Must try MOD - Foam inside the stamped steel baskets - YES!
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Ha ha no that isn't what I meant. I was referring to the fact that you said you didn't notice any difference in sound. This mod is about putting it inside the basket only, in order to absorb some of the backwave that would've mostly bounced around inside the basket and some of it would be perceived as distortion when it hits and transmits through the back of the cone, conflicting with the desired audio signal expression.
That stuff you used and what I used is not at all what you want for damping of mechanical vibrations. And also speaker enclosure volume needs something much more substantial and thick like the 6" x 6" BH5 to notice any appreciable amount of standing wave absorption etc. in my opinion, and born out by your experience. I also doubt that weatherstripping foam is at all the right stuff because it has a smooth shiny skin on it usually (at least the stuff I have used), to make a seal against a window or door. The Armacell by the way, is closed cell but it isn't smooth or shiny.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 -
Fwiw, having Sean's 1.2tl here, even cleaning the cabinet walls, black hole 5 was coming off after a month. I ripped it back off and used power grab to reattach and even two months later was super secure
No doubt this is the best way to secure them. My way was to use my air stapler and shoot a couple of staples into each strip so I could button the speakers right back up. I also cleaned the backs first with lacquer thinner. One of the strips was just a tad crooked which I unsuccessfully tried to reposition as that adhesive held tight despite my efforts. I felt that any more tugging on that strip would've resulted in taking off some of the wood with the adhesive and I certainly did not want that. Being that I'm not a fan of opening up my speakers I wanted to be doubly sure there would not be a problem like the falling foam strips were. After reading about your issues I'm glad now that I did secure them a bit more. -
Those are back-chambered RDO's with lamb's wool in the chamber and pole-piece.
I re-posted the pic because this mod mirrors the same mechanical concept/backwave correction that Gstater's basket frame mod is accomplishing.Don't take experimental gene therapies from known eugenicists. -
Those are back-chambered RDO's with lamb's wool in the chamber and pole-piece.
I re-posted the pic because this mod mirrors the same mechanical concept/backwave correction that Gstater's basket frame mod is accomplishing.
Do you have more pics of this piece before install? Also, how are you securing it to the tweeter?
Where were you lol? I believe I have the only two sets back-chambered on the planet. Thanks to VSAT's enabling thread lol....
https://forum.polkaudio.com/discussion/168239/a-real-sl-2000-hack-replace-stock-burnt-voice-coils-with-silk-diaphragm-dome/p15
I got the oil-doped silk Wuhans sounding better than the factory RD0-194's. I can't say that about the 198's as I have now A-B'd those in the 8TLs now in the back-chambers.
I now have Blue-Loctite with the pole-piece to billet chamber interface to answer your question.Don't take experimental gene therapies from known eugenicists. -
So I often take @Gardenstater comments with a grain of salt (no offense) but this mod may be legit due to the basket being in such close proximity to the cone. I'm planning on upgrading my SDA 1C's driver circuit caps, internal wiring and speaker cable posts and may actually consider this as well. Unfortunately I won't be able to comment on whether it helps due to the other mods but WTH. Blind faith can be awesome!Gustard X26 Pro DAC
Belles 21A Pre Upgraded with Mundorf Supremes
B&K M200 Sonata monoblocks refreshed and upgraded
Polk SDA 1C's modded / 1000Va Dreadnaught
Wireworld Silver Eclipse IC's and speaker cables
Harman Kardon T65C w/Grado Gold. (Don't laugh. It sounds great!)
There is about a 5% genetic difference between apes and men …but that difference is the difference between throwing your own poo when you are annoyed …and Einstein, Shakespeare and Miss January. by Dr. Sardonicus -
Ha ha welcome aboard. Any port in a storm eh? No need to trust me, trust Richard Vandersteen
https://worldwide.espacenet.com/publicationDetails/originalDocument?CC=US&NR=5073948A&KC=A&FT=D&ND=3&date=19911217&DB=EPODOC&locale=en_EP
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 -
Right under the red outlined box there is another fact about reflected waves that bounce back from the magnet and basket "being even more severe". I'd like to see more of that paragraph.Most people just listen to music and watch movies. I EXPERIENCE them.
“Anger is an acid that can do more harm to the vessel in which it is stored than to anything on which it is poured.”
--Mark Twain.
“If at first you don't succeed, then skydiving definitely isn't for you.” - Steven Wright -
No thanks, horrible speakers.No need to trust me, trust Richard Vandersteen -
Oh well. I don't remember if I heard/saw them or not. I think maybe 10 yrs ago at the New York Audio Show but that was back when there were so many high end exhibitors that it is a blurr. I *think* I was impressed and I remember something that wasn't too appealing to me, looking like a red stealth fighter. Anyway, the man is definitely not one to be lazy or stupid and is not striving for mediocrity, to say the least:
Searching for the Extreme: Richard Vandersteen of Vandersteen Audio: Part One
https://www.ultraaudio.com/features/20090901.htm
Searching for the Extreme: Richard Vandersteen of Vandersteen Audio: Part Two
https://www.ultraaudio.com/features/20091001.htm
I have to verify but these might be his driver technology licensed to ScanSpeak of Denmark:
https://www.scan-speak.dk/product-families/illuminator/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 -
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 -
Now Bose I'd agree with, on the horrible speakers comment.
So from the paper/patent, we can deduct that MW baskets are echo chambers and severity depends on frame to window area measurements/sizes?
....makes sense
Don't take experimental gene therapies from known eugenicists. -
Gardenstater wrote: »
Thank you.
I thought there was going to be a longer story on those reflections.
Most people just listen to music and watch movies. I EXPERIENCE them.
“Anger is an acid that can do more harm to the vessel in which it is stored than to anything on which it is poured.”
--Mark Twain.
“If at first you don't succeed, then skydiving definitely isn't for you.” - Steven Wright -
Ha ha no problem Tony. You should read the patent and look at the figures. It's pretty interesting and easy to understand and follow. It is interesting that he first shows his ideal design and then in figures 4 - 6 he basically shows what you can do with a more traditional stamped steel basket which is what we are dealing with. xschop - it would be awesome if we could get some thin foam between the spider and the basket/upper plate pole piece like in figure 5 of the patent. When you took one apart did you see how much clearance there was? Probably isn't enough but just wondering. Yes the frontal area of the spokes plus the magnet assy are the reflective areas. It is a very large percentage of the total area with our MW drivers.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 -
I have seen some cast baskets that have thinner spokes. I wonder if that was done for this topic of reflections.
Yesterday, I thought about an amplifier's SLEW rate, I think it's called. Where the amp senses the back wave elec. signal and stops the speaker's movement.
Subwoofer's servo controls do this, I think.Most people just listen to music and watch movies. I EXPERIENCE them.
“Anger is an acid that can do more harm to the vessel in which it is stored than to anything on which it is poured.”
--Mark Twain.
“If at first you don't succeed, then skydiving definitely isn't for you.” - Steven Wright -
I listened to the 8Tl's yesterday at shop for a little while after them being on burn in all week radio FM channel....
Impeccable imaging and clarity. More dynamic than the 5B's given the extra Midwoofer obviously. Incredible realism. Your mod is a keeper.Don't take experimental gene therapies from known eugenicists. -
#170 in the figure is the foam we would want.
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 -
I have seen some cast baskets that have thinner spokes. I wonder if that was done for this topic of reflections.
I think so no doubt. This patent is old and expired and anybody can do that now.
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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No, the cast aluminum baskets have thinner spokes because that's all that's needed for their structural integrity.Tony M wrote: »
I have seen some cast baskets that have thinner spokes. I wonder if that was done for this topic of reflections. -
Are you sure you're not confusing that with dampening factorYesterday, I thought about an amplifier's SLEW rate, I think it's called. Where the amp senses the back wave elec. signal and stops the speaker's movement.
I believe you're right. I think I read somewhere anything more than 50 is overkill.
Like another member just said about time flying, it's been supersonic speed for me.
But then again, at my age...I'm getting things wrong more often. My memory is scatterbrained it seems with all I'm doing the past few years as I got heathier. Body got healthier, brain, not so much.
Most people just listen to music and watch movies. I EXPERIENCE them.
“Anger is an acid that can do more harm to the vessel in which it is stored than to anything on which it is poured.”
--Mark Twain.
“If at first you don't succeed, then skydiving definitely isn't for you.” - Steven Wright -
No, the cast aluminum baskets have thinner spokes because that's all that's needed for their structural integrity.Tony M wrote: »
I have seen some cast baskets that have thinner spokes. I wonder if that was done for this topic of reflections.
Plus there's less surface for reflections.
Don't take experimental gene therapies from known eugenicists. -
No, the cast aluminum baskets have thinner spokes because that's all that's needed for their structural integrity.Tony M wrote: »
I have seen some cast baskets that have thinner spokes. I wonder if that was done for this topic of reflections.
Plus there's less surface for reflections.
Stop. -
Sorry F1, I've just begun. There's still performance to be had. I'll be relocating the terminal tabs next to remove them from the equation. I don't like them blocking the windows.Don't take experimental gene therapies from known eugenicists.
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I think you guys are over analyzing this one a little bit :-p- Not Tom ::::::: Any system can play Diana Krall. Only the best can play Limp Bizkit.
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I'll disagree as this mod has changed my mind on building billet frame baskets with only 1/4" dia. cylindrical uprights.
If Polk designed the new Legend drivers with even cast frames, I'd own a set. As for me I've NEVER heard Najee sound as accurate on any of my older Polks, even the ChimeraPolks.
Don't take experimental gene therapies from known eugenicists. -
I think you guys are over analyzing this one a little bit :-p
Understatement of the year. -
Live a little F1, if I donate the 99 cent foam, would that help your apprehension?
48 spokes is a little daunting lol.Don't take experimental gene therapies from known eugenicists. -
Try it you'll like it! Is that simple enough? If anyone sees the Grinch Who Stole The New Mods in their neighborhood please report to the authorities (kidding!)
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 -
Sorry F1, I've just begun. There's still performance to be had. I'll be relocating the terminal tabs next to remove them from the equation. I don't like them blocking the windows.
Didn't cost a dime, dremeled off tab rivet, cut an extra width insulator from the same .090" PVA foam, redrilled above basket 1/8" hole and 8-32 stainless machine screw. Then re-soldered leads to factory tabs after bending them downwards a bit. Windows are completely unobstructed and the leads pivot without any restriction.
Sorry for over thinking....
Don't take experimental gene therapies from known eugenicists. -
What do the red symbols mean?Lumin X1 file player, Westminster Labs interconnect cable
Sony XA-5400ES SACD; Pass XP-22 pre; X600.5 amps
Magico S5 MKII Mcast Rose speakers; SPOD spikes
Shunyata Triton v3/Typhon QR on source, Denali 2000 (2) on amps
Shunyata Sigma XLR analog ICs, Sigma speaker cables
Shunyata Sigma HC (2), Sigma Analog, Sigma Digital, Z Anaconda (3) power cables
Mapleshade Samson V.3 four shelf solid maple rack, Micropoint brass footers
Three 20 amp circuits.
