1982 Monitor 7B’s - birthday mods
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JayMX
Posts: 435
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…
Removing the dustcaps is nerve wracking.
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... 🤦🏻♂️
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…)
All clean (Except for the gunk on the tweeter domes. Anybody know how to clean them??) and singing. Seriously stupendous. 😁
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…
Removing the dustcaps is nerve wracking.
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... 🤦🏻♂️
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…)
All clean (Except for the gunk on the tweeter domes. Anybody know how to clean them??) and singing. Seriously stupendous. 😁
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 🤩
Comments
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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.
George / NJ
Polk 7B main speakers, std. mods+ (1979, orig owner)
Martin Logan Dynamo sub w/6ft 14awg Power Cord
Crown D150 amp
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 -
Awesome!
Next! Me Next! Me!
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"
Harry / Marietta GA -
Very nice! Some days I regret selling my 7b's.
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Wicked good. Wish I could hear them.Polk Audio first generation RTA-12s; 12 inch Polk Stands; DHS Speaker Service upgraded crossovers w/ Sonicap/Mills; the "westmassguy anti-lobing mod" (hyperdamped outer drivers/mirror imaged); tweeter anti-diffraction mod; Cardas binding posts; Neotech UPOCC internal wire; foam-lined inner driver baskets; xschop phase plugs; deleted fuses; Hurricane nuts; Sonic Barrier; Dynamat XtremeAyre K-5xeMP preamplifierCambridge Audio 840C CD player; Herbie's Audio Lab Super Black Hole CD MatD-Sonic Custom Audio M3a-600M monoblock amplifiersNAD 4155 FM/AM tunerSilnote Audio Morpheus Reference II Series II balanced interconnects; Virtue Audio single-ended interconnectsKimber 12TC speaker cable w/Furez connectors; VH Audio Flavor 4 power cables w/Furutech connectorsHerbie's Audio Lab system isolation: Tenderfeet, Big Fat Dots, Grungebuster Dots, Little Fat GlidersDedicated 20A/10 AWG circuit; Furutech GTX-D (G) outlet; Furutech eTP80; Shunyata Research Venom Defender; Synergistic Research Orange fuses
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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
Crown D150 amp
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 -
He already added Sonic Barrier on the rear walls.Gardenstater wrote: »Are you saving the foam inside the baskets mod to savor its improvements separately?
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 -
I agree with the others... Super jobStan
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
