My 5B - In Mod We Trust

plastic_avatar
plastic_avatar Posts: 687
edited November 2022 in Vintage Speakers
Prologue

I needed another project while the slog towards completing my 1C upgrades continues to hiccup along.

$35 and a handful of regret

I bought a rough pair of 5B from a friend 4 years ago (his Dad bought them new). After years of college apartment party life, they were... rough. But I wanted something to put with my awesome Realistic receiver and turntable of the same vintage.

One magnet-shifted tweeter in box A and a magnet-shifted midwoofer wrecked in box B = the 5B sat as decoration in my unfinished basement listening room for 4 years.

Mod Wars - A New Hope

While doing minor work and crossovers on my Monitor 12, I started reading everything I saw on mods and upgrades to vintage Polks. Soooooo... when I got my 1C at the beginning of the year, I went all in on everything I could afford to do (and was capable of trying).

I got a lot of help over the years from members here. And its amazing that Polk funds this resource for all of us.

But... I'm telling ya, if you try to put a Tie ion engine in an X-Wing or swap out the power convertors of a vintage land speeder? Some people will crucify you.

They'll strap you between 4 tauntauns and rip you a new access port from stem to stern.

Very Thulsa Doom meets Vader meets Spanish Inquisition.

But there are plenty of people experimenting and having fun, too.

So, because of those Rebel scum, these 5B get the full Frankenstein.

Dr. Strangemod or:
How I Learned to Stop Worrying and Embrace the Mod


- Worried you don't know enough to upgrade a crossover?

Relax! You can, and everyone here will help you get started.

- Thinking you can't swap out tweeters or terminal plugs, make custom cables, or rewire innards?

C'mon! You can refurbish a crossover! I told you so! This stuff is a breeze. All the info is in these forums!

- You want to jump off the pier and swim in the sea of madness, but worry you'll drown?

You'll live! Swim! Swim, you sweet, frelling wonder! Fly your freak mod flag and dive, dive, DIVE!

There are modding maniacs here, from royalty to street gangs, and you'll find support. From safe mods to strangemods, you do you- you'll live (they're just old, consumer-grade speakers, not a crate of undiscovered Rembrandts).

Me and Polkie 5B

I'm going to list all the mods, fixes, upgrades, and mistakes to my 5B in separate responses, with links to forum threads in them.

I hope it helps somebody.

[terminat auctor opus]

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The Thrifty Setups in Mah House Big thrifty stereo in the basement w/ my custom SDA-1C (built with help from kind forum members) * Beautiful 1966 MCM GE console upgraded w/ Bluetooth, Dual turntable, and Paradigm speakers in family room * Swanky 1980 Realistic system and great TEAC eq with dancing colored lights in the living room * Ye Olde college stereo in the garage
Post edited by plastic_avatar on
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Comments

  • plastic_avatar
    plastic_avatar Posts: 687
    edited November 2022
    Dynamat and Armacell

    2 sides of the same coin, fellas. Kinda a sticky Cain and Abel situation.

    Dynamat

    The tried and true safe mod is to get some kind of Dynamat (or clone, or butyl-backed aluminized pipe wrap) and cover the exterior of your cheap, thin, stamped metal speaker baskets. Those things ring like bells.

    https://forum.polkaudio.com/discussion/150260/dynamatted-my-drivers-today-should-i-do-the-prs-too/p1

    difficulty = waaay easy

    risk = very little

    reversibility = tough, but why take it off since it's a guaranteed positive- seriously

    cost = cheap, if you go with pipe wrap

    benefits = tighter bass, fewer distortions making it out through the cone from basket vibration

    Armacell

    This is a contentious mod amongst everyone who hasn't done it, so far.

    In an effort to tame reflections from the cone bouncing back through the cone, put Armacell (an open cell foam pipe wrap) on the interior of the midwoofer baskets.

    @Gardenstater's Armacell thread that convinced me to try it:

    https://forum.polkaudio.com/discussion/195562/must-try-mod-foam-inside-the-stamped-steel-baskets-yes/p1

    difficulty = a little tricky, I had to use tweezers and cussed a lot- the glue is very sticky, and there's not a lot of room in there

    risk = no reports of damage to spiders, cones, wires, or surrounds during (or after) installation- so far; there are like 8+ people here who've tried it, at least

    reversibility = Ugh, that stuff is sticky and hard to remove, but why would I want to if it's a positive and I know the risks?

    cost = cheap, and you can use it for gaskets

    benefits = anecdotally, by ear, reports are: more clarity, voices improved, and fewer distortions making it out through the cone from basket reflection

    5rdih4q4pxbc.jpeg

    The Thrifty Setups in Mah House Big thrifty stereo in the basement w/ my custom SDA-1C (built with help from kind forum members) * Beautiful 1966 MCM GE console upgraded w/ Bluetooth, Dual turntable, and Paradigm speakers in family room * Swanky 1980 Realistic system and great TEAC eq with dancing colored lights in the living room * Ye Olde college stereo in the garage
  • Phase Plugs

    Oh man, what a cool looking mod. Seriously slick, sick, wicked, rad, and totally boss.

    Phase plugs can help change how sound within the area of the cone interacts (or doesn't) with itself. Read up on them. They're cool.

    https://en.m.wikipedia.org/wiki/Phase_plug#:~:text=In a loudspeaker, a phase,interact destructively near the driver.

    The OG CNC Mod King's thread:

    https://forum.polkaudio.com/discussion/190301/phase-plug-design-for-mw65xx

    difficulty = nerve-wracking w/o the right tools (shims are required to make sure the plug is mounted correctly)

    risk = no reports of damage, but one whoopsie with too much thread locker adhesive

    reversibility = HARD but doable, but why?

    cost = not cheap, if you get beautiful milled versions from aluminum; cheaper if you f via

    benefits = anecdotally, by ear, reports are: more clarity, voices improved, and fewer distortions making it out through the cone from basket reflection

    You can, if you want to and have a 3D printer, make cheapie phase plugs. As an owner of xshop's work and some 3D printed versions, I'd take his all day long if I could afford them!

    And @Gardenstater made some chain-letter-shareable shims! I have them for now, but in a few weeks I'll post about sharing them with the next modder who needs them.

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    The Thrifty Setups in Mah House Big thrifty stereo in the basement w/ my custom SDA-1C (built with help from kind forum members) * Beautiful 1966 MCM GE console upgraded w/ Bluetooth, Dual turntable, and Paradigm speakers in family room * Swanky 1980 Realistic system and great TEAC eq with dancing colored lights in the living room * Ye Olde college stereo in the garage
  • Star-crossed tweeters: To 194, or TL Mod, or Wuhan the SL-2000?

    I can't stand the way the SL-2000 sounds. And they degrade. They're old. The material deforms over time/use/environment.

    Somehow, all 4 pair of my vintage Polks had them =[

    Because I'm high on learning this year, I decided to save 3/4 of the cost to replace the SL-2000 in my 1C by performing the established yet still controversial Wuhan tweeter mod.

    It was a blast. I'm satisfied with a better tweeter than the SL-2000, and I put the saved money elsewhere- places with compounding gains, like better caps for the crossovers.

    And now I have extra bits to Wuhan my 5B.

    @VSATT88 's original thread:

    https://forum.polkaudio.com/discussion/168239/a-real-sl-2000-hack-replace-stock-burnt-voice-coils-with-silk-diaphragm-dome/p1

    That's a long but awesome thread.

    difficulty = Really not that hard, just daunting with zero XP

    risk = you're irreversibly modding the tweeter plate (but you can sometimes by beautiful milled ones from @xschop), so it's all or nothing if you cut into the SL-2000 plate (I made my own 3D print version using xschop's images as a guide because these guys inspired me to go all out)

    reversibility = easy, if you use a different plate, but impossible if you mod the original

    cost = inexpensive compared to buying the 194 or upgrading to the 198, unless you also opt for gorgeous milled plates

    benefits = anecdotally, by ear, reports are: better than SL-2000, as good or better than 194, smooth sound with no SL-2000 fatigue, saving money, learning new things

    And you can go further, like I did. I designed my own plates and behind-the-dome diffusers:

    https://forum.polkaudio.com/discussion/168239/a-real-sl-2000-hack-replace-stock-burnt-voice-coils-with-silk-diaphragm-dome/p21

    https://forum.polkaudio.com/discussion/168239/a-real-sl-2000-hack-replace-stock-burnt-voice-coils-with-silk-diaphragm-dome/p22

    Side note:

    I designed a plate w/ xschop's name on it for all the help he gave me. I'm making one to pay homage to VSAT88, too, because it was his madness that infected the crew =)

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    The Thrifty Setups in Mah House Big thrifty stereo in the basement w/ my custom SDA-1C (built with help from kind forum members) * Beautiful 1966 MCM GE console upgraded w/ Bluetooth, Dual turntable, and Paradigm speakers in family room * Swanky 1980 Realistic system and great TEAC eq with dancing colored lights in the living room * Ye Olde college stereo in the garage
  • BlackHole5 is alive!

    This one is tricky.

    Most people love it, but if you go too far your speakers will... sound like the dead are speaking from their coffins.

    It's a foam product that can help cancel those nasty rear reflections from the inside of your cabinets. The standard dimensions for our vintage Polk's seems to be squares or strips of from a little smaller to the same width of the midwoofers on the front.

    Because if the generosity of @skipshot2 , I get to try 4x4 squares on my 1C and 5B.

    difficulty = super easy

    risk = zero, it just sticks on the back cabinet wall

    reversibility = easy, just pull it off

    cost = Like, $75+ shipped for a sheet of more than you need for a small speaker?

    benefits = when done right, anecdotally, by ear, reports are: better separation of sound sources in the music, tighter bass, voices clearer

    &Toolfan 's 1C thread experience. He used a lot:

    https://forum.polkaudio.com/discussion/99870/sonic-barrier-blackhole-in-my-sda-1cs

    I couldn't find a good, concise discussion about how much to use for each model... Maybe we can start one?

    g2vzvpiv7diq.jpeg
    The Thrifty Setups in Mah House Big thrifty stereo in the basement w/ my custom SDA-1C (built with help from kind forum members) * Beautiful 1966 MCM GE console upgraded w/ Bluetooth, Dual turntable, and Paradigm speakers in family room * Swanky 1980 Realistic system and great TEAC eq with dancing colored lights in the living room * Ye Olde college stereo in the garage
  • Another Brick in the Wall

    A/B comparisons are a little late in the process.

    Mod vid 1 = Wuhan, Phase Plug

    Mod vid 2 = Wuhan, Phase Plug, BlackHole 5, Dynamat outside of basket, Armacell inside arms of basket

    - same source (The Wall original CD version, Nakamichi player w/ digital out, Yamaha pre on Direct, Yamaha p2250 amp, only left channel active, volume at 20)

    - same positioning/mic (yes, I used my iPhone 14 Pro... but you can tell the difference between the sound in the vids with good headphones, 4 feet away from speaker)

    Will make more vids as other mods are added.

    https://forum.polkaudio.com/home/leaving?allowTrusted=1&target=https://www.youtube.com/watch?v=su5X0peXohE

    https://forum.polkaudio.com/home/leaving?allowTrusted=1&target=https://www.youtube.com/watch?v=iYrdVJaZ2bE
    The Thrifty Setups in Mah House Big thrifty stereo in the basement w/ my custom SDA-1C (built with help from kind forum members) * Beautiful 1966 MCM GE console upgraded w/ Bluetooth, Dual turntable, and Paradigm speakers in family room * Swanky 1980 Realistic system and great TEAC eq with dancing colored lights in the living room * Ye Olde college stereo in the garage
  • Oh!

    And I'll do a more thorough, layered A/B comparison on speaker #2, as I can, between 1C stuff, side projects, and adulting/parenting over the next few months.
    The Thrifty Setups in Mah House Big thrifty stereo in the basement w/ my custom SDA-1C (built with help from kind forum members) * Beautiful 1966 MCM GE console upgraded w/ Bluetooth, Dual turntable, and Paradigm speakers in family room * Swanky 1980 Realistic system and great TEAC eq with dancing colored lights in the living room * Ye Olde college stereo in the garage
  • xschop
    xschop Posts: 4,636
    Good job. I can definitely hear the difference by plugging in my JBL headphones to my quad-dac LG-G7.
    Don't take experimental gene therapies from known eugenicists.
  • skipshot12
    skipshot12 Posts: 990
    edited November 2022
    Looking back, I wish I had done recordings from the original without mod, recording with each step of the mods then a no mod original against all mods.

    Great job documenting with audio confirmation p_a.

    And a huge yes of the music too.....
  • Phase Plug correction

    Brought to my attention that my phase plug benefits section was the same as another entry.

    Copy/paste mix-up (I wrote all this on mah phone and copied it into the post).

    Benefits are a mix of things, but I'll just pull some quotes and droolworthy speaker ****:

    Jazzhead:

    "Transients, PRaT is better, perhaps that's playing a role in the "rightness" of it all. The amps I use have a reputation for fueling fast powerful transients and it's all getting through for sure. Also, plowing the low frequency depths and can better make out the pitch of the lowest bass/piano notes. The high's sound a bit less "hashy", "tizzy". Hard to describe... but better and more musical."

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    Gardenstater:

    "The thing I still marvel at the most is how much better and real the high hat "tsssss" sound is. There is more tonal accuracy and there is discernable texture in the sound that was not there. Less smearing for sure."

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    xschop:

    "Was pretty good beforehand, but now the string bass instrument is stunningly accurate and articulate with the plugs in the 8TLs. Reverberations of those low notes are now more revealing than ever..."

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    The Thrifty Setups in Mah House Big thrifty stereo in the basement w/ my custom SDA-1C (built with help from kind forum members) * Beautiful 1966 MCM GE console upgraded w/ Bluetooth, Dual turntable, and Paradigm speakers in family room * Swanky 1980 Realistic system and great TEAC eq with dancing colored lights in the living room * Ye Olde college stereo in the garage
  • plastic_avatar
    plastic_avatar Posts: 687
    edited November 2022
    Help me design a measurement process!

    My stuff:

    - I have some capable dynamic and nicer condenser mics + a little preamp I use(d) for my podcasting work.
    - I'm a Mac guy (the PC is in the corner for fames and 3D modeling).
    - I prefer to do measurements in my listening room.

    My ideas:

    - Want to take measurements of each step of the second 5B upgrade.
    - That'll be 8 upgrade measurements: stock, Wuhan, phase plug, dynamatted, Armacell'ed, BlackHole 5, ringed, crossover.
    - I'll put the stock one back together, use the same crossover as the modded one, and do my unscientific Pink Floyd test. Just to make everything even.

    - So, which mic should I use? iPhone, condenser, or dynamic?
    - How far away should I place the mic?
    - What should I use to record the tests?

    Help me work this checklist out!

    And, when the time comes to do this, if anyone has a spare 194 to let me test it against the Wuhan and SL-2000, I'll be gentle and print you out a pair of plastic phase plugs when I'm done (if you use them in something that fits what I made, they'll work).
    The Thrifty Setups in Mah House Big thrifty stereo in the basement w/ my custom SDA-1C (built with help from kind forum members) * Beautiful 1966 MCM GE console upgraded w/ Bluetooth, Dual turntable, and Paradigm speakers in family room * Swanky 1980 Realistic system and great TEAC eq with dancing colored lights in the living room * Ye Olde college stereo in the garage
  • Mods I haven't decided on

    - Felt/wool around the drivers. Like Gardenstater's above^

    - Internal wiring.

    - Removing the fuse.

    - Coils.

    - Freaky foamy diffraction additions to cabinet edges.

    And mods I just forgot to say I'll do:

    - Dowel bracing for cabinet interior.

    - Spikes.
    The Thrifty Setups in Mah House Big thrifty stereo in the basement w/ my custom SDA-1C (built with help from kind forum members) * Beautiful 1966 MCM GE console upgraded w/ Bluetooth, Dual turntable, and Paradigm speakers in family room * Swanky 1980 Realistic system and great TEAC eq with dancing colored lights in the living room * Ye Olde college stereo in the garage
  • xschop
    xschop Posts: 4,636
    edited November 2022
    Dowel bracing has my vote, even if you don't have backing rings/plates.

    Let me know how much length internal wire you need. I can send you some that I just acquired and compared to Supra Rondo. Free for the experiments.🙂

    I just rewired mine recently and think I had 14" length for MWs and 18" long for the tweeters. I always add extra than factory for ease of driver swapping/tweaking.

    For recording purposes, just use what you have, keeping the same for all steps in the progression.

    The scientific method still applies. You should feel proud that more thought and testing was put into your development than the recent multi-billion $ experimental gene therapies.
    Post edited by xschop on
    Don't take experimental gene therapies from known eugenicists.
  • Mods I haven't decided on

    - Felt/wool around the drivers. Like Gardenstater's above^

    - Internal wiring.

    - Removing the fuse.

    - Coils.

    - Freaky foamy diffraction additions to cabinet edges.

    And mods I just forgot to say I'll do:

    - Dowel bracing for cabinet interior.

    - Spikes.

    Watch your tongue mister lol 😉

    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
  • @Gardenstater

    [chuckles while reading from bed after a late night]

    Ha!

    Thought you'd like that ;)

    I'm thinking about that more for the 1C. I have the VR3 tweeter felt. Between the 2, cosmetically, it'll be my Lovecraft speaker. Polksogsothoth, Deceiver of Sound.

    That mod's all right with me!

    https://youtu.be/QYHxGBH6o4M
    The Thrifty Setups in Mah House Big thrifty stereo in the basement w/ my custom SDA-1C (built with help from kind forum members) * Beautiful 1966 MCM GE console upgraded w/ Bluetooth, Dual turntable, and Paradigm speakers in family room * Swanky 1980 Realistic system and great TEAC eq with dancing colored lights in the living room * Ye Olde college stereo in the garage
  • @plastic_avatar It definitely made my speakers disappear quite a bit more. If that is something you wouldn't like then be forewarned! :) I can share construction details and could even send you some parts. I haven't built my Prototype #3 yet, from what I learned from the first two.
    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
  • What's the link to your thread on this? Put it here so I've got it on the list =)
    The Thrifty Setups in Mah House Big thrifty stereo in the basement w/ my custom SDA-1C (built with help from kind forum members) * Beautiful 1966 MCM GE console upgraded w/ Bluetooth, Dual turntable, and Paradigm speakers in family room * Swanky 1980 Realistic system and great TEAC eq with dancing colored lights in the living room * Ye Olde college stereo in the garage
  • I don't have one yet. Maybe I'll do a thread after Proto #3.
    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
  • Wire = I'll measure my strands.

    Construction = Share, share your method/parts list!

    Testing = I'll:

    - print solid plugs for the replacement mw (I only did 75% fill on the tester)
    - I'll just use Audacity, unless there's a better option? Recommendations?
    - save the wire until the last.

    December will be fun.
    The Thrifty Setups in Mah House Big thrifty stereo in the basement w/ my custom SDA-1C (built with help from kind forum members) * Beautiful 1966 MCM GE console upgraded w/ Bluetooth, Dual turntable, and Paradigm speakers in family room * Swanky 1980 Realistic system and great TEAC eq with dancing colored lights in the living room * Ye Olde college stereo in the garage
  • I had to make a new plug design last night.

    Realized the ones I did printed the tips hollow. Error in the model. The tester midwoofer needs a new one.

    Fixed it. Now, in my printer off time, I'll print them for my Monitor 12.

    They weigh about 85% of @xschop 's gorgeous aluminum masters.

    Off-topic for the 5B, but should I make the Monitor 12 ones black, white, candy apple red, clear, or?

    2efnkcbqo3zq.jpeg
    The Thrifty Setups in Mah House Big thrifty stereo in the basement w/ my custom SDA-1C (built with help from kind forum members) * Beautiful 1966 MCM GE console upgraded w/ Bluetooth, Dual turntable, and Paradigm speakers in family room * Swanky 1980 Realistic system and great TEAC eq with dancing colored lights in the living room * Ye Olde college stereo in the garage
  • How did you find out they were hollow? Did you attempt to take some onboard an airplane and TSA went ballistic after what they saw on the Xray machine? :D
    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
  • I was feeling the balance on the first solid one, and it was off. Stopped the other mid-cone.

    Went back in and redid the cone part in Tinkercad.

    Now it's solid plastic.

    I have avoided the xray machine since they started using them.
    The Thrifty Setups in Mah House Big thrifty stereo in the basement w/ my custom SDA-1C (built with help from kind forum members) * Beautiful 1966 MCM GE console upgraded w/ Bluetooth, Dual turntable, and Paradigm speakers in family room * Swanky 1980 Realistic system and great TEAC eq with dancing colored lights in the living room * Ye Olde college stereo in the garage
  • plastic_avatar
    plastic_avatar Posts: 687
    edited December 2022
    In lieu of xschop's amazing loaner jig, seemingly absconded with by the previous loanee, I'm approximating a low rent version.

    Got a tweeter to fix...

    gbwhr9dss0rs.jpeg
    The Thrifty Setups in Mah House Big thrifty stereo in the basement w/ my custom SDA-1C (built with help from kind forum members) * Beautiful 1966 MCM GE console upgraded w/ Bluetooth, Dual turntable, and Paradigm speakers in family room * Swanky 1980 Realistic system and great TEAC eq with dancing colored lights in the living room * Ye Olde college stereo in the garage
  • I wrote a big post earlier, and the Ether ate it. I previewed it, and when I hit edit to change a typo? Poof! Argh.

    The Update Redo

    First off, give a listen:

    https://www.youtube.com/watch?v=0ktOBXGQ5bs&lc=UgwRhR2xrxd8zD05UO14AaABAg

    Tried to match volume and distance with the other videos (but it's been a while, I was trying to match db by memory).

    That's the left channel from 4 feet away. Right channel was off. I just have the one speaker up and running.

    Mods/upgrades

    - Daytons & custom printed plates. Thread for that is here at https://forum.polkaudio.com/discussion/198432/tweeter-fun-dayton-plates#latest

    - Mids from @xschop, complete with drilled pole piece and removable/exchangeable phase plug.

    - Re-wired with silver wire from xschop.

    - Semi-rings from xschop.

    - BH5 courtesy of @skipshot12.

    - Replaced terminals.

    - Craft foam gaskets on every opening.

    - Hurricane nuts and hex bolts everywhere.

    - New spades on wires.

    - Matted the passive.

    - Upgraded crossover with Clarity caps and Mundorf resistors.

    - Re-rolled upper chamber polyfill.

    Still to do

    - Complete speaker #2 and burn the pair in.

    - More mat on mids.

    - @Gardenstater's mid basket foam mod.

    - Line passive chamber with mat. I know this one is divisive, but I like the way it tightens up bass without killing it. Made my Monitor 12 Series 2 a lot less bloated.

    Now I'm sleepy, so I'll write the rest tomorrow.

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    The Thrifty Setups in Mah House Big thrifty stereo in the basement w/ my custom SDA-1C (built with help from kind forum members) * Beautiful 1966 MCM GE console upgraded w/ Bluetooth, Dual turntable, and Paradigm speakers in family room * Swanky 1980 Realistic system and great TEAC eq with dancing colored lights in the living room * Ye Olde college stereo in the garage
  • F1nut
    F1nut Posts: 49,711
    Please make it stop.
    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

  • xschop
    xschop Posts: 4,636
    Damn solid build. Hats off to you. Looking forward to more impressions from your listening perspective on these vintage Polk jewels.
    Don't take experimental gene therapies from known eugenicists.
  • If I'm right, only 3 mods I've done are in the 'not for everyone category':

    Phase plugs

    Worries of others = Hard to remove. Requires cutting away dust cap. Electrical changes, depending on material (metal/plastic/etc).

    Experiences of others = One negative SDA-related speaker modder experience. None on the non-SDA side.

    My experience is: On stereo, There's an added clarity to some things, like the pleasant, defined decay of sounds (guitar strings, voice echoes/reverb). On SDA, I have no non-plugged reference, but they sound great to me.

    Inner basket foam on mids

    Worries of others = Hard to remove. Fear of material degradation. Fear of over-damping.

    Experiences of others = One modder did not complete the mod, if I recall correctly, for fear of difficulty undoing it. No sound-related negatives from modders who did it.

    My experience is: I love it. Very difficult for me to do, but cleared up the separation of sounds. To me, this and the phase plug work well together. They're complimentary. In a way, what they do is attack a similar issue from 2 different directions.

    Matting/Peel-n-Sealing the passive chamber (in whole or just parts).

    Worries of others = Speculation is it will suck the life out if speaker and ruin bass. Hard to remive.

    Others experiences = I couldn't find anyone who used the materials I did on the passive chamber, specifically, here.

    My experience is: Works for me. Not so hard to peel off that particle/compressed wood board.The butyl backing of the Peel-n-Seal deadens vibrations of the enclosure. The aluminum face does not absorb sound energy the way Sonic Barrier or BH5 does.

    I don't include the tweeters in the sacrilege list

    The Wuhan, Dayton, and/or plate mods don't hurt anything. And I learned a lot doing them.
    The Thrifty Setups in Mah House Big thrifty stereo in the basement w/ my custom SDA-1C (built with help from kind forum members) * Beautiful 1966 MCM GE console upgraded w/ Bluetooth, Dual turntable, and Paradigm speakers in family room * Swanky 1980 Realistic system and great TEAC eq with dancing colored lights in the living room * Ye Olde college stereo in the garage
  • plastic_avatar
    plastic_avatar Posts: 687
    edited July 2023
    About 13 hours of crossover burn-in.

    Finally got them spaced correctly for AMAZING imaging *and* surprising impact. It was great initially, but they were too far from the wall and bass dropped off precipitously (and too soon). (Thanks to Gardenstater and xschop for the tips to remedy.)

    On my AirPods, the bass is a little boomy, but it was not like that in-person. Been testing intensely over the past 4 days.

    The placement of sounds solidly matches the 1C. Impressive! And it surprised me how close the location of elements in the soundstage was between basic stereo and SDA. That says, to me, the 2 models are set up in close to optimal positions for my room.

    https://youtu.be/uO5isb99wCA

    Not in this post: Vocally heavy tracks are a joy, from Sinatra to Nico Vega.

    - Will likely do the foam and matting basket mods next week.

    - Tried with and without phase plugs. Difficult to describe, but with plugs... mids tighter, less distortion (which I only niticed when I went back to no plugs). Switching back and forth really sold me on the gains via plugs.
    The Thrifty Setups in Mah House Big thrifty stereo in the basement w/ my custom SDA-1C (built with help from kind forum members) * Beautiful 1966 MCM GE console upgraded w/ Bluetooth, Dual turntable, and Paradigm speakers in family room * Swanky 1980 Realistic system and great TEAC eq with dancing colored lights in the living room * Ye Olde college stereo in the garage
  • Gardenstater
    Gardenstater Posts: 4,137

    Not in this post: Vocally heavy tracks are a joy, from Sinatra to Nico Vega.

    - Will likely do the foam and matting basket mods next week.

    - Tried with and without phase plugs. Difficult to describe, but with plugs... mids tighter, less distortion (which I only niticed when I went back to no plugs). Switching back and forth really sold me on the gains via plugs.

    And that's comparing the plugs with no plug + no dust cap. Since removing the dust cap (and resonant cavity underneath) is part of the effect of the plug, you can only imagine how much improvement there is relative to dust cap.

    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
  • xschop
    xschop Posts: 4,636
    Fully modded 5Bs ain't no joke. B)
    Don't take experimental gene therapies from known eugenicists.
  • ChrisD06
    ChrisD06 Posts: 883
    I assume this is due to the iPhone microphones being.... iPhone microphones but I found that the Round 2 video sounded really good on my Sennheiser open backs, but the Round 4 and the stereo imaging videos sound really... dead. Like ABITW was really nice on the Round 2 video and it was really lively but the videos after it made it sound almost completely lifeless. I think the minor reverb in the guitar solo is what really shows this off, it just disappears...