Must try MOD - Foam inside the stamped steel baskets - YES!

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  • F1nut
    F1nut Posts: 50,532
    So, up to 7 or 8 from maybe a few...LOL
    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

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  • plastic_avatar
    plastic_avatar Posts: 708
    1C preview cross-thread report

    I'll wager I foamed my baskets to a point no one else has.

    Preliminary bench report from 90 hours of burn-in for caps and Wuhans is positive.

    Clarity and separation is great. I can only compare to my other speakers, but I'm impressed.

    They don't sound lifeless. They're quite clear, with what I feel is the proper level of 'air' around instruments and voice. Spotify Premium (which I find has distortion on sections of all my music (streaming from my old iPhone on multiple sources, that isn't on Amazon Music).

    Recording was a little close, but it's just an anecdotal response. I might very well do this mod to my Monitor 12, if I keep them.

    Looking forward to actually A/B'ing the mod on my 5B.

    Abrupt cut at the end.

    https://youtu.be/TUlij8U4oKU
    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 * custom 5B on a system for my Dad * Ye Olde college stereo in the garage
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  • xschop
    xschop Posts: 5,000
    Sounds great through my XS-8TLs😉
    Don't take experimental gene therapies from known eugenicists.
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  • benjaminlea
    benjaminlea Posts: 38
    +1 Foamed my baskets too, heard an incredible difference in detail and clarity as many others who have done the mod have reported.

    Vocals are clearer, with more separation. Instruments sound like they are being played in front of me. Strings, white noise, details in tracks that I’ve not ever heard before are now coming through. The sound I hear now is nuanced and I would describe it as almost delicate.

    This $0 mod (thanks to a forum member sending me the foam) really elevated the listening experience for me.

    Side note - If anyone has some BH5 they wanna trade for some SL2000’s pm me?

    😂
    Polk 7B’s modded
    Velodyne CT 100
    Rega Elex R
    RME ADI2

    MacBook Pro
    Apple Music
    Tidal
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  • bcwsrt
    bcwsrt Posts: 1,878
    Well .... nice timing for this previously missed thread to come back to life out of nowhere after I just reinstalled my J-B Welded and Dynamated MWs this time last night. But, I suppose there's always another mod to consider/pursue to keep our hobby interesting.
    Brian

    One-owner Polk Audio RTA 15TL speakers refreshed w/ Sonicap, Vishay/Mills and Cardas components by "pitdogg2," "xschop" billet tweeter plates and BH5 | Stereo REL Acoustics T/5x subwoofers w/ Bassline Blue cables | Rogue Audio Cronus Magnum III integrated tube amp | Technics SL-1210G turntable w/ Ortofon 2M Black LVB 250 MM cart | Sony CDP-508ESD CD player (as a transport) | LampizatOr Baltic 4 tube DAC | Nordost & DH Labs cables/interconnects | APC H15 Power Conditioner | GIK Acoustics room treatments | Degritter RCM
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  • plastic_avatar
    plastic_avatar Posts: 708
    edited January 2023
    [chuckles]

    Well, if you keep giving them a listen right now as is, you can give a good comparison if you try this mod.

    Warning!

    For me, this was torture.

    When I try to do fine motor control, I get 'essential' tremors. And this requires detail-oriented application.

    The Armacel is really sticky. I used angled tweezers to set the pieces in place. I even put a thin strip of it around the top edge *below* the surround. (Doesn't impact or touch the surround at all.)

    Anyhow.

    Totally worth the... probably... 10 to 12 hours for me to do. Totally.

    I expect a normal person to take half that time.
    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 * custom 5B on a system for my Dad * Ye Olde college stereo in the garage
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  • Gardenstater
    Gardenstater Posts: 4,459
    @plastic_avatar Kind of like this:

    osxdnqb3745i.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
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  • plastic_avatar
    plastic_avatar Posts: 708
    Oh G/god(s)...

    Nooooooooooooooo... I *hated* that game.
    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 * custom 5B on a system for my Dad * Ye Olde college stereo in the garage
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  • skipshot12
    skipshot12 Posts: 1,158
    Not sure what your speakers sounded like before but, they sounded wonderful thru my earphones.
    Well done....
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  • plastic_avatar
    plastic_avatar Posts: 708
    Just so we know where this foam mod is on my end, in relation to whether or not it added negatively to how the box performs, my interior mods include:

    - Armacel on all interior basket surfaces (where reachable, and in the upper ring below the surround)
    - BH5 behind mws.
    - Aluminized rubber pipe wrap on passive chamber walls.
    - Same wrap (think of it as Dynamat lite) on exterior of all baskets.
    - xschop's semi-rings on mws.

    I know it's a difficult comparison, since there is no control in my observation. I'm only comparing to a similarly-structured model. And all we hear is the result of mods on a speaker with no reference.

    I do know there is a definition on voices I did not expect. And right now I'm very pleased with that result.

    More testing the next couple of days.

    My biggest question is:

    'If my speakers don't exhibit a negative with all that^, what are the chances the foam mod will mean worse sound for you?'

    57959fglzr0u.gif

    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 * custom 5B on a system for my Dad * Ye Olde college stereo in the garage
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  • skipshot12
    skipshot12 Posts: 1,158
    plastic_avatar wrote: »
    Just so we know where this foam mod is on my end, in relation to whether or not it added negatively to how the box performs, my interior mods include:

    - Armacel on all interior basket surfaces (where reachable, and in the upper ring below the surround)
    - BH5 behind mws.
    - Aluminized rubber pipe wrap on passive chamber walls.
    - Same wrap (think of it as Dynamat lite) on exterior of all baskets.
    - xschop's semi-rings on mws.

    I know it's a difficult comparison, since there is no control in my observation. I'm only comparing to a similarly-structured model. And all we hear is the result of mods on a speaker with no reference.

    I do know there is a definition on voices I did not expect. And right now I'm very pleased with that result.

    More testing the next couple of days.

    My biggest question is:

    'If my speakers don't exhibit a negative with all that^, what are the chances the foam mod will mean worse sound for you?'

    57959fglzr0u.gif

    With what I heard no negatives but…. Damn you guys with this mod!
    Do you know what kind of time this would be to do my SDA SRS’s?????

    🤣
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  • skipshot12
    skipshot12 Posts: 1,158
    ^ Regarding mods…. Today was a great day.
    I thought I had my cabinets sealed very well with taking care of the seam joints. I was getting about 1-1/2-2 seconds on my passive pressure test.
    Just got done with installing 1/4”x1” rubber fender washers to seal up the end caps on my sda’s. After installing those on my left speaker I did a post pressure test.
    Now have the 3-5 second mw leak down others reported about 👍
    Haven’t played any tunes yet to hear the difference. Gonna do the right speaker before a test listen.
    Very excited to hear what this has done….
    What a great day.
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  • plastic_avatar
    plastic_avatar Posts: 708
    skipshot12 wrote: »
    ^
    What a great day.

    Hooray for you catching that.

    I don't know about that particular test.

    [goes to Google]
    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 * custom 5B on a system for my Dad * Ye Olde college stereo in the garage
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  • skipshot12
    skipshot12 Posts: 1,158
    ^ 👍
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  • gp4jesus
    gp4jesus Posts: 1,987
    edited January 2023
    @skipshot12

    “… Aluminized rubber pipe wrap on passive chamber walls.”?

    My plumber brother drew a blank. He did find it. IMHO having a reflective surface seems counter to what’s desirable in a speaker closure
    Samsung 60" UN60ES6100 LED Outlaw Audio 976 Pre/Pro Samsung BDP, Amazon Firestick, Phillips CD Changer Canare 14 ga - LCR tweeters inside*; Ctr Ch outside BJC 10 ga - LCR mids, inside* & out 8 ga Powerline: LR woofers, inside* & out *soldered LR: Tri-amped RTi A7 w/Rotels. Woofers - 980BX; Tweets & “Plugged*” Mids - 981, connected w/MP Premiere ICs Ctr Ch: Rotel RB981 -> Bi-amped CSi A6 Surrounds: Premiere ICs ->Rotel 981 -> AR 12 ga -> RTi A3. 5 Subs: Sunfire True SW Signature -> LFE & Ctr Ch; 4 Audio Pro Evidence @ the “Corners”. Power Conditioning & Distribution: 4 dedicated 20A feeds; APC H15; 5 Furman Miniport 20s *Xschop's handy work
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  • Gardenstater
    Gardenstater Posts: 4,459
    edited January 2023
    gp4jesus wrote: »
    @plasticavatar

    “… Aluminized rubber pipe wrap on passive chamber walls.”?

    My plumber brother drew a blank. He did find it. IMHO having a reflective surface seems counter to what’s desirable in a speaker closure

    @plasticavatar

    Fixed it for you Tony

    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
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  • plastic_avatar
    plastic_avatar Posts: 708
    The walls are hard and wooden. They reflect.

    The thin aluminum side of the wrap reflects, but differently than the wood. The rubber helps control resonant vibrations. To my ears, it helps tighten up low frequencies, without taking the bass away.

    This is a contentious mod. I'll take more about it over in my thread =)
    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 * custom 5B on a system for my Dad * Ye Olde college stereo in the garage
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  • xschop
    xschop Posts: 5,000
    It's all about the thwack.
    Don't take experimental gene therapies from known eugenicists.
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  • plastic_avatar
    plastic_avatar Posts: 708
    Speaker got thwack.

    19x2mrx68n34.gif

    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 * custom 5B on a system for my Dad * Ye Olde college stereo in the garage
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  • skipshot12
    skipshot12 Posts: 1,158
    ^ Shazaaaam…
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  • plastic_avatar
    plastic_avatar Posts: 708
    Every time I see that frakking Operation picture up there I both die a little inside *and* laugh a little on the outside.

    My family thought it was funny. Which says a lot about my family and how they treat me...

    =P

    https://www.youtube.com/watch?v=uq3IVfL69oI
    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 * custom 5B on a system for my Dad * Ye Olde college stereo in the garage
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  • Jazzhead
    Jazzhead Posts: 533
    It's all about the thwack and the slam.
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  • xschop
    xschop Posts: 5,000
    Al Capone and Eva Peron would agree.🙂
    Don't take experimental gene therapies from known eugenicists.
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  • xschop
    xschop Posts: 5,000
    Bump for @melchionda
    Don't take experimental gene therapies from known eugenicists.
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  • odcics2
    odcics2 Posts: 331
    Gardenstater wrote: »
    I previously mentioned this in a couple of scattered places and didn't open up a dedicated thread. I suppose I didn't want to stick my neck out until there was confirmation from another who has tried it ✔. I've been living with this for almost 6 mos. now and I still continue to be super pleased with the benefits (I think the foam is still breaking in...kidding)! I used Armacell closed cell 1/8" thick foam but this is open to experimentation with perhaps open cell, composite of open cell over closed, felt over closed, felt alone......just keep it relatively thin like maybe 1/4" max(?). Let's get some more people trying this because it is a super rewarding mod and not all that difficult to do.

    I won't get super long winded but I posted my initial report over in the other thread "What did you do to your stereo today" on p. 122.

    https://forum.polkaudio.com/discussion/184609/what-did-you-do-to-your-stereo-rig-today/p122

    Pictures are always worth more than words. I think the benefit of this is 3 fold: 1) Mechanical vibration dampening of the basket, 2) Sound proofing of the basket preventing acoustical into mechanical excitation, and 3) some amount of reflection attenuation of backwave reflections that would come back and hit the back of the cone. 3) is last but not least because when I did just one speaker initially I had to rebalance with whitenoise by lowering the unmodded speaker's channel by 0.4dB to compensate. I believe that is due to the reduction in reflected backwave which comes out as audible sPL through the cone. That has to be distorted due to time delays and phase differences and varying transmission/reflection for different frequencies.

    Anyway, Merry Christmas and let's have fun with this mod. I'll add pictures when I find them.

    Initial sizing on a spare driver I had. Settled on 1-1/4" x 1-5/16" but not super critical as long as you don't block the basket windows. You can even trim the windows with an Xacto knife after install:

    vm0hg9xg7e74.png

    kg4v5hx7uhm0.jpg

    2i3akx0munzv.jpg

    Completed driver with the Armacell inside of the spokes and the section between spokes near the spider. I cut off the 3 vestigial tabs with a dremel cut off wheel - be careful not to get metal dust inside the driver:

    q7kd5pr6l6h7.jpg

    Same idea, different execution. 9qwpc8mbs4so.jpeg
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  • Gardenstater
    Gardenstater Posts: 4,459
    Ha! Yes, I believe I already posted those pictures earlier in this thread (or somewhere else maybe?). That is the Vandersteen midrange driver that came out of the patent I posted earlier in this thread.
    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
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  • odcics2
    odcics2 Posts: 331
    I believe you posted a currently available Scan Speak driver. Similar idea.
    Here's a better pic showing the back side of an older Vandersteen 3A Signature midrange.
    Note the thick green felt directly over the magnet.
    87mymab4mqdo.jpg
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  • Gardenstater
    Gardenstater Posts: 4,459
    That's an interesting picture^ thanks.

    I don't really remember what I posted where lol, but this is the article where I encountered those pictures of his midwoofer driver and the patented midrange driver:

    https://www.ultraaudio.com/features/20090901.htm

    https://www.ultraaudio.com/features/20091001.htm
    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
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  • odcics2
    odcics2 Posts: 331
    Ah, yes! I remember that article from 14 years ago!!
    I think the 4.5” midrange driver is made by Vifa.
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  • Gardenstater
    Gardenstater Posts: 4,459
    odcics2 wrote: »
    Ah, yes! I remember that article from 14 years ago!!
    I think the 4.5” midrange driver is made by Vifa.

    Yep. Confirmed.

    https://www.stereophile.com/floorloudspeakers/128/index.html

    acihth6237pe.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
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