1982 Monitor 7B’s - birthday mods

JayMX
JayMX Posts: 446
edited September 2022 in Vintage Speakers
I’ve hoarded these beautiful Monitor 7’s in the queue for a while, waiting patiently. They’re turning 40 this year, figured it was time to give them some birthday presents. 😊

I picked them up for $50 from the original owner a couple years back. Nearly perfect condition physically. Rosewood vinyl finish which I plan on replacing at some point with mahogany veneer.
Finished all of the “regular” mods today, along with new phase plugs and dangerous ninja throwing weapons ‘er mounting “rings” from @xschop. Hurricane nuts everywhere else. Noico on the baskets (much cheaper than Dynamat,) Sonic Barrier on the rear walls, SoniCaps, Clarity CSA and Mills in the crossovers. All internal wiring replaced, 12AWG high-strand OFC in the crossover cups (the old stuff was corroding), Kimber Kable 8TC out to the drivers (overkill but I had a spare length that worked out perfect for the four small segments required.). New binding posts and a thorough cleaning finished them off. (For now…)

Been listing to them this afternoon. Even without the caps burned in, I am blown away by the transparency and soundstage. Midrange clarity is fantastic. Detailed vocals and separation, not muddy anywhere. It actually took me a minute to adjust to the increased resolution. Low end is extremely tight - better than my mod 7C’s. I speculate that since the midwoofers aren’t countersunk in the B’s, the baffle is that much stiffer and with the mounting rings the drivers are perfectly coupled with the baffle - very much inert. Overall, I am very pleased. Dumb grin on my face, seriously. 🤩

I didn’t do a great job documenting the process but here are a few pics. Fantastic project, well worth the time and $$. Now need to decide what to do with the 7C’s.

Lots of presents…
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Removing the dustcaps is nerve wracking.
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Just a dot of loctite is needed for the phase plugs. I used too much and had to do some driver surgery to clean them up... 🤦🏻‍♂️
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New internal wiring and crossover mods. Terminal cups each got almost a full stick of hot glue in them to seal things up (no pics…)
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All clean (Except for the gunk on the tweeter domes. Anybody know how to clean them??) and singing. Seriously stupendous. 😁
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Current Collection: Monitor 4a (Peerless), Monitor 5B (Peerless), Modified Monitor 7b (Peerless), RTA15TL (SL3000), SDA CRS+ (194’s), SDA SRS 2.3TL, R100's, R200’s, R300 🤩
Pairs that have passed through: Monitor 4b (Peerless), Monitor 5a (Peerless), Monitor 5b (SL1000), Monitor 5b (SL2000) (4x pair), Monitor 7b (Peerless), Modified Monitor 7c’s (194’s), Monitor 10a (Peerless), Monitor 10b (5x pair), RTA8, RTA8TL, RTA 11T, RTA12c (194's), SDA CRS, SDA 2 (2x pair), SDA 2a, SDA 2b, SDA 1b, SDA 1c, SDA SRS 2 (2x pair), SDA SRS 3.1TL (198’s) (2x pair)...and more to come, it’s a sickness.

Comments

  • xschop
    xschop Posts: 5,000
    There needs to be a badazz reply button.
    You can meticulously remove dome lint by using sticky tape.
    Don't take experimental gene therapies from known eugenicists.
  • Yes it can be done! eBay shipper got glass fibers and styrofoam all over a Peerless I bought. Before and after.

    incz2tagkmhz.jpg

    u5m5ut9j0w1r.jpg
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Onkyo A-8017 integrated
    Logitech Squeezebox Touch Streamer w/EDO applet
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    Custom Steve Wilson 1m UPOCC Interconnect
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
  • SIHAB
    SIHAB Posts: 4,969
    Awesome!

    Next! Me Next! Me! :D
    Speakers: Polk Lsim, ATC SCM19 v2, NHT SuperzeroSpeaker Cables: DH Labs, Transparent, Wireworld, Canare, Monster: Beer budget, Bose ears
  • The pictures of your work are incredible.
    "Sometimes you have to look to the past to understand where you are going in the future"

    Anger is just anger. It isn’t good. It isn’t bad. It just is. What you do with it is what matters.
    You can use it to build or to destroy. You just have to make the choice.
    Jim Butcher




    Harry / Marietta GA
  • Faustin
    Faustin Posts: 1,149
    Very nice! Some days I regret selling my 7b's. :(
  • Wicked good. Wish I could hear them.
  • xschop
    xschop Posts: 5,000
    Looking forward to the completed mahogony veneer package Jay.
    Don't take experimental gene therapies from known eugenicists.
  • Fantastic job of tricking these out! Are you saving the foam inside the baskets mod to savor its improvements separately?
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Onkyo A-8017 integrated
    Logitech Squeezebox Touch Streamer w/EDO applet
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    Custom Steve Wilson 1m UPOCC Interconnect
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
  • F1nut
    F1nut Posts: 50,654
    Are you saving the foam inside the baskets mod to savor its improvements separately?
    He already added Sonic Barrier on the rear walls.

    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."


    President of Club Polk

  • skrol
    skrol Posts: 3,387
    I agree with the others... Super job
    Stan

    Main 2ch:
    Polk LSi15 (DB840 upgrade), Parasound: P/LD-1100, HCA-1000A; Denon: DVD-2910, DRM-800A; Benchmark DAC1, Monster HTS3600-MKII, Grado SR-225i; Technics SL-J2, Parasound PPH-100.

    HT:
    Marantz SR7010, Polk: RTA11TL (RDO198-1, XO and Damping Upgrades), S4, CS250, PSW110 , Marantz UD5005, Pioneer PL-530, Panasonic TC-P42S60

    Other stuff:
    Denon: DRA-835R, AVR-888, DCD-660, DRM-700A, DRR-780; Polk: S8, Monitor 5A, 5B, TSi100, RM7, PSW10 (DXi104 upgrade); Pioneer: CT-6R; Onkyo CP-1046F; Ortofon OM5E, Marantz: PM5004, CD5004, CDR-615; Parasound C/PT-600, HCA-800ii, Sony CDP-650ESD, Technics SA 5070, B&W DM601
  • xschop
    xschop Posts: 5,000
    Hey Jay, any update, veneer work on these jewels?
    Don't take experimental gene therapies from known eugenicists.
  • Toolfan66
    Toolfan66 Posts: 17,310
    I like the braid work. Not sure how I missed this thread..
    Polk Audio SDA 2.3tl Fully Hot Rodded. 😎

    SVS SB16 X2

    Cary SLP-05/Ultimate Upgrade.
    Cary SA-500.1 ES Amps
    Cary DMS 800PV Network
    OPPO UDP 205/ModWright Modification
    VPI Scout TT / Dynavector 20x2
    Jolida JD9 Fully Modified

    VPI MW-1 Cyclone RCM

    MIT Shotgun 3 cables throughout / Except TT, and PC’s
  • JayMX
    JayMX Posts: 446
    Toolfan66 wrote: »
    I like the braid work. Not sure how I missed this thread..
    That’s Kimber 8TC, total overkill. But cool nonetheless… 😎
    Current Collection: Monitor 4a (Peerless), Monitor 5B (Peerless), Modified Monitor 7b (Peerless), RTA15TL (SL3000), SDA CRS+ (194’s), SDA SRS 2.3TL, R100's, R200’s, R300 🤩
    Pairs that have passed through: Monitor 4b (Peerless), Monitor 5a (Peerless), Monitor 5b (SL1000), Monitor 5b (SL2000) (4x pair), Monitor 7b (Peerless), Modified Monitor 7c’s (194’s), Monitor 10a (Peerless), Monitor 10b (5x pair), RTA8, RTA8TL, RTA 11T, RTA12c (194's), SDA CRS, SDA 2 (2x pair), SDA 2a, SDA 2b, SDA 1b, SDA 1c, SDA SRS 2 (2x pair), SDA SRS 3.1TL (198’s) (2x pair)...and more to come, it’s a sickness.
  • boston1450
    boston1450 Posts: 7,658
    Those look nice. Great job. What was it you were looking for awhile back ? Those stands remind me of Bose 901 tulip stands.
    ..
  • JayMX
    JayMX Posts: 446
    boston1450 wrote: »
    Those look nice. Great job. What was it you were looking for awhile back ? Those stands remind me of Bose 901 tulip stands.
    Yea, I found one in Ohio but couldn’t find a helper so it went away… so I built a stand for it and called it good. The original KLH tulip stands are a little shorter than the 901 stands.

    And for the record, above I meant to say it was a “full electronic and aesthetic restoration” 🤦🏻‍♂️
    Current Collection: Monitor 4a (Peerless), Monitor 5B (Peerless), Modified Monitor 7b (Peerless), RTA15TL (SL3000), SDA CRS+ (194’s), SDA SRS 2.3TL, R100's, R200’s, R300 🤩
    Pairs that have passed through: Monitor 4b (Peerless), Monitor 5a (Peerless), Monitor 5b (SL1000), Monitor 5b (SL2000) (4x pair), Monitor 7b (Peerless), Modified Monitor 7c’s (194’s), Monitor 10a (Peerless), Monitor 10b (5x pair), RTA8, RTA8TL, RTA 11T, RTA12c (194's), SDA CRS, SDA 2 (2x pair), SDA 2a, SDA 2b, SDA 1b, SDA 1c, SDA SRS 2 (2x pair), SDA SRS 3.1TL (198’s) (2x pair)...and more to come, it’s a sickness.
  • boston1450
    boston1450 Posts: 7,658
    Looks great. Cool sub. Love the vintage look. Once in awhile up here in Maine we'll see a old tube console on the market & they range from 200.00 up to 800.00+ $$$ & they don't last long. Especially the ones with R2R
    ..