.polkaudio.com/discussion/92655/home-cookin-the-audiodharma-cable-cooker/p1

    "So hot it burns Mice!"~DK
    "Polk SDA-SRSs are hopelessly out of date both sonically and technologically... I see no value whatsoever in older SDA speakers."~Audio Asylum Member
    "Knowledge, without understanding, is a path to failure."~DK
    "Those who irrationally rail against something or someone that is no threat to them, actually desire (or desire to be like) the thing or person they are railing against."~DK
  • rpf65rpf65 Posts: 2,075
    Curious on your thoughts on how changing cables on the front three affected the surrounds?

  • DarqueKnightDarqueKnight Posts: 6,603
    rpf65 wrote: »
    Curious on your thoughts on how changing cables on the front three affected the surrounds?

    Noise and distortion have an overall masking, as well as a distracting, effect. Clearer sound, with less noise and distortion in the front, facilitates less masking of, and distraction from, the surrounds.
    "So hot it burns Mice!"~DK
    "Polk SDA-SRSs are hopelessly out of date both sonically and technologically... I see no value whatsoever in older SDA speakers."~Audio Asylum Member
    "Knowledge, without understanding, is a path to failure."~DK
    "Those who irrationally rail against something or someone that is no threat to them, actually desire (or desire to be like) the thing or person they are railing against."~DK
  • dromundsdromunds Posts: 8,337
    Doug has re-terminated several speaker cables for me, and I am a big fan of the Furutech connections. I've used the FT-212R Rhodium plated (which I believe are the same as the connections on your cables above except they are bananas rather than spades), and also the FT-212G Gold plated, as I prefer the locking bananas for my uses. I also have a pair of bi-wire speaker cables that have the Furutech FP-202G Gold plated angled locking bananas, which allow you to use the bi-wires with speakers that only have two binding posts - the angled connections also have the added benefit of allowing your wires to hang at a more natural angle. Doug does great work. Check out his website, and also the Flea Market for some great deals on his cables with proceeds helping his son's GoFundMe efforts.
  • WillowWillow Posts: 9,716
    @DarqueKnight Looking good!! and that's quite the analysis you've done. What is that little keyboard/monitor thing on your coffee table?
    2Ch- B&W 703, SVS PB10 NSD, Marantz NR1607, Parasound 1500a, Pro-Ject Debut Carbon (Yellow) with Acrylic platter, Pro-Ject phono pre, MIT AVT 2 speaker cables, MIT AVT 1 and AVT 2 ICs, XLO Jumpers, Signal Dig Coax, Signal Cable Magic Power Cables x3, Samsung 55JS7000, Harmony 1100, Sony BDP-S6200, Marantz DV-4200 (as Transport), Cambridge Audio DAC Magic100, Monster 3600MKII, Android Mi Box3 and Apple TV. - Pool /Gazebo Yamaha RX-A1010, Polk Patio 25x4, Rotel RDV 1045 (as CDP) MIT AVT3 ICs - Work - Spotify Premium or Neutron App to my FiiO Kunlun into my Grado SR125e

  • DarqueKnightDarqueKnight Posts: 6,603
    @Willow,

    That is a Dell VenuPro 11model 7140 tablet computer, and dock, with a Logitech K810 wireless keyboard and Logitech MX Anywhere wireless mouse. I use it to control the home theater electronics via their web interfaces.
    "So hot it burns Mice!"~DK
    "Polk SDA-SRSs are hopelessly out of date both sonically and technologically... I see no value whatsoever in older SDA speakers."~Audio Asylum Member
    "Knowledge, without understanding, is a path to failure."~DK
    "Those who irrationally rail against something or someone that is no threat to them, actually desire (or desire to be like) the thing or person they are railing against."~DK
  • verb wrote: »
    Does this mean that the affects of conditioning diminish over time? And the cables must be reconditioned periodically?

    It's possible depending on the dielectric properties of the insulation and how much the cables are used.

    This is from the Cable Cooker website:

    "Unless cabling is completely disconnected for a long period of time, we don’t think they completely revert back to their original, raw state. However, in our experience, all cables retrograde in performance over time. Break-in or conditioning is a long-term, but not permanent phenomenon. Cabling performance improves (as does one’s system) with a periodic “recharge” of 24 to 36 hours every few months, and many long-time Cooker owners continue to enjoy this benefit."

    I have never tried doing a recook on cables myself, and wondered if it really makes any difference. It just so happens, I recently had a customer who wanted me to do a recook on all his cables. I finished cooking them and got them back to him last Monday. We are talking 3 pair RCA interconnects, 3 1/2 pair Balanced XLR interconnects, and 2 1/2 pair of speaker cables. Then there were 6 power cables too. I have the Ground Breaker power cable adaptor to do them, so cooked them too. He asked me to cook everything 72 hours. This may have overcooked them a bit, but he let them run in his system for a couple of days before giving me his thoughts.

    Here is what he texted me:
    "I think there is definitely an improvement at the low end as well as the low level details. For anyone to really distinguish the difference between cooked and uncooked, it will take an audio purist. The improvement I can hear means a lot because those small improvements are the hardest to achieve. A lot of audiophiles will appreciate the improvements. The bass is much deeper and the sound stage seems to have widened a little more. I can hear a lot of decay information than before, and I think that’s the most notable change. My Niece was able to notice the improvement in bass. It definitely works! The improvements are quite remarkable. It definitely works. The improvements are quite remarkable. Last night the more I was listening to more high resolution recordings, the more I was realizing the big improvements."

    After this experience, I really do believe the Audiodharma cable cooker works for initial as well as periodic treatments.

    Sunfire Theater Grand IV
    Sunfire Cinema Grand Signature
    SRS 2.1TL
    SDA 2BTL's
    CSiA6
    FXiA4
    FXiA6
    SDA 2A's
    Monitor 10A's

    http://www.douglasconnection.com
  • I would like to do a study on the effects of periodic treatments with the Cable Cooker, but accessing my cables behind their respective barriers (heavy equipment cabinets, bookcases, etc) is not practical. I wanted to do a pre-cooked and post-cooked listening comparison of the DCF-92 cables in this thread, and compare them to the pre-and post-cooked Z3 Reference cables, but the thought of the multiple torturous removal-installation-reinstallation iterations precluded that.

    I did recook the former Z3 center channel cables for 25 hours. This cable had previously been in use since June 2017. I didn't see a difference in the pre-recooked and post-recooked scope waveforms. I didn't do any listening tests. I'll save that for later...when I'm more dedicated to audio than I am now.

    wfp1eqvhpmk8.jpg
    Figure 17. Recooking Monster Z3 Reference speaker cable - at 0 hours on the cable cooker.

    r01s1vb2uaeu.jpg
    Figure 17. Recooking Monster Z3 Reference speaker cable - at 25 hours on the cable cooker.


    "So hot it burns Mice!"~DK
    "Polk SDA-SRSs are hopelessly out of date both sonically and technologically... I see no value whatsoever in older SDA speakers."~Audio Asylum Member
    "Knowledge, without understanding, is a path to failure."~DK
    "Those who irrationally rail against something or someone that is no threat to them, actually desire (or desire to be like) the thing or person they are railing against."~DK
  • schwarcwschwarcw Posts: 7,208
    Such good cookin' B)
    Carl

Sign In or Register to comment.

Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!